ruleutils.c 116.84 KiB
/**********************************************************************
* ruleutils.c - Functions to convert stored expressions/querytrees
* back to source text
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.187 2004/12/13 00:33:06 tgl Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
* The author hereby grants permission to use, copy, modify,
* distribute, and license this software and its documentation
* for any purpose, provided that existing copyright notices are
* retained in all copies and that this notice is included
* verbatim in any distributions. No written agreement, license,
* or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their
* author and need not follow the licensing terms described
* here, provided that the new terms are clearly indicated on
* the first page of each file where they apply.
*
* IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY
* PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
* CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS
* SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN
* IF THE AUTHOR HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON
* AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAVE NO
* OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
* ENHANCEMENTS, OR MODIFICATIONS.
*
**********************************************************************/
#include "postgres.h"
#include <unistd.h>
#include <fcntl.h>
#include "access/genam.h"
#include "catalog/catname.h"
#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/index.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_cast.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_depend.h"
#include "catalog/pg_index.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_shadow.h"
#include "catalog/pg_trigger.h"
#include "executor/spi.h"
#include "lib/stringinfo.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/tlist.h"
#include "parser/keywords.h"
#include "parser/parse_expr.h"
#include "parser/parse_func.h"
#include "parser/parse_oper.h"
#include "parser/parse_type.h"
#include "parser/parsetree.h"
#include "rewrite/rewriteManip.h"#include "rewrite/rewriteSupport.h"
#include "utils/array.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/typcache.h"
/* ----------
* Pretty formatting constants
* ----------
*/
/* Indent counts */
#define PRETTYINDENT_STD 8
#define PRETTYINDENT_JOIN 13
#define PRETTYINDENT_JOIN_ON (PRETTYINDENT_JOIN-PRETTYINDENT_STD)
#define PRETTYINDENT_VAR 4
/* Pretty flags */
#define PRETTYFLAG_PAREN 1
#define PRETTYFLAG_INDENT 2
/* macro to test if pretty action needed */
#define PRETTY_PAREN(context) ((context)->prettyFlags & PRETTYFLAG_PAREN)
#define PRETTY_INDENT(context) ((context)->prettyFlags & PRETTYFLAG_INDENT)
/* ----------
* Local data types
* ----------
*/
/* Context info needed for invoking a recursive querytree display routine */
typedef struct
{
StringInfo buf; /* output buffer to append to */
List *namespaces; /* List of deparse_namespace nodes */
int prettyFlags; /* enabling of pretty-print functions */
int indentLevel; /* current indent level for prettyprint */
bool varprefix; /* TRUE to print prefixes on Vars */
} deparse_context;
/*
* Each level of query context around a subtree needs a level of Var namespace.
* A Var having varlevelsup=N refers to the N'th item (counting from 0) in
* the current context's namespaces list.
*
* The rangetable is the list of actual RTEs from the query tree.
*
* For deparsing plan trees, we allow two special RTE entries that are not
* part of the rtable list (mainly because they don't have consecutively
* allocated varnos).
*/
typedef struct
{
List *rtable; /* List of RangeTblEntry nodes */
int outer_varno; /* varno for outer_rte */
RangeTblEntry *outer_rte; /* special RangeTblEntry, or NULL */
int inner_varno; /* varno for inner_rte */
RangeTblEntry *inner_rte; /* special RangeTblEntry, or NULL */
} deparse_namespace;
/* ----------
* Global data
* ----------
*/
static void *plan_getrulebyoid = NULL;
static char *query_getrulebyoid = "SELECT * FROM pg_catalog.pg_rewrite WHERE oid = $1";
static void *plan_getviewrule = NULL;static char *query_getviewrule = "SELECT * FROM pg_catalog.pg_rewrite WHERE ev_class = $1 AND rulename = $2";
/* ----------
* Local functions
*
* Most of these functions used to use fixed-size buffers to build their
* results. Now, they take an (already initialized) StringInfo object
* as a parameter, and append their text output to its contents.
* ----------
*/
static char *deparse_expression_pretty(Node *expr, List *dpcontext,
bool forceprefix, bool showimplicit,
int prettyFlags, int startIndent);
static char *pg_get_viewdef_worker(Oid viewoid, int prettyFlags);
static void decompile_column_index_array(Datum column_index_array, Oid relId,
StringInfo buf);
static char *pg_get_ruledef_worker(Oid ruleoid, int prettyFlags);
static char *pg_get_indexdef_worker(Oid indexrelid, int colno,
int prettyFlags);
static char *pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
int prettyFlags);
static char *pg_get_expr_worker(text *expr, Oid relid, char *relname,
int prettyFlags);
static void make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags);
static void make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags);
static void get_query_def(Query *query, StringInfo buf, List *parentnamespace,
TupleDesc resultDesc, int prettyFlags, int startIndent);
static void get_select_query_def(Query *query, deparse_context *context,
TupleDesc resultDesc);
static void get_insert_query_def(Query *query, deparse_context *context);
static void get_update_query_def(Query *query, deparse_context *context);
static void get_delete_query_def(Query *query, deparse_context *context);
static void get_utility_query_def(Query *query, deparse_context *context);
static void get_basic_select_query(Query *query, deparse_context *context,
TupleDesc resultDesc);
static void get_setop_query(Node *setOp, Query *query,
deparse_context *context,
TupleDesc resultDesc);
static Node *get_rule_sortgroupclause(SortClause *srt, List *tlist,
bool force_colno,
deparse_context *context);
static void get_names_for_var(Var *var, deparse_context *context,
char **schemaname, char **refname, char **attname);
static RangeTblEntry *find_rte_by_refname(const char *refname,
deparse_context *context);
static const char *get_simple_binary_op_name(OpExpr *expr);
static bool isSimpleNode(Node *node, Node *parentNode, int prettyFlags);
static void appendStringInfoSpaces(StringInfo buf, int count);
static void appendContextKeyword(deparse_context *context, const char *str,
int indentBefore, int indentAfter, int indentPlus);
static void get_rule_expr(Node *node, deparse_context *context,
bool showimplicit);
static void get_oper_expr(OpExpr *expr, deparse_context *context);
static void get_func_expr(FuncExpr *expr, deparse_context *context,
bool showimplicit);
static void get_agg_expr(Aggref *aggref, deparse_context *context);
static void get_const_expr(Const *constval, deparse_context *context);
static void get_sublink_expr(SubLink *sublink, deparse_context *context);
static void get_from_clause(Query *query, deparse_context *context);
static void get_from_clause_item(Node *jtnode, Query *query,
deparse_context *context);
static void get_from_clause_alias(Alias *alias, int varno,
Query *query, deparse_context *context);
static void get_from_clause_coldeflist(List *coldeflist,
deparse_context *context);
static void get_opclass_name(Oid opclass, Oid actual_datatype,
StringInfo buf);static Node *processIndirection(Node *node, deparse_context *context);
static void printSubscripts(ArrayRef *aref, deparse_context *context);
static char *generate_relation_name(Oid relid);
static char *generate_function_name(Oid funcid, int nargs, Oid *argtypes);
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void print_operator_name(StringInfo buf, List *opname);
static text *string_to_text(char *str);
#define only_marker(rte) ((rte)->inh ? "" : "ONLY ")
/* ----------
* get_ruledef - Do it all and return a text
* that could be used as a statement
* to recreate the rule
* ----------
*/
Datum
pg_get_ruledef(PG_FUNCTION_ARGS)
{
Oid ruleoid = PG_GETARG_OID(0);
PG_RETURN_TEXT_P(string_to_text(pg_get_ruledef_worker(ruleoid, 0)));
}
Datum
pg_get_ruledef_ext(PG_FUNCTION_ARGS)
{
Oid ruleoid = PG_GETARG_OID(0);
bool pretty = PG_GETARG_BOOL(1);
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
PG_RETURN_TEXT_P(string_to_text(pg_get_ruledef_worker(ruleoid, prettyFlags)));
}
static char *
pg_get_ruledef_worker(Oid ruleoid, int prettyFlags)
{
Datum args[1];
char nulls[1];
int spirc;
HeapTuple ruletup;
TupleDesc rulettc;
StringInfoData buf;
/*
* Do this first so that string is alloc'd in outer context not SPI's.
*/
initStringInfo(&buf);
/*
* Connect to SPI manager
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* On the first call prepare the plan to lookup pg_rewrite. We read
* pg_rewrite over the SPI manager instead of using the syscache to be
* checked for read access on pg_rewrite.
*/
if (plan_getrulebyoid == NULL)
{
Oid argtypes[1];
void *plan;
argtypes[0] = OIDOID; plan = SPI_prepare(query_getrulebyoid, 1, argtypes);
if (plan == NULL)
elog(ERROR, "SPI_prepare failed for \"%s\"", query_getrulebyoid);
plan_getrulebyoid = SPI_saveplan(plan);
}
/*
* Get the pg_rewrite tuple for this rule
*/
args[0] = ObjectIdGetDatum(ruleoid);
nulls[0] = ' ';
spirc = SPI_execute_plan(plan_getrulebyoid, args, nulls, true, 1);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_rewrite tuple for rule %u", ruleoid);
if (SPI_processed != 1)
appendStringInfo(&buf, "-");
else
{
/*
* Get the rules definition and put it into executors memory
*/
ruletup = SPI_tuptable->vals[0];
rulettc = SPI_tuptable->tupdesc;
make_ruledef(&buf, ruletup, rulettc, prettyFlags);
}
/*
* Disconnect from SPI manager
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
return buf.data;
}
/* ----------
* get_viewdef - Mainly the same thing, but we
* only return the SELECT part of a view
* ----------
*/
Datum
pg_get_viewdef(PG_FUNCTION_ARGS)
{
/* By OID */
Oid viewoid = PG_GETARG_OID(0);
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, 0)));
}
Datum
pg_get_viewdef_ext(PG_FUNCTION_ARGS)
{
/* By OID */
Oid viewoid = PG_GETARG_OID(0);
bool pretty = PG_GETARG_BOOL(1);
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags)));
}
Datum
pg_get_viewdef_name(PG_FUNCTION_ARGS)
{
/* By qualified name */
text *viewname = PG_GETARG_TEXT_P(0);
RangeVar *viewrel;
Oid viewoid;
viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname,
"get_viewdef"));
viewoid = RangeVarGetRelid(viewrel, false);
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, 0)));
}
Datum
pg_get_viewdef_name_ext(PG_FUNCTION_ARGS)
{
/* By qualified name */
text *viewname = PG_GETARG_TEXT_P(0);
bool pretty = PG_GETARG_BOOL(1);
int prettyFlags;
RangeVar *viewrel;
Oid viewoid;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
viewrel = makeRangeVarFromNameList(textToQualifiedNameList(viewname,
"get_viewdef"));
viewoid = RangeVarGetRelid(viewrel, false);
PG_RETURN_TEXT_P(string_to_text(pg_get_viewdef_worker(viewoid, prettyFlags)));
}
/*
* Common code for by-OID and by-name variants of pg_get_viewdef
*/
static char *
pg_get_viewdef_worker(Oid viewoid, int prettyFlags)
{
Datum args[2];
char nulls[2];
int spirc;
HeapTuple ruletup;
TupleDesc rulettc;
StringInfoData buf;
/*
* Do this first so that string is alloc'd in outer context not SPI's.
*/
initStringInfo(&buf);
/*
* Connect to SPI manager
*/
if (SPI_connect() != SPI_OK_CONNECT)
elog(ERROR, "SPI_connect failed");
/*
* On the first call prepare the plan to lookup pg_rewrite. We read
* pg_rewrite over the SPI manager instead of using the syscache to be
* checked for read access on pg_rewrite.
*/
if (plan_getviewrule == NULL)
{
Oid argtypes[2];
void *plan;
argtypes[0] = OIDOID;
argtypes[1] = NAMEOID;
plan = SPI_prepare(query_getviewrule, 2, argtypes);
if (plan == NULL)
elog(ERROR, "SPI_prepare failed for \"%s\"", query_getviewrule);
plan_getviewrule = SPI_saveplan(plan);
}
/* * Get the pg_rewrite tuple for the view's SELECT rule
*/
args[0] = ObjectIdGetDatum(viewoid);
args[1] = PointerGetDatum(ViewSelectRuleName);
nulls[0] = ' ';
nulls[1] = ' ';
spirc = SPI_execute_plan(plan_getviewrule, args, nulls, true, 2);
if (spirc != SPI_OK_SELECT)
elog(ERROR, "failed to get pg_rewrite tuple for view %u", viewoid);
if (SPI_processed != 1)
appendStringInfo(&buf, "Not a view");
else
{
/*
* Get the rules definition and put it into executors memory
*/
ruletup = SPI_tuptable->vals[0];
rulettc = SPI_tuptable->tupdesc;
make_viewdef(&buf, ruletup, rulettc, prettyFlags);
}
/*
* Disconnect from SPI manager
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
return buf.data;
}
/* ----------
* get_triggerdef - Get the definition of a trigger
* ----------
*/
Datum
pg_get_triggerdef(PG_FUNCTION_ARGS)
{
Oid trigid = PG_GETARG_OID(0);
HeapTuple ht_trig;
Form_pg_trigger trigrec;
StringInfoData buf;
Relation tgrel;
ScanKeyData skey[1];
SysScanDesc tgscan;
int findx = 0;
char *tgname;
/*
* Fetch the pg_trigger tuple by the Oid of the trigger
*/
tgrel = heap_openr(TriggerRelationName, AccessShareLock);
ScanKeyInit(&skey[0],
ObjectIdAttributeNumber,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(trigid));
tgscan = systable_beginscan(tgrel, TriggerOidIndex, true,
SnapshotNow, 1, skey);
ht_trig = systable_getnext(tgscan);
if (!HeapTupleIsValid(ht_trig))
elog(ERROR, "could not find tuple for trigger %u", trigid);
trigrec = (Form_pg_trigger) GETSTRUCT(ht_trig);
/*
* Start the trigger definition. Note that the trigger's name should
* never be schema-qualified, but the trigger rel's name may be. */
initStringInfo(&buf);
tgname = NameStr(trigrec->tgname);
appendStringInfo(&buf, "CREATE %sTRIGGER %s ",
trigrec->tgisconstraint ? "CONSTRAINT " : "",
quote_identifier(tgname));
if (TRIGGER_FOR_BEFORE(trigrec->tgtype))
appendStringInfo(&buf, "BEFORE");
else
appendStringInfo(&buf, "AFTER");
if (TRIGGER_FOR_INSERT(trigrec->tgtype))
{
appendStringInfo(&buf, " INSERT");
findx++;
}
if (TRIGGER_FOR_DELETE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfo(&buf, " OR DELETE");
else
appendStringInfo(&buf, " DELETE");
findx++;
}
if (TRIGGER_FOR_UPDATE(trigrec->tgtype))
{
if (findx > 0)
appendStringInfo(&buf, " OR UPDATE");
else
appendStringInfo(&buf, " UPDATE");
}
appendStringInfo(&buf, " ON %s ",
generate_relation_name(trigrec->tgrelid));
if (trigrec->tgisconstraint)
{
if (trigrec->tgconstrrelid != InvalidOid)
appendStringInfo(&buf, "FROM %s ",
generate_relation_name(trigrec->tgconstrrelid));
if (!trigrec->tgdeferrable)
appendStringInfo(&buf, "NOT ");
appendStringInfo(&buf, "DEFERRABLE INITIALLY ");
if (trigrec->tginitdeferred)
appendStringInfo(&buf, "DEFERRED ");
else
appendStringInfo(&buf, "IMMEDIATE ");
}
if (TRIGGER_FOR_ROW(trigrec->tgtype))
appendStringInfo(&buf, "FOR EACH ROW ");
else
appendStringInfo(&buf, "FOR EACH STATEMENT ");
appendStringInfo(&buf, "EXECUTE PROCEDURE %s(",
generate_function_name(trigrec->tgfoid, 0, NULL));
if (trigrec->tgnargs > 0)
{
bytea *val;
bool isnull;
char *p;
int i;
val = (bytea *) fastgetattr(ht_trig,
Anum_pg_trigger_tgargs,
tgrel->rd_att, &isnull);
if (isnull)
elog(ERROR, "tgargs is null for trigger %u", trigid); p = (char *) VARDATA(val);
for (i = 0; i < trigrec->tgnargs; i++)
{
if (i > 0)
appendStringInfo(&buf, ", ");
appendStringInfoChar(&buf, '\'');
while (*p)
{
/* escape quotes and backslashes */
if (*p == '\'' || *p == '\\')
appendStringInfoChar(&buf, '\\');
appendStringInfoChar(&buf, *p++);
}
p++;
appendStringInfoChar(&buf, '\'');
}
}
/* We deliberately do not put semi-colon at end */
appendStringInfo(&buf, ")");
/* Clean up */
systable_endscan(tgscan);
heap_close(tgrel, AccessShareLock);
PG_RETURN_TEXT_P(string_to_text(buf.data));
}
/* ----------
* get_indexdef - Get the definition of an index
*
* In the extended version, there is a colno argument as well as pretty bool.
* if colno == 0, we want a complete index definition.
* if colno > 0, we only want the Nth index key's variable or expression.
* ----------
*/
Datum
pg_get_indexdef(PG_FUNCTION_ARGS)
{
Oid indexrelid = PG_GETARG_OID(0);
PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, 0, 0)));
}
Datum
pg_get_indexdef_ext(PG_FUNCTION_ARGS)
{
Oid indexrelid = PG_GETARG_OID(0);
int32 colno = PG_GETARG_INT32(1);
bool pretty = PG_GETARG_BOOL(2);
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, colno, prettyFlags)));
}
/* Internal version that returns a palloc'd C string */
char *
pg_get_indexdef_string(Oid indexrelid)
{
return pg_get_indexdef_worker(indexrelid, 0, 0);
}
static char *
pg_get_indexdef_worker(Oid indexrelid, int colno, int prettyFlags)
{
HeapTuple ht_idx;
HeapTuple ht_idxrel;
HeapTuple ht_am; Form_pg_index idxrec;
Form_pg_class idxrelrec;
Form_pg_am amrec;
List *indexprs;
ListCell *indexpr_item;
List *context;
Oid indrelid;
int keyno;
Oid keycoltype;
StringInfoData buf;
char *str;
char *sep;
/*
* Fetch the pg_index tuple by the Oid of the index
*/
ht_idx = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(indexrelid),
0, 0, 0);
if (!HeapTupleIsValid(ht_idx))
elog(ERROR, "cache lookup failed for index %u", indexrelid);
idxrec = (Form_pg_index) GETSTRUCT(ht_idx);
indrelid = idxrec->indrelid;
Assert(indexrelid == idxrec->indexrelid);
/*
* Fetch the pg_class tuple of the index relation
*/
ht_idxrel = SearchSysCache(RELOID,
ObjectIdGetDatum(indexrelid),
0, 0, 0);
if (!HeapTupleIsValid(ht_idxrel))
elog(ERROR, "cache lookup failed for relation %u", indexrelid);
idxrelrec = (Form_pg_class) GETSTRUCT(ht_idxrel);
/*
* Fetch the pg_am tuple of the index' access method
*/
ht_am = SearchSysCache(AMOID,
ObjectIdGetDatum(idxrelrec->relam),
0, 0, 0);
if (!HeapTupleIsValid(ht_am))
elog(ERROR, "cache lookup failed for access method %u",
idxrelrec->relam);
amrec = (Form_pg_am) GETSTRUCT(ht_am);
/*
* Get the index expressions, if any. (NOTE: we do not use the
* relcache versions of the expressions and predicate, because we want
* to display non-const-folded expressions.)
*/
if (!heap_attisnull(ht_idx, Anum_pg_index_indexprs))
{
Datum exprsDatum;
bool isnull;
char *exprsString;
exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
Anum_pg_index_indexprs, &isnull);
Assert(!isnull);
exprsString = DatumGetCString(DirectFunctionCall1(textout,
exprsDatum));
indexprs = (List *) stringToNode(exprsString);
pfree(exprsString);
}
else
indexprs = NIL;
indexpr_item = list_head(indexprs);
context = deparse_context_for(get_rel_name(indrelid), indrelid);
/*
* Start the index definition. Note that the index's name should
* never be schema-qualified, but the indexed rel's name may be.
*/
initStringInfo(&buf);
if (!colno)
appendStringInfo(&buf, "CREATE %sINDEX %s ON %s USING %s (",
idxrec->indisunique ? "UNIQUE " : "",
quote_identifier(NameStr(idxrelrec->relname)),
generate_relation_name(indrelid),
quote_identifier(NameStr(amrec->amname)));
/*
* Report the indexed attributes
*/
sep = "";
for (keyno = 0; keyno < idxrec->indnatts; keyno++)
{
AttrNumber attnum = idxrec->indkey[keyno];
if (!colno)
appendStringInfo(&buf, sep);
sep = ", ";
if (attnum != 0)
{
/* Simple index column */
char *attname;
attname = get_relid_attribute_name(indrelid, attnum);
if (!colno || colno == keyno + 1)
appendStringInfoString(&buf, quote_identifier(attname));
keycoltype = get_atttype(indrelid, attnum);
}
else
{
/* expressional index */
Node *indexkey;
if (indexpr_item == NULL)
elog(ERROR, "too few entries in indexprs list");
indexkey = (Node *) lfirst(indexpr_item);
indexpr_item = lnext(indexpr_item);
/* Deparse */
str = deparse_expression_pretty(indexkey, context, false, false,
prettyFlags, 0);
if (!colno || colno == keyno + 1)
{
/* Need parens if it's not a bare function call */
if (indexkey && IsA(indexkey, FuncExpr) &&
((FuncExpr *) indexkey)->funcformat == COERCE_EXPLICIT_CALL)
appendStringInfoString(&buf, str);
else
appendStringInfo(&buf, "(%s)", str);
}
keycoltype = exprType(indexkey);
}
/*
* Add the operator class name
*/
if (!colno)
get_opclass_name(idxrec->indclass[keyno], keycoltype,
&buf);
}
if (!colno)
{
appendStringInfoChar(&buf, ')');
/*
* If it's a partial index, decompile and append the predicate
*/
if (!heap_attisnull(ht_idx, Anum_pg_index_indpred))
{
Node *node;
Datum predDatum;
bool isnull;
char *predString;
/* Convert text string to node tree */
predDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
Anum_pg_index_indpred, &isnull);
Assert(!isnull);
predString = DatumGetCString(DirectFunctionCall1(textout,
predDatum));
node = (Node *) stringToNode(predString);
pfree(predString);
/* Deparse */
str = deparse_expression_pretty(node, context, false, false,
prettyFlags, 0);
appendStringInfo(&buf, " WHERE %s", str);
}
}
/* Clean up */
ReleaseSysCache(ht_idx);
ReleaseSysCache(ht_idxrel);
ReleaseSysCache(ht_am);
return buf.data;
}
/*
* pg_get_constraintdef
*
* Returns the definition for the constraint, ie, everything that needs to
* appear after "ALTER TABLE ... ADD CONSTRAINT <constraintname>".
*/
Datum
pg_get_constraintdef(PG_FUNCTION_ARGS)
{
Oid constraintId = PG_GETARG_OID(0);
PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId,
false, 0)));
}
Datum
pg_get_constraintdef_ext(PG_FUNCTION_ARGS)
{
Oid constraintId = PG_GETARG_OID(0);
bool pretty = PG_GETARG_BOOL(1);
int prettyFlags;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId,
false, prettyFlags)));
}
/* Internal version that returns a palloc'd C string */
char *
pg_get_constraintdef_string(Oid constraintId)
{ return pg_get_constraintdef_worker(constraintId, true, 0);
}
static char *
pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
int prettyFlags)
{
StringInfoData buf;
Relation conDesc;
SysScanDesc conscan;
ScanKeyData skey[1];
HeapTuple tup;
Form_pg_constraint conForm;
/*
* Fetch the pg_constraint row. There's no syscache for pg_constraint
* so we must do it the hard way.
*/
conDesc = heap_openr(ConstraintRelationName, AccessShareLock);
ScanKeyInit(&skey[0],
ObjectIdAttributeNumber,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(constraintId));
conscan = systable_beginscan(conDesc, ConstraintOidIndex, true,
SnapshotNow, 1, skey);
tup = systable_getnext(conscan);
if (!HeapTupleIsValid(tup))
elog(ERROR, "could not find tuple for constraint %u", constraintId);
conForm = (Form_pg_constraint) GETSTRUCT(tup);
initStringInfo(&buf);
if (fullCommand && OidIsValid(conForm->conrelid))
{
appendStringInfo(&buf, "ALTER TABLE ONLY %s ADD CONSTRAINT %s ",
generate_relation_name(conForm->conrelid),
quote_identifier(NameStr(conForm->conname)));
}
switch (conForm->contype)
{
case CONSTRAINT_FOREIGN:
{
Datum val;
bool isnull;
const char *string;
/* Start off the constraint definition */
appendStringInfo(&buf, "FOREIGN KEY (");
/* Fetch and build referencing-column list */
val = heap_getattr(tup, Anum_pg_constraint_conkey,
RelationGetDescr(conDesc), &isnull);
if (isnull)
elog(ERROR, "null conkey for constraint %u",
constraintId);
decompile_column_index_array(val, conForm->conrelid, &buf);
/* add foreign relation name */
appendStringInfo(&buf, ") REFERENCES %s(",
generate_relation_name(conForm->confrelid));
/* Fetch and build referenced-column list */
val = heap_getattr(tup, Anum_pg_constraint_confkey,
RelationGetDescr(conDesc), &isnull);
if (isnull) elog(ERROR, "null confkey for constraint %u",
constraintId);
decompile_column_index_array(val, conForm->confrelid, &buf);
appendStringInfo(&buf, ")");
/* Add match type */
switch (conForm->confmatchtype)
{
case FKCONSTR_MATCH_FULL:
string = " MATCH FULL";
break;
case FKCONSTR_MATCH_PARTIAL:
string = " MATCH PARTIAL";
break;
case FKCONSTR_MATCH_UNSPECIFIED:
string = "";
break;
default:
elog(ERROR, "unrecognized confmatchtype: %d",
conForm->confmatchtype);
string = ""; /* keep compiler quiet */
break;
}
appendStringInfoString(&buf, string);
/* Add ON UPDATE and ON DELETE clauses, if needed */
switch (conForm->confupdtype)
{
case FKCONSTR_ACTION_NOACTION:
string = NULL; /* suppress default */
break;
case FKCONSTR_ACTION_RESTRICT:
string = "RESTRICT";
break;
case FKCONSTR_ACTION_CASCADE:
string = "CASCADE";
break;
case FKCONSTR_ACTION_SETNULL:
string = "SET NULL";
break;
case FKCONSTR_ACTION_SETDEFAULT:
string = "SET DEFAULT";
break;
default:
elog(ERROR, "unrecognized confupdtype: %d",
conForm->confupdtype);
string = NULL; /* keep compiler quiet */
break;
}
if (string)
appendStringInfo(&buf, " ON UPDATE %s", string);
switch (conForm->confdeltype)
{
case FKCONSTR_ACTION_NOACTION:
string = NULL; /* suppress default */
break;
case FKCONSTR_ACTION_RESTRICT:
string = "RESTRICT";
break;
case FKCONSTR_ACTION_CASCADE:
string = "CASCADE";
break;
case FKCONSTR_ACTION_SETNULL:
string = "SET NULL";
break;
case FKCONSTR_ACTION_SETDEFAULT:
string = "SET DEFAULT"; break;
default:
elog(ERROR, "unrecognized confdeltype: %d",
conForm->confdeltype);
string = NULL; /* keep compiler quiet */
break;
}
if (string)
appendStringInfo(&buf, " ON DELETE %s", string);
if (conForm->condeferrable)
appendStringInfo(&buf, " DEFERRABLE");
if (conForm->condeferred)
appendStringInfo(&buf, " INITIALLY DEFERRED");
break;
}
case CONSTRAINT_PRIMARY:
case CONSTRAINT_UNIQUE:
{
Datum val;
bool isnull;
/* Start off the constraint definition */
if (conForm->contype == CONSTRAINT_PRIMARY)
appendStringInfo(&buf, "PRIMARY KEY (");
else
appendStringInfo(&buf, "UNIQUE (");
/* Fetch and build target column list */
val = heap_getattr(tup, Anum_pg_constraint_conkey,
RelationGetDescr(conDesc), &isnull);
if (isnull)
elog(ERROR, "null conkey for constraint %u",
constraintId);
decompile_column_index_array(val, conForm->conrelid, &buf);
appendStringInfo(&buf, ")");
break;
}
case CONSTRAINT_CHECK:
{
Datum val;
bool isnull;
char *conbin;
char *consrc;
Node *expr;
List *context;
/* Fetch constraint expression in parsetree form */
val = heap_getattr(tup, Anum_pg_constraint_conbin,
RelationGetDescr(conDesc), &isnull);
if (isnull)
elog(ERROR, "null conbin for constraint %u",
constraintId);
conbin = DatumGetCString(DirectFunctionCall1(textout, val));
expr = stringToNode(conbin);
/* Set up deparsing context for Var nodes in constraint */
if (conForm->conrelid != InvalidOid)
{
/* relation constraint */
context = deparse_context_for(get_rel_name(conForm->conrelid),
conForm->conrelid);
}
else
{
/* domain constraint --- can't have Vars */ context = NIL;
}
consrc = deparse_expression_pretty(expr, context, false, false,
prettyFlags, 0);
/*
* Now emit the constraint definition. There are cases
* where the constraint expression will be fully
* parenthesized and we don't need the outer parens ...
* but there are other cases where we do need 'em. Be
* conservative for now.
*
* Note that simply checking for leading '(' and trailing ')'
* would NOT be good enough, consider "(x > 0) AND (y >
* 0)".
*/
appendStringInfo(&buf, "CHECK (%s)", consrc);
break;
}
default:
elog(ERROR, "invalid constraint type \"%c\"", conForm->contype);
break;
}
/* Cleanup */
systable_endscan(conscan);
heap_close(conDesc, AccessShareLock);
return buf.data;
}
/*
* Convert an int16[] Datum into a comma-separated list of column names
* for the indicated relation; append the list to buf.
*/
static void
decompile_column_index_array(Datum column_index_array, Oid relId,
StringInfo buf)
{
Datum *keys;
int nKeys;
int j;
/* Extract data from array of int16 */
deconstruct_array(DatumGetArrayTypeP(column_index_array),
INT2OID, 2, true, 's',
&keys, &nKeys);
for (j = 0; j < nKeys; j++)
{
char *colName;
colName = get_relid_attribute_name(relId, DatumGetInt16(keys[j]));
if (j == 0)
appendStringInfoString(buf, quote_identifier(colName));
else
appendStringInfo(buf, ", %s", quote_identifier(colName));
}
}
/* ----------
* get_expr - Decompile an expression tree
*
* Input: an expression tree in nodeToString form, and a relation OID
* * Output: reverse-listed expression
*
* Currently, the expression can only refer to a single relation, namely
* the one specified by the second parameter. This is sufficient for
* partial indexes, column default expressions, etc.
* ----------
*/
Datum
pg_get_expr(PG_FUNCTION_ARGS)
{
text *expr = PG_GETARG_TEXT_P(0);
Oid relid = PG_GETARG_OID(1);
char *relname;
/* Get the name for the relation */
relname = get_rel_name(relid);
if (relname == NULL)
PG_RETURN_NULL(); /* should we raise an error? */
PG_RETURN_TEXT_P(string_to_text(pg_get_expr_worker(expr, relid, relname, 0)));
}
Datum
pg_get_expr_ext(PG_FUNCTION_ARGS)
{
text *expr = PG_GETARG_TEXT_P(0);
Oid relid = PG_GETARG_OID(1);
bool pretty = PG_GETARG_BOOL(2);
int prettyFlags;
char *relname;
prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
/* Get the name for the relation */
relname = get_rel_name(relid);
if (relname == NULL)
PG_RETURN_NULL(); /* should we raise an error? */
PG_RETURN_TEXT_P(string_to_text(pg_get_expr_worker(expr, relid, relname, prettyFlags)));
}
static char *
pg_get_expr_worker(text *expr, Oid relid, char *relname, int prettyFlags)
{
Node *node;
List *context;
char *exprstr;
char *str;
/* Convert input TEXT object to C string */
exprstr = DatumGetCString(DirectFunctionCall1(textout,
PointerGetDatum(expr)));
/* Convert expression to node tree */
node = (Node *) stringToNode(exprstr);
/* Deparse */
context = deparse_context_for(relname, relid);
str = deparse_expression_pretty(node, context, false, false,
prettyFlags, 0);
return str;
}
/* ----------
* get_userbyid - Get a user name by usesysid and
* fallback to 'unknown (UID=n)'
* ----------
*/Datum
pg_get_userbyid(PG_FUNCTION_ARGS)
{
int32 uid = PG_GETARG_INT32(0);
Name result;
HeapTuple usertup;
Form_pg_shadow user_rec;
/*
* Allocate space for the result
*/
result = (Name) palloc(NAMEDATALEN);
memset(NameStr(*result), 0, NAMEDATALEN);
/*
* Get the pg_shadow entry and print the result
*/
usertup = SearchSysCache(SHADOWSYSID,
ObjectIdGetDatum(uid),
0, 0, 0);
if (HeapTupleIsValid(usertup))
{
user_rec = (Form_pg_shadow) GETSTRUCT(usertup);
StrNCpy(NameStr(*result), NameStr(user_rec->usename), NAMEDATALEN);
ReleaseSysCache(usertup);
}
else
sprintf(NameStr(*result), "unknown (UID=%d)", uid);
PG_RETURN_NAME(result);
}
/*
* pg_get_serial_sequence
* Get the name of the sequence used by a serial column,
* formatted suitably for passing to setval, nextval or currval.
*/
Datum
pg_get_serial_sequence(PG_FUNCTION_ARGS)
{
text *tablename = PG_GETARG_TEXT_P(0);
text *columnname = PG_GETARG_TEXT_P(1);
RangeVar *tablerv;
Oid tableOid;
char *column;
AttrNumber attnum;
Oid sequenceId = InvalidOid;
Relation depRel;
ScanKeyData key[3];
SysScanDesc scan;
HeapTuple tup;
/* Get the OID of the table */
tablerv = makeRangeVarFromNameList(textToQualifiedNameList(tablename,
"pg_get_serial_sequence"));
tableOid = RangeVarGetRelid(tablerv, false);
/* Get the number of the column */
column = DatumGetCString(DirectFunctionCall1(textout,
PointerGetDatum(columnname)));
attnum = get_attnum(tableOid, column);
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
column, tablerv->relname)));
/* Search the dependency table for the dependent sequence */ depRel = heap_openr(DependRelationName, AccessShareLock);
ScanKeyInit(&key[0],
Anum_pg_depend_refclassid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelOid_pg_class));
ScanKeyInit(&key[1],
Anum_pg_depend_refobjid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(tableOid));
ScanKeyInit(&key[2],
Anum_pg_depend_refobjsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(attnum));
scan = systable_beginscan(depRel, DependReferenceIndex, true,
SnapshotNow, 3, key);
while (HeapTupleIsValid(tup = systable_getnext(scan)))
{
Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup);
/*
* We assume any internal dependency of a relation on a column
* must be what we are looking for.
*/
if (deprec->classid == RelOid_pg_class &&
deprec->objsubid == 0 &&
deprec->deptype == DEPENDENCY_INTERNAL)
{
sequenceId = deprec->objid;
break;
}
}
systable_endscan(scan);
heap_close(depRel, AccessShareLock);
if (OidIsValid(sequenceId))
{
HeapTuple classtup;
Form_pg_class classtuple;
char *nspname;
char *result;
/* Get the sequence's pg_class entry */
classtup = SearchSysCache(RELOID,
ObjectIdGetDatum(sequenceId),
0, 0, 0);
if (!HeapTupleIsValid(classtup))
elog(ERROR, "cache lookup failed for relation %u", sequenceId);
classtuple = (Form_pg_class) GETSTRUCT(classtup);
/* Get the namespace */
nspname = get_namespace_name(classtuple->relnamespace);
if (!nspname)
elog(ERROR, "cache lookup failed for namespace %u",
classtuple->relnamespace);
/* And construct the result string */
result = quote_qualified_identifier(nspname,
NameStr(classtuple->relname));
ReleaseSysCache(classtup);
PG_RETURN_TEXT_P(string_to_text(result));
}
PG_RETURN_NULL();
}
/* ----------
* deparse_expression - General utility for deparsing expressions
*
* calls deparse_expression_pretty with all prettyPrinting disabled
*/
char *
deparse_expression(Node *expr, List *dpcontext,
bool forceprefix, bool showimplicit)
{
return deparse_expression_pretty(expr, dpcontext, forceprefix,
showimplicit, 0, 0);
}
/* ----------
* deparse_expression_pretty - General utility for deparsing expressions
*
* expr is the node tree to be deparsed. It must be a transformed expression
* tree (ie, not the raw output of gram.y).
*
* dpcontext is a list of deparse_namespace nodes representing the context
* for interpreting Vars in the node tree.
*
* forceprefix is TRUE to force all Vars to be prefixed with their table names.
*
* showimplicit is TRUE to force all implicit casts to be shown explicitly.
*
* tries to pretty up the output according to prettyFlags and startIndent.
*
* The result is a palloc'd string.
* ----------
*/
static char *
deparse_expression_pretty(Node *expr, List *dpcontext,
bool forceprefix, bool showimplicit,
int prettyFlags, int startIndent)
{
StringInfoData buf;
deparse_context context;
initStringInfo(&buf);
context.buf = &buf;
context.namespaces = dpcontext;
context.varprefix = forceprefix;
context.prettyFlags = prettyFlags;
context.indentLevel = startIndent;
get_rule_expr(expr, &context, showimplicit);
return buf.data;
}
/* ----------
* deparse_context_for - Build deparse context for a single relation
*
* Given the reference name (alias) and OID of a relation, build deparsing
* context for an expression referencing only that relation (as varno 1,
* varlevelsup 0). This is sufficient for many uses of deparse_expression.
* ----------
*/
List *
deparse_context_for(const char *aliasname, Oid relid)
{
deparse_namespace *dpns;
RangeTblEntry *rte;
dpns = (deparse_namespace *) palloc(sizeof(deparse_namespace));
/* Build a minimal RTE for the rel */ rte = makeNode(RangeTblEntry);
rte->rtekind = RTE_RELATION;
rte->relid = relid;
rte->eref = makeAlias(aliasname, NIL);
rte->inh = false;
rte->inFromCl = true;
/* Build one-element rtable */
dpns->rtable = list_make1(rte);
dpns->outer_varno = dpns->inner_varno = 0;
dpns->outer_rte = dpns->inner_rte = NULL;
/* Return a one-deep namespace stack */
return list_make1(dpns);
}
/*
* deparse_context_for_plan - Build deparse context for a plan node
*
* We assume we are dealing with an upper-level plan node having either
* one or two referenceable children (pass innercontext = NULL if only one).
* The passed-in Nodes should be made using deparse_context_for_subplan
* and/or deparse_context_for_relation. The resulting context will work
* for deparsing quals, tlists, etc of the plan node.
*
* An rtable list can also be passed in case plain Vars might be seen.
* This is not needed for true upper-level expressions, but is helpful for
* Sort nodes and similar cases with slightly bogus targetlists.
*/
List *
deparse_context_for_plan(int outer_varno, Node *outercontext,
int inner_varno, Node *innercontext,
List *rtable)
{
deparse_namespace *dpns;
dpns = (deparse_namespace *) palloc(sizeof(deparse_namespace));
dpns->rtable = rtable;
dpns->outer_varno = outer_varno;
dpns->outer_rte = (RangeTblEntry *) outercontext;
dpns->inner_varno = inner_varno;
dpns->inner_rte = (RangeTblEntry *) innercontext;
/* Return a one-deep namespace stack */
return list_make1(dpns);
}
/*
* deparse_context_for_rte - Build deparse context for 1 relation
*
* Helper routine to build one of the inputs for deparse_context_for_plan.
*
* The returned node is actually the given RangeTblEntry, but we declare it
* as just Node to discourage callers from assuming anything.
*/
Node *
deparse_context_for_rte(RangeTblEntry *rte)
{
return (Node *) rte;
}
/*
* deparse_context_for_subplan - Build deparse context for a plan node
*
* Helper routine to build one of the inputs for deparse_context_for_plan.
* Pass the tlist of the subplan node, plus the query rangetable.
*
* The returned node is actually a RangeTblEntry, but we declare it as just
* Node to discourage callers from assuming anything. */
Node *
deparse_context_for_subplan(const char *name, List *tlist,
List *rtable)
{
RangeTblEntry *rte = makeNode(RangeTblEntry);
List *attrs = NIL;
int nattrs = 0;
int rtablelength = list_length(rtable);
ListCell *tl;
char buf[32];
foreach(tl, tlist)
{
TargetEntry *tle = lfirst(tl);
Resdom *resdom = tle->resdom;
nattrs++;
Assert(resdom->resno == nattrs);
if (resdom->resname)
{
attrs = lappend(attrs, makeString(resdom->resname));
continue;
}
if (tle->expr && IsA(tle->expr, Var))
{
Var *var = (Var *) tle->expr;
/* varno/varattno won't be any good, but varnoold might be */
if (var->varnoold > 0 && var->varnoold <= rtablelength)
{
RangeTblEntry *varrte = rt_fetch(var->varnoold, rtable);
char *varname;
varname = get_rte_attribute_name(varrte, var->varoattno);
attrs = lappend(attrs, makeString(varname));
continue;
}
}
/* Fallback if can't get name */
snprintf(buf, sizeof(buf), "?column%d?", resdom->resno);
attrs = lappend(attrs, makeString(pstrdup(buf)));
}
rte->rtekind = RTE_SPECIAL; /* XXX */
rte->relid = InvalidOid;
rte->eref = makeAlias(name, attrs);
rte->inh = false;
rte->inFromCl = true;
return (Node *) rte;
}
/* ----------
* make_ruledef - reconstruct the CREATE RULE command
* for a given pg_rewrite tuple
* ----------
*/
static void
make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags)
{
char *rulename;
char ev_type;
Oid ev_class;
int2 ev_attr;
bool is_instead;
char *ev_qual;
char *ev_action;
List *actions = NIL; int fno;
Datum dat;
bool isnull;
/*
* Get the attribute values from the rules tuple
*/
fno = SPI_fnumber(rulettc, "rulename");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
rulename = NameStr(*(DatumGetName(dat)));
fno = SPI_fnumber(rulettc, "ev_type");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
ev_type = DatumGetChar(dat);
fno = SPI_fnumber(rulettc, "ev_class");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
ev_class = DatumGetObjectId(dat);
fno = SPI_fnumber(rulettc, "ev_attr");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
ev_attr = DatumGetInt16(dat);
fno = SPI_fnumber(rulettc, "is_instead");
dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
Assert(!isnull);
is_instead = DatumGetBool(dat);
/* these could be nulls */
fno = SPI_fnumber(rulettc, "ev_qual");
ev_qual = SPI_getvalue(ruletup, rulettc, fno);
fno = SPI_fnumber(rulettc, "ev_action");
ev_action = SPI_getvalue(ruletup, rulettc, fno);
if (ev_action != NULL)
actions = (List *) stringToNode(ev_action);
/*
* Build the rules definition text
*/
appendStringInfo(buf, "CREATE RULE %s AS",
quote_identifier(rulename));
if (prettyFlags & PRETTYFLAG_INDENT)
appendStringInfoString(buf, "\n ON ");
else
appendStringInfoString(buf, " ON ");
/* The event the rule is fired for */
switch (ev_type)
{
case '1':
appendStringInfo(buf, "SELECT");
break;
case '2':
appendStringInfo(buf, "UPDATE");
break;
case '3':
appendStringInfo(buf, "INSERT");
break;
case '4':
appendStringInfo(buf, "DELETE");
break;
default:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rule \"%s\" has unsupported event type %d",
rulename, ev_type)));
break;
}
/* The relation the rule is fired on */
appendStringInfo(buf, " TO %s", generate_relation_name(ev_class));
if (ev_attr > 0)
appendStringInfo(buf, ".%s",
quote_identifier(get_relid_attribute_name(ev_class,
ev_attr)));
/* If the rule has an event qualification, add it */
if (ev_qual == NULL)
ev_qual = "";
if (strlen(ev_qual) > 0 && strcmp(ev_qual, "<>") != 0)
{
Node *qual;
Query *query;
deparse_context context;
deparse_namespace dpns;
if (prettyFlags & PRETTYFLAG_INDENT)
appendStringInfoString(buf, "\n ");
appendStringInfo(buf, " WHERE ");
qual = stringToNode(ev_qual);
/*
* We need to make a context for recognizing any Vars in the qual
* (which can only be references to OLD and NEW). Use the rtable
* of the first query in the action list for this purpose.
*/
query = (Query *) linitial(actions);
/*
* If the action is INSERT...SELECT, OLD/NEW have been pushed down
* into the SELECT, and that's what we need to look at. (Ugly
* kluge ... try to fix this when we redesign querytrees.)
*/
query = getInsertSelectQuery(query, NULL);
context.buf = buf;
context.namespaces = list_make1(&dpns);
context.varprefix = (list_length(query->rtable) != 1);
context.prettyFlags = prettyFlags;
context.indentLevel = PRETTYINDENT_STD;
dpns.rtable = query->rtable;
dpns.outer_varno = dpns.inner_varno = 0;
dpns.outer_rte = dpns.inner_rte = NULL;
get_rule_expr(qual, &context, false);
}
appendStringInfo(buf, " DO ");
/* The INSTEAD keyword (if so) */
if (is_instead)
appendStringInfo(buf, "INSTEAD ");
/* Finally the rules actions */
if (list_length(actions) > 1)
{
ListCell *action;
Query *query;
appendStringInfo(buf, "(");
foreach(action, actions)
{
query = (Query *) lfirst(action);
get_query_def(query, buf, NIL, NULL, prettyFlags, 0);
if (prettyFlags)
appendStringInfo(buf, ";\n");
else
appendStringInfo(buf, "; ");
}
appendStringInfo(buf, ");");
}
else if (list_length(actions) == 0)
{
appendStringInfo(buf, "NOTHING;");
}
else
{
Query *query;
query = (Query *) linitial(actions);
get_query_def(query, buf, NIL, NULL, prettyFlags, 0);
appendStringInfo(buf, ";");
}
}
/* ----------
* make_viewdef - reconstruct the SELECT part of a
* view rewrite rule
* ----------
*/
static void
make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
int prettyFlags)
{
Query *query;
char ev_type;
Oid ev_class;
int2 ev_attr;
bool is_instead;
char *ev_qual;
char *ev_action;
List *actions = NIL;
Relation ev_relation;
int fno;
bool isnull;
/*
* Get the attribute values from the rules tuple
*/
fno = SPI_fnumber(rulettc, "ev_type");
ev_type = (char) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_class");
ev_class = (Oid) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_attr");
ev_attr = (int2) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "is_instead");
is_instead = (bool) SPI_getbinval(ruletup, rulettc, fno, &isnull);
fno = SPI_fnumber(rulettc, "ev_qual");
ev_qual = SPI_getvalue(ruletup, rulettc, fno);
fno = SPI_fnumber(rulettc, "ev_action");
ev_action = SPI_getvalue(ruletup, rulettc, fno);
if (ev_action != NULL)
actions = (List *) stringToNode(ev_action);
if (list_length(actions) != 1)
{
appendStringInfo(buf, "Not a view");
return;
}
query = (Query *) linitial(actions);
if (ev_type != '1' || ev_attr >= 0 || !is_instead ||
strcmp(ev_qual, "<>") != 0 || query->commandType != CMD_SELECT)
{
appendStringInfo(buf, "Not a view");
return;
}
ev_relation = heap_open(ev_class, AccessShareLock);
get_query_def(query, buf, NIL, RelationGetDescr(ev_relation),
prettyFlags, 0);
appendStringInfo(buf, ";");
heap_close(ev_relation, AccessShareLock);
}
/* ----------
* get_query_def - Parse back one query parsetree
*
* If resultDesc is not NULL, then it is the output tuple descriptor for
* the view represented by a SELECT query.
* ----------
*/
static void
get_query_def(Query *query, StringInfo buf, List *parentnamespace,
TupleDesc resultDesc, int prettyFlags, int startIndent)
{
deparse_context context;
deparse_namespace dpns;
context.buf = buf;
context.namespaces = lcons(&dpns, list_copy(parentnamespace));
context.varprefix = (parentnamespace != NIL ||
list_length(query->rtable) != 1);
context.prettyFlags = prettyFlags;
context.indentLevel = startIndent;
dpns.rtable = query->rtable;
dpns.outer_varno = dpns.inner_varno = 0;
dpns.outer_rte = dpns.inner_rte = NULL;
switch (query->commandType)
{
case CMD_SELECT:
get_select_query_def(query, &context, resultDesc);
break;
case CMD_UPDATE:
get_update_query_def(query, &context);
break;
case CMD_INSERT:
get_insert_query_def(query, &context);
break;
case CMD_DELETE:
get_delete_query_def(query, &context);
break;
case CMD_NOTHING: appendStringInfo(buf, "NOTHING");
break;
case CMD_UTILITY:
get_utility_query_def(query, &context);
break;
default:
elog(ERROR, "unrecognized query command type: %d",
query->commandType);
break;
}
}
/* ----------
* get_select_query_def - Parse back a SELECT parsetree
* ----------
*/
static void
get_select_query_def(Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
bool force_colno;
char *sep;
ListCell *l;
/*
* If the Query node has a setOperations tree, then it's the top level
* of a UNION/INTERSECT/EXCEPT query; only the ORDER BY and LIMIT
* fields are interesting in the top query itself.
*/
if (query->setOperations)
{
get_setop_query(query->setOperations, query, context, resultDesc);
/* ORDER BY clauses must be simple in this case */
force_colno = true;
}
else
{
get_basic_select_query(query, context, resultDesc);
force_colno = false;
}
/* Add the ORDER BY clause if given */
if (query->sortClause != NIL)
{
appendContextKeyword(context, " ORDER BY ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
sep = "";
foreach(l, query->sortClause)
{
SortClause *srt = (SortClause *) lfirst(l);
Node *sortexpr;
Oid sortcoltype;
TypeCacheEntry *typentry;
appendStringInfo(buf, sep);
sortexpr = get_rule_sortgroupclause(srt, query->targetList,
force_colno, context);
sortcoltype = exprType(sortexpr);
/* See whether operator is default < or > for datatype */
typentry = lookup_type_cache(sortcoltype,
TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
if (srt->sortop == typentry->lt_opr)
/* ASC is default, so emit nothing */ ;
else if (srt->sortop == typentry->gt_opr)
appendStringInfo(buf, " DESC");
else appendStringInfo(buf, " USING %s",
generate_operator_name(srt->sortop,
sortcoltype,
sortcoltype));
sep = ", ";
}
}
/* Add the LIMIT clause if given */
if (query->limitOffset != NULL)
{
appendContextKeyword(context, " OFFSET ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
get_rule_expr(query->limitOffset, context, false);
}
if (query->limitCount != NULL)
{
appendContextKeyword(context, " LIMIT ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
if (IsA(query->limitCount, Const) &&
((Const *) query->limitCount)->constisnull)
appendStringInfo(buf, "ALL");
else
get_rule_expr(query->limitCount, context, false);
}
}
static void
get_basic_select_query(Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
char *sep;
ListCell *l;
int colno;
/*
* Build up the query string - first we say SELECT
*/
if (PRETTY_INDENT(context))
{
context->indentLevel += PRETTYINDENT_STD;
appendStringInfoChar(buf, ' ');
}
appendStringInfo(buf, "SELECT");
/* Add the DISTINCT clause if given */
if (query->distinctClause != NIL)
{
if (has_distinct_on_clause(query))
{
appendStringInfo(buf, " DISTINCT ON (");
sep = "";
foreach(l, query->distinctClause)
{
SortClause *srt = (SortClause *) lfirst(l);
appendStringInfo(buf, sep);
get_rule_sortgroupclause(srt, query->targetList,
false, context);
sep = ", ";
}
appendStringInfo(buf, ")");
}
else
appendStringInfo(buf, " DISTINCT");
}
/* Then we tell what to select (the targetlist) */
sep = " "; colno = 0;
foreach(l, query->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
char *colname;
if (tle->resdom->resjunk)
continue; /* ignore junk entries */
appendStringInfo(buf, sep);
sep = ", ";
colno++;
get_rule_expr((Node *) tle->expr, context, true);
/*
* Figure out what the result column should be called. In the
* context of a view, use the view's tuple descriptor (so as to
* pick up the effects of any column RENAME that's been done on
* the view). Otherwise, just use what we can find in the TLE.
*/
if (resultDesc && colno <= resultDesc->natts)
colname = NameStr(resultDesc->attrs[colno - 1]->attname);
else
colname = tle->resdom->resname;
if (colname) /* resname could be NULL */
{
/* Check if we must say AS ... */
bool tell_as;
if (!IsA(tle->expr, Var))
tell_as = (strcmp(colname, "?column?") != 0);
else
{
Var *var = (Var *) (tle->expr);
char *schemaname;
char *refname;
char *attname;
get_names_for_var(var, context,
&schemaname, &refname, &attname);
tell_as = (attname == NULL ||
strcmp(attname, colname) != 0);
}
/* and do if so */
if (tell_as)
appendStringInfo(buf, " AS %s", quote_identifier(colname));
}
}
/* Add the FROM clause if needed */
get_from_clause(query, context);
/* Add the WHERE clause if given */
if (query->jointree->quals != NULL)
{
appendContextKeyword(context, " WHERE ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_expr(query->jointree->quals, context, false);
}
/* Add the GROUP BY clause if given */
if (query->groupClause != NULL)
{
appendContextKeyword(context, " GROUP BY ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
sep = "";
foreach(l, query->groupClause) {
GroupClause *grp = (GroupClause *) lfirst(l);
appendStringInfo(buf, sep);
get_rule_sortgroupclause(grp, query->targetList,
false, context);
sep = ", ";
}
}
/* Add the HAVING clause if given */
if (query->havingQual != NULL)
{
appendContextKeyword(context, " HAVING ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
get_rule_expr(query->havingQual, context, false);
}
}
static void
get_setop_query(Node *setOp, Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
bool need_paren;
if (IsA(setOp, RangeTblRef))
{
RangeTblRef *rtr = (RangeTblRef *) setOp;
RangeTblEntry *rte = rt_fetch(rtr->rtindex, query->rtable);
Query *subquery = rte->subquery;
Assert(subquery != NULL);
Assert(subquery->setOperations == NULL);
/* Need parens if ORDER BY, FOR UPDATE, or LIMIT; see gram.y */
need_paren = (subquery->sortClause ||
subquery->rowMarks ||
subquery->limitOffset ||
subquery->limitCount);
if (need_paren)
appendStringInfoChar(buf, '(');
get_query_def(subquery, buf, context->namespaces, resultDesc,
context->prettyFlags, context->indentLevel);
if (need_paren)
appendStringInfoChar(buf, ')');
}
else if (IsA(setOp, SetOperationStmt))
{
SetOperationStmt *op = (SetOperationStmt *) setOp;
/*
* We force parens whenever nesting two SetOperationStmts. There
* are some cases in which parens are needed around a leaf query
* too, but those are more easily handled at the next level down
* (see code above).
*/
need_paren = !IsA(op->larg, RangeTblRef);
if (need_paren)
appendStringInfoChar(buf, '(');
get_setop_query(op->larg, query, context, resultDesc);
if (need_paren)
appendStringInfoChar(buf, ')');
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
switch (op->op)
{
case SETOP_UNION:
appendContextKeyword(context, "UNION ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
case SETOP_INTERSECT:
appendContextKeyword(context, "INTERSECT ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
case SETOP_EXCEPT:
appendContextKeyword(context, "EXCEPT ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 0);
break;
default:
elog(ERROR, "unrecognized set op: %d",
(int) op->op);
}
if (op->all)
appendStringInfo(buf, "ALL ");
if (PRETTY_INDENT(context))
appendContextKeyword(context, "", 0, 0, 0);
need_paren = !IsA(op->rarg, RangeTblRef);
if (need_paren)
appendStringInfoChar(buf, '(');
get_setop_query(op->rarg, query, context, resultDesc);
if (need_paren)
appendStringInfoChar(buf, ')');
}
else
{
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(setOp));
}
}
/*
* Display a sort/group clause.
*
* Also returns the expression tree, so caller need not find it again.
*/
static Node *
get_rule_sortgroupclause(SortClause *srt, List *tlist, bool force_colno,
deparse_context *context)
{
StringInfo buf = context->buf;
TargetEntry *tle;
Node *expr;
tle = get_sortgroupclause_tle(srt, tlist);
expr = (Node *) tle->expr;
/*
* Use column-number form if requested by caller or if expression is a
* constant --- a constant is ambiguous (and will be misinterpreted by
* findTargetlistEntry()) if we dump it explicitly.
*/
if (force_colno || (expr && IsA(expr, Const)))
{
Assert(!tle->resdom->resjunk);
appendStringInfo(buf, "%d", tle->resdom->resno);
}
else
get_rule_expr(expr, context, true);
return expr;
}
/* ----------
* get_insert_query_def - Parse back an INSERT parsetree
* ---------- */
static void
get_insert_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
RangeTblEntry *select_rte = NULL;
RangeTblEntry *rte;
char *sep;
ListCell *l;
List *strippedexprs;
/*
* If it's an INSERT ... SELECT there will be a single subquery RTE
* for the SELECT.
*/
foreach(l, query->rtable)
{
rte = (RangeTblEntry *) lfirst(l);
if (rte->rtekind != RTE_SUBQUERY)
continue;
if (select_rte)
elog(ERROR, "too many RTEs in INSERT");
select_rte = rte;
}
/*
* Start the query with INSERT INTO relname
*/
rte = rt_fetch(query->resultRelation, query->rtable);
Assert(rte->rtekind == RTE_RELATION);
if (PRETTY_INDENT(context))
{
context->indentLevel += PRETTYINDENT_STD;
appendStringInfoChar(buf, ' ');
}
appendStringInfo(buf, "INSERT INTO %s (",
generate_relation_name(rte->relid));
/*
* Add the insert-column-names list, and make a list of the actual
* assignment source expressions.
*/
strippedexprs = NIL;
sep = "";
foreach(l, query->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
if (tle->resdom->resjunk)
continue; /* ignore junk entries */
appendStringInfo(buf, sep);
sep = ", ";
/*
* Put out name of target column; look in the catalogs, not at
* tle->resname, since resname will fail to track RENAME.
*/
appendStringInfoString(buf,
quote_identifier(get_relid_attribute_name(rte->relid,
tle->resdom->resno)));
/*
* Print any indirection needed (subfields or subscripts), and
* strip off the top-level nodes representing the indirection
* assignments.
*/
strippedexprs = lappend(strippedexprs,
processIndirection((Node *) tle->expr, context));
}
appendStringInfo(buf, ") ");
/* Add the VALUES or the SELECT */
if (select_rte == NULL)
{
appendContextKeyword(context, "VALUES (",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 2);
get_rule_expr((Node *) strippedexprs, context, false);
appendStringInfoChar(buf, ')');
}
else
get_query_def(select_rte->subquery, buf, NIL, NULL,
context->prettyFlags, context->indentLevel);
}
/* ----------
* get_update_query_def - Parse back an UPDATE parsetree
* ----------
*/
static void
get_update_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
char *sep;
RangeTblEntry *rte;
ListCell *l;
/*
* Start the query with UPDATE relname SET
*/
rte = rt_fetch(query->resultRelation, query->rtable);
Assert(rte->rtekind == RTE_RELATION);
if (PRETTY_INDENT(context))
{
appendStringInfoChar(buf, ' ');
context->indentLevel += PRETTYINDENT_STD;
}
appendStringInfo(buf, "UPDATE %s%s SET ",
only_marker(rte),
generate_relation_name(rte->relid));
/* Add the comma separated list of 'attname = value' */
sep = "";
foreach(l, query->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Node *expr;
if (tle->resdom->resjunk)
continue; /* ignore junk entries */
appendStringInfo(buf, sep);
sep = ", ";
/*
* Put out name of target column; look in the catalogs, not at
* tle->resname, since resname will fail to track RENAME.
*/
appendStringInfoString(buf,
quote_identifier(get_relid_attribute_name(rte->relid,
tle->resdom->resno)));
/*
* Print any indirection needed (subfields or subscripts), and
* strip off the top-level nodes representing the indirection
* assignments.
*/ expr = processIndirection((Node *) tle->expr, context);
appendStringInfo(buf, " = ");
get_rule_expr(expr, context, false);
}
/* Add the FROM clause if needed */
get_from_clause(query, context);
/* Finally add a WHERE clause if given */
if (query->jointree->quals != NULL)
{
appendContextKeyword(context, " WHERE ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_expr(query->jointree->quals, context, false);
}
}
/* ----------
* get_delete_query_def - Parse back a DELETE parsetree
* ----------
*/
static void
get_delete_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
RangeTblEntry *rte;
/*
* Start the query with DELETE FROM relname
*/
rte = rt_fetch(query->resultRelation, query->rtable);
Assert(rte->rtekind == RTE_RELATION);
if (PRETTY_INDENT(context))
{
context->indentLevel += PRETTYINDENT_STD;
appendStringInfoChar(buf, ' ');
}
appendStringInfo(buf, "DELETE FROM %s%s",
only_marker(rte),
generate_relation_name(rte->relid));
/* Add a WHERE clause if given */
if (query->jointree->quals != NULL)
{
appendContextKeyword(context, " WHERE ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
get_rule_expr(query->jointree->quals, context, false);
}
}
/* ----------
* get_utility_query_def - Parse back a UTILITY parsetree
* ----------
*/
static void
get_utility_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
if (query->utilityStmt && IsA(query->utilityStmt, NotifyStmt))
{
NotifyStmt *stmt = (NotifyStmt *) query->utilityStmt;
appendContextKeyword(context, "",
0, PRETTYINDENT_STD, 1);
appendStringInfo(buf, "NOTIFY %s", quote_qualified_identifier(stmt->relation->schemaname,
stmt->relation->relname));
}
else
{
/* Currently only NOTIFY utility commands can appear in rules */
elog(ERROR, "unexpected utility statement type");
}
}
/*
* Get the schemaname, refname and attname for a (possibly nonlocal) Var.
*
* schemaname is usually returned as NULL. It will be non-null only if
* use of the unqualified refname would find the wrong RTE.
*
* refname will be returned as NULL if the Var references an unnamed join.
* In this case the Var *must* be displayed without any qualification.
*
* attname will be returned as NULL if the Var represents a whole tuple
* of the relation. (Typically we'd want to display the Var as "foo.*",
* but it's convenient to return NULL to make it easier for callers to
* distinguish this case.)
*/
static void
get_names_for_var(Var *var, deparse_context *context,
char **schemaname, char **refname, char **attname)
{
deparse_namespace *dpns;
RangeTblEntry *rte;
/* Find appropriate nesting depth */
if (var->varlevelsup >= list_length(context->namespaces))
elog(ERROR, "bogus varlevelsup: %d", var->varlevelsup);
dpns = (deparse_namespace *) list_nth(context->namespaces,
var->varlevelsup);
/* Find the relevant RTE */
if (var->varno >= 1 && var->varno <= list_length(dpns->rtable))
rte = rt_fetch(var->varno, dpns->rtable);
else if (var->varno == dpns->outer_varno)
rte = dpns->outer_rte;
else if (var->varno == dpns->inner_varno)
rte = dpns->inner_rte;
else
rte = NULL;
if (rte == NULL)
elog(ERROR, "bogus varno: %d", var->varno);
/* Emit results */
*schemaname = NULL; /* default assumptions */
*refname = rte->eref->aliasname;
/* Exceptions occur only if the RTE is alias-less */
if (rte->alias == NULL)
{
if (rte->rtekind == RTE_RELATION)
{
/*
* It's possible that use of the bare refname would find
* another more-closely-nested RTE, or be ambiguous, in which
* case we need to specify the schemaname to avoid these
* errors.
*/
if (find_rte_by_refname(rte->eref->aliasname, context) != rte)
*schemaname =
get_namespace_name(get_rel_namespace(rte->relid));
}
else if (rte->rtekind == RTE_JOIN) {
/*
* If it's an unnamed join, look at the expansion of the alias
* variable. If it's a simple reference to one of the input
* vars then recursively find the name of that var, instead.
* (This allows correct decompiling of cases where there are
* identically named columns on both sides of the join.)
* When it's not a simple reference, we have to just return
* the unqualified variable name (this can only happen with
* columns that were merged by USING or NATURAL clauses).
*/
if (var->varattno > 0)
{
Var *aliasvar;
aliasvar = (Var *) list_nth(rte->joinaliasvars,
var->varattno-1);
if (IsA(aliasvar, Var))
{
get_names_for_var(aliasvar, context,
schemaname, refname, attname);
return;
}
}
/* Unnamed join has neither schemaname nor refname */
*refname = NULL;
}
}
if (var->varattno == InvalidAttrNumber)
*attname = NULL;
else
*attname = get_rte_attribute_name(rte, var->varattno);
}
/*
* find_rte_by_refname - look up an RTE by refname in a deparse context
*
* Returns NULL if there is no matching RTE or the refname is ambiguous.
*
* NOTE: this code is not really correct since it does not take account of
* the fact that not all the RTEs in a rangetable may be visible from the
* point where a Var reference appears. For the purposes we need, however,
* the only consequence of a false match is that we might stick a schema
* qualifier on a Var that doesn't really need it. So it seems close
* enough.
*/
static RangeTblEntry *
find_rte_by_refname(const char *refname, deparse_context *context)
{
RangeTblEntry *result = NULL;
ListCell *nslist;
foreach(nslist, context->namespaces)
{
deparse_namespace *dpns = (deparse_namespace *) lfirst(nslist);
ListCell *rtlist;
foreach(rtlist, dpns->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rtlist);
if (strcmp(rte->eref->aliasname, refname) == 0)
{
if (result)
return NULL; /* it's ambiguous */
result = rte;
}
}
if (dpns->outer_rte && strcmp(dpns->outer_rte->eref->aliasname, refname) == 0)
{
if (result)
return NULL; /* it's ambiguous */
result = dpns->outer_rte;
}
if (dpns->inner_rte &&
strcmp(dpns->inner_rte->eref->aliasname, refname) == 0)
{
if (result)
return NULL; /* it's ambiguous */
result = dpns->inner_rte;
}
if (result)
break;
}
return result;
}
/*
* get_simple_binary_op_name
*
* helper function for isSimpleNode
* will return single char binary operator name, or NULL if it's not
*/
static const char *
get_simple_binary_op_name(OpExpr *expr)
{
List *args = expr->args;
if (list_length(args) == 2)
{
/* binary operator */
Node *arg1 = (Node *) linitial(args);
Node *arg2 = (Node *) lsecond(args);
const char *op;
op = generate_operator_name(expr->opno, exprType(arg1), exprType(arg2));
if (strlen(op) == 1)
return op;
}
return NULL;
}
/*
* isSimpleNode - check if given node is simple (doesn't need parenthesizing)
*
* true : simple in the context of parent node's type
* false : not simple
*/
static bool
isSimpleNode(Node *node, Node *parentNode, int prettyFlags)
{
if (!node)
return false;
switch (nodeTag(node))
{
case T_Var:
case T_Const:
case T_Param:
case T_CoerceToDomainValue:
case T_SetToDefault:
/* single words: always simple */
return true;
case T_ArrayRef:
case T_ArrayExpr: case T_RowExpr:
case T_CoalesceExpr:
case T_NullIfExpr:
case T_Aggref:
case T_FuncExpr:
/* function-like: name(..) or name[..] */
return true;
/* CASE keywords act as parentheses */
case T_CaseExpr:
return true;
case T_FieldSelect:
/*
* appears simple since . has top precedence, unless parent is
* T_FieldSelect itself!
*/
return (IsA(parentNode, FieldSelect) ? false : true);
case T_FieldStore:
/*
* treat like FieldSelect (probably doesn't matter)
*/
return (IsA(parentNode, FieldStore) ? false : true);
case T_CoerceToDomain:
/* maybe simple, check args */
return isSimpleNode((Node *) ((CoerceToDomain *) node)->arg,
node, prettyFlags);
case T_RelabelType:
return isSimpleNode((Node *) ((RelabelType *) node)->arg,
node, prettyFlags);
case T_ConvertRowtypeExpr:
return isSimpleNode((Node *) ((ConvertRowtypeExpr *) node)->arg,
node, prettyFlags);
case T_OpExpr:
{
/* depends on parent node type; needs further checking */
if (prettyFlags & PRETTYFLAG_PAREN && IsA(parentNode, OpExpr))
{
const char *op;
const char *parentOp;
bool is_lopriop;
bool is_hipriop;
bool is_lopriparent;
bool is_hipriparent;
op = get_simple_binary_op_name((OpExpr *) node);
if (!op)
return false;
/* We know only the basic operators + - and * / % */
is_lopriop = (strchr("+-", *op) != NULL);
is_hipriop = (strchr("*/%", *op) != NULL);
if (!(is_lopriop || is_hipriop))
return false;
parentOp = get_simple_binary_op_name((OpExpr *) parentNode);
if (!parentOp)
return false;
is_lopriparent = (strchr("+-", *parentOp) != NULL);
is_hipriparent = (strchr("*/%", *parentOp) != NULL);
if (!(is_lopriparent || is_hipriparent))
return false;
if (is_hipriop && is_lopriparent) return true; /* op binds tighter than parent */
if (is_lopriop && is_hipriparent)
return false;
/*
* Operators are same priority --- can skip parens
* only if we have (a - b) - c, not a - (b - c).
*/
if (node == (Node *) linitial(((OpExpr *) parentNode)->args))
return true;
return false;
}
/* else do the same stuff as for T_SubLink et al. */
/* FALL THROUGH */
}
case T_SubLink:
case T_NullTest:
case T_BooleanTest:
case T_DistinctExpr:
switch (nodeTag(parentNode))
{
case T_FuncExpr:
{
/* special handling for casts */
CoercionForm type = ((FuncExpr *) parentNode)->funcformat;
if (type == COERCE_EXPLICIT_CAST ||
type == COERCE_IMPLICIT_CAST)
return false;
return true; /* own parentheses */
}
case T_BoolExpr: /* lower precedence */
case T_ArrayRef: /* other separators */
case T_ArrayExpr: /* other separators */
case T_RowExpr: /* other separators */
case T_CoalesceExpr: /* own parentheses */
case T_NullIfExpr: /* other separators */
case T_Aggref: /* own parentheses */
case T_CaseExpr: /* other separators */
return true;
default:
return false;
}
case T_BoolExpr:
switch (nodeTag(parentNode))
{
case T_BoolExpr:
if (prettyFlags & PRETTYFLAG_PAREN)
{
BoolExprType type;
BoolExprType parentType;
type = ((BoolExpr *) node)->boolop;
parentType = ((BoolExpr *) parentNode)->boolop;
switch (type)
{
case NOT_EXPR:
case AND_EXPR:
if (parentType == AND_EXPR || parentType == OR_EXPR)
return true;
break;
case OR_EXPR:
if (parentType == OR_EXPR)
return true;
break;
} }
return false;
case T_FuncExpr:
{
/* special handling for casts */
CoercionForm type = ((FuncExpr *) parentNode)->funcformat;
if (type == COERCE_EXPLICIT_CAST ||
type == COERCE_IMPLICIT_CAST)
return false;
return true; /* own parentheses */
}
case T_ArrayRef: /* other separators */
case T_ArrayExpr: /* other separators */
case T_RowExpr: /* other separators */
case T_CoalesceExpr: /* own parentheses */
case T_NullIfExpr: /* other separators */
case T_Aggref: /* own parentheses */
case T_CaseExpr: /* other separators */
return true;
default:
return false;
}
default:
break;
}
/* those we don't know: in dubio complexo */
return false;
}
/*
* appendStringInfoSpaces - append spaces to buffer
*/
static void
appendStringInfoSpaces(StringInfo buf, int count)
{
while (count-- > 0)
appendStringInfoChar(buf, ' ');
}
/*
* appendContextKeyword - append a keyword to buffer
*
* If prettyPrint is enabled, perform a line break, and adjust indentation.
* Otherwise, just append the keyword.
*/
static void
appendContextKeyword(deparse_context *context, const char *str,
int indentBefore, int indentAfter, int indentPlus)
{
if (PRETTY_INDENT(context))
{
context->indentLevel += indentBefore;
appendStringInfoChar(context->buf, '\n');
appendStringInfoSpaces(context->buf,
Max(context->indentLevel, 0) + indentPlus);
appendStringInfoString(context->buf, str);
context->indentLevel += indentAfter;
if (context->indentLevel < 0)
context->indentLevel = 0;
}
else
appendStringInfoString(context->buf, str);
}
/* * get_rule_expr_paren - deparse expr using get_rule_expr,
* embracing the string with parentheses if necessary for prettyPrint.
*
* Never embrace if prettyFlags=0, because it's done in the calling node.
*
* Any node that does *not* embrace its argument node by sql syntax (with
* parentheses, non-operator keywords like CASE/WHEN/ON, or comma etc) should
* use get_rule_expr_paren instead of get_rule_expr so parentheses can be
* added.
*/
static void
get_rule_expr_paren(Node *node, deparse_context *context,
bool showimplicit, Node *parentNode)
{
bool need_paren;
need_paren = PRETTY_PAREN(context) &&
!isSimpleNode(node, parentNode, context->prettyFlags);
if (need_paren)
appendStringInfoChar(context->buf, '(');
get_rule_expr(node, context, showimplicit);
if (need_paren)
appendStringInfoChar(context->buf, ')');
}
/* ----------
* get_rule_expr - Parse back an expression
*
* Note: showimplicit determines whether we display any implicit cast that
* is present at the top of the expression tree. It is a passed argument,
* not a field of the context struct, because we change the value as we
* recurse down into the expression. In general we suppress implicit casts
* when the result type is known with certainty (eg, the arguments of an
* OR must be boolean). We display implicit casts for arguments of functions
* and operators, since this is needed to be certain that the same function
* or operator will be chosen when the expression is re-parsed.
* ----------
*/
static void
get_rule_expr(Node *node, deparse_context *context,
bool showimplicit)
{
StringInfo buf = context->buf;
if (node == NULL)
return;
/*
* Each level of get_rule_expr must emit an indivisible term
* (parenthesized if necessary) to ensure result is reparsed into the
* same expression tree. The only exception is that when the input
* is a List, we emit the component items comma-separated with no
* surrounding decoration; this is convenient for most callers.
*
* There might be some work left here to support additional node types.
*/
switch (nodeTag(node))
{
case T_Var:
{
Var *var = (Var *) node;
char *schemaname;
char *refname;
char *attname;
get_names_for_var(var, context, &schemaname, &refname, &attname);
if (refname && (context->varprefix || attname == NULL))
{
if (schemaname)
appendStringInfo(buf, "%s.",
quote_identifier(schemaname));
if (strcmp(refname, "*NEW*") == 0)
appendStringInfo(buf, "new.");
else if (strcmp(refname, "*OLD*") == 0)
appendStringInfo(buf, "old.");
else
appendStringInfo(buf, "%s.",
quote_identifier(refname));
}
if (attname)
appendStringInfoString(buf, quote_identifier(attname));
else
appendStringInfo(buf, "*");
}
break;
case T_Const:
get_const_expr((Const *) node, context);
break;
case T_Param:
{
Param *param = (Param *) node;
switch (param->paramkind)
{
case PARAM_NAMED:
appendStringInfo(buf, "$%s", param->paramname);
break;
case PARAM_NUM:
case PARAM_EXEC:
appendStringInfo(buf, "$%d", param->paramid);
break;
default:
appendStringInfo(buf, "(param)");
break;
}
}
break;
case T_Aggref:
get_agg_expr((Aggref *) node, context);
break;
case T_ArrayRef:
{
ArrayRef *aref = (ArrayRef *) node;
bool need_parens;
/*
* Parenthesize the argument unless it's a simple Var or a
* FieldSelect. (In particular, if it's another ArrayRef,
* we *must* parenthesize to avoid confusion.)
*/
need_parens = !IsA(aref->refexpr, Var) &&
!IsA(aref->refexpr, FieldSelect);
if (need_parens)
appendStringInfoChar(buf, '(');
get_rule_expr((Node *) aref->refexpr, context, showimplicit);
if (need_parens)
appendStringInfoChar(buf, ')');
printSubscripts(aref, context);
/* * Array assignment nodes should have been handled in
* processIndirection().
*/
if (aref->refassgnexpr)
elog(ERROR, "unexpected refassgnexpr");
}
break;
case T_FuncExpr:
get_func_expr((FuncExpr *) node, context, showimplicit);
break;
case T_OpExpr:
get_oper_expr((OpExpr *) node, context);
break;
case T_DistinctExpr:
{
DistinctExpr *expr = (DistinctExpr *) node;
List *args = expr->args;
Node *arg1 = (Node *) linitial(args);
Node *arg2 = (Node *) lsecond(args);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg1, context, true, node);
appendStringInfo(buf, " IS DISTINCT FROM ");
get_rule_expr_paren(arg2, context, true, node);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_ScalarArrayOpExpr:
{
ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
List *args = expr->args;
Node *arg1 = (Node *) linitial(args);
Node *arg2 = (Node *) lsecond(args);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg1, context, true, node);
appendStringInfo(buf, " %s %s (",
generate_operator_name(expr->opno,
exprType(arg1),
get_element_type(exprType(arg2))),
expr->useOr ? "ANY" : "ALL");
get_rule_expr_paren(arg2, context, true, node);
appendStringInfoChar(buf, ')');
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_BoolExpr:
{
BoolExpr *expr = (BoolExpr *) node;
Node *first_arg = linitial(expr->args);
ListCell *arg = lnext(list_head(expr->args));
switch (expr->boolop)
{
case AND_EXPR:
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(first_arg, context,
false, node);
while (arg)
{ appendStringInfo(buf, " AND ");
get_rule_expr_paren((Node *) lfirst(arg), context,
false, node);
arg = lnext(arg);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
break;
case OR_EXPR:
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(first_arg, context,
false, node);
while (arg)
{
appendStringInfo(buf, " OR ");
get_rule_expr_paren((Node *) lfirst(arg), context,
false, node);
arg = lnext(arg);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
break;
case NOT_EXPR:
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
appendStringInfo(buf, "NOT ");
get_rule_expr_paren(first_arg, context,
false, node);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
break;
default:
elog(ERROR, "unrecognized boolop: %d",
(int) expr->boolop);
}
}
break;
case T_SubLink:
get_sublink_expr((SubLink *) node, context);
break;
case T_SubPlan:
{
/*
* We cannot see an already-planned subplan in rule
* deparsing, only while EXPLAINing a query plan. For now,
* just punt.
*/
if (((SubPlan *) node)->useHashTable)
appendStringInfo(buf, "(hashed subplan)");
else
appendStringInfo(buf, "(subplan)");
}
break;
case T_FieldSelect:
{
FieldSelect *fselect = (FieldSelect *) node;
Oid argType = exprType((Node *) fselect->arg);
Oid typrelid;
char *fieldname;
bool need_parens;
/* lookup arg type and get the field name */
typrelid = get_typ_typrelid(argType); if (!OidIsValid(typrelid))
elog(ERROR, "argument type %s of FieldSelect is not a tuple type",
format_type_be(argType));
fieldname = get_relid_attribute_name(typrelid,
fselect->fieldnum);
/*
* Parenthesize the argument unless it's an ArrayRef or
* another FieldSelect. Note in particular that it would
* be WRONG to not parenthesize a Var argument; simplicity
* is not the issue here, having the right number of names
* is.
*/
need_parens = !IsA(fselect->arg, ArrayRef) &&
!IsA(fselect->arg, FieldSelect);
if (need_parens)
appendStringInfoChar(buf, '(');
get_rule_expr((Node *) fselect->arg, context, true);
if (need_parens)
appendStringInfoChar(buf, ')');
appendStringInfo(buf, ".%s", quote_identifier(fieldname));
}
break;
case T_FieldStore:
/*
* We shouldn't see FieldStore here; it should have been
* stripped off by processIndirection().
*/
elog(ERROR, "unexpected FieldStore");
break;
case T_RelabelType:
{
RelabelType *relabel = (RelabelType *) node;
Node *arg = (Node *) relabel->arg;
if (relabel->relabelformat == COERCE_IMPLICIT_CAST &&
!showimplicit)
{
/* don't show the implicit cast */
get_rule_expr_paren(arg, context, false, node);
}
else
{
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg, context, false, node);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
appendStringInfo(buf, "::%s",
format_type_with_typemod(relabel->resulttype,
relabel->resulttypmod));
}
}
break;
case T_ConvertRowtypeExpr:
{
ConvertRowtypeExpr *convert = (ConvertRowtypeExpr *) node;
Node *arg = (Node *) convert->arg;
if (convert->convertformat == COERCE_IMPLICIT_CAST &&
!showimplicit)
{
/* don't show the implicit cast */
get_rule_expr_paren(arg, context, false, node);
}
else {
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg, context, false, node);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
appendStringInfo(buf, "::%s",
format_type_with_typemod(convert->resulttype, -1));
}
}
break;
case T_CaseExpr:
{
CaseExpr *caseexpr = (CaseExpr *) node;
ListCell *temp;
appendContextKeyword(context, "CASE",
0, PRETTYINDENT_VAR, 0);
if (caseexpr->arg)
{
appendStringInfoChar(buf, ' ');
get_rule_expr((Node *) caseexpr->arg, context, true);
}
foreach(temp, caseexpr->args)
{
CaseWhen *when = (CaseWhen *) lfirst(temp);
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
appendContextKeyword(context, "WHEN ",
0, 0, 0);
if (caseexpr->arg)
{
/* Show only the RHS of "CaseTestExpr = RHS" */
Node *rhs;
Assert(IsA(when->expr, OpExpr));
rhs = (Node *) lsecond(((OpExpr *) when->expr)->args);
get_rule_expr(rhs, context, false);
}
else
get_rule_expr((Node *) when->expr, context, false);
appendStringInfo(buf, " THEN ");
get_rule_expr((Node *) when->result, context, true);
}
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
appendContextKeyword(context, "ELSE ",
0, 0, 0);
get_rule_expr((Node *) caseexpr->defresult, context, true);
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
appendContextKeyword(context, "END",
-PRETTYINDENT_VAR, 0, 0);
}
break;
case T_ArrayExpr:
{
ArrayExpr *arrayexpr = (ArrayExpr *) node;
appendStringInfo(buf, "ARRAY[");
get_rule_expr((Node *) arrayexpr->elements, context, true);
appendStringInfoChar(buf, ']');
}
break;
case T_RowExpr:
{ RowExpr *rowexpr = (RowExpr *) node;
TupleDesc tupdesc = NULL;
ListCell *arg;
int i;
char *sep;
/*
* If it's a named type and not RECORD, we may have to
* skip dropped columns and/or claim there are NULLs for
* added columns.
*/
if (rowexpr->row_typeid != RECORDOID)
{
tupdesc = lookup_rowtype_tupdesc(rowexpr->row_typeid, -1);
Assert(list_length(rowexpr->args) <= tupdesc->natts);
}
/*
* SQL99 allows "ROW" to be omitted when there is more
* than one column, but for simplicity we always print it.
*/
appendStringInfo(buf, "ROW(");
sep = "";
i = 0;
foreach(arg, rowexpr->args)
{
Node *e = (Node *) lfirst(arg);
if (tupdesc == NULL ||
!tupdesc->attrs[i]->attisdropped)
{
appendStringInfo(buf, sep);
get_rule_expr(e, context, true);
sep = ", ";
}
i++;
}
if (tupdesc != NULL)
{
while (i < tupdesc->natts)
{
if (!tupdesc->attrs[i]->attisdropped)
{
appendStringInfo(buf, sep);
appendStringInfo(buf, "NULL");
sep = ", ";
}
i++;
}
}
appendStringInfo(buf, ")");
if (rowexpr->row_format == COERCE_EXPLICIT_CAST)
appendStringInfo(buf, "::%s",
format_type_with_typemod(rowexpr->row_typeid, -1));
}
break;
case T_CoalesceExpr:
{
CoalesceExpr *coalesceexpr = (CoalesceExpr *) node;
appendStringInfo(buf, "COALESCE(");
get_rule_expr((Node *) coalesceexpr->args, context, true);
appendStringInfoChar(buf, ')');
}
break;
case T_NullIfExpr:
{
NullIfExpr *nullifexpr = (NullIfExpr *) node;
appendStringInfo(buf, "NULLIF(");
get_rule_expr((Node *) nullifexpr->args, context, true);
appendStringInfoChar(buf, ')');
}
break;
case T_NullTest:
{
NullTest *ntest = (NullTest *) node;
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren((Node *) ntest->arg, context, true, node);
switch (ntest->nulltesttype)
{
case IS_NULL:
appendStringInfo(buf, " IS NULL");
break;
case IS_NOT_NULL:
appendStringInfo(buf, " IS NOT NULL");
break;
default:
elog(ERROR, "unrecognized nulltesttype: %d",
(int) ntest->nulltesttype);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_BooleanTest:
{
BooleanTest *btest = (BooleanTest *) node;
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren((Node *) btest->arg, context, false, node);
switch (btest->booltesttype)
{
case IS_TRUE:
appendStringInfo(buf, " IS TRUE");
break;
case IS_NOT_TRUE:
appendStringInfo(buf, " IS NOT TRUE");
break;
case IS_FALSE:
appendStringInfo(buf, " IS FALSE");
break;
case IS_NOT_FALSE:
appendStringInfo(buf, " IS NOT FALSE");
break;
case IS_UNKNOWN:
appendStringInfo(buf, " IS UNKNOWN");
break;
case IS_NOT_UNKNOWN:
appendStringInfo(buf, " IS NOT UNKNOWN");
break;
default:
elog(ERROR, "unrecognized booltesttype: %d",
(int) btest->booltesttype);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
break;
case T_CoerceToDomain:
{
CoerceToDomain *ctest = (CoerceToDomain *) node; Node *arg = (Node *) ctest->arg;
if (ctest->coercionformat == COERCE_IMPLICIT_CAST &&
!showimplicit)
{
/* don't show the implicit cast */
get_rule_expr(arg, context, false);
}
else
{
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg, context, false, node);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
appendStringInfo(buf, "::%s",
format_type_with_typemod(ctest->resulttype,
ctest->resulttypmod));
}
}
break;
case T_CoerceToDomainValue:
appendStringInfo(buf, "VALUE");
break;
case T_SetToDefault:
appendStringInfo(buf, "DEFAULT");
break;
case T_List:
{
char *sep;
ListCell *l;
sep = "";
foreach(l, (List *) node)
{
appendStringInfo(buf, sep);
get_rule_expr((Node *) lfirst(l), context, showimplicit);
sep = ", ";
}
}
break;
default:
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
break;
}
}
/*
* get_oper_expr - Parse back an OpExpr node
*/
static void
get_oper_expr(OpExpr *expr, deparse_context *context)
{
StringInfo buf = context->buf;
Oid opno = expr->opno;
List *args = expr->args;
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
if (list_length(args) == 2)
{
/* binary operator */
Node *arg1 = (Node *) linitial(args);
Node *arg2 = (Node *) lsecond(args);
get_rule_expr_paren(arg1, context, true, (Node *) expr);
appendStringInfo(buf, " %s ",
generate_operator_name(opno,
exprType(arg1),
exprType(arg2)));
get_rule_expr_paren(arg2, context, true, (Node *) expr);
}
else
{
/* unary operator --- but which side? */
Node *arg = (Node *) linitial(args);
HeapTuple tp;
Form_pg_operator optup;
tp = SearchSysCache(OPEROID,
ObjectIdGetDatum(opno),
0, 0, 0);
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for operator %u", opno);
optup = (Form_pg_operator) GETSTRUCT(tp);
switch (optup->oprkind)
{
case 'l':
appendStringInfo(buf, "%s ",
generate_operator_name(opno,
InvalidOid,
exprType(arg)));
get_rule_expr_paren(arg, context, true, (Node *) expr);
break;
case 'r':
get_rule_expr_paren(arg, context, true, (Node *) expr);
appendStringInfo(buf, " %s",
generate_operator_name(opno,
exprType(arg),
InvalidOid));
break;
default:
elog(ERROR, "bogus oprkind: %d", optup->oprkind);
}
ReleaseSysCache(tp);
}
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
/*
* get_func_expr - Parse back a FuncExpr node
*/
static void
get_func_expr(FuncExpr *expr, deparse_context *context,
bool showimplicit)
{
StringInfo buf = context->buf;
Oid funcoid = expr->funcid;
Oid argtypes[FUNC_MAX_ARGS];
int nargs;
ListCell *l;
/*
* If the function call came from an implicit coercion, then just show
* the first argument --- unless caller wants to see implicit
* coercions.
*/
if (expr->funcformat == COERCE_IMPLICIT_CAST && !showimplicit)
{
get_rule_expr_paren((Node *) linitial(expr->args), context,
false, (Node *) expr);
return;
}
/*
* If the function call came from a cast, then show the first argument
* plus an explicit cast operation.
*/
if (expr->funcformat == COERCE_EXPLICIT_CAST ||
expr->funcformat == COERCE_IMPLICIT_CAST)
{
Node *arg = linitial(expr->args);
Oid rettype = expr->funcresulttype;
int32 coercedTypmod;
/* Get the typmod if this is a length-coercion function */
(void) exprIsLengthCoercion((Node *) expr, &coercedTypmod);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr_paren(arg, context, false, (Node *) expr);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
appendStringInfo(buf, "::%s",
format_type_with_typemod(rettype, coercedTypmod));
return;
}
/*
* Normal function: display as proname(args). First we need to
* extract the argument datatypes.
*/
nargs = 0;
foreach(l, expr->args)
{
Assert(nargs < FUNC_MAX_ARGS);
argtypes[nargs] = exprType((Node *) lfirst(l));
nargs++;
}
appendStringInfo(buf, "%s(",
generate_function_name(funcoid, nargs, argtypes));
get_rule_expr((Node *) expr->args, context, true);
appendStringInfoChar(buf, ')');
}
/*
* get_agg_expr - Parse back an Aggref node
*/
static void
get_agg_expr(Aggref *aggref, deparse_context *context)
{
StringInfo buf = context->buf;
Oid argtype = exprType((Node *) aggref->target);
appendStringInfo(buf, "%s(%s",
generate_function_name(aggref->aggfnoid, 1, &argtype),
aggref->aggdistinct ? "DISTINCT " : "");
if (aggref->aggstar)
appendStringInfo(buf, "*");
else
get_rule_expr((Node *) aggref->target, context, true);
appendStringInfoChar(buf, ')');
}
/* ----------
* get_const_expr
*
* Make a string representation of a Const
* ----------
*/
static voidget_const_expr(Const *constval, deparse_context *context)
{
StringInfo buf = context->buf;
Oid typoutput;
Oid typioparam;
bool typIsVarlena;
char *extval;
char *valptr;
bool isfloat = false;
bool needlabel;
if (constval->constisnull)
{
/*
* Always label the type of a NULL constant to prevent
* misdecisions about type when reparsing.
*/
appendStringInfo(buf, "NULL::%s",
format_type_with_typemod(constval->consttype, -1));
return;
}
getTypeOutputInfo(constval->consttype,
&typoutput, &typioparam, &typIsVarlena);
extval = DatumGetCString(OidFunctionCall3(typoutput,
constval->constvalue,
ObjectIdGetDatum(typioparam),
Int32GetDatum(-1)));
switch (constval->consttype)
{
case INT2OID:
case INT4OID:
case INT8OID:
case OIDOID:
case FLOAT4OID:
case FLOAT8OID:
case NUMERICOID:
{
/*
* These types are printed without quotes unless they
* contain values that aren't accepted by the scanner
* unquoted (e.g., 'NaN'). Note that strtod() and friends
* might accept NaN, so we can't use that to test.
*
* In reality we only need to defend against infinity and
* NaN, so we need not get too crazy about pattern
* matching here.
*/
if (strspn(extval, "0123456789+-eE.") == strlen(extval))
{
appendStringInfoString(buf, extval);
if (strcspn(extval, "eE.") != strlen(extval))
isfloat = true; /* it looks like a float */
}
else
appendStringInfo(buf, "'%s'", extval);
}
break;
case BITOID:
case VARBITOID:
appendStringInfo(buf, "B'%s'", extval);
break;
case BOOLOID:
if (strcmp(extval, "t") == 0)
appendStringInfo(buf, "true");
else appendStringInfo(buf, "false");
break;
default:
/*
* We must quote any funny characters in the constant's
* representation. XXX Any MULTIBYTE considerations here?
*/
appendStringInfoChar(buf, '\'');
for (valptr = extval; *valptr; valptr++)
{
char ch = *valptr;
if (ch == '\'' || ch == '\\')
{
appendStringInfoChar(buf, '\\');
appendStringInfoChar(buf, ch);
}
else if (((unsigned char) ch) < ((unsigned char) ' '))
appendStringInfo(buf, "\\%03o", (int) ch);
else
appendStringInfoChar(buf, ch);
}
appendStringInfoChar(buf, '\'');
break;
}
pfree(extval);
/*
* Append ::typename unless the constant will be implicitly typed as
* the right type when it is read in. XXX this code has to be kept in
* sync with the behavior of the parser, especially make_const.
*/
switch (constval->consttype)
{
case BOOLOID:
case INT4OID:
case UNKNOWNOID:
/* These types can be left unlabeled */
needlabel = false;
break;
case NUMERICOID:
/* Float-looking constants will be typed as numeric */
needlabel = !isfloat;
break;
default:
needlabel = true;
break;
}
if (needlabel)
appendStringInfo(buf, "::%s",
format_type_with_typemod(constval->consttype, -1));
}
/* ----------
* get_sublink_expr - Parse back a sublink
* ----------
*/
static void
get_sublink_expr(SubLink *sublink, deparse_context *context)
{
StringInfo buf = context->buf;
Query *query = (Query *) (sublink->subselect);
bool need_paren;
if (sublink->subLinkType == ARRAY_SUBLINK)
appendStringInfo(buf, "ARRAY("); else
appendStringInfoChar(buf, '(');
if (sublink->lefthand != NIL)
{
need_paren = (list_length(sublink->lefthand) > 1);
if (need_paren)
appendStringInfoChar(buf, '(');
get_rule_expr((Node *) sublink->lefthand, context, true);
if (need_paren)
appendStringInfoChar(buf, ')');
appendStringInfoChar(buf, ' ');
}
need_paren = true;
/*
* XXX we regurgitate the originally given operator name, with or
* without schema qualification. This is not necessarily 100% right
* but it's the best we can do, since the operators actually used
* might not all be in the same schema.
*/
switch (sublink->subLinkType)
{
case EXISTS_SUBLINK:
appendStringInfo(buf, "EXISTS ");
break;
case ANY_SUBLINK:
if (list_length(sublink->operName) == 1 &&
strcmp(strVal(linitial(sublink->operName)), "=") == 0)
{
/* Represent = ANY as IN */
appendStringInfo(buf, "IN ");
}
else
{
print_operator_name(buf, sublink->operName);
appendStringInfo(buf, " ANY ");
}
break;
case ALL_SUBLINK:
print_operator_name(buf, sublink->operName);
appendStringInfo(buf, " ALL ");
break;
case MULTIEXPR_SUBLINK:
print_operator_name(buf, sublink->operName);
appendStringInfoChar(buf, ' ');
break;
case EXPR_SUBLINK:
case ARRAY_SUBLINK:
need_paren = false;
break;
default:
elog(ERROR, "unrecognized sublink type: %d",
(int) sublink->subLinkType);
break;
}
if (need_paren)
appendStringInfoChar(buf, '(');
get_query_def(query, buf, context->namespaces, NULL,
context->prettyFlags, context->indentLevel);
if (need_paren) appendStringInfo(buf, "))");
else
appendStringInfoChar(buf, ')');
}
/* ----------
* get_from_clause - Parse back a FROM clause
* ----------
*/
static void
get_from_clause(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
bool first = true;
ListCell *l;
/*
* We use the query's jointree as a guide to what to print. However,
* we must ignore auto-added RTEs that are marked not inFromCl. (These
* can only appear at the top level of the jointree, so it's
* sufficient to check here.) Also ignore the rule pseudo-RTEs for NEW
* and OLD.
*/
foreach(l, query->jointree->fromlist)
{
Node *jtnode = (Node *) lfirst(l);
if (IsA(jtnode, RangeTblRef))
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
RangeTblEntry *rte = rt_fetch(varno, query->rtable);
if (!rte->inFromCl)
continue;
if (strcmp(rte->eref->aliasname, "*NEW*") == 0)
continue;
if (strcmp(rte->eref->aliasname, "*OLD*") == 0)
continue;
}
if (first)
{
appendContextKeyword(context, " FROM ",
-PRETTYINDENT_STD, PRETTYINDENT_STD, 2);
first = false;
}
else
appendStringInfoString(buf, ", ");
get_from_clause_item(jtnode, query, context);
}
}
static void
get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
if (IsA(jtnode, RangeTblRef))
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
RangeTblEntry *rte = rt_fetch(varno, query->rtable);
List *coldeflist = NIL;
bool gavealias = false;
switch (rte->rtekind)
{
case RTE_RELATION:
/* Normal relation RTE */ appendStringInfo(buf, "%s%s",
only_marker(rte),
generate_relation_name(rte->relid));
break;
case RTE_SUBQUERY:
/* Subquery RTE */
appendStringInfoChar(buf, '(');
get_query_def(rte->subquery, buf, context->namespaces, NULL,
context->prettyFlags, context->indentLevel);
appendStringInfoChar(buf, ')');
break;
case RTE_FUNCTION:
/* Function RTE */
get_rule_expr(rte->funcexpr, context, true);
/* might need to emit column list for RECORD function */
coldeflist = rte->coldeflist;
break;
default:
elog(ERROR, "unrecognized RTE kind: %d", (int) rte->rtekind);
break;
}
if (rte->alias != NULL)
{
appendStringInfo(buf, " %s",
quote_identifier(rte->alias->aliasname));
gavealias = true;
if (coldeflist == NIL)
get_from_clause_alias(rte->alias, varno, query, context);
}
else if (rte->rtekind == RTE_RELATION &&
strcmp(rte->eref->aliasname, get_rel_name(rte->relid)) != 0)
{
/*
* Apparently the rel has been renamed since the rule was
* made. Emit a fake alias clause so that variable references
* will still work. This is not a 100% solution but should
* work in most reasonable situations.
*/
appendStringInfo(buf, " %s",
quote_identifier(rte->eref->aliasname));
gavealias = true;
}
if (coldeflist != NIL)
{
if (!gavealias)
appendStringInfo(buf, " AS ");
get_from_clause_coldeflist(coldeflist, context);
}
}
else if (IsA(jtnode, JoinExpr))
{
JoinExpr *j = (JoinExpr *) jtnode;
bool need_paren_on_right;
need_paren_on_right = PRETTY_PAREN(context) &&
!IsA(j->rarg, RangeTblRef) &&
!(IsA(j->rarg, JoinExpr) && ((JoinExpr*) j->rarg)->alias != NULL);
if (!PRETTY_PAREN(context) || j->alias != NULL)
appendStringInfoChar(buf, '(');
get_from_clause_item(j->larg, query, context);
if (j->isNatural)
{
if (!PRETTY_INDENT(context))
appendStringInfoChar(buf, ' ');
switch (j->jointype)
{
case JOIN_INNER: appendContextKeyword(context, "NATURAL JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
case JOIN_LEFT:
appendContextKeyword(context, "NATURAL LEFT JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
case JOIN_FULL:
appendContextKeyword(context, "NATURAL FULL JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
case JOIN_RIGHT:
appendContextKeyword(context, "NATURAL RIGHT JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
case JOIN_UNION:
appendContextKeyword(context, "NATURAL UNION JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 0);
break;
default:
elog(ERROR, "unrecognized join type: %d",
(int) j->jointype);
}
}
else
{
switch (j->jointype)
{
case JOIN_INNER:
if (j->quals)
appendContextKeyword(context, " JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
else
appendContextKeyword(context, " CROSS JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 1);
break;
case JOIN_LEFT:
appendContextKeyword(context, " LEFT JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
break;
case JOIN_FULL:
appendContextKeyword(context, " FULL JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
break;
case JOIN_RIGHT:
appendContextKeyword(context, " RIGHT JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
break;
case JOIN_UNION:
appendContextKeyword(context, " UNION JOIN ",
-PRETTYINDENT_JOIN,
PRETTYINDENT_JOIN, 2);
break;
default:
elog(ERROR, "unrecognized join type: %d",
(int) j->jointype);
}
}
if (need_paren_on_right) appendStringInfoChar(buf, '(');
get_from_clause_item(j->rarg, query, context);
if (need_paren_on_right)
appendStringInfoChar(buf, ')');
context->indentLevel -= PRETTYINDENT_JOIN_ON;
if (!j->isNatural)
{
if (j->using)
{
ListCell *col;
appendStringInfo(buf, " USING (");
foreach(col, j->using)
{
if (col != list_head(j->using))
appendStringInfo(buf, ", ");
appendStringInfoString(buf,
quote_identifier(strVal(lfirst(col))));
}
appendStringInfoChar(buf, ')');
}
else if (j->quals)
{
appendStringInfo(buf, " ON ");
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, '(');
get_rule_expr(j->quals, context, false);
if (!PRETTY_PAREN(context))
appendStringInfoChar(buf, ')');
}
}
if (!PRETTY_PAREN(context) || j->alias != NULL)
appendStringInfoChar(buf, ')');
/* Yes, it's correct to put alias after the right paren ... */
if (j->alias != NULL)
{
appendStringInfo(buf, " %s",
quote_identifier(j->alias->aliasname));
get_from_clause_alias(j->alias, j->rtindex, query, context);
}
}
else
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(jtnode));
}
/*
* get_from_clause_alias - reproduce column alias list
*
* This is tricky because we must ignore dropped columns.
*/
static void
get_from_clause_alias(Alias *alias, int varno,
Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
ListCell *col;
AttrNumber attnum;
bool first = true;
if (alias == NULL || alias->colnames == NIL)
return; /* definitely nothing to do */
attnum = 0;
foreach(col, alias->colnames)
{
attnum++; if (get_rte_attribute_is_dropped(query->rtable, varno, attnum))
continue;
if (first)
{
appendStringInfoChar(buf, '(');
first = false;
}
else
appendStringInfo(buf, ", ");
appendStringInfoString(buf,
quote_identifier(strVal(lfirst(col))));
}
if (!first)
appendStringInfoChar(buf, ')');
}
/*
* get_from_clause_coldeflist - reproduce FROM clause coldeflist
*
* The coldeflist is appended immediately (no space) to buf. Caller is
* responsible for ensuring that an alias or AS is present before it.
*/
static void
get_from_clause_coldeflist(List *coldeflist, deparse_context *context)
{
StringInfo buf = context->buf;
ListCell *col;
int i = 0;
appendStringInfoChar(buf, '(');
foreach(col, coldeflist)
{
ColumnDef *n = lfirst(col);
char *attname;
Oid atttypeid;
int32 atttypmod;
attname = n->colname;
atttypeid = typenameTypeId(n->typename);
atttypmod = n->typename->typmod;
if (i > 0)
appendStringInfo(buf, ", ");
appendStringInfo(buf, "%s %s",
quote_identifier(attname),
format_type_with_typemod(atttypeid, atttypmod));
i++;
}
appendStringInfoChar(buf, ')');
}
/*
* get_opclass_name - fetch name of an index operator class
*
* The opclass name is appended (after a space) to buf.
*
* Output is suppressed if the opclass is the default for the given
* actual_datatype. (If you don't want this behavior, just pass
* InvalidOid for actual_datatype.)
*/
static void
get_opclass_name(Oid opclass, Oid actual_datatype,
StringInfo buf)
{
HeapTuple ht_opc;
Form_pg_opclass opcrec;
char *opcname;
char *nspname; bool isvisible;
/* Domains use their base type's default opclass */
if (OidIsValid(actual_datatype))
actual_datatype = getBaseType(actual_datatype);
ht_opc = SearchSysCache(CLAOID,
ObjectIdGetDatum(opclass),
0, 0, 0);
if (!HeapTupleIsValid(ht_opc))
elog(ERROR, "cache lookup failed for opclass %u", opclass);
opcrec = (Form_pg_opclass) GETSTRUCT(ht_opc);
/*
* Special case for ARRAY_OPS: pretend it is default for any array
* type
*/
if (OidIsValid(actual_datatype))
{
if (opcrec->opcintype == ANYARRAYOID &&
OidIsValid(get_element_type(actual_datatype)))
actual_datatype = opcrec->opcintype;
}
/* Must force use of opclass name if not in search path */
isvisible = OpclassIsVisible(opclass);
if (actual_datatype != opcrec->opcintype || !opcrec->opcdefault ||
!isvisible)
{
/* Okay, we need the opclass name. Do we need to qualify it? */
opcname = NameStr(opcrec->opcname);
if (isvisible)
appendStringInfo(buf, " %s", quote_identifier(opcname));
else
{
nspname = get_namespace_name(opcrec->opcnamespace);
appendStringInfo(buf, " %s.%s",
quote_identifier(nspname),
quote_identifier(opcname));
}
}
ReleaseSysCache(ht_opc);
}
/*
* processIndirection - take care of array and subfield assignment
*
* We strip any top-level FieldStore or assignment ArrayRef nodes that
* appear in the input, printing out the appropriate decoration for the
* base column name (that the caller just printed). We return the
* subexpression that's to be assigned.
*/
static Node *
processIndirection(Node *node, deparse_context *context)
{
StringInfo buf = context->buf;
for (;;)
{
if (node == NULL)
break;
if (IsA(node, FieldStore))
{
FieldStore *fstore = (FieldStore *) node;
Oid typrelid;
char *fieldname;
/* lookup tuple type */
typrelid = get_typ_typrelid(fstore->resulttype); if (!OidIsValid(typrelid))
elog(ERROR, "argument type %s of FieldStore is not a tuple type",
format_type_be(fstore->resulttype));
/*
* Get the field name. Note we assume here that there's only
* one field being assigned to. This is okay in stored rules
* but could be wrong in executable target lists. Presently
* no problem since explain.c doesn't print plan targetlists,
* but someday may have to think of something ...
*/
fieldname = get_relid_attribute_name(typrelid,
linitial_int(fstore->fieldnums));
appendStringInfo(buf, ".%s", quote_identifier(fieldname));
/*
* We ignore arg since it should be an uninteresting reference
* to the target column or subcolumn.
*/
node = (Node *) linitial(fstore->newvals);
}
else if (IsA(node, ArrayRef))
{
ArrayRef *aref = (ArrayRef *) node;
if (aref->refassgnexpr == NULL)
break;
printSubscripts(aref, context);
/*
* We ignore refexpr since it should be an uninteresting
* reference to the target column or subcolumn.
*/
node = (Node *) aref->refassgnexpr;
}
else
break;
}
return node;
}
static void
printSubscripts(ArrayRef *aref, deparse_context *context)
{
StringInfo buf = context->buf;
ListCell *lowlist_item;
ListCell *uplist_item;
lowlist_item = list_head(aref->reflowerindexpr); /* could be NULL */
foreach(uplist_item, aref->refupperindexpr)
{
appendStringInfoChar(buf, '[');
if (lowlist_item)
{
get_rule_expr((Node *) lfirst(lowlist_item), context, false);
appendStringInfoChar(buf, ':');
lowlist_item = lnext(lowlist_item);
}
get_rule_expr((Node *) lfirst(uplist_item), context, false);
appendStringInfoChar(buf, ']');
}
}
/*
* quote_identifier - Quote an identifier only if needed
*
* When quotes are needed, we palloc the required space; slightly
* space-wasteful but well worth it for notational simplicity.
*/const char *
quote_identifier(const char *ident)
{
/*
* Can avoid quoting if ident starts with a lowercase letter or
* underscore and contains only lowercase letters, digits, and
* underscores, *and* is not any SQL keyword. Otherwise, supply
* quotes.
*/
int nquotes = 0;
bool safe;
const char *ptr;
char *result;
char *optr;
/*
* would like to use <ctype.h> macros here, but they might yield
* unwanted locale-specific results...
*/
safe = ((ident[0] >= 'a' && ident[0] <= 'z') || ident[0] == '_');
for (ptr = ident; *ptr; ptr++)
{
char ch = *ptr;
if ((ch >= 'a' && ch <= 'z') ||
(ch >= '0' && ch <= '9') ||
(ch == '_'))
{
/* okay */
}
else
{
safe = false;
if (ch == '"')
nquotes++;
}
}
if (safe)
{
/*
* Check for keyword. This test is overly strong, since many of
* the "keywords" known to the parser are usable as column names,
* but the parser doesn't provide any easy way to test for whether
* an identifier is safe or not... so be safe not sorry.
*
* Note: ScanKeywordLookup() does case-insensitive comparison, but
* that's fine, since we already know we have all-lower-case.
*/
if (ScanKeywordLookup(ident) != NULL)
safe = false;
}
if (safe)
return ident; /* no change needed */
result = (char *) palloc(strlen(ident) + nquotes + 2 + 1);
optr = result;
*optr++ = '"';
for (ptr = ident; *ptr; ptr++)
{
char ch = *ptr;
if (ch == '"')
*optr++ = '"';
*optr++ = ch;
}
*optr++ = '"'; *optr = '\0';
return result;
}
/*
* quote_qualified_identifier - Quote a possibly-qualified identifier
*
* Return a name of the form namespace.ident, or just ident if namespace
* is NULL, quoting each component if necessary. The result is palloc'd.
*/
char *
quote_qualified_identifier(const char *namespace,
const char *ident)
{
StringInfoData buf;
initStringInfo(&buf);
if (namespace)
appendStringInfo(&buf, "%s.", quote_identifier(namespace));
appendStringInfoString(&buf, quote_identifier(ident));
return buf.data;
}
/*
* generate_relation_name
* Compute the name to display for a relation specified by OID
*
* The result includes all necessary quoting and schema-prefixing.
*/
static char *
generate_relation_name(Oid relid)
{
HeapTuple tp;
Form_pg_class reltup;
char *nspname;
char *result;
tp = SearchSysCache(RELOID,
ObjectIdGetDatum(relid),
0, 0, 0);
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for relation %u", relid);
reltup = (Form_pg_class) GETSTRUCT(tp);
/* Qualify the name if not visible in search path */
if (RelationIsVisible(relid))
nspname = NULL;
else
nspname = get_namespace_name(reltup->relnamespace);
result = quote_qualified_identifier(nspname, NameStr(reltup->relname));
ReleaseSysCache(tp);
return result;
}
/*
* generate_function_name
* Compute the name to display for a function specified by OID,
* given that it is being called with the specified actual arg types.
* (Arg types matter because of ambiguous-function resolution rules.)
*
* The result includes all necessary quoting and schema-prefixing.
*/
static char *
generate_function_name(Oid funcid, int nargs, Oid *argtypes)
{
HeapTuple proctup; Form_pg_proc procform;
char *proname;
char *nspname;
char *result;
FuncDetailCode p_result;
Oid p_funcid;
Oid p_rettype;
bool p_retset;
Oid *p_true_typeids;
proctup = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcid),
0, 0, 0);
if (!HeapTupleIsValid(proctup))
elog(ERROR, "cache lookup failed for function %u", funcid);
procform = (Form_pg_proc) GETSTRUCT(proctup);
proname = NameStr(procform->proname);
Assert(nargs == procform->pronargs);
/*
* The idea here is to schema-qualify only if the parser would fail to
* resolve the correct function given the unqualified func name with
* the specified argtypes.
*/
p_result = func_get_detail(list_make1(makeString(proname)),
NIL, nargs, argtypes,
&p_funcid, &p_rettype,
&p_retset, &p_true_typeids);
if ((p_result == FUNCDETAIL_NORMAL || p_result == FUNCDETAIL_AGGREGATE) &&
p_funcid == funcid)
nspname = NULL;
else
nspname = get_namespace_name(procform->pronamespace);
result = quote_qualified_identifier(nspname, proname);
ReleaseSysCache(proctup);
return result;
}
/*
* generate_operator_name
* Compute the name to display for an operator specified by OID,
* given that it is being called with the specified actual arg types.
* (Arg types matter because of ambiguous-operator resolution rules.
* Pass InvalidOid for unused arg of a unary operator.)
*
* The result includes all necessary quoting and schema-prefixing,
* plus the OPERATOR() decoration needed to use a qualified operator name
* in an expression.
*/
static char *
generate_operator_name(Oid operid, Oid arg1, Oid arg2)
{
StringInfoData buf;
HeapTuple opertup;
Form_pg_operator operform;
char *oprname;
char *nspname;
Operator p_result;
initStringInfo(&buf);
opertup = SearchSysCache(OPEROID,
ObjectIdGetDatum(operid),
0, 0, 0);
if (!HeapTupleIsValid(opertup))
elog(ERROR, "cache lookup failed for operator %u", operid);
operform = (Form_pg_operator) GETSTRUCT(opertup); oprname = NameStr(operform->oprname);
/*
* The idea here is to schema-qualify only if the parser would fail to
* resolve the correct operator given the unqualified op name with the
* specified argtypes.
*/
switch (operform->oprkind)
{
case 'b':
p_result = oper(list_make1(makeString(oprname)), arg1, arg2, true);
break;
case 'l':
p_result = left_oper(list_make1(makeString(oprname)), arg2, true);
break;
case 'r':
p_result = right_oper(list_make1(makeString(oprname)), arg1, true);
break;
default:
elog(ERROR, "unrecognized oprkind: %d", operform->oprkind);
p_result = NULL; /* keep compiler quiet */
break;
}
if (p_result != NULL && oprid(p_result) == operid)
nspname = NULL;
else
{
nspname = get_namespace_name(operform->oprnamespace);
appendStringInfo(&buf, "OPERATOR(%s.", quote_identifier(nspname));
}
appendStringInfoString(&buf, oprname);
if (nspname)
appendStringInfoChar(&buf, ')');
if (p_result != NULL)
ReleaseSysCache(p_result);
ReleaseSysCache(opertup);
return buf.data;
}
/*
* Print out a possibly-qualified operator name
*/
static void
print_operator_name(StringInfo buf, List *opname)
{
ListCell *op = list_head(opname);
int nnames = list_length(opname);
if (nnames == 1)
appendStringInfoString(buf, strVal(lfirst(op)));
else
{
appendStringInfo(buf, "OPERATOR(");
while (nnames-- > 1)
{
appendStringInfo(buf, "%s.",
quote_identifier(strVal(lfirst(op))));
op = lnext(op);
}
appendStringInfo(buf, "%s)", strVal(lfirst(op)));
}
}
/* * Given a C string, produce a TEXT datum.
*
* We assume that the input was palloc'd and may be freed.
*/
static text *
string_to_text(char *str)
{
text *result;
int slen = strlen(str);
int tlen;
tlen = slen + VARHDRSZ;
result = (text *) palloc(tlen);
VARATT_SIZEP(result) = tlen;
memcpy(VARDATA(result), str, slen);
pfree(str);
return result;
}