From decdaf3592dfa05642373a7bffcb431e45cc5aac Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 3 Mar 2006 23:38:30 +0000
Subject: [PATCH] Improve pg_dump and psql to use libpq's newer COPY support
routines, instead of the old deprecated ones. Volkan Yazici, with some
editorializing by moi.
---
src/bin/pg_dump/pg_backup_db.c | 27 +++--
src/bin/pg_dump/pg_dump.c | 51 ++++-----
src/bin/psql/common.c | 11 +-
src/bin/psql/copy.c | 190 +++++++++++++++++----------------
4 files changed, 145 insertions(+), 134 deletions(-)
diff --git a/src/bin/pg_dump/pg_backup_db.c b/src/bin/pg_dump/pg_backup_db.c
index 531ddb9e566..77c4086d3d2 100644
--- a/src/bin/pg_dump/pg_backup_db.c
+++ b/src/bin/pg_dump/pg_backup_db.c
@@ -5,7 +5,7 @@
* Implements the basic DB functions used by the archiver.
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_db.c,v 1.69 2006/02/12 06:11:50 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_db.c,v 1.70 2006/03/03 23:38:29 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -391,22 +391,29 @@ _sendCopyLine(ArchiveHandle *AH, char *qry, char *eos)
* enter COPY mode; this allows us to behave reasonably when trying
* to continue after an error in a COPY command.
*/
- if (AH->pgCopyIn && PQputline(AH->connection, AH->pgCopyBuf->data) != 0)
- die_horribly(AH, modulename, "error returned by PQputline: %s",
+ if (AH->pgCopyIn &&
+ PQputCopyData(AH->connection, AH->pgCopyBuf->data,
+ AH->pgCopyBuf->len) <= 0)
+ die_horribly(AH, modulename, "error returned by PQputCopyData: %s",
PQerrorMessage(AH->connection));
resetPQExpBuffer(AH->pgCopyBuf);
- /*
- * fprintf(stderr, "Buffer is '%s'\n", AH->pgCopyBuf->data);
- */
-
- if (isEnd)
+ if (isEnd && AH->pgCopyIn)
{
- if (AH->pgCopyIn && PQendcopy(AH->connection) != 0)
- die_horribly(AH, modulename, "error returned by PQendcopy: %s",
+ PGresult *res;
+
+ if (PQputCopyEnd(AH->connection, NULL) <= 0)
+ die_horribly(AH, modulename, "error returned by PQputCopyEnd: %s",
PQerrorMessage(AH->connection));
+ /* Check command status and return to normal libpq state */
+ res = PQgetResult(AH->connection);
+ if (PQresultStatus(res) != PGRES_COMMAND_OK)
+ warn_or_die_horribly(AH, modulename, "COPY failed: %s",
+ PQerrorMessage(AH->connection));
+ PQclear(res);
+
AH->pgCopyIn = false;
}
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 4eb2cafc19d..535104d83e7 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -12,7 +12,7 @@
* by PostgreSQL
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.431 2006/03/02 01:18:25 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.432 2006/03/03 23:38:29 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -831,8 +831,6 @@ selectDumpableObject(DumpableObject *dobj)
* to be dumped.
*/
-#define COPYBUFSIZ 8192
-
static int
dumpTableData_copy(Archive *fout, void *dcontext)
{
@@ -844,8 +842,7 @@ dumpTableData_copy(Archive *fout, void *dcontext)
PQExpBuffer q = createPQExpBuffer();
PGresult *res;
int ret;
- bool copydone;
- char copybuf[COPYBUFSIZ];
+ char *copybuf;
const char *column_list;
if (g_verbose)
@@ -886,33 +883,19 @@ dumpTableData_copy(Archive *fout, void *dcontext)
}
res = PQexec(g_conn, q->data);
check_sql_result(res, g_conn, q->data, PGRES_COPY_OUT);
+ PQclear(res);
- copydone = false;
-
- while (!copydone)
+ for (;;)
{
- ret = PQgetline(g_conn, copybuf, COPYBUFSIZ);
+ ret = PQgetCopyData(g_conn, ©buf, 0);
+
+ if (ret < 0)
+ break; /* done or error */
- if (copybuf[0] == '\\' &&
- copybuf[1] == '.' &&
- copybuf[2] == '\0')
+ if (copybuf)
{
- copydone = true; /* don't print this... */
- }
- else
- {
- archputs(copybuf, fout);
- switch (ret)
- {
- case EOF:
- copydone = true;
- /* FALLTHROUGH */
- case 0:
- archputs("\n", fout);
- break;
- case 1:
- break;
- }
+ WriteData(fout, copybuf, ret);
+ PQfreemem(copybuf);
}
/*
@@ -920,7 +903,7 @@ dumpTableData_copy(Archive *fout, void *dcontext)
*
* There was considerable discussion in late July, 2000 regarding
* slowing down pg_dump when backing up large tables. Users with both
- * slow & fast (muti-processor) machines experienced performance
+ * slow & fast (multi-processor) machines experienced performance
* degradation when doing a backup.
*
* Initial attempts based on sleeping for a number of ms for each ms
@@ -957,16 +940,20 @@ dumpTableData_copy(Archive *fout, void *dcontext)
}
archprintf(fout, "\\.\n\n\n");
- ret = PQendcopy(g_conn);
- if (ret != 0)
+ if (ret == -2)
{
- write_msg(NULL, "SQL command to dump the contents of table \"%s\" failed: PQendcopy() failed.\n", classname);
+ /* copy data transfer failed */
+ write_msg(NULL, "Dumping the contents of table \"%s\" failed: PQgetCopyData() failed.\n", classname);
write_msg(NULL, "Error message from server: %s", PQerrorMessage(g_conn));
write_msg(NULL, "The command was: %s\n", q->data);
exit_nicely();
}
+ /* Check command status and return to normal libpq state */
+ res = PQgetResult(g_conn);
+ check_sql_result(res, g_conn, q->data, PGRES_COMMAND_OK);
PQclear(res);
+
destroyPQExpBuffer(q);
return 1;
}
diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index 8f6d03561ae..7e436d5f390 100644
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -3,7 +3,7 @@
*
* Copyright (c) 2000-2005, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.112 2006/02/12 03:30:21 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.113 2006/03/03 23:38:30 tgl Exp $
*/
#include "postgres_fe.h"
#include "common.h"
@@ -685,7 +685,10 @@ AcceptResult(const PGresult *result, const char *query)
break;
case PGRES_COPY_OUT:
- /* keep cancel connection for copy out state */
+ /*
+ * Keep cancel connection active during copy out state.
+ * The matching ResetCancelConn() is in handleCopyOut.
+ */
SetCancelConn();
break;
@@ -702,6 +705,7 @@ AcceptResult(const PGresult *result, const char *query)
psql_error("%s", error);
ReportSyntaxErrorPosition(result, query);
+
CheckConnection();
}
@@ -720,6 +724,9 @@ AcceptResult(const PGresult *result, const char *query)
* is true; nothing special is done when start_xact is false. Typically,
* start_xact = false is used for SELECTs and explicit BEGIN/COMMIT commands.
*
+ * Caller is responsible for handling the ensuing processing if a COPY
+ * command is sent.
+ *
* Note: we don't bother to check PQclientEncoding; it is assumed that no
* caller uses this path to issue "SET CLIENT_ENCODING".
*/
diff --git a/src/bin/psql/copy.c b/src/bin/psql/copy.c
index bd1763c5ac4..6dd1b521855 100644
--- a/src/bin/psql/copy.c
+++ b/src/bin/psql/copy.c
@@ -3,7 +3,7 @@
*
* Copyright (c) 2000-2005, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/bin/psql/copy.c,v 1.58 2005/10/15 02:49:40 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/copy.c,v 1.59 2006/03/03 23:38:30 tgl Exp $
*/
#include "postgres_fe.h"
#include "copy.h"
@@ -568,7 +568,9 @@ do_copy(const char *args)
break;
default:
success = false;
- psql_error("\\copy: unexpected response (%d)\n", PQresultStatus(result));
+ psql_error("\\copy: unexpected response (%d)\n",
+ PQresultStatus(result));
+ break;
}
PQclear(result);
@@ -586,85 +588,92 @@ do_copy(const char *args)
}
-#define COPYBUFSIZ 8192 /* size doesn't matter */
-
+/*
+ * Functions for handling COPY IN/OUT data transfer.
+ *
+ * If you want to use COPY TO STDOUT/FROM STDIN in your application,
+ * this is the code to steal ;)
+ */
/*
* handleCopyOut
- * receives data as a result of a COPY ... TO stdout command
+ * receives data as a result of a COPY ... TO STDOUT command
*
- * If you want to use COPY TO in your application, this is the code to steal :)
+ * conn should be a database connection that you just issued COPY TO on
+ * and got back a PGRES_COPY_OUT result.
+ * copystream is the file stream for the data to go to.
*
- * conn should be a database connection that you just called COPY TO on
- * (and which gave you PGRES_COPY_OUT back);
- * copystream is the file stream you want the output to go to
+ * result is true if successful, false if not.
*/
bool
handleCopyOut(PGconn *conn, FILE *copystream)
{
- bool copydone = false; /* haven't started yet */
- char copybuf[COPYBUFSIZ];
- int ret;
+ bool OK = true;
+ char *buf;
+ int ret;
+ PGresult *res;
- while (!copydone)
+ for (;;)
{
- ret = PQgetline(conn, copybuf, COPYBUFSIZ);
+ ret = PQgetCopyData(conn, &buf, 0);
- if (copybuf[0] == '\\' &&
- copybuf[1] == '.' &&
- copybuf[2] == '\0')
- {
- copydone = true; /* we're at the end */
- }
- else
+ if (ret < 0)
+ break; /* done or error */
+
+ if (buf)
{
- fputs(copybuf, copystream);
- switch (ret)
- {
- case EOF:
- copydone = true;
- /* FALLTHROUGH */
- case 0:
- fputc('\n', copystream);
- break;
- case 1:
- break;
- }
+ fputs(buf, copystream);
+ PQfreemem(buf);
}
}
+
fflush(copystream);
- ret = !PQendcopy(conn);
- ResetCancelConn();
- return ret;
-}
+ if (ret == -2)
+ {
+ psql_error("COPY data transfer failed: %s", PQerrorMessage(conn));
+ OK = false;
+ }
+
+ /* Check command status and return to normal libpq state */
+ res = PQgetResult(conn);
+ if (PQresultStatus(res) != PGRES_COMMAND_OK)
+ {
+ psql_error("%s", PQerrorMessage(conn));
+ OK = false;
+ }
+ PQclear(res);
+ /* Disable cancel connection (see AcceptResult in common.c) */
+ ResetCancelConn();
+
+ return OK;
+}
/*
* handleCopyIn
- * receives data as a result of a COPY ... FROM stdin command
+ * sends data to complete a COPY ... FROM STDIN command
*
- * Again, if you want to use COPY FROM in your application, copy this.
+ * conn should be a database connection that you just issued COPY FROM on
+ * and got back a PGRES_COPY_IN result.
+ * copystream is the file stream to read the data from.
*
- * conn should be a database connection that you just called COPY FROM on
- * (and which gave you PGRES_COPY_IN back);
- * copystream is the file stream you want the input to come from
+ * result is true if successful, false if not.
*/
+/* read chunk size for COPY IN - size is not critical */
+#define COPYBUFSIZ 8192
+
bool
handleCopyIn(PGconn *conn, FILE *copystream)
{
+ bool OK = true;
const char *prompt;
bool copydone = false;
bool firstload;
bool linedone;
- bool saw_cr = false;
- char copybuf[COPYBUFSIZ];
- char *s;
- int bufleft;
- int c = 0;
- int ret;
- unsigned int linecount = 0;
+ char buf[COPYBUFSIZ];
+ PGresult *res;
/* Prompt if interactive input */
if (isatty(fileno(copystream)))
@@ -684,64 +693,65 @@ handleCopyIn(PGconn *conn, FILE *copystream)
fputs(prompt, stdout);
fflush(stdout);
}
+
firstload = true;
linedone = false;
while (!linedone)
{ /* for each bufferload in line ... */
- /* Fetch string until \n, EOF, or buffer full */
- s = copybuf;
- for (bufleft = COPYBUFSIZ - 1; bufleft > 0; bufleft--)
- {
- c = getc(copystream);
- if (c == EOF)
- {
- linedone = true;
- break;
- }
- *s++ = c;
- if (c == '\n')
- {
- linedone = true;
- break;
- }
- if (c == '\r')
- saw_cr = true;
- }
- *s = '\0';
- /* EOF with empty line-so-far? */
- if (c == EOF && s == copybuf && firstload)
+ int linelen;
+
+ if (!fgets(buf, COPYBUFSIZ, copystream))
{
- /*
- * We are guessing a little bit as to the right line-ending
- * here...
- */
- if (saw_cr)
- PQputline(conn, "\\.\r\n");
- else
- PQputline(conn, "\\.\n");
+ if (ferror(copystream))
+ OK = false;
copydone = true;
- if (pset.cur_cmd_interactive)
- puts("\\.");
break;
}
- /* No, so pass the data to the backend */
- PQputline(conn, copybuf);
- /* Check for line consisting only of \. */
+
+ linelen = strlen(buf);
+
+ /* current line is done? */
+ if (linelen > 0 && buf[linelen-1] == '\n')
+ linedone = true;
+
+ /* check for EOF marker, but not on a partial line */
if (firstload)
{
- if (strcmp(copybuf, "\\.\n") == 0 ||
- strcmp(copybuf, "\\.\r\n") == 0)
+ if (strcmp(buf, "\\.\n") == 0 ||
+ strcmp(buf, "\\.\r\n") == 0)
{
copydone = true;
break;
}
+
firstload = false;
}
+
+ if (PQputCopyData(conn, buf, linelen) <= 0)
+ {
+ OK = false;
+ copydone = true;
+ break;
+ }
}
- linecount++;
+
+ pset.lineno++;
+ }
+
+ /* Terminate data transfer */
+ if (PQputCopyEnd(conn,
+ OK ? NULL : _("aborted due to read failure")) <= 0)
+ OK = false;
+
+ /* Check command status and return to normal libpq state */
+ res = PQgetResult(conn);
+ if (PQresultStatus(res) != PGRES_COMMAND_OK)
+ {
+ psql_error("%s", PQerrorMessage(conn));
+ OK = false;
}
- ret = !PQendcopy(conn);
- pset.lineno += linecount;
- return ret;
+ PQclear(res);
+
+ return OK;
}
--
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