From 4b48ad4fb2edf897b87d04467f8eaaaba82a258f Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Fri, 19 Jan 2007 16:58:46 +0000
Subject: [PATCH] Add support for converting binary values (i.e. bytea) into
xml values, with new GUC parameter "xmlbinary" that controls the output
encoding, as per SQL/XML standard.
---
doc/src/sgml/config.sgml | 29 +++++++++++++++++++++++++-
src/backend/utils/adt/xml.c | 26 ++++++++++++++++++++++-
src/backend/utils/misc/guc.c | 32 ++++++++++++++++++++++++++++-
src/include/utils/xml.h | 10 ++++++++-
src/test/regress/expected/xml.out | 14 +++++++++++++
src/test/regress/expected/xml_1.out | 6 ++++++
src/test/regress/sql/xml.sql | 4 ++++
7 files changed, 117 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index ef809027476..2c697152e0a 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.102 2007/01/16 18:26:02 alvherre Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.103 2007/01/19 16:58:45 petere Exp $ -->
<chapter Id="runtime-config">
<title>Server Configuration</title>
@@ -3502,6 +3502,33 @@ SELECT * FROM parent WHERE key = 2400;
</listitem>
</varlistentry>
+ <varlistentry id="guc-xmlbinary" xreflabel="xmlbinary">
+ <term><varname>xmlbinary</varname> (<type>string</type>)</term>
+ <indexterm>
+ <primary><varname>xmlbinary</> configuration parameter</primary>
+ </indexterm>
+ <listitem>
+ <para>
+ Sets how binary values are to be encoded in XML. This applies
+ for example when <type>bytea</type> values are converted to
+ XML by the functions <function>xmlelement</function> or
+ <function>xmlforest</function>. Possible values are
+ <literal>base64</literal> and <literal>hex</literal>, which
+ are both defined in the XML Schema standard. The default is
+ <literal>base64</literal>. For further information about
+ XML-related functions, see <xref linkend="functions-xml">.
+ </para>
+
+ <para>
+ The actual choice here is mostly a matter of taste,
+ constrained only by possible restrictions in client
+ applications. Both methods support all possible values,
+ although the hex encoding will be somewhat larger than the
+ base64 encoding.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</sect2>
<sect2 id="runtime-config-client-format">
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 03bbda97ddf..5f3fafe1e70 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.18 2007/01/18 13:59:11 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.19 2007/01/19 16:58:46 petere Exp $
*
*-------------------------------------------------------------------------
*/
@@ -73,6 +73,8 @@ static xmlDocPtr xml_parse(text *data, bool is_document, bool preserve_whitespac
#endif /* USE_LIBXML */
+XmlBinaryType xmlbinary;
+
#define NO_XML_SUPPORT() \
ereport(ERROR, \
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), \
@@ -1500,6 +1502,28 @@ map_sql_value_to_xml_value(Datum value, Oid type)
if (type == XMLOID)
return str;
+#ifdef USE_LIBXML
+ if (type == BYTEAOID)
+ {
+ xmlBufferPtr buf;
+ xmlTextWriterPtr writer;
+ char *result;
+
+ buf = xmlBufferCreate();
+ writer = xmlNewTextWriterMemory(buf, 0);
+
+ if (xmlbinary == XMLBINARY_BASE64)
+ xmlTextWriterWriteBase64(writer, VARDATA(value), 0, VARSIZE(value) - VARHDRSZ);
+ else
+ xmlTextWriterWriteBinHex(writer, VARDATA(value), 0, VARSIZE(value) - VARHDRSZ);
+
+ xmlFreeTextWriter(writer);
+ result = pstrdup((const char *) xmlBufferContent(buf));
+ xmlBufferFree(buf);
+ return result;
+ }
+#endif /* USE_LIBXML */
+
for (p = str; *p; p += pg_mblen(p))
{
switch (*p)
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index d04bacc58ee..7962c992acc 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
* Written by Peter Eisentraut <peter_e@gmx.net>.
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.368 2007/01/16 18:26:02 alvherre Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.369 2007/01/19 16:58:46 petere Exp $
*
*--------------------------------------------------------------------
*/
@@ -61,6 +61,7 @@
#include "utils/pg_locale.h"
#include "utils/ps_status.h"
#include "utils/tzparser.h"
+#include "utils/xml.h"
#ifndef PG_KRB_SRVTAB
#define PG_KRB_SRVTAB ""
@@ -142,6 +143,7 @@ static bool assign_transaction_read_only(bool newval, bool doit, GucSource sourc
static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
static const char *assign_backslash_quote(const char *newval, bool doit, GucSource source);
static const char *assign_timezone_abbreviations(const char *newval, bool doit, GucSource source);
+static const char *assign_xmlbinary(const char *newval, bool doit, GucSource source);
static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
@@ -229,6 +231,7 @@ static char *timezone_abbreviations_string;
static char *XactIsoLevel_string;
static char *data_directory;
static char *custom_variable_classes;
+static char *xmlbinary_string;
static int max_function_args;
static int max_index_keys;
static int max_identifier_length;
@@ -2279,6 +2282,15 @@ static struct config_string ConfigureNamesString[] =
NULL, assign_canonical_path, NULL
},
+ {
+ {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Sets how binary values are to be encoded in XML."),
+ gettext_noop("Valid values are BASE64 and HEX.")
+ },
+ &xmlbinary_string,
+ "base64", assign_xmlbinary, NULL
+ },
+
/* End-of-list marker */
{
{NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
@@ -6475,6 +6487,24 @@ pg_timezone_abbrev_initialize(void)
}
}
+static const char *
+assign_xmlbinary(const char *newval, bool doit, GucSource source)
+{
+ XmlBinaryType xb;
+
+ if (pg_strcasecmp(newval, "base64") == 0)
+ xb = XMLBINARY_BASE64;
+ else if (pg_strcasecmp(newval, "hex") == 0)
+ xb = XMLBINARY_HEX;
+ else
+ return NULL; /* reject */
+
+ if (doit)
+ xmlbinary = xb;
+
+ return newval;
+}
+
static bool
assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
{
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 9e576bdecbe..ec39368891a 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/xml.h,v 1.10 2007/01/14 13:11:54 petere Exp $
+ * $PostgreSQL: pgsql/src/include/utils/xml.h,v 1.11 2007/01/19 16:58:46 petere Exp $
*
*-------------------------------------------------------------------------
*/
@@ -43,4 +43,12 @@ extern char *map_sql_identifier_to_xml_name(char *ident, bool fully_escaped);
extern char *map_xml_name_to_sql_identifier(char *name);
extern char *map_sql_value_to_xml_value(Datum value, Oid type);
+typedef enum
+{
+ XMLBINARY_BASE64,
+ XMLBINARY_HEX
+} XmlBinaryType;
+
+extern XmlBinaryType xmlbinary;
+
#endif /* XML_H */
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index db03e43f2ab..cfac9105d96 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -121,6 +121,20 @@ SELECT xmlelement(name foo, array[1, 2, 3]);
<foo><element>1</element><element>2</element><element>3</element></foo>
(1 row)
+SET xmlbinary TO base64;
+SELECT xmlelement(name foo, bytea 'bar');
+ xmlelement
+-----------------
+ <foo>YmFy</foo>
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlelement(name foo, bytea 'bar');
+ xmlelement
+-------------------
+ <foo>626172</foo>
+(1 row)
+
SELECT xmlparse(content 'abc');
xmlparse
----------
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 4534ae98cc5..b25df3d24b9 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -58,6 +58,12 @@ SELECT xmlelement(name foo, xml 'b<a/>r');
ERROR: no XML support in this installation
SELECT xmlelement(name foo, array[1, 2, 3]);
ERROR: no XML support in this installation
+SET xmlbinary TO base64;
+SELECT xmlelement(name foo, bytea 'bar');
+ERROR: no XML support in this installation
+SET xmlbinary TO hex;
+SELECT xmlelement(name foo, bytea 'bar');
+ERROR: no XML support in this installation
SELECT xmlparse(content 'abc');
ERROR: no XML support in this installation
SELECT xmlparse(content '<abc>x</abc>');
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 4492a62cdb0..804cd2c2d67 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -45,6 +45,10 @@ SELECT xmlelement(name foo, xml 'bar');
SELECT xmlelement(name foo, text 'b<a/>r');
SELECT xmlelement(name foo, xml 'b<a/>r');
SELECT xmlelement(name foo, array[1, 2, 3]);
+SET xmlbinary TO base64;
+SELECT xmlelement(name foo, bytea 'bar');
+SET xmlbinary TO hex;
+SELECT xmlelement(name foo, bytea 'bar');
SELECT xmlparse(content 'abc');
--
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