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.

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index ef8090274764f876d23df48703866e2978287e1e..2c697152e0a91d8596f45e60147f416578f7bc5b 100644 (file)
--- 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 03bbda97ddf544e445336b6377ffb08d98118077..5f3fafe1e702c44131a89b71f5db1e5bfeb12d8e 100644 (file)
--- 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 d04bacc58eec23edc061cde097c464bed6d25af9..7962c992acc6c0ee5b96d2e7d3b28293fe8c5aa1 100644 (file)
--- 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 9e576bdecbecefe9eac1effb1b3174cb91747498..ec39368891a548037e87d26b9c75668e839fa9ba 100644 (file)
--- 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 db03e43f2abc671c5d20419839baf5b1be2e509b..cfac9105d96caa150968cbbb820145a6b7678294 100644 (file)
--- 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 4534ae98cc573842c71bd71c7b19ab3565e26a9a..b25df3d24b90830842200286f84daede7343f7f1 100644 (file)
--- 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 4492a62cdb0ce3afa4521ed7531645e224ee000f..804cd2c2d676e4ed2f4f196bf6f705b8e503730b 100644 (file)
--- 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');