8000 Reactivate libxml memory management via palloc, now that I think I've · postgrespro/postgres_cluster@915abb3 · GitHub
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Commit 915abb3

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peterepetere
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Reactivate libxml memory management via palloc, now that I think I've
classified the conditions under which this is safe to do (see source code comment).
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  • src/backend/utils/adt

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‎src/backend/utils/adt/xml.c

Lines changed: 17 additions & 13 deletions
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Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.23 2007/01/27 11:48:31 petere Exp $
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* $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.24 2007/01/27 14:50:51 petere Exp $
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*
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*-------------------------------------------------------------------------
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*/
@@ -23,6 +23,21 @@
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* else does.
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*/
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/*
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* Note on memory management: Via callbacks, libxml is told to use
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* palloc and friends for memory management. Sometimes, libxml
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* allocates global structures in the hope that it can reuse them
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* later on, but if "later" is much later, the memory context
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* management of PostgreSQL will have blown those structures away
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* without telling libxml about it. Therefore, it is important to
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* call xmlCleanupParser() or perhaps some other cleanup function
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* after using such functions, for example something from
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* libxml/parser.h or libxml/xmlsave.h. Unfortunately, you cannot
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* readily tell from the API documentation when that happens, so
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* careful evaluation is necessary when introducing new libxml APIs
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* here.
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*/
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#include "postgres.h"
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#ifdef USE_LIBXML
@@ -31,7 +46,6 @@
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#include <libxml/tree.h>
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#include <libxml/uri.h>
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#include <libxml/xmlerror.h>
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#include <libxml/xmlsave.h>
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#include <libxml/xmlwriter.h>
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#endif /* USE_LIBXML */
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@@ -54,12 +68,10 @@
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static StringInfo xml_err_buf = NULL;
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static void xml_init(void);
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#ifdef NOT_USED
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static void *xml_palloc(size_t size);
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static void *xml_repalloc(void *ptr, size_t size);
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static void xml_pfree(void *ptr);
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static char *xml_pstrdup(const char *string);
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#endif
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static void xml_ereport(int level, int sqlcode,
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const char *msg);
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static void xml_errorHandler(void *ctxt, const char *msg, ...);
@@ -782,14 +794,8 @@ xml_init(void)
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/* Now that xml_err_buf exists, safe to call xml_errorHandler */
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xmlSetGenericErrorFunc(NULL, xml_errorHandler);
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#ifdef NOT_USED
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/*
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* FIXME: This doesn't work because libxml assumes that whatever
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* libxml allocates, only libxml will free, so we can't just drop
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* memory contexts behind it. This needs to be refined.
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*/
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xmlMemSetup(xml_pfree, xml_palloc, xml_repalloc, xml_pstrdup);
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#endif
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xmlInitParser();
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LIBXML_TEST_VERSION;
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}
@@ -1098,7 +1104,6 @@ xml_text2xmlChar(text *in)
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}
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#ifdef NOT_USED
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/*
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* Wrappers for memory management functions
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*/
@@ -1128,7 +1133,6 @@ xml_pstrdup(const char *string)
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{
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return pstrdup(string);
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}
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#endif /* NOT_USED */
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/*

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