Add a hook to let loadable modules get control at ProcessUtility execution,

and use it to extend contrib/pg_stat_statements to track utility commands.

Itagaki Takahiro, reviewed by Euler Taveira de Oliveira.
This commit is contained in:
Tom Lane 2009-12-15 20:04:49 +00:00
parent 34d26872ed
commit a5495cd841
4 changed files with 135 additions and 11 deletions

View File

@ -14,7 +14,7 @@
* Copyright (c) 2008-2009, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgsql/contrib/pg_stat_statements/pg_stat_statements.c,v 1.8 2009/12/15 04:57:46 rhaas Exp $
* $PostgreSQL: pgsql/contrib/pg_stat_statements/pg_stat_statements.c,v 1.9 2009/12/15 20:04:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -32,6 +32,7 @@
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/spin.h"
#include "tcop/utility.h"
#include "utils/builtins.h"
#include "utils/hsearch.h"
#include "utils/guc.h"
@ -113,6 +114,7 @@ static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
static ExecutorStart_hook_type prev_ExecutorStart = NULL;
static ExecutorRun_hook_type prev_ExecutorRun = NULL;
static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
static ProcessUtility_hook_type prev_ProcessUtility = NULL;
/* Links to shared memory state */
static pgssSharedState *pgss = NULL;
@ -124,7 +126,7 @@ typedef enum
{
PGSS_TRACK_NONE, /* track no statements */
PGSS_TRACK_TOP, /* only top level statements */
PGSS_TRACK_ALL, /* all statements, including nested ones */
PGSS_TRACK_ALL /* all statements, including nested ones */
} PGSSTrackLevel;
static const struct config_enum_entry track_options[] = {
@ -136,6 +138,7 @@ static const struct config_enum_entry track_options[] = {
static int pgss_max; /* max # statements to track */
static int pgss_track; /* tracking level */
static bool pgss_track_utility; /* whether to track utility commands */
static bool pgss_save; /* whether to save stats across shutdown */
@ -161,10 +164,12 @@ static void pgss_ExecutorRun(QueryDesc *queryDesc,
ScanDirection direction,
long count);
static void pgss_ExecutorEnd(QueryDesc *queryDesc);
static void pgss_ProcessUtility(Node *parsetree,
const char *queryString, ParamListInfo params, bool isTopLevel,
DestReceiver *dest, char *completionTag);
static uint32 pgss_hash_fn(const void *key, Size keysize);
static int pgss_match_fn(const void *key1, const void *key2, Size keysize);
static void pgss_store(const char *query,
const Instrumentation *instr, uint32 rows);
static void pgss_store(const char *query, double total_time, uint64 rows);
static Size pgss_memsize(void);
static pgssEntry *entry_alloc(pgssHashKey *key);
static void entry_dealloc(void);
@ -214,6 +219,16 @@ _PG_init(void)
NULL,
NULL);
DefineCustomBoolVariable("pg_stat_statements.track_utility",
"Selects whether utility commands are tracked by pg_stat_statements.",
NULL,
&pgss_track_utility,
true,
PGC_SUSET,
0,
NULL,
NULL);
DefineCustomBoolVariable("pg_stat_statements.save",
"Save pg_stat_statements statistics across server shutdowns.",
NULL,
@ -245,6 +260,8 @@ _PG_init(void)
ExecutorRun_hook = pgss_ExecutorRun;
prev_ExecutorEnd = ExecutorEnd_hook;
ExecutorEnd_hook = pgss_ExecutorEnd;
prev_ProcessUtility = ProcessUtility_hook;
ProcessUtility_hook = pgss_ProcessUtility;
}
/*
@ -254,10 +271,11 @@ void
_PG_fini(void)
{
/* Uninstall hooks. */
shmem_startup_hook = prev_shmem_startup_hook;
ExecutorStart_hook = prev_ExecutorStart;
ExecutorRun_hook = prev_ExecutorRun;
ExecutorEnd_hook = prev_ExecutorEnd;
shmem_startup_hook = prev_shmem_startup_hook;
ProcessUtility_hook = prev_ProcessUtility;
}
/*
@ -539,7 +557,7 @@ pgss_ExecutorEnd(QueryDesc *queryDesc)
InstrEndLoop(queryDesc->totaltime);
pgss_store(queryDesc->sourceText,
queryDesc->totaltime,
queryDesc->totaltime->total,
queryDesc->estate->es_processed);
}
@ -549,6 +567,61 @@ pgss_ExecutorEnd(QueryDesc *queryDesc)
standard_ExecutorEnd(queryDesc);
}
/*
* ProcessUtility hook
*/
static void
pgss_ProcessUtility(Node *parsetree, const char *queryString,
ParamListInfo params, bool isTopLevel,
DestReceiver *dest, char *completionTag)
{
if (pgss_track_utility && pgss_enabled())
{
instr_time start;
instr_time duration;
uint64 rows = 0;
INSTR_TIME_SET_CURRENT(start);
nested_level++;
PG_TRY();
{
if (prev_ProcessUtility)
prev_ProcessUtility(parsetree, queryString, params,
isTopLevel, dest, completionTag);
else
standard_ProcessUtility(parsetree, queryString, params,
isTopLevel, dest, completionTag);
nested_level--;
}
PG_CATCH();
{
nested_level--;
PG_RE_THROW();
}
PG_END_TRY();
INSTR_TIME_SET_CURRENT(duration);
INSTR_TIME_SUBTRACT(duration, start);
/* parse command tag to retrieve the number of affected rows. */
if (completionTag &&
sscanf(completionTag, "COPY " UINT64_FORMAT, &rows) != 1)
rows = 0;
pgss_store(queryString, INSTR_TIME_GET_DOUBLE(duration), rows);
}
else
{
if (prev_ProcessUtility)
prev_ProcessUtility(parsetree, queryString, params,
isTopLevel, dest, completionTag);
else
standard_ProcessUtility(parsetree, queryString, params,
isTopLevel, dest, completionTag);
}
}
/*
* Calculate hash value for a key
*/
@ -587,7 +660,7 @@ pgss_match_fn(const void *key1, const void *key2, Size keysize)
* Store some statistics for a statement.
*/
static void
pgss_store(const char *query, const Instrumentation *instr, uint32 rows)
pgss_store(const char *query, double total_time, uint64 rows)
{
pgssHashKey key;
double usage;
@ -631,7 +704,7 @@ pgss_store(const char *query, const Instrumentation *instr, uint32 rows)
SpinLockAcquire(&e->mutex);
e->counters.calls += 1;
e->counters.total_time += instr->total;
e->counters.total_time += total_time;
e->counters.rows += rows;
e->counters.usage += usage;
SpinLockRelease(&e->mutex);

View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/pgstatstatements.sgml,v 1.4 2009/12/01 02:31:11 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/pgstatstatements.sgml,v 1.5 2009/12/15 20:04:49 tgl Exp $ -->
<sect1 id="pgstatstatements">
<title>pg_stat_statements</title>
@ -174,6 +174,23 @@
</listitem>
</varlistentry>
<varlistentry>
<term>
<varname>pg_stat_statements.track_utility</varname> (<type>boolean</type>)
</term>
<listitem>
<para>
<varname>pg_stat_statements.track_utility</varname> controls whether
utility commands are tracked by the module. Utility commands are
all those other than <command>SELECT</>, <command>INSERT</>,
<command>UPDATE</> and <command>DELETE</>.
The default value is <literal>on</>.
Only superusers can change this setting.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<varname>pg_stat_statements.save</varname> (<type>boolean</type>)

View File

@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.323 2009/12/11 03:34:55 itagaki Exp $
* $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.324 2009/12/15 20:04:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -58,6 +58,10 @@
#include "utils/syscache.h"
/* Hook for plugins to get control in ProcessUtility() */
ProcessUtility_hook_type ProcessUtility_hook = NULL;
/*
* Verify user has ownership of specified relation, else ereport.
*
@ -274,6 +278,27 @@ ProcessUtility(Node *parsetree,
{
Assert(queryString != NULL); /* required as of 8.4 */
/*
* We provide a function hook variable that lets loadable plugins
* get control when ProcessUtility is called. Such a plugin would
* normally call standard_ProcessUtility().
*/
if (ProcessUtility_hook)
(*ProcessUtility_hook) (parsetree, queryString, params,
isTopLevel, dest, completionTag);
else
standard_ProcessUtility(parsetree, queryString, params,
isTopLevel, dest, completionTag);
}
void
standard_ProcessUtility(Node *parsetree,
const char *queryString,
ParamListInfo params,
bool isTopLevel,
DestReceiver *dest,
char *completionTag)
{
check_xact_readonly(parsetree);
if (completionTag)

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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/tcop/utility.h,v 1.37 2009/12/01 02:31:13 momjian Exp $
* $PostgreSQL: pgsql/src/include/tcop/utility.h,v 1.38 2009/12/15 20:04:49 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -17,9 +17,18 @@
#include "tcop/tcopprot.h"
/* Hook for plugins to get control in ProcessUtility() */
typedef void (*ProcessUtility_hook_type) (Node *parsetree,
const char *queryString, ParamListInfo params, bool isTopLevel,
DestReceiver *dest, char *completionTag);
extern PGDLLIMPORT ProcessUtility_hook_type ProcessUtility_hook;
extern void ProcessUtility(Node *parsetree, const char *queryString,
ParamListInfo params, bool isTopLevel,
DestReceiver *dest, char *completionTag);
extern void standard_ProcessUtility(Node *parsetree, const char *queryString,
ParamListInfo params, bool isTopLevel,
DestReceiver *dest, char *completionTag);
extern bool UtilityReturnsTuples(Node *parsetree);