database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-05 07:21:24 +03:00
Code Activity

Add support for invoking parser callback hooks via SPI and in cached plans.

Browse Source 
As proof of concept, modify plpgsql to use the hooks.  plpgsql is still
inserting $n symbols textually, but the "back end" of the parsing process now
goes through the ParamRef hook instead of using a fixed parameter-type array,
and then execution only fetches actually-referenced parameters, using a hook
added to ParamListInfo.

Although there's a lot left to be done in plpgsql, this already cures the
"if (TG_OP = 'INSERT' and NEW.foo ...)"  problem, as illustrated by the
changed regression test.
This commit is contained in:
Tom Lane
2009-11-04 22:26:08 +00:00
parent 48912acc08
commit 9bedd128d6
23 changed files with 1110 additions and 533 deletions
Download Patch File Download Diff File Expand all files Collapse all files

53
src/backend/utils/cache/plancache.c vendored
View File

@ -35,7 +35,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/cache/plancache.c,v 1.30 2009/10/26 02:26:41 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/cache/plancache.c,v 1.31 2009/11/04 22:26:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -99,8 +99,8 @@ InitPlanCache(void)
* raw_parse_tree: output of raw_parser()
* query_string: original query text (as of PG 8.4, must not be NULL)
* commandTag: compile-time-constant tag for query, or NULL if empty query
* param_types: array of parameter type OIDs, or NULL if none
* num_params: number of parameters
* param_types: array of fixed parameter type OIDs, or NULL if none
* num_params: number of fixed parameters
* cursor_options: options bitmask that was/will be passed to planner
* stmt_list: list of PlannedStmts/utility stmts, or list of Query trees
* fully_planned: are we caching planner or rewriter output?
@ -156,6 +156,9 @@ CreateCachedPlan(Node *raw_parse_tree,
else
plansource->param_types = NULL;
plansource->num_params = num_params;
/* these can be set later with CachedPlanSetParserHook: */
plansource->parserSetup = NULL;
plansource->parserSetupArg = NULL;
plansource->cursor_options = cursor_options;
plansource->fully_planned = fully_planned;
plansource->fixed_result = fixed_result;
@ -240,6 +243,9 @@ FastCreateCachedPlan(Node *raw_parse_tree,
plansource->commandTag = commandTag; /* no copying needed */
plansource->param_types = param_types;
plansource->num_params = num_params;
/* these can be set later with CachedPlanSetParserHook: */
plansource->parserSetup = NULL;
plansource->parserSetupArg = NULL;
plansource->cursor_options = cursor_options;
plansource->fully_planned = fully_planned;
plansource->fixed_result = fixed_result;
@ -274,6 +280,27 @@ FastCreateCachedPlan(Node *raw_parse_tree,
return plansource;
}
/*
* CachedPlanSetParserHook: set up to use parser callback hooks
*
* Use this when a caller wants to manage parameter information via parser
* callbacks rather than a fixed parameter-types list. Beware that the
* information pointed to by parserSetupArg must be valid for as long as
* the cached plan might be replanned!
*/
void
CachedPlanSetParserHook(CachedPlanSource *plansource,
ParserSetupHook parserSetup,
void *parserSetupArg)
{
/* Must not have specified a fixed parameter-types list */
Assert(plansource->param_types == NULL);
Assert(plansource->num_params == 0);
/* OK, save hook info */
plansource->parserSetup = parserSetup;
plansource->parserSetupArg = parserSetupArg;
}
/*
* StoreCachedPlan: store a built or rebuilt plan into a plancache entry.
*
@ -466,6 +493,7 @@ RevalidateCachedPlan(CachedPlanSource *plansource, bool useResOwner)
if (!plan)
{
bool snapshot_set = false;
Node *rawtree;
List *slist;
TupleDesc resultDesc;
@ -491,14 +519,19 @@ RevalidateCachedPlan(CachedPlanSource *plansource, bool useResOwner)
/*
* Run parse analysis and rule rewriting. The parser tends to
* scribble on its input, so we must copy the raw parse tree to
* prevent corruption of the cache. Note that we do not use
* parse_analyze_varparams(), assuming that the caller never wants the
* parameter types to change from the original values.
* prevent corruption of the cache.
*/
slist = pg_analyze_and_rewrite(copyObject(plansource->raw_parse_tree),
plansource->query_string,
plansource->param_types,
plansource->num_params);
rawtree = copyObject(plansource->raw_parse_tree);
if (plansource->parserSetup != NULL)
slist = pg_analyze_and_rewrite_params(rawtree,
plansource->query_string,
plansource->parserSetup,
plansource->parserSetupArg);
else
slist = pg_analyze_and_rewrite(rawtree,
plansource->query_string,
plansource->param_types,
plansource->num_params);
if (plansource->fully_planned)
{