diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/executor/nodeAgg.c | 76 | ||||
| -rw-r--r-- | src/backend/utils/adt/array_userfuncs.c | 14 | ||||
| -rw-r--r-- | src/backend/utils/adt/float.c | 20 | ||||
| -rw-r--r-- | src/backend/utils/adt/int8.c | 17 | ||||
| -rw-r--r-- | src/backend/utils/adt/numeric.c | 28 | ||||
| -rw-r--r-- | src/backend/utils/adt/varlena.c | 40 | ||||
| -rw-r--r-- | src/include/fmgr.h | 16 |
7 files changed, 118 insertions, 93 deletions
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c index fbdbebfa166..ea722f1ee3b 100644 --- a/src/backend/executor/nodeAgg.c +++ b/src/backend/executor/nodeAgg.c @@ -44,30 +44,34 @@ * is used to run finalize functions and compute the output tuple; * this context can be reset once per output tuple. * - * Beginning in PostgreSQL 8.1, the executor's AggState node is passed as - * the fmgr "context" value in all transfunc and finalfunc calls. It is - * not really intended that the transition functions will look into the - * AggState node, but they can use code like - * if (fcinfo->context && IsA(fcinfo->context, AggState)) - * to verify that they are being called by nodeAgg.c and not as ordinary - * SQL functions. The main reason a transition function might want to know - * that is that it can avoid palloc'ing a fixed-size pass-by-ref transition - * value on every call: it can instead just scribble on and return its left - * input. Ordinarily it is completely forbidden for functions to modify - * pass-by-ref inputs, but in the aggregate case we know the left input is - * either the initial transition value or a previous function result, and - * in either case its value need not be preserved. See int8inc() for an - * example. Notice that advance_transition_function() is coded to avoid a - * data copy step when the previous transition value pointer is returned. - * Also, some transition functions make use of the aggcontext to store - * working state. + * The executor's AggState node is passed as the fmgr "context" value in + * all transfunc and finalfunc calls. It is not recommended that the + * transition functions look at the AggState node directly, but they can + * use AggCheckCallContext() to verify that they are being called by + * nodeAgg.c (and not as ordinary SQL functions). The main reason a + * transition function might want to know this is so that it can avoid + * palloc'ing a fixed-size pass-by-ref transition value on every call: + * it can instead just scribble on and return its left input. Ordinarily + * it is completely forbidden for functions to modify pass-by-ref inputs, + * but in the aggregate case we know the left input is either the initial + * transition value or a previous function result, and in either case its + * value need not be preserved. See int8inc() for an example. Notice that + * advance_transition_function() is coded to avoid a data copy step when + * the previous transition value pointer is returned. Also, some + * transition functions want to store working state in addition to the + * nominal transition value; they can use the memory context returned by + * AggCheckCallContext() to do that. + * + * Note: AggCheckCallContext() is available as of PostgreSQL 9.0. The + * AggState is available as context in earlier releases (back to 8.1), + * but direct examination of the node is needed to use it before 9.0. * * * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.171 2010/01/02 16:57:41 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.172 2010/02/08 20:39:51 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1970,6 +1974,42 @@ ExecReScanAgg(AggState *node, ExprContext *exprCtxt) } /* + * AggCheckCallContext - test if a SQL function is being called as an aggregate + * + * The transition and/or final functions of an aggregate may want to verify + * that they are being called as aggregates, rather than as plain SQL + * functions. They should use this function to do so. The return value + * is nonzero if being called as an aggregate, or zero if not. (Specific + * nonzero values are AGG_CONTEXT_AGGREGATE or AGG_CONTEXT_WINDOW, but more + * values could conceivably appear in future.) + * + * If aggcontext isn't NULL, the function also stores at *aggcontext the + * identity of the memory context that aggregate transition values are + * being stored in. + */ +int +AggCheckCallContext(FunctionCallInfo fcinfo, MemoryContext *aggcontext) +{ + if (fcinfo->context && IsA(fcinfo->context, AggState)) + { + if (aggcontext) + *aggcontext = ((AggState *) fcinfo->context)->aggcontext; + return AGG_CONTEXT_AGGREGATE; + } + if (fcinfo->context && IsA(fcinfo->context, WindowAggState)) + { + if (aggcontext) + *aggcontext = ((WindowAggState *) fcinfo->context)->wincontext; + return AGG_CONTEXT_WINDOW; + } + + /* this is just to prevent "uninitialized variable" warnings */ + if (aggcontext) + *aggcontext = NULL; + return 0; +} + +/* * aggregate_dummy - dummy execution routine for aggregate functions * * This function is listed as the implementation (prosrc field) of pg_proc diff --git a/src/backend/utils/adt/array_userfuncs.c b/src/backend/utils/adt/array_userfuncs.c index 0bdb3d8a8a8..7d4ea11bf8b 100644 --- a/src/backend/utils/adt/array_userfuncs.c +++ b/src/backend/utils/adt/array_userfuncs.c @@ -6,13 +6,12 @@ * Copyright (c) 2003-2010, PostgreSQL Global Development Group * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/array_userfuncs.c,v 1.33 2010/01/02 16:57:53 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/array_userfuncs.c,v 1.34 2010/02/08 20:39:51 tgl Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" -#include "nodes/execnodes.h" #include "utils/array.h" #include "utils/builtins.h" #include "utils/lsyscache.h" @@ -484,15 +483,10 @@ array_agg_transfn(PG_FUNCTION_ARGS) (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("could not determine input data type"))); - if (fcinfo->context && IsA(fcinfo->context, AggState)) - aggcontext = ((AggState *) fcinfo->context)->aggcontext; - else if (fcinfo->context && IsA(fcinfo->context, WindowAggState)) - aggcontext = ((WindowAggState *) fcinfo->context)->wincontext; - else + if (!AggCheckCallContext(fcinfo, &aggcontext)) { /* cannot be called directly because of internal-type argument */ elog(ERROR, "array_agg_transfn called in non-aggregate context"); - aggcontext = NULL; /* keep compiler quiet */ } state = PG_ARGISNULL(0) ? NULL : (ArrayBuildState *) PG_GETARG_POINTER(0); @@ -528,9 +522,7 @@ array_agg_finalfn(PG_FUNCTION_ARGS) PG_RETURN_NULL(); /* returns null iff no input values */ /* cannot be called directly because of internal-type argument */ - Assert(fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))); + Assert(AggCheckCallContext(fcinfo, NULL)); state = (ArrayBuildState *) PG_GETARG_POINTER(0); diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c index 9f194f2785f..82e95704fb1 100644 --- a/src/backend/utils/adt/float.c +++ b/src/backend/utils/adt/float.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.164 2010/01/02 16:57:53 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.165 2010/02/08 20:39:51 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1765,13 +1765,11 @@ float8_accum(PG_FUNCTION_ARGS) CHECKFLOATVAL(sumX2, isinf(transvalues[2]) || isinf(newval), true); /* - * If we're invoked by nodeAgg, we can cheat and modify our first + * If we're invoked as an aggregate, we can cheat and modify our first * parameter in-place to reduce palloc overhead. Otherwise we construct a * new array with the updated transition data and return it. */ - if (fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))) + if (AggCheckCallContext(fcinfo, NULL)) { transvalues[0] = N; transvalues[1] = sumX; @@ -1820,13 +1818,11 @@ float4_accum(PG_FUNCTION_ARGS) CHECKFLOATVAL(sumX2, isinf(transvalues[2]) || isinf(newval), true); /* - * If we're invoked by nodeAgg, we can cheat and modify our first + * If we're invoked as an aggregate, we can cheat and modify our first * parameter in-place to reduce palloc overhead. Otherwise we construct a * new array with the updated transition data and return it. */ - if (fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))) + if (AggCheckCallContext(fcinfo, NULL)) { transvalues[0] = N; transvalues[1] = sumX; @@ -2039,13 +2035,11 @@ float8_regr_accum(PG_FUNCTION_ARGS) isinf(newvalY), true); /* - * If we're invoked by nodeAgg, we can cheat and modify our first + * If we're invoked as an aggregate, we can cheat and modify our first * parameter in-place to reduce palloc overhead. Otherwise we construct a * new array with the updated transition data and return it. */ - if (fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))) + if (AggCheckCallContext(fcinfo, NULL)) { transvalues[0] = N; transvalues[1] = sumX; diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c index 6707b79e548..1482017561d 100644 --- a/src/backend/utils/adt/int8.c +++ b/src/backend/utils/adt/int8.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/int8.c,v 1.77 2010/01/07 04:53:34 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/int8.c,v 1.78 2010/02/08 20:39:51 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -19,7 +19,6 @@ #include "funcapi.h" #include "libpq/pqformat.h" -#include "nodes/nodes.h" #include "utils/int8.h" @@ -654,15 +653,13 @@ int8inc(PG_FUNCTION_ARGS) { /* * When int8 is pass-by-reference, we provide this special case to avoid - * palloc overhead for COUNT(): when called from nodeAgg, we know that the - * argument is modifiable local storage, so just update it in-place. (If - * int8 is pass-by-value, then of course this is useless as well as - * incorrect, so just ifdef it out.) + * palloc overhead for COUNT(): when called as an aggregate, we know that + * the argument is modifiable local storage, so just update it + * in-place. (If int8 is pass-by-value, then of course this is useless as + * well as incorrect, so just ifdef it out.) */ #ifndef USE_FLOAT8_BYVAL /* controls int8 too */ - if (fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))) + if (AggCheckCallContext(fcinfo, NULL)) { int64 *arg = (int64 *) PG_GETARG_POINTER(0); int64 result; @@ -680,7 +677,7 @@ int8inc(PG_FUNCTION_ARGS) else #endif { - /* Not called by nodeAgg, so just do it the dumb way */ + /* Not called as an aggregate, so just do it the dumb way */ int64 arg = PG_GETARG_INT64(0); int64 result; diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c index 2892b5d2fbf..1b9f7944959 100644 --- a/src/backend/utils/adt/numeric.c +++ b/src/backend/utils/adt/numeric.c @@ -14,7 +14,7 @@ * Copyright (c) 1998-2010, PostgreSQL Global Development Group * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.121 2010/01/07 04:53:34 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.122 2010/02/08 20:39:51 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -2679,16 +2679,14 @@ int2_sum(PG_FUNCTION_ARGS) } /* - * If we're invoked by nodeAgg, we can cheat and modify our first + * If we're invoked as an aggregate, we can cheat and modify our first * parameter in-place to avoid palloc overhead. If not, we need to return * the new value of the transition variable. (If int8 is pass-by-value, * then of course this is useless as well as incorrect, so just ifdef it * out.) */ #ifndef USE_FLOAT8_BYVAL /* controls int8 too */ - if (fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))) + if (AggCheckCallContext(fcinfo, NULL)) { int64 *oldsum = (int64 *) PG_GETARG_POINTER(0); @@ -2730,16 +2728,14 @@ int4_sum(PG_FUNCTION_ARGS) } /* - * If we're invoked by nodeAgg, we can cheat and modify our first + * If we're invoked as an aggregate, we can cheat and modify our first * parameter in-place to avoid palloc overhead. If not, we need to return * the new value of the transition variable. (If int8 is pass-by-value, * then of course this is useless as well as incorrect, so just ifdef it * out.) */ #ifndef USE_FLOAT8_BYVAL /* controls int8 too */ - if (fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))) + if (AggCheckCallContext(fcinfo, NULL)) { int64 *oldsum = (int64 *) PG_GETARG_POINTER(0); @@ -2782,7 +2778,7 @@ int8_sum(PG_FUNCTION_ARGS) } /* - * Note that we cannot special-case the nodeAgg case here, as we do for + * Note that we cannot special-case the aggregate case here, as we do for * int2_sum and int4_sum: numeric is of variable size, so we cannot modify * our first parameter in-place. */ @@ -2820,13 +2816,11 @@ int2_avg_accum(PG_FUNCTION_ARGS) Int8TransTypeData *transdata; /* - * If we're invoked by nodeAgg, we can cheat and modify our first + * If we're invoked as an aggregate, we can cheat and modify our first * parameter in-place to reduce palloc overhead. Otherwise we need to make * a copy of it before scribbling on it. */ - if (fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))) + if (AggCheckCallContext(fcinfo, NULL)) transarray = PG_GETARG_ARRAYTYPE_P(0); else transarray = PG_GETARG_ARRAYTYPE_P_COPY(0); @@ -2850,13 +2844,11 @@ int4_avg_accum(PG_FUNCTION_ARGS) Int8TransTypeData *transdata; /* - * If we're invoked by nodeAgg, we can cheat and modify our first + * If we're invoked as an aggregate, we can cheat and modify our first * parameter in-place to reduce palloc overhead. Otherwise we need to make * a copy of it before scribbling on it. */ - if (fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))) + if (AggCheckCallContext(fcinfo, NULL)) transarray = PG_GETARG_ARRAYTYPE_P(0); else transarray = PG_GETARG_ARRAYTYPE_P_COPY(0); diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c index 096ca75bf93..652e1e6add4 100644 --- a/src/backend/utils/adt/varlena.c +++ b/src/backend/utils/adt/varlena.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.175 2010/02/01 03:14:43 itagaki Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.176 2010/02/08 20:39:51 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -21,7 +21,6 @@ #include "libpq/md5.h" #include "libpq/pqformat.h" #include "miscadmin.h" -#include "nodes/execnodes.h" #include "parser/scansup.h" #include "regex/regex.h" #include "utils/builtins.h" @@ -74,7 +73,7 @@ static bytea *bytea_substring(Datum str, int L, bool length_not_specified); static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl); -static StringInfo makeStringAggState(fmNodePtr context); +static StringInfo makeStringAggState(FunctionCallInfo fcinfo); /***************************************************************************** @@ -3327,25 +3326,25 @@ pg_column_size(PG_FUNCTION_ARGS) * actually used at all, and on subsequent calls the delimiter precedes * the associated value. */ + +/* subroutine to initialize state */ static StringInfo -makeStringAggState(fmNodePtr context) +makeStringAggState(FunctionCallInfo fcinfo) { StringInfo state; MemoryContext aggcontext; MemoryContext oldcontext; - if (context && IsA(context, AggState)) - aggcontext = ((AggState *) context)->aggcontext; - else if (context && IsA(context, WindowAggState)) - aggcontext = ((WindowAggState *) context)->wincontext; - else + if (!AggCheckCallContext(fcinfo, &aggcontext)) { /* cannot be called directly because of internal-type argument */ elog(ERROR, "string_agg_transfn called in non-aggregate context"); - aggcontext = NULL; /* keep compiler quiet */ } - /* Create state in aggregate context */ + /* + * Create state in aggregate context. It'll stay there across subsequent + * calls. + */ oldcontext = MemoryContextSwitchTo(aggcontext); state = makeStringInfo(); MemoryContextSwitchTo(oldcontext); @@ -3360,11 +3359,11 @@ string_agg_transfn(PG_FUNCTION_ARGS) state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0); - /* Append the element unless not null. */ + /* Append the element unless null. */ if (!PG_ARGISNULL(1)) { if (state == NULL) - state = makeStringAggState(fcinfo->context); + state = makeStringAggState(fcinfo); appendStringInfoText(state, PG_GETARG_TEXT_PP(1)); /* value */ } @@ -3382,11 +3381,12 @@ string_agg_delim_transfn(PG_FUNCTION_ARGS) state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0); - /* Append the value unless not null. */ + /* Append the value unless null. */ if (!PG_ARGISNULL(1)) { + /* On the first time through, we ignore the delimiter. */ if (state == NULL) - state = makeStringAggState(fcinfo->context); + state = makeStringAggState(fcinfo); else if (!PG_ARGISNULL(2)) appendStringInfoText(state, PG_GETARG_TEXT_PP(2)); /* delimiter */ @@ -3405,15 +3405,11 @@ string_agg_finalfn(PG_FUNCTION_ARGS) { StringInfo state; - if (PG_ARGISNULL(0)) - PG_RETURN_NULL(); - /* cannot be called directly because of internal-type argument */ - Assert(fcinfo->context && - (IsA(fcinfo->context, AggState) || - IsA(fcinfo->context, WindowAggState))); + Assert(AggCheckCallContext(fcinfo, NULL)); + + state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0); - state = (StringInfo) PG_GETARG_POINTER(0); if (state != NULL) PG_RETURN_TEXT_P(cstring_to_text(state->data)); else diff --git a/src/include/fmgr.h b/src/include/fmgr.h index 2c05dfc134a..b5e7435828b 100644 --- a/src/include/fmgr.h +++ b/src/include/fmgr.h @@ -11,7 +11,7 @@ * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.63 2010/01/02 16:58:00 momjian Exp $ + * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.64 2010/02/08 20:39:52 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -530,6 +530,20 @@ extern PGFunction lookup_external_function(void *filehandle, char *funcname); extern void load_file(const char *filename, bool restricted); extern void **find_rendezvous_variable(const char *varName); +/* + * Support for aggregate functions + * + * This is actually in executor/nodeAgg.c, but we declare it here since the + * whole point is for callers of it to not be overly friendly with nodeAgg. + */ + +/* AggCheckCallContext can return one of the following codes, or 0: */ +#define AGG_CONTEXT_AGGREGATE 1 /* regular aggregate */ +#define AGG_CONTEXT_WINDOW 2 /* window function */ + +extern int AggCheckCallContext(FunctionCallInfo fcinfo, + MemoryContext *aggcontext); + /* * !!! OLD INTERFACE !!! |