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postgresql/src/backend/executor/spi.c

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/*-------------------------------------------------------------------------
*
* spi.c
* Server Programming Interface
*
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.154 2006/08/12 02:52:04 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/printtup.h"
#include "catalog/heap.h"
#include "commands/trigger.h"
#include "executor/spi_priv.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/typcache.h"
uint32 SPI_processed = 0;
Oid SPI_lastoid = InvalidOid;
SPITupleTable *SPI_tuptable = NULL;
int SPI_result;
static _SPI_connection *_SPI_stack = NULL;
static _SPI_connection *_SPI_current = NULL;
static int _SPI_stack_depth = 0; /* allocated size of _SPI_stack */
static int _SPI_connected = -1;
static int _SPI_curid = -1;
static void _SPI_prepare_plan(const char *src, _SPI_plan *plan);
static int _SPI_execute_plan(_SPI_plan *plan,
Datum *Values, const char *Nulls,
Snapshot snapshot, Snapshot crosscheck_snapshot,
bool read_only, long tcount);
static int _SPI_pquery(QueryDesc *queryDesc, long tcount);
static void _SPI_error_callback(void *arg);
static void _SPI_cursor_operation(Portal portal, bool forward, long count,
DestReceiver *dest);
static _SPI_plan *_SPI_copy_plan(_SPI_plan *plan, int location);
static int _SPI_begin_call(bool execmem);
static int _SPI_end_call(bool procmem);
static MemoryContext _SPI_execmem(void);
static MemoryContext _SPI_procmem(void);
static bool _SPI_checktuples(void);
/* =================== interface functions =================== */
int
SPI_connect(void)
{
int newdepth;
/*
* When procedure called by Executor _SPI_curid expected to be equal to
* _SPI_connected
*/
if (_SPI_curid != _SPI_connected)
return SPI_ERROR_CONNECT;
if (_SPI_stack == NULL)
{
if (_SPI_connected != -1 || _SPI_stack_depth != 0)
elog(ERROR, "SPI stack corrupted");
newdepth = 16;
_SPI_stack = (_SPI_connection *)
MemoryContextAlloc(TopTransactionContext,
newdepth * sizeof(_SPI_connection));
_SPI_stack_depth = newdepth;
}
else
{
if (_SPI_stack_depth <= 0 || _SPI_stack_depth <= _SPI_connected)
elog(ERROR, "SPI stack corrupted");
if (_SPI_stack_depth == _SPI_connected + 1)
{
newdepth = _SPI_stack_depth * 2;
_SPI_stack = (_SPI_connection *)
repalloc(_SPI_stack,
newdepth * sizeof(_SPI_connection));
_SPI_stack_depth = newdepth;
}
}
/*
* We're entering procedure where _SPI_curid == _SPI_connected - 1
*/
_SPI_connected++;
Assert(_SPI_connected >= 0 && _SPI_connected < _SPI_stack_depth);
_SPI_current = &(_SPI_stack[_SPI_connected]);
_SPI_current->processed = 0;
_SPI_current->lastoid = InvalidOid;
_SPI_current->tuptable = NULL;
_SPI_current->procCxt = NULL; /* in case we fail to create 'em */
_SPI_current->execCxt = NULL;
_SPI_current->connectSubid = GetCurrentSubTransactionId();
/*
* Create memory contexts for this procedure
*
* XXX it would be better to use PortalContext as the parent context, but
* we may not be inside a portal (consider deferred-trigger execution).
* Perhaps CurTransactionContext would do? For now it doesn't matter
* because we clean up explicitly in AtEOSubXact_SPI().
*/
_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
"SPI Proc",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
_SPI_current->execCxt = AllocSetContextCreate(TopTransactionContext,
"SPI Exec",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/* ... and switch to procedure's context */
_SPI_current->savedcxt = MemoryContextSwitchTo(_SPI_current->procCxt);
return SPI_OK_CONNECT;
}
int
SPI_finish(void)
{
int res;
res = _SPI_begin_call(false); /* live in procedure memory */
if (res < 0)
return res;
/* Restore memory context as it was before procedure call */
MemoryContextSwitchTo(_SPI_current->savedcxt);
/* Release memory used in procedure call */
MemoryContextDelete(_SPI_current->execCxt);
_SPI_current->execCxt = NULL;
MemoryContextDelete(_SPI_current->procCxt);
_SPI_current->procCxt = NULL;
/*
* Reset result variables, especially SPI_tuptable which is probably
* pointing at a just-deleted tuptable
*/
SPI_processed = 0;
SPI_lastoid = InvalidOid;
SPI_tuptable = NULL;
/*
* After _SPI_begin_call _SPI_connected == _SPI_curid. Now we are closing
* connection to SPI and returning to upper Executor and so _SPI_connected
* must be equal to _SPI_curid.
*/
_SPI_connected--;
_SPI_curid--;
if (_SPI_connected == -1)
_SPI_current = NULL;
else
_SPI_current = &(_SPI_stack[_SPI_connected]);
return SPI_OK_FINISH;
}
/*
* Clean up SPI state at transaction commit or abort.
*/
void
AtEOXact_SPI(bool isCommit)
{
/*
* Note that memory contexts belonging to SPI stack entries will be freed
* automatically, so we can ignore them here. We just need to restore our
* static variables to initial state.
*/
if (isCommit && _SPI_connected != -1)
ereport(WARNING,
(errcode(ERRCODE_WARNING),
errmsg("transaction left non-empty SPI stack"),
errhint("Check for missing \"SPI_finish\" calls.")));
_SPI_current = _SPI_stack = NULL;
_SPI_stack_depth = 0;
_SPI_connected = _SPI_curid = -1;
SPI_processed = 0;
SPI_lastoid = InvalidOid;
SPI_tuptable = NULL;
}
/*
* Clean up SPI state at subtransaction commit or abort.
*
* During commit, there shouldn't be any unclosed entries remaining from
* the current subtransaction; we emit a warning if any are found.
*/
void
AtEOSubXact_SPI(bool isCommit, SubTransactionId mySubid)
{
bool found = false;
while (_SPI_connected >= 0)
{
_SPI_connection *connection = &(_SPI_stack[_SPI_connected]);
if (connection->connectSubid != mySubid)
break; /* couldn't be any underneath it either */
found = true;
/*
* Release procedure memory explicitly (see note in SPI_connect)
*/
if (connection->execCxt)
{
MemoryContextDelete(connection->execCxt);
connection->execCxt = NULL;
}
if (connection->procCxt)
{
MemoryContextDelete(connection->procCxt);
connection->procCxt = NULL;
}
/*
* Pop the stack entry and reset global variables. Unlike
* SPI_finish(), we don't risk switching to memory contexts that might
* be already gone.
*/
_SPI_connected--;
_SPI_curid = _SPI_connected;
if (_SPI_connected == -1)
_SPI_current = NULL;
else
_SPI_current = &(_SPI_stack[_SPI_connected]);
SPI_processed = 0;
SPI_lastoid = InvalidOid;
SPI_tuptable = NULL;
}
if (found && isCommit)
ereport(WARNING,
(errcode(ERRCODE_WARNING),
errmsg("subtransaction left non-empty SPI stack"),
errhint("Check for missing \"SPI_finish\" calls.")));
}
/* Pushes SPI stack to allow recursive SPI calls */
void
SPI_push(void)
{
_SPI_curid++;
}
/* Pops SPI stack to allow recursive SPI calls */
void
SPI_pop(void)
{
_SPI_curid--;
}
/* Restore state of SPI stack after aborting a subtransaction */
void
SPI_restore_connection(void)
{
Assert(_SPI_connected >= 0);
_SPI_curid = _SPI_connected - 1;
}
/* Parse, plan, and execute a query string */
int
SPI_execute(const char *src, bool read_only, long tcount)
{
_SPI_plan plan;
int res;
if (src == NULL || tcount < 0)
return SPI_ERROR_ARGUMENT;
res = _SPI_begin_call(true);
if (res < 0)
return res;
plan.plancxt = NULL; /* doesn't have own context */
plan.query = src;
plan.nargs = 0;
plan.argtypes = NULL;
_SPI_prepare_plan(src, &plan);
res = _SPI_execute_plan(&plan, NULL, NULL,
InvalidSnapshot, InvalidSnapshot,
read_only, tcount);
_SPI_end_call(true);
return res;
}
/* Obsolete version of SPI_execute */
int
SPI_exec(const char *src, long tcount)
{
return SPI_execute(src, false, tcount);
}
/* Execute a previously prepared plan */
int
SPI_execute_plan(void *plan, Datum *Values, const char *Nulls,
bool read_only, long tcount)
{
int res;
if (plan == NULL || tcount < 0)
return SPI_ERROR_ARGUMENT;
if (((_SPI_plan *) plan)->nargs > 0 && Values == NULL)
return SPI_ERROR_PARAM;
res = _SPI_begin_call(true);
if (res < 0)
return res;
res = _SPI_execute_plan((_SPI_plan *) plan,
Values, Nulls,
InvalidSnapshot, InvalidSnapshot,
read_only, tcount);
_SPI_end_call(true);
return res;
}
/* Obsolete version of SPI_execute_plan */
int
SPI_execp(void *plan, Datum *Values, const char *Nulls, long tcount)
{
return SPI_execute_plan(plan, Values, Nulls, false, tcount);
}
/*
* SPI_execute_snapshot -- identical to SPI_execute_plan, except that we allow
* the caller to specify exactly which snapshots to use. This is currently
* not documented in spi.sgml because it is only intended for use by RI
* triggers.
*
* Passing snapshot == InvalidSnapshot will select the normal behavior of
* fetching a new snapshot for each query.
*/
int
SPI_execute_snapshot(void *plan,
Datum *Values, const char *Nulls,
Snapshot snapshot, Snapshot crosscheck_snapshot,
bool read_only, long tcount)
{
int res;
if (plan == NULL || tcount < 0)
return SPI_ERROR_ARGUMENT;
if (((_SPI_plan *) plan)->nargs > 0 && Values == NULL)
return SPI_ERROR_PARAM;
res = _SPI_begin_call(true);
if (res < 0)
return res;
res = _SPI_execute_plan((_SPI_plan *) plan,
Values, Nulls,
snapshot, crosscheck_snapshot,
read_only, tcount);
_SPI_end_call(true);
return res;
}
void *
SPI_prepare(const char *src, int nargs, Oid *argtypes)
{
_SPI_plan plan;
_SPI_plan *result;
if (src == NULL || nargs < 0 || (nargs > 0 && argtypes == NULL))
{
SPI_result = SPI_ERROR_ARGUMENT;
return NULL;
}
SPI_result = _SPI_begin_call(true);
if (SPI_result < 0)
return NULL;
plan.plancxt = NULL; /* doesn't have own context */
plan.query = src;
plan.nargs = nargs;
plan.argtypes = argtypes;
_SPI_prepare_plan(src, &plan);
/* copy plan to procedure context */
result = _SPI_copy_plan(&plan, _SPI_CPLAN_PROCXT);
_SPI_end_call(true);
return (void *) result;
}
void *
SPI_saveplan(void *plan)
{
_SPI_plan *newplan;
if (plan == NULL)
{
SPI_result = SPI_ERROR_ARGUMENT;
return NULL;
}
SPI_result = _SPI_begin_call(false); /* don't change context */
if (SPI_result < 0)
return NULL;
newplan = _SPI_copy_plan((_SPI_plan *) plan, _SPI_CPLAN_TOPCXT);
_SPI_curid--;
SPI_result = 0;
return (void *) newplan;
}
int
SPI_freeplan(void *plan)
{
_SPI_plan *spiplan = (_SPI_plan *) plan;
if (plan == NULL)
return SPI_ERROR_ARGUMENT;
MemoryContextDelete(spiplan->plancxt);
return 0;
}
HeapTuple
SPI_copytuple(HeapTuple tuple)
{
MemoryContext oldcxt = NULL;
HeapTuple ctuple;
if (tuple == NULL)
{
SPI_result = SPI_ERROR_ARGUMENT;
return NULL;
}
if (_SPI_curid + 1 == _SPI_connected) /* connected */
{
if (_SPI_current != &(_SPI_stack[_SPI_curid + 1]))
elog(ERROR, "SPI stack corrupted");
oldcxt = MemoryContextSwitchTo(_SPI_current->savedcxt);
}
ctuple = heap_copytuple(tuple);
if (oldcxt)
MemoryContextSwitchTo(oldcxt);
return ctuple;
}
HeapTupleHeader
SPI_returntuple(HeapTuple tuple, TupleDesc tupdesc)
{
MemoryContext oldcxt = NULL;
HeapTupleHeader dtup;
if (tuple == NULL || tupdesc == NULL)
{
SPI_result = SPI_ERROR_ARGUMENT;
return NULL;
}
/* For RECORD results, make sure a typmod has been assigned */
if (tupdesc->tdtypeid == RECORDOID &&
tupdesc->tdtypmod < 0)
assign_record_type_typmod(tupdesc);
if (_SPI_curid + 1 == _SPI_connected) /* connected */
{
if (_SPI_current != &(_SPI_stack[_SPI_curid + 1]))
elog(ERROR, "SPI stack corrupted");
oldcxt = MemoryContextSwitchTo(_SPI_current->savedcxt);
}
dtup = (HeapTupleHeader) palloc(tuple->t_len);
memcpy((char *) dtup, (char *) tuple->t_data, tuple->t_len);
HeapTupleHeaderSetDatumLength(dtup, tuple->t_len);
HeapTupleHeaderSetTypeId(dtup, tupdesc->tdtypeid);
HeapTupleHeaderSetTypMod(dtup, tupdesc->tdtypmod);
if (oldcxt)
MemoryContextSwitchTo(oldcxt);
return dtup;
}
HeapTuple
SPI_modifytuple(Relation rel, HeapTuple tuple, int natts, int *attnum,
Datum *Values, const char *Nulls)
{
MemoryContext oldcxt = NULL;
HeapTuple mtuple;
int numberOfAttributes;
Datum *v;
char *n;
int i;
if (rel == NULL || tuple == NULL || natts < 0 || attnum == NULL || Values == NULL)
{
SPI_result = SPI_ERROR_ARGUMENT;
return NULL;
}
if (_SPI_curid + 1 == _SPI_connected) /* connected */
{
if (_SPI_current != &(_SPI_stack[_SPI_curid + 1]))
elog(ERROR, "SPI stack corrupted");
oldcxt = MemoryContextSwitchTo(_SPI_current->savedcxt);
}
SPI_result = 0;
numberOfAttributes = rel->rd_att->natts;
v = (Datum *) palloc(numberOfAttributes * sizeof(Datum));
n = (char *) palloc(numberOfAttributes * sizeof(char));
/* fetch old values and nulls */
heap_deformtuple(tuple, rel->rd_att, v, n);
/* replace values and nulls */
for (i = 0; i < natts; i++)
{
if (attnum[i] <= 0 || attnum[i] > numberOfAttributes)
break;
v[attnum[i] - 1] = Values[i];
n[attnum[i] - 1] = (Nulls && Nulls[i] == 'n') ? 'n' : ' ';
}
if (i == natts) /* no errors in *attnum */
{
mtuple = heap_formtuple(rel->rd_att, v, n);
/*
* copy the identification info of the old tuple: t_ctid, t_self, and
* OID (if any)
*/
mtuple->t_data->t_ctid = tuple->t_data->t_ctid;
mtuple->t_self = tuple->t_self;
mtuple->t_tableOid = tuple->t_tableOid;
if (rel->rd_att->tdhasoid)
HeapTupleSetOid(mtuple, HeapTupleGetOid(tuple));
}
else
{
mtuple = NULL;
SPI_result = SPI_ERROR_NOATTRIBUTE;
}
pfree(v);
pfree(n);
if (oldcxt)
MemoryContextSwitchTo(oldcxt);
return mtuple;
}
int
SPI_fnumber(TupleDesc tupdesc, const char *fname)
{
int res;
Form_pg_attribute sysatt;
for (res = 0; res < tupdesc->natts; res++)
{
if (namestrcmp(&tupdesc->attrs[res]->attname, fname) == 0)
return res + 1;
}
sysatt = SystemAttributeByName(fname, true /* "oid" will be accepted */ );
if (sysatt != NULL)
return sysatt->attnum;
/* SPI_ERROR_NOATTRIBUTE is different from all sys column numbers */
return SPI_ERROR_NOATTRIBUTE;
}
char *
SPI_fname(TupleDesc tupdesc, int fnumber)
{
Form_pg_attribute att;
SPI_result = 0;
if (fnumber > tupdesc->natts || fnumber == 0 ||
fnumber <= FirstLowInvalidHeapAttributeNumber)
{
SPI_result = SPI_ERROR_NOATTRIBUTE;
return NULL;
}
if (fnumber > 0)
att = tupdesc->attrs[fnumber - 1];
else
att = SystemAttributeDefinition(fnumber, true);
return pstrdup(NameStr(att->attname));
}
char *
SPI_getvalue(HeapTuple tuple, TupleDesc tupdesc, int fnumber)
{
char *result;
Datum origval,
val;
bool isnull;
Oid typoid,
foutoid;
bool typisvarlena;
SPI_result = 0;
if (fnumber > tuple->t_data->t_natts || fnumber == 0 ||
fnumber <= FirstLowInvalidHeapAttributeNumber)
{
SPI_result = SPI_ERROR_NOATTRIBUTE;
return NULL;
}
origval = heap_getattr(tuple, fnumber, tupdesc, &isnull);
if (isnull)
return NULL;
if (fnumber > 0)
typoid = tupdesc->attrs[fnumber - 1]->atttypid;
else
typoid = (SystemAttributeDefinition(fnumber, true))->atttypid;
getTypeOutputInfo(typoid, &foutoid, &typisvarlena);
/*
* If we have a toasted datum, forcibly detoast it here to avoid memory
* leakage inside the type's output routine.
*/
if (typisvarlena)
val = PointerGetDatum(PG_DETOAST_DATUM(origval));
else
val = origval;
result = OidOutputFunctionCall(foutoid, val);
/* Clean up detoasted copy, if any */
if (val != origval)
pfree(DatumGetPointer(val));
return result;
}
Datum
SPI_getbinval(HeapTuple tuple, TupleDesc tupdesc, int fnumber, bool *isnull)
{
SPI_result = 0;
if (fnumber > tuple->t_data->t_natts || fnumber == 0 ||
fnumber <= FirstLowInvalidHeapAttributeNumber)
{
SPI_result = SPI_ERROR_NOATTRIBUTE;
*isnull = true;
return (Datum) NULL;
}
return heap_getattr(tuple, fnumber, tupdesc, isnull);
}
char *
SPI_gettype(TupleDesc tupdesc, int fnumber)
{
Oid typoid;
HeapTuple typeTuple;
char *result;
SPI_result = 0;
if (fnumber > tupdesc->natts || fnumber == 0 ||
fnumber <= FirstLowInvalidHeapAttributeNumber)
{
SPI_result = SPI_ERROR_NOATTRIBUTE;
return NULL;
}
if (fnumber > 0)
typoid = tupdesc->attrs[fnumber - 1]->atttypid;
else
typoid = (SystemAttributeDefinition(fnumber, true))->atttypid;
typeTuple = SearchSysCache(TYPEOID,
ObjectIdGetDatum(typoid),
0, 0, 0);
if (!HeapTupleIsValid(typeTuple))
{
SPI_result = SPI_ERROR_TYPUNKNOWN;
return NULL;
}
result = pstrdup(NameStr(((Form_pg_type) GETSTRUCT(typeTuple))->typname));
ReleaseSysCache(typeTuple);
return result;
}
Oid
SPI_gettypeid(TupleDesc tupdesc, int fnumber)
{
SPI_result = 0;
if (fnumber > tupdesc->natts || fnumber == 0 ||
fnumber <= FirstLowInvalidHeapAttributeNumber)
{
SPI_result = SPI_ERROR_NOATTRIBUTE;
return InvalidOid;
}
if (fnumber > 0)
return tupdesc->attrs[fnumber - 1]->atttypid;
else
return (SystemAttributeDefinition(fnumber, true))->atttypid;
}
char *
SPI_getrelname(Relation rel)
{
return pstrdup(RelationGetRelationName(rel));
}
char *
SPI_getnspname(Relation rel)
{
return get_namespace_name(RelationGetNamespace(rel));
}
void *
SPI_palloc(Size size)
{
MemoryContext oldcxt = NULL;
void *pointer;
if (_SPI_curid + 1 == _SPI_connected) /* connected */
{
if (_SPI_current != &(_SPI_stack[_SPI_curid + 1]))
elog(ERROR, "SPI stack corrupted");
oldcxt = MemoryContextSwitchTo(_SPI_current->savedcxt);
}
pointer = palloc(size);
if (oldcxt)
MemoryContextSwitchTo(oldcxt);
return pointer;
}
void *
SPI_repalloc(void *pointer, Size size)
{
/* No longer need to worry which context chunk was in... */
return repalloc(pointer, size);
}
void
SPI_pfree(void *pointer)
{
/* No longer need to worry which context chunk was in... */
pfree(pointer);
}
void
SPI_freetuple(HeapTuple tuple)
{
/* No longer need to worry which context tuple was in... */
heap_freetuple(tuple);
}
void
SPI_freetuptable(SPITupleTable *tuptable)
{
if (tuptable != NULL)
MemoryContextDelete(tuptable->tuptabcxt);
}
/*
* SPI_cursor_open()
*
* Open a prepared SPI plan as a portal
*/
Portal
SPI_cursor_open(const char *name, void *plan,
Datum *Values, const char *Nulls,
bool read_only)
{
_SPI_plan *spiplan = (_SPI_plan *) plan;
List *qtlist = spiplan->qtlist;
List *ptlist = spiplan->ptlist;
Query *queryTree;
Plan *planTree;
ParamListInfo paramLI;
Snapshot snapshot;
MemoryContext oldcontext;
Portal portal;
int k;
/* Ensure that the plan contains only one query */
if (list_length(ptlist) != 1 || list_length(qtlist) != 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
errmsg("cannot open multi-query plan as cursor")));
queryTree = (Query *) linitial((List *) linitial(qtlist));
planTree = (Plan *) linitial(ptlist);
/* Must be a query that returns tuples */
switch (queryTree->commandType)
{
case CMD_SELECT:
if (queryTree->into != NULL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
errmsg("cannot open SELECT INTO query as cursor")));
break;
case CMD_UTILITY:
if (!UtilityReturnsTuples(queryTree->utilityStmt))
ereport(ERROR,
(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
errmsg("cannot open non-SELECT query as cursor")));
break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_CURSOR_DEFINITION),
errmsg("cannot open non-SELECT query as cursor")));
break;
}
/* Reset SPI result (note we deliberately don't touch lastoid) */
SPI_processed = 0;
SPI_tuptable = NULL;
_SPI_current->processed = 0;
_SPI_current->tuptable = NULL;
/* Create the portal */
if (name == NULL || name[0] == '\0')
{
/* Use a random nonconflicting name */
portal = CreateNewPortal();
}
else
{
/* In this path, error if portal of same name already exists */
portal = CreatePortal(name, false, false);
}
/* Switch to portals memory and copy the parsetree and plan to there */
oldcontext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
queryTree = copyObject(queryTree);
planTree = copyObject(planTree);
/* If the plan has parameters, set them up */
if (spiplan->nargs > 0)
{
/* sizeof(ParamListInfoData) includes the first array element */
paramLI = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
(spiplan->nargs - 1) * sizeof(ParamExternData));
paramLI->numParams = spiplan->nargs;
for (k = 0; k < spiplan->nargs; k++)
{
ParamExternData *prm = &paramLI->params[k];
prm->ptype = spiplan->argtypes[k];
prm->isnull = (Nulls && Nulls[k] == 'n');
if (prm->isnull)
{
/* nulls just copy */
prm->value = Values[k];
}
else
{
/* pass-by-ref values must be copied into portal context */
int16 paramTypLen;
bool paramTypByVal;
get_typlenbyval(prm->ptype, &paramTypLen, &paramTypByVal);
prm->value = datumCopy(Values[k],
paramTypByVal, paramTypLen);
}
}
}
else
paramLI = NULL;
/*
* Set up the portal.
*/
PortalDefineQuery(portal,
NULL,
spiplan->query,
"SELECT", /* don't have the raw parse tree... */
list_make1(queryTree),
list_make1(planTree),
PortalGetHeapMemory(portal));
MemoryContextSwitchTo(oldcontext);
/*
* Set up options for portal.
*/
portal->cursorOptions &= ~(CURSOR_OPT_SCROLL | CURSOR_OPT_NO_SCROLL);
if (planTree == NULL || ExecSupportsBackwardScan(planTree))
portal->cursorOptions |= CURSOR_OPT_SCROLL;
else
portal->cursorOptions |= CURSOR_OPT_NO_SCROLL;
/*
* Set up the snapshot to use. (PortalStart will do CopySnapshot, so we
* skip that here.)
*/
if (read_only)
snapshot = ActiveSnapshot;
else
{
CommandCounterIncrement();
snapshot = GetTransactionSnapshot();
}
/*
* Start portal execution.
*/
PortalStart(portal, paramLI, snapshot);
Assert(portal->strategy == PORTAL_ONE_SELECT ||
portal->strategy == PORTAL_ONE_RETURNING ||
portal->strategy == PORTAL_UTIL_SELECT);
/* Return the created portal */
return portal;
}
/*
* SPI_cursor_find()
*
* Find the portal of an existing open cursor
*/
Portal
SPI_cursor_find(const char *name)
{
return GetPortalByName(name);
}
/*
* SPI_cursor_fetch()
*
* Fetch rows in a cursor
*/
void
SPI_cursor_fetch(Portal portal, bool forward, long count)
{
_SPI_cursor_operation(portal, forward, count,
CreateDestReceiver(DestSPI, NULL));
/* we know that the DestSPI receiver doesn't need a destroy call */
}
/*
* SPI_cursor_move()
*
* Move in a cursor
*/
void
SPI_cursor_move(Portal portal, bool forward, long count)
{
_SPI_cursor_operation(portal, forward, count, None_Receiver);
}
/*
* SPI_cursor_close()
*
* Close a cursor
*/
void
SPI_cursor_close(Portal portal)
{
if (!PortalIsValid(portal))
elog(ERROR, "invalid portal in SPI cursor operation");
PortalDrop(portal, false);
}
/*
* Returns the Oid representing the type id for argument at argIndex. First
* parameter is at index zero.
*/
Oid
SPI_getargtypeid(void *plan, int argIndex)
{
if (plan == NULL || argIndex < 0 || argIndex >= ((_SPI_plan *) plan)->nargs)
{
SPI_result = SPI_ERROR_ARGUMENT;
return InvalidOid;
}
return ((_SPI_plan *) plan)->argtypes[argIndex];
}
/*
* Returns the number of arguments for the prepared plan.
*/
int
SPI_getargcount(void *plan)
{
if (plan == NULL)
{
SPI_result = SPI_ERROR_ARGUMENT;
return -1;
}
return ((_SPI_plan *) plan)->nargs;
}
/*
* Returns true if the plan contains exactly one command
* and that command originates from normal SELECT (i.e.
* *not* a SELECT ... INTO). In essence, the result indicates
* if the command can be used with SPI_cursor_open
*
* Parameters
* plan A plan previously prepared using SPI_prepare
*/
bool
SPI_is_cursor_plan(void *plan)
{
_SPI_plan *spiplan = (_SPI_plan *) plan;
List *qtlist;
if (spiplan == NULL)
{
SPI_result = SPI_ERROR_ARGUMENT;
return false;
}
qtlist = spiplan->qtlist;
if (list_length(spiplan->ptlist) == 1 && list_length(qtlist) == 1)
{
Query *queryTree = (Query *) linitial((List *) linitial(qtlist));
if (queryTree->commandType == CMD_SELECT && queryTree->into == NULL)
return true;
}
return false;
}
/*
* SPI_result_code_string --- convert any SPI return code to a string
*
* This is often useful in error messages. Most callers will probably
* only pass negative (error-case) codes, but for generality we recognize
* the success codes too.
*/
const char *
SPI_result_code_string(int code)
{
static char buf[64];
switch (code)
{
case SPI_ERROR_CONNECT:
return "SPI_ERROR_CONNECT";
case SPI_ERROR_COPY:
return "SPI_ERROR_COPY";
case SPI_ERROR_OPUNKNOWN:
return "SPI_ERROR_OPUNKNOWN";
case SPI_ERROR_UNCONNECTED:
return "SPI_ERROR_UNCONNECTED";
case SPI_ERROR_CURSOR:
return "SPI_ERROR_CURSOR";
case SPI_ERROR_ARGUMENT:
return "SPI_ERROR_ARGUMENT";
case SPI_ERROR_PARAM:
return "SPI_ERROR_PARAM";
case SPI_ERROR_TRANSACTION:
return "SPI_ERROR_TRANSACTION";
case SPI_ERROR_NOATTRIBUTE:
return "SPI_ERROR_NOATTRIBUTE";
case SPI_ERROR_NOOUTFUNC:
return "SPI_ERROR_NOOUTFUNC";
case SPI_ERROR_TYPUNKNOWN:
return "SPI_ERROR_TYPUNKNOWN";
case SPI_OK_CONNECT:
return "SPI_OK_CONNECT";
case SPI_OK_FINISH:
return "SPI_OK_FINISH";
case SPI_OK_FETCH:
return "SPI_OK_FETCH";
case SPI_OK_UTILITY:
return "SPI_OK_UTILITY";
case SPI_OK_SELECT:
return "SPI_OK_SELECT";
case SPI_OK_SELINTO:
return "SPI_OK_SELINTO";
case SPI_OK_INSERT:
return "SPI_OK_INSERT";
case SPI_OK_DELETE:
return "SPI_OK_DELETE";
case SPI_OK_UPDATE:
return "SPI_OK_UPDATE";
case SPI_OK_CURSOR:
return "SPI_OK_CURSOR";
}
/* Unrecognized code ... return something useful ... */
sprintf(buf, "Unrecognized SPI code %d", code);
return buf;
}
/* =================== private functions =================== */
/*
* spi_dest_startup
* Initialize to receive tuples from Executor into SPITupleTable
* of current SPI procedure
*/
void
spi_dest_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
{
SPITupleTable *tuptable;
MemoryContext oldcxt;
MemoryContext tuptabcxt;
/*
* When called by Executor _SPI_curid expected to be equal to
* _SPI_connected
*/
if (_SPI_curid != _SPI_connected || _SPI_connected < 0)
elog(ERROR, "improper call to spi_dest_startup");
if (_SPI_current != &(_SPI_stack[_SPI_curid]))
elog(ERROR, "SPI stack corrupted");
if (_SPI_current->tuptable != NULL)
elog(ERROR, "improper call to spi_dest_startup");
oldcxt = _SPI_procmem(); /* switch to procedure memory context */
tuptabcxt = AllocSetContextCreate(CurrentMemoryContext,
"SPI TupTable",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
MemoryContextSwitchTo(tuptabcxt);
_SPI_current->tuptable = tuptable = (SPITupleTable *)
palloc(sizeof(SPITupleTable));
tuptable->tuptabcxt = tuptabcxt;
tuptable->alloced = tuptable->free = 128;
tuptable->vals = (HeapTuple *) palloc(tuptable->alloced * sizeof(HeapTuple));
tuptable->tupdesc = CreateTupleDescCopy(typeinfo);
MemoryContextSwitchTo(oldcxt);
}
/*
* spi_printtup
* store tuple retrieved by Executor into SPITupleTable
* of current SPI procedure
*/
void
spi_printtup(TupleTableSlot *slot, DestReceiver *self)
{
SPITupleTable *tuptable;
MemoryContext oldcxt;
/*
* When called by Executor _SPI_curid expected to be equal to
* _SPI_connected
*/
if (_SPI_curid != _SPI_connected || _SPI_connected < 0)
elog(ERROR, "improper call to spi_printtup");
if (_SPI_current != &(_SPI_stack[_SPI_curid]))
elog(ERROR, "SPI stack corrupted");
tuptable = _SPI_current->tuptable;
if (tuptable == NULL)
elog(ERROR, "improper call to spi_printtup");
oldcxt = MemoryContextSwitchTo(tuptable->tuptabcxt);
if (tuptable->free == 0)
{
tuptable->free = 256;
tuptable->alloced += tuptable->free;
tuptable->vals = (HeapTuple *) repalloc(tuptable->vals,
tuptable->alloced * sizeof(HeapTuple));
}
tuptable->vals[tuptable->alloced - tuptable->free] =
ExecCopySlotTuple(slot);
(tuptable->free)--;
MemoryContextSwitchTo(oldcxt);
}
/*
* Static functions
*/
/*
* Parse and plan a querystring.
*
* At entry, plan->argtypes and plan->nargs must be valid.
*
* Query and plan lists are stored into *plan.
*/
static void
_SPI_prepare_plan(const char *src, _SPI_plan *plan)
{
List *raw_parsetree_list;
List *query_list_list;
List *plan_list;
ListCell *list_item;
ErrorContextCallback spierrcontext;
Oid *argtypes = plan->argtypes;
int nargs = plan->nargs;
/*
* Increment CommandCounter to see changes made by now. We must do this
* to be sure of seeing any schema changes made by a just-preceding SPI
* command. (But we don't bother advancing the snapshot, since the
* planner generally operates under SnapshotNow rules anyway.)
*/
CommandCounterIncrement();
/*
* Setup error traceback support for ereport()
*/
spierrcontext.callback = _SPI_error_callback;
spierrcontext.arg = (void *) src;
spierrcontext.previous = error_context_stack;
error_context_stack = &spierrcontext;
/*
* Parse the request string into a list of raw parse trees.
*/
raw_parsetree_list = pg_parse_query(src);
/*
* Do parse analysis and rule rewrite for each raw parsetree.
*
* We save the querytrees from each raw parsetree as a separate sublist.
* This allows _SPI_execute_plan() to know where the boundaries between
* original queries fall.
*/
query_list_list = NIL;
plan_list = NIL;
foreach(list_item, raw_parsetree_list)
{
Node *parsetree = (Node *) lfirst(list_item);
List *query_list;
query_list = pg_analyze_and_rewrite(parsetree, src, argtypes, nargs);
query_list_list = lappend(query_list_list, query_list);
plan_list = list_concat(plan_list,
pg_plan_queries(query_list, NULL, false));
}
plan->qtlist = query_list_list;
plan->ptlist = plan_list;
/*
* Pop the error context stack
*/
error_context_stack = spierrcontext.previous;
}
/*
* Execute the given plan with the given parameter values
*
* snapshot: query snapshot to use, or InvalidSnapshot for the normal
* behavior of taking a new snapshot for each query.
* crosscheck_snapshot: for RI use, all others pass InvalidSnapshot
* read_only: TRUE for read-only execution (no CommandCounterIncrement)
* tcount: execution tuple-count limit, or 0 for none
*/
static int
_SPI_execute_plan(_SPI_plan *plan, Datum *Values, const char *Nulls,
Snapshot snapshot, Snapshot crosscheck_snapshot,
bool read_only, long tcount)
{
volatile int res = 0;
volatile uint32 my_processed = 0;
volatile Oid my_lastoid = InvalidOid;
SPITupleTable *volatile my_tuptable = NULL;
Snapshot saveActiveSnapshot;
/* Be sure to restore ActiveSnapshot on error exit */
saveActiveSnapshot = ActiveSnapshot;
PG_TRY();
{
List *query_list_list = plan->qtlist;
ListCell *plan_list_item = list_head(plan->ptlist);
ListCell *query_list_list_item;
ErrorContextCallback spierrcontext;
int nargs = plan->nargs;
ParamListInfo paramLI;
/* Convert parameters to form wanted by executor */
if (nargs > 0)
{
int k;
/* sizeof(ParamListInfoData) includes the first array element */
paramLI = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
(nargs - 1) * sizeof(ParamExternData));
paramLI->numParams = nargs;
for (k = 0; k < nargs; k++)
{
ParamExternData *prm = &paramLI->params[k];
prm->value = Values[k];
prm->isnull = (Nulls && Nulls[k] == 'n');
prm->ptype = plan->argtypes[k];
}
}
else
paramLI = NULL;
/*
* Setup error traceback support for ereport()
*/
spierrcontext.callback = _SPI_error_callback;
spierrcontext.arg = (void *) plan->query;
spierrcontext.previous = error_context_stack;
error_context_stack = &spierrcontext;
foreach(query_list_list_item, query_list_list)
{
List *query_list = lfirst(query_list_list_item);
ListCell *query_list_item;
foreach(query_list_item, query_list)
{
Query *queryTree = (Query *) lfirst(query_list_item);
Plan *planTree;
QueryDesc *qdesc;
DestReceiver *dest;
planTree = lfirst(plan_list_item);
plan_list_item = lnext(plan_list_item);
_SPI_current->processed = 0;
_SPI_current->lastoid = InvalidOid;
_SPI_current->tuptable = NULL;
if (queryTree->commandType == CMD_UTILITY)
{
if (IsA(queryTree->utilityStmt, CopyStmt))
{
CopyStmt *stmt = (CopyStmt *) queryTree->utilityStmt;
if (stmt->filename == NULL)
{
res = SPI_ERROR_COPY;
goto fail;
}
}
else if (IsA(queryTree->utilityStmt, DeclareCursorStmt) ||
IsA(queryTree->utilityStmt, ClosePortalStmt) ||
IsA(queryTree->utilityStmt, FetchStmt))
{
res = SPI_ERROR_CURSOR;
goto fail;
}
else if (IsA(queryTree->utilityStmt, TransactionStmt))
{
res = SPI_ERROR_TRANSACTION;
goto fail;
}
}
if (read_only && !QueryIsReadOnly(queryTree))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
/* translator: %s is a SQL statement name */
errmsg("%s is not allowed in a non-volatile function",
CreateQueryTag(queryTree))));
/*
* If not read-only mode, advance the command counter before
* each command.
*/
if (!read_only)
CommandCounterIncrement();
dest = CreateDestReceiver(queryTree->canSetTag ? DestSPI : DestNone,
NULL);
if (snapshot == InvalidSnapshot)
{
/*
* Default read_only behavior is to use the entry-time
* ActiveSnapshot; if read-write, grab a full new snap.
*/
if (read_only)
ActiveSnapshot = CopySnapshot(saveActiveSnapshot);
else
ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());
}
else
{
/*
* We interpret read_only with a specified snapshot to be
* exactly that snapshot, but read-write means use the
* snap with advancing of command ID.
*/
ActiveSnapshot = CopySnapshot(snapshot);
if (!read_only)
ActiveSnapshot->curcid = GetCurrentCommandId();
}
if (queryTree->commandType == CMD_UTILITY)
{
ProcessUtility(queryTree->utilityStmt, paramLI,
dest, NULL);
res = SPI_OK_UTILITY;
}
else
{
qdesc = CreateQueryDesc(queryTree, planTree,
ActiveSnapshot,
crosscheck_snapshot,
dest,
paramLI, false);
res = _SPI_pquery(qdesc,
queryTree->canSetTag ? tcount : 0);
FreeQueryDesc(qdesc);
}
FreeSnapshot(ActiveSnapshot);
ActiveSnapshot = NULL;
/*
* The last canSetTag query sets the auxiliary values returned
* to the caller. Be careful to free any tuptables not
* returned, to avoid intratransaction memory leak.
*/
if (queryTree->canSetTag)
{
my_processed = _SPI_current->processed;
my_lastoid = _SPI_current->lastoid;
SPI_freetuptable(my_tuptable);
my_tuptable = _SPI_current->tuptable;
}
else
{
SPI_freetuptable(_SPI_current->tuptable);
_SPI_current->tuptable = NULL;
}
/* we know that the receiver doesn't need a destroy call */
if (res < 0)
goto fail;
}
}
fail:
/*
* Pop the error context stack
*/
error_context_stack = spierrcontext.previous;
}
PG_CATCH();
{
/* Restore global vars and propagate error */
ActiveSnapshot = saveActiveSnapshot;
PG_RE_THROW();
}
PG_END_TRY();
ActiveSnapshot = saveActiveSnapshot;
/* Save results for caller */
SPI_processed = my_processed;
SPI_lastoid = my_lastoid;
SPI_tuptable = my_tuptable;
return res;
}
static int
_SPI_pquery(QueryDesc *queryDesc, long tcount)
{
int operation = queryDesc->operation;
int res;
switch (operation)
{
case CMD_SELECT:
if (queryDesc->parsetree->into) /* select into table? */
res = SPI_OK_SELINTO;
else if (queryDesc->dest->mydest != DestSPI)
{
/* Don't return SPI_OK_SELECT if we're discarding result */
res = SPI_OK_UTILITY;
}
else
res = SPI_OK_SELECT;
break;
case CMD_INSERT:
res = SPI_OK_INSERT;
break;
case CMD_DELETE:
res = SPI_OK_DELETE;
break;
case CMD_UPDATE:
res = SPI_OK_UPDATE;
break;
default:
return SPI_ERROR_OPUNKNOWN;
}
#ifdef SPI_EXECUTOR_STATS
if (ShowExecutorStats)
ResetUsage();
#endif
AfterTriggerBeginQuery();
ExecutorStart(queryDesc, 0);
ExecutorRun(queryDesc, ForwardScanDirection, tcount);
_SPI_current->processed = queryDesc->estate->es_processed;
_SPI_current->lastoid = queryDesc->estate->es_lastoid;
if (operation == CMD_SELECT && queryDesc->dest->mydest == DestSPI)
{
if (_SPI_checktuples())
elog(ERROR, "consistency check on SPI tuple count failed");
}
/* Take care of any queued AFTER triggers */
AfterTriggerEndQuery(queryDesc->estate);
ExecutorEnd(queryDesc);
#ifdef SPI_EXECUTOR_STATS
if (ShowExecutorStats)
ShowUsage("SPI EXECUTOR STATS");
#endif
return res;
}
/*
* _SPI_error_callback
*
* Add context information when a query invoked via SPI fails
*/
static void
_SPI_error_callback(void *arg)
{
const char *query = (const char *) arg;
int syntaxerrposition;
/*
* If there is a syntax error position, convert to internal syntax error;
* otherwise treat the query as an item of context stack
*/
syntaxerrposition = geterrposition();
if (syntaxerrposition > 0)
{
errposition(0);
internalerrposition(syntaxerrposition);
internalerrquery(query);
}
else
errcontext("SQL statement \"%s\"", query);
}
/*
* _SPI_cursor_operation()
*
* Do a FETCH or MOVE in a cursor
*/
static void
_SPI_cursor_operation(Portal portal, bool forward, long count,
DestReceiver *dest)
{
long nfetched;
/* Check that the portal is valid */
if (!PortalIsValid(portal))
elog(ERROR, "invalid portal in SPI cursor operation");
/* Push the SPI stack */
if (_SPI_begin_call(true) < 0)
elog(ERROR, "SPI cursor operation called while not connected");
/* Reset the SPI result (note we deliberately don't touch lastoid) */
SPI_processed = 0;
SPI_tuptable = NULL;
_SPI_current->processed = 0;
_SPI_current->tuptable = NULL;
/* Run the cursor */
nfetched = PortalRunFetch(portal,
forward ? FETCH_FORWARD : FETCH_BACKWARD,
count,
dest);
/*
* Think not to combine this store with the preceding function call. If
* the portal contains calls to functions that use SPI, then SPI_stack is
* likely to move around while the portal runs. When control returns,
* _SPI_current will point to the correct stack entry... but the pointer
* may be different than it was beforehand. So we must be sure to re-fetch
* the pointer after the function call completes.
*/
_SPI_current->processed = nfetched;
if (dest->mydest == DestSPI && _SPI_checktuples())
elog(ERROR, "consistency check on SPI tuple count failed");
/* Put the result into place for access by caller */
SPI_processed = _SPI_current->processed;
SPI_tuptable = _SPI_current->tuptable;
/* Pop the SPI stack */
_SPI_end_call(true);
}
static MemoryContext
_SPI_execmem(void)
{
return MemoryContextSwitchTo(_SPI_current->execCxt);
}
static MemoryContext
_SPI_procmem(void)
{
return MemoryContextSwitchTo(_SPI_current->procCxt);
}
/*
* _SPI_begin_call: begin a SPI operation within a connected procedure
*/
static int
_SPI_begin_call(bool execmem)
{
if (_SPI_curid + 1 != _SPI_connected)
return SPI_ERROR_UNCONNECTED;
_SPI_curid++;
if (_SPI_current != &(_SPI_stack[_SPI_curid]))
elog(ERROR, "SPI stack corrupted");
if (execmem) /* switch to the Executor memory context */
_SPI_execmem();
return 0;
}
/*
* _SPI_end_call: end a SPI operation within a connected procedure
*
* Note: this currently has no failure return cases, so callers don't check
*/
static int
_SPI_end_call(bool procmem)
{
/*
* We're returning to procedure where _SPI_curid == _SPI_connected - 1
*/
_SPI_curid--;
if (procmem) /* switch to the procedure memory context */
{
_SPI_procmem();
/* and free Executor memory */
MemoryContextResetAndDeleteChildren(_SPI_current->execCxt);
}
return 0;
}
static bool
_SPI_checktuples(void)
{
uint32 processed = _SPI_current->processed;
SPITupleTable *tuptable = _SPI_current->tuptable;
bool failed = false;
if (tuptable == NULL) /* spi_dest_startup was not called */
failed = true;
else if (processed != (tuptable->alloced - tuptable->free))
failed = true;
return failed;
}
static _SPI_plan *
_SPI_copy_plan(_SPI_plan *plan, int location)
{
_SPI_plan *newplan;
MemoryContext oldcxt;
MemoryContext plancxt;
MemoryContext parentcxt;
/* Determine correct parent for the plan's memory context */
if (location == _SPI_CPLAN_PROCXT)
parentcxt = _SPI_current->procCxt;
else if (location == _SPI_CPLAN_TOPCXT)
parentcxt = TopMemoryContext;
else
/* (this case not currently used) */
parentcxt = CurrentMemoryContext;
/*
* Create a memory context for the plan. We don't expect the plan to be
* very large, so use smaller-than-default alloc parameters.
*/
plancxt = AllocSetContextCreate(parentcxt,
"SPI Plan",
ALLOCSET_SMALL_MINSIZE,
ALLOCSET_SMALL_INITSIZE,
ALLOCSET_SMALL_MAXSIZE);
oldcxt = MemoryContextSwitchTo(plancxt);
/* Copy the SPI plan into its own context */
newplan = (_SPI_plan *) palloc(sizeof(_SPI_plan));
newplan->plancxt = plancxt;
newplan->query = pstrdup(plan->query);
newplan->qtlist = (List *) copyObject(plan->qtlist);
newplan->ptlist = (List *) copyObject(plan->ptlist);
newplan->nargs = plan->nargs;
if (plan->nargs > 0)
{
newplan->argtypes = (Oid *) palloc(plan->nargs * sizeof(Oid));
memcpy(newplan->argtypes, plan->argtypes, plan->nargs * sizeof(Oid));
}
else
newplan->argtypes = NULL;
MemoryContextSwitchTo(oldcxt);
return newplan;
}
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