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Simplify SRFs using materialize mode in contrib/ modules

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9e98583 introduced a helper to centralize building their needed state
(tuplestore, tuple descriptors, etc.), checking for any errors.  This
commit updates all places of contrib/ that can be switched to use
SetSingleFuncCall() as a drop-in replacement, resulting in the removal
of a lot of boilerplate code in all the modules updated by this commit.

Per analysis, some places remain as they are:
- pg_logdir_ls() in adminpack/ uses historically TYPEFUNC_RECORD as
return type, and I suspect that changing it may cause issues at run-time
with some of its past versions, down to 1.0.
- dblink/ uses a wrapper function doing exactly the work of
SetSingleFuncCall().  Here the switch should be possible, but rather
invasive so it does not seem the extra backpatch maintenance cost.
- tablefunc/, similarly, uses multiple helper functions with portions of
SetSingleFuncCall() spread across the code paths of this module.

Author: Melanie Plageman
Discussion: https://postgr.es/m/CAAKRu_bvDPJoL9mH6eYwvBpPtTGQwbDzfJbCM-OjkSZDu5yTPg@mail.gmail.com
pull/81/head
Michael Paquier 3 years ago
parent d5ed9da41d
commit 5b81703787
8 changed files with 32 additions and 301 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 46
      contrib/amcheck/verify_heapam.c
  2. 26
      contrib/dblink/dblink.c
  3. 31
      contrib/pageinspect/brinfuncs.c
  4. 60
      contrib/pageinspect/gistfuncs.c
  5. 33
      contrib/pg_stat_statements/pg_stat_statements.c
  6. 34
      contrib/pgrowlocks/pgrowlocks.c
  7. 31
      contrib/postgres_fdw/connection.c
  8. 72
      contrib/xml2/xpath.c

46
contrib/amcheck/verify_heapam.c
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@ -165,7 +165,6 @@ static bool check_tuple_visibility(HeapCheckContext *ctx);
static void report_corruption(HeapCheckContext *ctx, char *msg);
static void report_toast_corruption(HeapCheckContext *ctx,
ToastedAttribute *ta, char *msg);
static TupleDesc verify_heapam_tupdesc(void);
static FullTransactionId FullTransactionIdFromXidAndCtx(TransactionId xid,
const HeapCheckContext *ctx);
static void update_cached_xid_range(HeapCheckContext *ctx);
@ -214,8 +213,6 @@ Datum
verify_heapam(PG_FUNCTION_ARGS)
{
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
MemoryContext old_context;
bool random_access;
HeapCheckContext ctx;
Buffer vmbuffer = InvalidBuffer;
Oid relid;
@ -227,16 +224,6 @@ verify_heapam(PG_FUNCTION_ARGS)
BlockNumber nblocks;
const char *skip;
/* Check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("materialize mode required, but it is not allowed in this context")));
/* Check supplied arguments */
if (PG_ARGISNULL(0))
ereport(ERROR,
@ -290,15 +277,10 @@ verify_heapam(PG_FUNCTION_ARGS)
*/
ctx.attnum = -1;
/* The tupdesc and tuplestore must be created in ecxt_per_query_memory */
old_context = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
random_access = (rsinfo->allowedModes & SFRM_Materialize_Random) != 0;
ctx.tupdesc = verify_heapam_tupdesc();
ctx.tupstore = tuplestore_begin_heap(random_access, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = ctx.tupstore;
rsinfo->setDesc = ctx.tupdesc;
MemoryContextSwitchTo(old_context);
/* Construct the tuplestore and tuple descriptor */
SetSingleFuncCall(fcinfo, 0);
ctx.tupdesc = rsinfo->setDesc;
ctx.tupstore = rsinfo->setResult;
/* Open relation, check relkind and access method */
ctx.rel = relation_open(relid, AccessShareLock);
@ -630,26 +612,6 @@ report_toast_corruption(HeapCheckContext *ctx, ToastedAttribute *ta,
ctx->is_corrupt = true;
}
/*
* Construct the TupleDesc used to report messages about corruptions found
* while scanning the heap.
*/
static TupleDesc
verify_heapam_tupdesc(void)
{
TupleDesc tupdesc;
AttrNumber a = 0;
tupdesc = CreateTemplateTupleDesc(HEAPCHECK_RELATION_COLS);
TupleDescInitEntry(tupdesc, ++a, "blkno", INT8OID, -1, 0);
TupleDescInitEntry(tupdesc, ++a, "offnum", INT4OID, -1, 0);
TupleDescInitEntry(tupdesc, ++a, "attnum", INT4OID, -1, 0);
TupleDescInitEntry(tupdesc, ++a, "msg", TEXTOID, -1, 0);
Assert(a == HEAPCHECK_RELATION_COLS);
return BlessTupleDesc(tupdesc);
}
/*
* Check for tuple header corruption.
*

26
contrib/dblink/dblink.c
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@ -1928,12 +1928,6 @@ dblink_get_notify(PG_FUNCTION_ARGS)
PGconn *conn;
PGnotify *notify;
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
MemoryContext per_query_ctx;
MemoryContext oldcontext;
prepTuplestoreResult(fcinfo);
dblink_init();
if (PG_NARGS() == 1)
@ -1941,23 +1935,7 @@ dblink_get_notify(PG_FUNCTION_ARGS)
else
conn = pconn->conn;
/* create the tuplestore in per-query memory */
per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
oldcontext = MemoryContextSwitchTo(per_query_ctx);
tupdesc = CreateTemplateTupleDesc(DBLINK_NOTIFY_COLS);
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "notify_name",
TEXTOID, -1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "be_pid",
INT4OID, -1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 3, "extra",
TEXTOID, -1, 0);
tupstore = tuplestore_begin_heap(true, false, work_mem);
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
SetSingleFuncCall(fcinfo, 0);
PQconsumeInput(conn);
while ((notify = PQnotifies(conn)) != NULL)
@ -1980,7 +1958,7 @@ dblink_get_notify(PG_FUNCTION_ARGS)
else
nulls[2] = true;
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
PQfreemem(notify);
PQconsumeInput(conn);

31
contrib/pageinspect/brinfuncs.c
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@ -126,9 +126,6 @@ brin_page_items(PG_FUNCTION_ARGS)
bytea *raw_page = PG_GETARG_BYTEA_P(0);
Oid indexRelid = PG_GETARG_OID(1);
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
TupleDesc tupdesc;
MemoryContext oldcontext;
Tuplestorestate *tupstore;
Relation indexRel;
brin_column_state **columns;
BrinDesc *bdesc;
@ -143,29 +140,7 @@ brin_page_items(PG_FUNCTION_ARGS)
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
/* check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("materialize mode required, but it is not allowed in this context")));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
/* Build tuplestore to hold the result rows */
oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
tupstore = tuplestore_begin_heap(true, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
SetSingleFuncCall(fcinfo, 0);
indexRel = index_open(indexRelid, AccessShareLock);
bdesc = brin_build_desc(indexRel);
@ -251,7 +226,7 @@ brin_page_items(PG_FUNCTION_ARGS)
int att = attno - 1;
values[0] = UInt16GetDatum(offset);
switch (TupleDescAttr(tupdesc, 1)->atttypid)
switch (TupleDescAttr(rsinfo->setDesc, 1)->atttypid)
{
case INT8OID:
values[1] = Int64GetDatum((int64) dtup->bt_blkno);
@ -301,7 +276,7 @@ brin_page_items(PG_FUNCTION_ARGS)
}
}
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
/*
* If the item was unused, jump straight to the next one; otherwise,

60
contrib/pageinspect/gistfuncs.c
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@ -97,10 +97,6 @@ gist_page_items_bytea(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
bool randomAccess;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
MemoryContext oldcontext;
Page page;
OffsetNumber offset;
OffsetNumber maxoff = InvalidOffsetNumber;
@ -110,29 +106,7 @@ gist_page_items_bytea(PG_FUNCTION_ARGS)
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
/* check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("materialize mode required, but it is not allowed in this context")));
/* The tupdesc and tuplestore must be created in ecxt_per_query_memory */
oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
randomAccess = (rsinfo->allowedModes & SFRM_Materialize_Random) != 0;
tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
SetSingleFuncCall(fcinfo, 0);
page = get_page_from_raw(raw_page);
@ -173,7 +147,7 @@ gist_page_items_bytea(PG_FUNCTION_ARGS)
values[3] = BoolGetDatum(ItemIdIsDead(id));
values[4] = PointerGetDatum(tuple_bytea);
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
}
return (Datum) 0;
@ -185,11 +159,7 @@ gist_page_items(PG_FUNCTION_ARGS)
bytea *raw_page = PG_GETARG_BYTEA_P(0);
Oid indexRelid = PG_GETARG_OID(1);
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
bool randomAccess;
Relation indexRel;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
MemoryContext oldcontext;
Page page;
OffsetNumber offset;
OffsetNumber maxoff = InvalidOffsetNumber;
@ -199,29 +169,7 @@ gist_page_items(PG_FUNCTION_ARGS)
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
/* check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("materialize mode required, but it is not allowed in this context")));
/* The tupdesc and tuplestore must be created in ecxt_per_query_memory */
oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
randomAccess = (rsinfo->allowedModes & SFRM_Materialize_Random) != 0;
tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
SetSingleFuncCall(fcinfo, 0);
/* Open the relation */
indexRel = index_open(indexRelid, AccessShareLock);
@ -272,7 +220,7 @@ gist_page_items(PG_FUNCTION_ARGS)
nulls[4] = true;
}
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
}
relation_close(indexRel, AccessShareLock);

33
contrib/pg_stat_statements/pg_stat_statements.c
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@ -1494,10 +1494,6 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
bool showtext)
{
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
MemoryContext per_query_ctx;
MemoryContext oldcontext;
Oid userid = GetUserId();
bool is_allowed_role = false;
char *qbuffer = NULL;
@ -1516,30 +1512,14 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
/* check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("materialize mode required, but it is not allowed in this context")));
/* Switch into long-lived context to construct returned data structures */
per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
oldcontext = MemoryContextSwitchTo(per_query_ctx);
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
SetSingleFuncCall(fcinfo, 0);
/*
* Check we have the expected number of output arguments. Aside from
* being a good safety check, we need a kluge here to detect API version
* 1.1, which was wedged into the code in an ill-considered way.
*/
switch (tupdesc->natts)
switch (rsinfo->setDesc->natts)
{
case PG_STAT_STATEMENTS_COLS_V1_0:
if (api_version != PGSS_V1_0)
@ -1571,13 +1551,6 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
elog(ERROR, "incorrect number of output arguments");
}
tupstore = tuplestore_begin_heap(true, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
/*
* We'd like to load the query text file (if needed) while not holding any
* lock on pgss->lock. In the worst case we'll have to do this again
@ -1800,7 +1773,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
api_version == PGSS_V1_9 ? PG_STAT_STATEMENTS_COLS_V1_9 :
-1 /* fail if you forget to update this assert */ ));
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
}
LWLockRelease(pgss->lock);

34
contrib/pgrowlocks/pgrowlocks.c
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@ -66,42 +66,16 @@ pgrowlocks(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_PP(0);
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
bool randomAccess;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
AttInMetadata *attinmeta;
Relation rel;
RangeVar *relrv;
TableScanDesc scan;
HeapScanDesc hscan;
HeapTuple tuple;
MemoryContext oldcontext;
AclResult aclresult;
char **values;
/* check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("materialize mode required, but it is not allowed in this context")));
/* The tupdesc and tuplestore must be created in ecxt_per_query_memory */
oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
randomAccess = (rsinfo->allowedModes & SFRM_Materialize_Random) != 0;
tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
SetSingleFuncCall(fcinfo, 0);
/* Access the table */
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
@ -140,9 +114,9 @@ pgrowlocks(PG_FUNCTION_ARGS)
scan = table_beginscan(rel, GetActiveSnapshot(), 0, NULL);
hscan = (HeapScanDesc) scan;
attinmeta = TupleDescGetAttInMetadata(tupdesc);
attinmeta = TupleDescGetAttInMetadata(rsinfo->setDesc);
values = (char **) palloc(tupdesc->natts * sizeof(char *));
values = (char **) palloc(rsinfo->setDesc->natts * sizeof(char *));
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
@ -288,7 +262,7 @@ pgrowlocks(PG_FUNCTION_ARGS)
/* build a tuple */
tuple = BuildTupleFromCStrings(attinmeta, values);
tuplestore_puttuple(tupstore, tuple);
tuplestore_puttuple(rsinfo->setResult, tuple);
}
else
{

31
contrib/postgres_fdw/connection.c
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@ -1661,37 +1661,10 @@ postgres_fdw_get_connections(PG_FUNCTION_ARGS)
{
#define POSTGRES_FDW_GET_CONNECTIONS_COLS 2
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
MemoryContext per_query_ctx;
MemoryContext oldcontext;
HASH_SEQ_STATUS scan;
ConnCacheEntry *entry;
/* check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("materialize mode required, but it is not allowed in this context")));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
/* Build tuplestore to hold the result rows */
per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
oldcontext = MemoryContextSwitchTo(per_query_ctx);
tupstore = tuplestore_begin_heap(true, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
SetSingleFuncCall(fcinfo, 0);
/* If cache doesn't exist, we return no records */
if (!ConnectionHash)
@ -1757,7 +1730,7 @@ postgres_fdw_get_connections(PG_FUNCTION_ARGS)
values[1] = BoolGetDatum(!entry->invalidated);
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
}

72
contrib/xml2/xpath.c
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@ -491,15 +491,9 @@ xpath_table(PG_FUNCTION_ARGS)
HeapTuple spi_tuple;
TupleDesc spi_tupdesc;
/* Output tuple (tuplestore) support */
Tuplestorestate *tupstore = NULL;
TupleDesc ret_tupdesc;
HeapTuple ret_tuple;
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
AttInMetadata *attinmeta;
MemoryContext per_query_ctx;
MemoryContext oldcontext;
char **values;
xmlChar **xpaths;
@ -517,48 +511,10 @@ xpath_table(PG_FUNCTION_ARGS)
PgXmlErrorContext *xmlerrcxt;
volatile xmlDocPtr doctree = NULL;
/* We only have a valid tuple description in table function mode */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (rsinfo->expectedDesc == NULL)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("xpath_table must be called as a table function")));
/*
* We want to materialise because it means that we don't have to carry
* libxml2 parser state between invocations of this function
*/
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("xpath_table requires Materialize mode, but it is not "
"allowed in this context")));
/*
* The tuplestore must exist in a higher context than this function call
* (per_query_ctx is used)
*/
per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
oldcontext = MemoryContextSwitchTo(per_query_ctx);
/*
* Create the tuplestore - work_mem is the max in-memory size before a
* file is created on disk to hold it.
*/
tupstore =
tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random,
false, work_mem);
MemoryContextSwitchTo(oldcontext);
/* get the requested return tuple description */
ret_tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
SetSingleFuncCall(fcinfo, SRF_SINGLE_USE_EXPECTED);
/* must have at least one output column (for the pkey) */
if (ret_tupdesc->natts < 1)
if (rsinfo->setDesc->natts < 1)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("xpath_table must have at least one output column")));
@ -571,14 +527,10 @@ xpath_table(PG_FUNCTION_ARGS)
* representation.
*/
attinmeta = TupleDescGetAttInMetadata(ret_tupdesc);
/* Set return mode and allocate value space. */
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setDesc = ret_tupdesc;
attinmeta = TupleDescGetAttInMetadata(rsinfo->setDesc);
values = (char **) palloc(ret_tupdesc->natts * sizeof(char *));
xpaths = (xmlChar **) palloc(ret_tupdesc->natts * sizeof(xmlChar *));
values = (char **) palloc(rsinfo->setDesc->natts * sizeof(char *));
xpaths = (xmlChar **) palloc(rsinfo->setDesc->natts * sizeof(xmlChar *));
/*
* Split XPaths. xpathset is a writable CString.
@ -587,7 +539,7 @@ xpath_table(PG_FUNCTION_ARGS)
*/
numpaths = 0;
pos = xpathset;
while (numpaths < (ret_tupdesc->natts - 1))
while (numpaths < (rsinfo->setDesc->natts - 1))
{
xpaths[numpaths++] = (xmlChar *) pos;
pos = strstr(pos, pathsep);
@ -621,9 +573,6 @@ xpath_table(PG_FUNCTION_ARGS)
tuptable = SPI_tuptable;
spi_tupdesc = tuptable->tupdesc;
/* Switch out of SPI context */
MemoryContextSwitchTo(oldcontext);
/*
* Check that SPI returned correct result. If you put a comma into one of
* the function parameters, this will catch it when the SPI query returns
@ -655,6 +604,7 @@ xpath_table(PG_FUNCTION_ARGS)
xmlXPathObjectPtr res;
xmlChar *resstr;
xmlXPathCompExprPtr comppath;
HeapTuple ret_tuple;
/* Extract the row data as C Strings */
spi_tuple = tuptable->vals[i];
@ -666,7 +616,7 @@ xpath_table(PG_FUNCTION_ARGS)
* return NULL in all columns. Note that this also means that
* spare columns will be NULL.
*/
for (j = 0; j < ret_tupdesc->natts; j++)
for (j = 0; j < rsinfo->setDesc->natts; j++)
values[j] = NULL;
/* Insert primary key */
@ -682,7 +632,7 @@ xpath_table(PG_FUNCTION_ARGS)
{
/* not well-formed, so output all-NULL tuple */
ret_tuple = BuildTupleFromCStrings(attinmeta, values);
tuplestore_puttuple(tupstore, ret_tuple);
tuplestore_puttuple(rsinfo->setResult, ret_tuple);
heap_freetuple(ret_tuple);
}
else
@ -749,7 +699,7 @@ xpath_table(PG_FUNCTION_ARGS)
if (had_values)
{
ret_tuple = BuildTupleFromCStrings(attinmeta, values);
tuplestore_puttuple(tupstore, ret_tuple);
tuplestore_puttuple(rsinfo->setResult, ret_tuple);
heap_freetuple(ret_tuple);
}
@ -785,8 +735,6 @@ xpath_table(PG_FUNCTION_ARGS)
SPI_finish();
rsinfo->setResult = tupstore;
/*
* SFRM_Materialize mode expects us to return a NULL Datum. The actual
* tuples are in our tuplestore and passed back through rsinfo->setResult.

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