postgresql/contrib/pageinspect/ginfuncs.c
Tom Lane 41b45576d5 Remove useless pfree()s at the ends of various ValuePerCall SRFs.
We don't need to manually clean up allocations in a SRF's
multi_call_memory_ctx, because the SRF_RETURN_DONE infrastructure
takes care of that (and also ensures that it will happen even if the
function never gets a final call, which simple manual cleanup cannot
do).

Hence, the code removed by this patch is a waste of code and cycles.
Worse, it gives the impression that cleaning up manually is a thing,
which can lead to more serious errors such as those fixed in
commits 085b6b667 and b4570d33a.  So we should get rid of it.

These are not quite actual bugs though, so I couldn't muster the
enthusiasm to back-patch.  Fix in HEAD only.

Justin Pryzby

Discussion: https://postgr.es/m/20200308173103.GC1357@telsasoft.com
2020-03-16 21:36:53 -04:00

266 lines
7.4 KiB
C

/*
* ginfuncs.c
* Functions to investigate the content of GIN indexes
*
* Copyright (c) 2014-2020, PostgreSQL Global Development Group
*
* IDENTIFICATION
* contrib/pageinspect/ginfuncs.c
*/
#include "postgres.h"
#include "access/gin.h"
#include "access/gin_private.h"
#include "access/htup_details.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "pageinspect.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/rel.h"
#define DatumGetItemPointer(X) ((ItemPointer) DatumGetPointer(X))
#define ItemPointerGetDatum(X) PointerGetDatum(X)
PG_FUNCTION_INFO_V1(gin_metapage_info);
PG_FUNCTION_INFO_V1(gin_page_opaque_info);
PG_FUNCTION_INFO_V1(gin_leafpage_items);
Datum
gin_metapage_info(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
TupleDesc tupdesc;
Page page;
GinPageOpaque opaq;
GinMetaPageData *metadata;
HeapTuple resultTuple;
Datum values[10];
bool nulls[10];
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
page = get_page_from_raw(raw_page);
opaq = (GinPageOpaque) PageGetSpecialPointer(page);
if (opaq->flags != GIN_META)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page is not a GIN metapage"),
errdetail("Flags %04X, expected %04X",
opaq->flags, GIN_META)));
/* 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");
metadata = GinPageGetMeta(page);
memset(nulls, 0, sizeof(nulls));
values[0] = Int64GetDatum(metadata->head);
values[1] = Int64GetDatum(metadata->tail);
values[2] = Int32GetDatum(metadata->tailFreeSize);
values[3] = Int64GetDatum(metadata->nPendingPages);
values[4] = Int64GetDatum(metadata->nPendingHeapTuples);
/* statistics, updated by VACUUM */
values[5] = Int64GetDatum(metadata->nTotalPages);
values[6] = Int64GetDatum(metadata->nEntryPages);
values[7] = Int64GetDatum(metadata->nDataPages);
values[8] = Int64GetDatum(metadata->nEntries);
values[9] = Int32GetDatum(metadata->ginVersion);
/* Build and return the result tuple. */
resultTuple = heap_form_tuple(tupdesc, values, nulls);
return HeapTupleGetDatum(resultTuple);
}
Datum
gin_page_opaque_info(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
TupleDesc tupdesc;
Page page;
GinPageOpaque opaq;
HeapTuple resultTuple;
Datum values[3];
bool nulls[3];
Datum flags[16];
int nflags = 0;
uint16 flagbits;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
page = get_page_from_raw(raw_page);
opaq = (GinPageOpaque) PageGetSpecialPointer(page);
/* 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");
/* Convert the flags bitmask to an array of human-readable names */
flagbits = opaq->flags;
if (flagbits & GIN_DATA)
flags[nflags++] = CStringGetTextDatum("data");
if (flagbits & GIN_LEAF)
flags[nflags++] = CStringGetTextDatum("leaf");
if (flagbits & GIN_DELETED)
flags[nflags++] = CStringGetTextDatum("deleted");
if (flagbits & GIN_META)
flags[nflags++] = CStringGetTextDatum("meta");
if (flagbits & GIN_LIST)
flags[nflags++] = CStringGetTextDatum("list");
if (flagbits & GIN_LIST_FULLROW)
flags[nflags++] = CStringGetTextDatum("list_fullrow");
if (flagbits & GIN_INCOMPLETE_SPLIT)
flags[nflags++] = CStringGetTextDatum("incomplete_split");
if (flagbits & GIN_COMPRESSED)
flags[nflags++] = CStringGetTextDatum("compressed");
flagbits &= ~(GIN_DATA | GIN_LEAF | GIN_DELETED | GIN_META | GIN_LIST |
GIN_LIST_FULLROW | GIN_INCOMPLETE_SPLIT | GIN_COMPRESSED);
if (flagbits)
{
/* any flags we don't recognize are printed in hex */
flags[nflags++] = DirectFunctionCall1(to_hex32, Int32GetDatum(flagbits));
}
memset(nulls, 0, sizeof(nulls));
values[0] = Int64GetDatum(opaq->rightlink);
values[1] = Int32GetDatum(opaq->maxoff);
values[2] = PointerGetDatum(construct_array(flags, nflags,
TEXTOID,
-1, false, TYPALIGN_INT));
/* Build and return the result tuple. */
resultTuple = heap_form_tuple(tupdesc, values, nulls);
return HeapTupleGetDatum(resultTuple);
}
typedef struct gin_leafpage_items_state
{
TupleDesc tupd;
GinPostingList *seg;
GinPostingList *lastseg;
} gin_leafpage_items_state;
Datum
gin_leafpage_items(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
FuncCallContext *fctx;
gin_leafpage_items_state *inter_call_data;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
if (SRF_IS_FIRSTCALL())
{
TupleDesc tupdesc;
MemoryContext mctx;
Page page;
GinPageOpaque opaq;
fctx = SRF_FIRSTCALL_INIT();
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
page = get_page_from_raw(raw_page);
if (PageGetSpecialSize(page) != MAXALIGN(sizeof(GinPageOpaqueData)))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page is not a valid GIN data leaf page"),
errdetail("Special size %d, expected %d",
(int) PageGetSpecialSize(page),
(int) MAXALIGN(sizeof(GinPageOpaqueData)))));
opaq = (GinPageOpaque) PageGetSpecialPointer(page);
if (opaq->flags != (GIN_DATA | GIN_LEAF | GIN_COMPRESSED))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page is not a compressed GIN data leaf page"),
errdetail("Flags %04X, expected %04X",
opaq->flags,
(GIN_DATA | GIN_LEAF | GIN_COMPRESSED))));
inter_call_data = palloc(sizeof(gin_leafpage_items_state));
/* 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");
inter_call_data->tupd = tupdesc;
inter_call_data->seg = GinDataLeafPageGetPostingList(page);
inter_call_data->lastseg = (GinPostingList *)
(((char *) inter_call_data->seg) +
GinDataLeafPageGetPostingListSize(page));
fctx->user_fctx = inter_call_data;
MemoryContextSwitchTo(mctx);
}
fctx = SRF_PERCALL_SETUP();
inter_call_data = fctx->user_fctx;
if (inter_call_data->seg != inter_call_data->lastseg)
{
GinPostingList *cur = inter_call_data->seg;
HeapTuple resultTuple;
Datum result;
Datum values[3];
bool nulls[3];
int ndecoded,
i;
ItemPointer tids;
Datum *tids_datum;
memset(nulls, 0, sizeof(nulls));
values[0] = ItemPointerGetDatum(&cur->first);
values[1] = UInt16GetDatum(cur->nbytes);
/* build an array of decoded item pointers */
tids = ginPostingListDecode(cur, &ndecoded);
tids_datum = (Datum *) palloc(ndecoded * sizeof(Datum));
for (i = 0; i < ndecoded; i++)
tids_datum[i] = ItemPointerGetDatum(&tids[i]);
values[2] = PointerGetDatum(construct_array(tids_datum,
ndecoded,
TIDOID,
sizeof(ItemPointerData),
false, TYPALIGN_SHORT));
pfree(tids_datum);
pfree(tids);
/* Build and return the result tuple. */
resultTuple = heap_form_tuple(inter_call_data->tupd, values, nulls);
result = HeapTupleGetDatum(resultTuple);
inter_call_data->seg = GinNextPostingListSegment(cur);
SRF_RETURN_NEXT(fctx, result);
}
SRF_RETURN_DONE(fctx);
}