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Postgres FD Implementation
Commit 94d626ff authored by Alvaro Herrera's avatar Alvaro Herrera
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Use materialize SRF mode in brin_page_items 

This function was using the single-value-per-call mechanism, but the
code relied on a relcache entry that wasn't kept open across calls.
This manifested as weird errors in buildfarm during the short time that
the "brin-1" isolation test lived.

Backpatch to 9.5, where it was introduced.
parent 36e863bb
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Showing with 101 additions and 122 deletions
contrib/pageinspect/brinfuncs.c
View file @ 94d626ff
......@@ -37,18 +37,6 @@ typedef struct brin_column_state
FmgrInfo outputFn[FLEXIBLE_ARRAY_MEMBER];
} brin_column_state;
typedef struct brin_page_state
{
BrinDesc *bdesc;
Page page;
OffsetNumber offset;
bool unusedItem;
bool done;
AttrNumber attno;
BrinMemTuple *dtup;
brin_column_state *columns[FLEXIBLE_ARRAY_MEMBER];
} brin_page_state;
static Page verify_brin_page(bytea *raw_page, uint16 type,
const char *strtype);
......@@ -119,54 +107,63 @@ verify_brin_page(bytea *raw_page, uint16 type, const char *strtype)
Datum
brin_page_items(PG_FUNCTION_ARGS)
{
brin_page_state *state;
FuncCallContext *fctx;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use raw page functions"))));
if (SRF_IS_FIRSTCALL())
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
Oid indexRelid = PG_GETARG_OID(1);
Page page;
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
TupleDesc tupdesc;
MemoryContext mctx;
MemoryContext oldcontext;
Tuplestorestate *tupstore;
Relation indexRel;
brin_column_state **columns;
BrinDesc *bdesc;
BrinMemTuple *dtup;
Page page;
OffsetNumber offset;
AttrNumber attno;
bool unusedItem;
/* minimally verify the page we got */
page = verify_brin_page(raw_page, BRIN_PAGETYPE_REGULAR, "regular");
/* create a function context for cross-call persistence */
fctx = SRF_FIRSTCALL_INIT();
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use raw page functions"))));
/* switch to memory context appropriate for multiple function calls */
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
/* 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) ||
rsinfo->expectedDesc == NULL)
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");
indexRel = index_open(indexRelid, AccessShareLock);
/* 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;
state = palloc(offsetof(brin_page_state, columns) +
sizeof(brin_column_state) * RelationGetDescr(indexRel)->natts);
MemoryContextSwitchTo(oldcontext);
state->bdesc = brin_build_desc(indexRel);
state->page = page;
state->offset = FirstOffsetNumber;
state->unusedItem = false;
state->done = false;
state->dtup = NULL;
indexRel = index_open(indexRelid, AccessShareLock);
bdesc = brin_build_desc(indexRel);
/* minimally verify the page we got */
page = verify_brin_page(raw_page, BRIN_PAGETYPE_REGULAR, "regular");
/*
* Initialize output functions for all indexed datatypes; simplifies
* calling them later.
*/
for (attno = 1; attno <= state->bdesc->bd_tupdesc->natts; attno++)
columns = palloc(sizeof(brin_column_state *) * RelationGetDescr(indexRel)->natts);
for (attno = 1; attno <= bdesc->bd_tupdesc->natts; attno++)
{
Oid output;
bool isVarlena;
......@@ -174,7 +171,7 @@ brin_page_items(PG_FUNCTION_ARGS)
int i;
brin_column_state *column;
opcinfo = state->bdesc->bd_info[attno - 1];
opcinfo = bdesc->bd_info[attno - 1];
column = palloc(offsetof(brin_column_state, outputFn) +
sizeof(FmgrInfo) * opcinfo->oi_nstored);
......@@ -185,23 +182,14 @@ brin_page_items(PG_FUNCTION_ARGS)
fmgr_info(output, &column->outputFn[i]);
}
state->columns[attno - 1] = column;
columns[attno - 1] = column;
}
index_close(indexRel, AccessShareLock);
fctx->user_fctx = state;
fctx->tuple_desc = BlessTupleDesc(tupdesc);
MemoryContextSwitchTo(mctx);
}
fctx = SRF_PERCALL_SETUP();
state = fctx->user_fctx;
if (!state->done)
offset = FirstOffsetNumber;
unusedItem = false;
dtup = NULL;
for (;;)
{
HeapTuple result;
Datum values[7];
bool nulls[7];
......@@ -211,39 +199,30 @@ brin_page_items(PG_FUNCTION_ARGS)
* signal for obtaining and decoding the next one. If that's not the
* case, we output the next attribute.
*/
if (state->dtup == NULL)
if (dtup == NULL)
{
BrinTuple *tup;
MemoryContext mctx;
ItemId itemId;
/* deformed tuple must live across calls */
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
/* verify item status: if there's no data, we can't decode */
itemId = PageGetItemId(state->page, state->offset);
itemId = PageGetItemId(page, offset);
if (ItemIdIsUsed(itemId))
{
tup = (BrinTuple *) PageGetItem(state->page,
PageGetItemId(state->page,
state->offset));
state->dtup = brin_deform_tuple(state->bdesc, tup);
state->attno = 1;
state->unusedItem = false;
dtup = brin_deform_tuple(bdesc,
(BrinTuple *) PageGetItem(page, itemId));
attno = 1;
unusedItem = false;
}
else
state->unusedItem = true;
MemoryContextSwitchTo(mctx);
unusedItem = true;
}
else
state->attno++;
attno++;
MemSet(nulls, 0, sizeof(nulls));
if (state->unusedItem)
if (unusedItem)
{
values[0] = UInt16GetDatum(state->offset);
values[0] = UInt16GetDatum(offset);
nulls[1] = true;
nulls[2] = true;
nulls[3] = true;
......@@ -253,17 +232,17 @@ brin_page_items(PG_FUNCTION_ARGS)
}
else
{
int att = state->attno - 1;
values[0] = UInt16GetDatum(state->offset);
values[1] = UInt32GetDatum(state->dtup->bt_blkno);
values[2] = UInt16GetDatum(state->attno);
values[3] = BoolGetDatum(state->dtup->bt_columns[att].bv_allnulls);
values[4] = BoolGetDatum(state->dtup->bt_columns[att].bv_hasnulls);
values[5] = BoolGetDatum(state->dtup->bt_placeholder);
if (!state->dtup->bt_columns[att].bv_allnulls)
int att = attno - 1;
values[0] = UInt16GetDatum(offset);
values[1] = UInt32GetDatum(dtup->bt_blkno);
values[2] = UInt16GetDatum(attno);
values[3] = BoolGetDatum(dtup->bt_columns[att].bv_allnulls);
values[4] = BoolGetDatum(dtup->bt_columns[att].bv_hasnulls);
values[5] = BoolGetDatum(dtup->bt_placeholder);
if (!dtup->bt_columns[att].bv_allnulls)
{
BrinValues *bvalues = &state->dtup->bt_columns[att];
BrinValues *bvalues = &dtup->bt_columns[att];
StringInfoData s;
bool first;
int i;
......@@ -272,14 +251,14 @@ brin_page_items(PG_FUNCTION_ARGS)
appendStringInfoChar(&s, '{');
first = true;
for (i = 0; i < state->columns[att]->nstored; i++)
for (i = 0; i < columns[att]->nstored; i++)
{
char *val;
if (!first)
appendStringInfoString(&s, " .. ");
first = false;
val = OutputFunctionCall(&state->columns[att]->outputFn[i],
val = OutputFunctionCall(&columns[att]->outputFn[i],
bvalues->bv_values[i]);
appendStringInfoString(&s, val);
pfree(val);
......@@ -295,35 +274,35 @@ brin_page_items(PG_FUNCTION_ARGS)
}
}
result = heap_form_tuple(fctx->tuple_desc, values, nulls);
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
/*
* If the item was unused, jump straight to the next one; otherwise,
* the only cleanup needed here is to set our signal to go to the next
* tuple in the following iteration, by freeing the current one.
*/
if (state->unusedItem)
state->offset = OffsetNumberNext(state->offset);
else if (state->attno >= state->bdesc->bd_tupdesc->natts)
if (unusedItem)
offset = OffsetNumberNext(offset);
else if (attno >= bdesc->bd_tupdesc->natts)
{
pfree(state->dtup);
state->dtup = NULL;
state->offset = OffsetNumberNext(state->offset);
pfree(dtup);
dtup = NULL;
offset = OffsetNumberNext(offset);
}
/*
* If we're beyond the end of the page, set flag to end the function
* in the following iteration.
* If we're beyond the end of the page, we're done.
*/
if (state->offset > PageGetMaxOffsetNumber(state->page))
state->done = true;
SRF_RETURN_NEXT(fctx, HeapTupleGetDatum(result));
if (offset > PageGetMaxOffsetNumber(page))
break;
}
brin_free_desc(state->bdesc);
/* clean up and return the tuplestore */
brin_free_desc(bdesc);
tuplestore_donestoring(tupstore);
index_close(indexRel, AccessShareLock);
SRF_RETURN_DONE(fctx);
return (Datum) 0;
}
Datum
......
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