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-rw-r--r--contrib/pageinspect/brinfuncs.c422
1 files changed, 422 insertions, 0 deletions
diff --git a/contrib/pageinspect/brinfuncs.c b/contrib/pageinspect/brinfuncs.c
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+/*
+ * brinfuncs.c
+ * Functions to investigate BRIN indexes
+ *
+ * Copyright (c) 2014-2023, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * contrib/pageinspect/brinfuncs.c
+ */
+#include "postgres.h"
+
+#include "access/brin.h"
+#include "access/brin_internal.h"
+#include "access/brin_page.h"
+#include "access/brin_revmap.h"
+#include "access/brin_tuple.h"
+#include "access/htup_details.h"
+#include "catalog/index.h"
+#include "catalog/pg_am_d.h"
+#include "catalog/pg_type.h"
+#include "funcapi.h"
+#include "lib/stringinfo.h"
+#include "miscadmin.h"
+#include "pageinspect.h"
+#include "utils/array.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/rel.h"
+
+PG_FUNCTION_INFO_V1(brin_page_type);
+PG_FUNCTION_INFO_V1(brin_page_items);
+PG_FUNCTION_INFO_V1(brin_metapage_info);
+PG_FUNCTION_INFO_V1(brin_revmap_data);
+
+#define IS_BRIN(r) ((r)->rd_rel->relam == BRIN_AM_OID)
+
+typedef struct brin_column_state
+{
+ int nstored;
+ FmgrInfo outputFn[FLEXIBLE_ARRAY_MEMBER];
+} brin_column_state;
+
+
+static Page verify_brin_page(bytea *raw_page, uint16 type,
+ const char *strtype);
+
+Datum
+brin_page_type(PG_FUNCTION_ARGS)
+{
+ bytea *raw_page = PG_GETARG_BYTEA_P(0);
+ Page page;
+ char *type;
+
+ if (!superuser())
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("must be superuser to use raw page functions")));
+
+ page = get_page_from_raw(raw_page);
+
+ if (PageIsNew(page))
+ PG_RETURN_NULL();
+
+ /* verify the special space has the expected size */
+ if (PageGetSpecialSize(page) != MAXALIGN(sizeof(BrinSpecialSpace)))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("input page is not a valid %s page", "BRIN"),
+ errdetail("Expected special size %d, got %d.",
+ (int) MAXALIGN(sizeof(BrinSpecialSpace)),
+ (int) PageGetSpecialSize(page))));
+
+ switch (BrinPageType(page))
+ {
+ case BRIN_PAGETYPE_META:
+ type = "meta";
+ break;
+ case BRIN_PAGETYPE_REVMAP:
+ type = "revmap";
+ break;
+ case BRIN_PAGETYPE_REGULAR:
+ type = "regular";
+ break;
+ default:
+ type = psprintf("unknown (%02x)", BrinPageType(page));
+ break;
+ }
+
+ PG_RETURN_TEXT_P(cstring_to_text(type));
+}
+
+/*
+ * Verify that the given bytea contains a BRIN page of the indicated page
+ * type, or die in the attempt. A pointer to the page is returned.
+ */
+static Page
+verify_brin_page(bytea *raw_page, uint16 type, const char *strtype)
+{
+ Page page = get_page_from_raw(raw_page);
+
+ if (PageIsNew(page))
+ return page;
+
+ /* verify the special space has the expected size */
+ if (PageGetSpecialSize(page) != MAXALIGN(sizeof(BrinSpecialSpace)))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("input page is not a valid %s page", "BRIN"),
+ errdetail("Expected special size %d, got %d.",
+ (int) MAXALIGN(sizeof(BrinSpecialSpace)),
+ (int) PageGetSpecialSize(page))));
+
+ /* verify the special space says this page is what we want */
+ if (BrinPageType(page) != type)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("page is not a BRIN page of type \"%s\"", strtype),
+ errdetail("Expected special type %08x, got %08x.",
+ type, BrinPageType(page))));
+
+ return page;
+}
+
+
+/*
+ * Extract all item values from a BRIN index page
+ *
+ * Usage: SELECT * FROM brin_page_items(get_raw_page('idx', 1), 'idx'::regclass);
+ */
+Datum
+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;
+ Relation indexRel;
+ brin_column_state **columns;
+ BrinDesc *bdesc;
+ BrinMemTuple *dtup;
+ Page page;
+ OffsetNumber offset;
+ AttrNumber attno;
+ bool unusedItem;
+
+ if (!superuser())
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("must be superuser to use raw page functions")));
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ indexRel = index_open(indexRelid, AccessShareLock);
+
+ if (!IS_BRIN(indexRel))
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("\"%s\" is not a %s index",
+ RelationGetRelationName(indexRel), "BRIN")));
+
+ bdesc = brin_build_desc(indexRel);
+
+ /* minimally verify the page we got */
+ page = verify_brin_page(raw_page, BRIN_PAGETYPE_REGULAR, "regular");
+
+ if (PageIsNew(page))
+ {
+ brin_free_desc(bdesc);
+ index_close(indexRel, AccessShareLock);
+ PG_RETURN_NULL();
+ }
+
+ /*
+ * Initialize output functions for all indexed datatypes; simplifies
+ * calling them later.
+ */
+ columns = palloc(sizeof(brin_column_state *) * RelationGetDescr(indexRel)->natts);
+ for (attno = 1; attno <= bdesc->bd_tupdesc->natts; attno++)
+ {
+ Oid output;
+ bool isVarlena;
+ BrinOpcInfo *opcinfo;
+ int i;
+ brin_column_state *column;
+
+ opcinfo = bdesc->bd_info[attno - 1];
+ column = palloc(offsetof(brin_column_state, outputFn) +
+ sizeof(FmgrInfo) * opcinfo->oi_nstored);
+
+ column->nstored = opcinfo->oi_nstored;
+ for (i = 0; i < opcinfo->oi_nstored; i++)
+ {
+ getTypeOutputInfo(opcinfo->oi_typcache[i]->type_id, &output, &isVarlena);
+ fmgr_info(output, &column->outputFn[i]);
+ }
+
+ columns[attno - 1] = column;
+ }
+
+ offset = FirstOffsetNumber;
+ unusedItem = false;
+ dtup = NULL;
+ for (;;)
+ {
+ Datum values[8];
+ bool nulls[8] = {0};
+
+ /*
+ * This loop is called once for every attribute of every tuple in the
+ * page. At the start of a tuple, we get a NULL dtup; that's our
+ * signal for obtaining and decoding the next one. If that's not the
+ * case, we output the next attribute.
+ */
+ if (dtup == NULL)
+ {
+ ItemId itemId;
+
+ /* verify item status: if there's no data, we can't decode */
+ itemId = PageGetItemId(page, offset);
+ if (ItemIdIsUsed(itemId))
+ {
+ dtup = brin_deform_tuple(bdesc,
+ (BrinTuple *) PageGetItem(page, itemId),
+ NULL);
+ attno = 1;
+ unusedItem = false;
+ }
+ else
+ unusedItem = true;
+ }
+ else
+ attno++;
+
+ if (unusedItem)
+ {
+ values[0] = UInt16GetDatum(offset);
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[3] = true;
+ nulls[4] = true;
+ nulls[5] = true;
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+ else
+ {
+ int att = attno - 1;
+
+ values[0] = UInt16GetDatum(offset);
+ switch (TupleDescAttr(rsinfo->setDesc, 1)->atttypid)
+ {
+ case INT8OID:
+ values[1] = Int64GetDatum((int64) dtup->bt_blkno);
+ break;
+ case INT4OID:
+ /* support for old extension version */
+ values[1] = UInt32GetDatum(dtup->bt_blkno);
+ break;
+ default:
+ elog(ERROR, "incorrect output types");
+ }
+ 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);
+ values[6] = BoolGetDatum(dtup->bt_empty_range);
+ if (!dtup->bt_columns[att].bv_allnulls)
+ {
+ BrinValues *bvalues = &dtup->bt_columns[att];
+ StringInfoData s;
+ bool first;
+ int i;
+
+ initStringInfo(&s);
+ appendStringInfoChar(&s, '{');
+
+ first = true;
+ for (i = 0; i < columns[att]->nstored; i++)
+ {
+ char *val;
+
+ if (!first)
+ appendStringInfoString(&s, " .. ");
+ first = false;
+ val = OutputFunctionCall(&columns[att]->outputFn[i],
+ bvalues->bv_values[i]);
+ appendStringInfoString(&s, val);
+ pfree(val);
+ }
+ appendStringInfoChar(&s, '}');
+
+ values[7] = CStringGetTextDatum(s.data);
+ pfree(s.data);
+ }
+ else
+ {
+ nulls[7] = true;
+ }
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, 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 (unusedItem)
+ offset = OffsetNumberNext(offset);
+ else if (attno >= bdesc->bd_tupdesc->natts)
+ {
+ pfree(dtup);
+ dtup = NULL;
+ offset = OffsetNumberNext(offset);
+ }
+
+ /*
+ * If we're beyond the end of the page, we're done.
+ */
+ if (offset > PageGetMaxOffsetNumber(page))
+ break;
+ }
+
+ brin_free_desc(bdesc);
+ index_close(indexRel, AccessShareLock);
+
+ return (Datum) 0;
+}
+
+Datum
+brin_metapage_info(PG_FUNCTION_ARGS)
+{
+ bytea *raw_page = PG_GETARG_BYTEA_P(0);
+ Page page;
+ BrinMetaPageData *meta;
+ TupleDesc tupdesc;
+ Datum values[4];
+ bool nulls[4] = {0};
+ HeapTuple htup;
+
+ if (!superuser())
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("must be superuser to use raw page functions")));
+
+ page = verify_brin_page(raw_page, BRIN_PAGETYPE_META, "metapage");
+
+ if (PageIsNew(page))
+ PG_RETURN_NULL();
+
+ /* 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");
+ tupdesc = BlessTupleDesc(tupdesc);
+
+ /* Extract values from the metapage */
+ meta = (BrinMetaPageData *) PageGetContents(page);
+ values[0] = CStringGetTextDatum(psprintf("0x%08X", meta->brinMagic));
+ values[1] = Int32GetDatum(meta->brinVersion);
+ values[2] = Int32GetDatum(meta->pagesPerRange);
+ values[3] = Int64GetDatum(meta->lastRevmapPage);
+
+ htup = heap_form_tuple(tupdesc, values, nulls);
+
+ PG_RETURN_DATUM(HeapTupleGetDatum(htup));
+}
+
+/*
+ * Return the TID array stored in a BRIN revmap page
+ */
+Datum
+brin_revmap_data(PG_FUNCTION_ARGS)
+{
+ struct
+ {
+ ItemPointerData *tids;
+ int idx;
+ } *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);
+ MemoryContext mctx;
+ Page page;
+
+ /* create a function context for cross-call persistence */
+ fctx = SRF_FIRSTCALL_INIT();
+
+ /* switch to memory context appropriate for multiple function calls */
+ mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
+
+ /* minimally verify the page we got */
+ page = verify_brin_page(raw_page, BRIN_PAGETYPE_REVMAP, "revmap");
+
+ if (PageIsNew(page))
+ {
+ MemoryContextSwitchTo(mctx);
+ PG_RETURN_NULL();
+ }
+
+ state = palloc(sizeof(*state));
+ state->tids = ((RevmapContents *) PageGetContents(page))->rm_tids;
+ state->idx = 0;
+
+ fctx->user_fctx = state;
+
+ MemoryContextSwitchTo(mctx);
+ }
+
+ fctx = SRF_PERCALL_SETUP();
+ state = fctx->user_fctx;
+
+ if (state->idx < REVMAP_PAGE_MAXITEMS)
+ SRF_RETURN_NEXT(fctx, PointerGetDatum(&state->tids[state->idx++]));
+
+ SRF_RETURN_DONE(fctx);
+}
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