From ad096719f321364a32b171fda4a21c26f04db3a1 Mon Sep 17 00:00:00 2001 From: Bharath Rupireddy Date: Thu, 17 Mar 2022 07:47:16 +0000 Subject: [PATCH v11] pg_walinspect --- contrib/Makefile | 1 + contrib/pg_walinspect/.gitignore | 4 + contrib/pg_walinspect/Makefile | 26 + contrib/pg_walinspect/pg_walinspect--1.0.sql | 95 +++ contrib/pg_walinspect/pg_walinspect.c | 594 +++++++++++++++++++ contrib/pg_walinspect/pg_walinspect.control | 5 + src/backend/access/transam/xlogreader.c | 14 +- src/bin/pg_waldump/pg_waldump.c | 5 + src/common/relpath.c | 18 + src/include/access/xlog.h | 2 +- src/include/access/xlog_internal.h | 2 +- src/include/access/xlogreader.h | 2 - src/include/common/relpath.h | 1 + 13 files changed, 758 insertions(+), 11 deletions(-) create mode 100644 contrib/pg_walinspect/.gitignore create mode 100644 contrib/pg_walinspect/Makefile create mode 100644 contrib/pg_walinspect/pg_walinspect--1.0.sql create mode 100644 contrib/pg_walinspect/pg_walinspect.c create mode 100644 contrib/pg_walinspect/pg_walinspect.control diff --git a/contrib/Makefile b/contrib/Makefile index 332b486ecc..bbf220407b 100644 --- a/contrib/Makefile +++ b/contrib/Makefile @@ -41,6 +41,7 @@ SUBDIRS = \ pgrowlocks \ pgstattuple \ pg_visibility \ + pg_walinspect \ postgres_fdw \ seg \ spi \ diff --git a/contrib/pg_walinspect/.gitignore b/contrib/pg_walinspect/.gitignore new file mode 100644 index 0000000000..5dcb3ff972 --- /dev/null +++ b/contrib/pg_walinspect/.gitignore @@ -0,0 +1,4 @@ +# Generated subdirectories +/log/ +/results/ +/tmp_check/ diff --git a/contrib/pg_walinspect/Makefile b/contrib/pg_walinspect/Makefile new file mode 100644 index 0000000000..c92a97447f --- /dev/null +++ b/contrib/pg_walinspect/Makefile @@ -0,0 +1,26 @@ +# contrib/pg_walinspect/Makefile + +MODULE_big = pg_walinspect +OBJS = \ + $(WIN32RES) \ + pg_walinspect.o +PGFILEDESC = "pg_walinspect - functions to inspect contents of PostgreSQL Write-Ahead Log" + +PG_CPPFLAGS = -I$(libpq_srcdir) +SHLIB_LINK_INTERNAL = $(libpq) + +EXTENSION = pg_walinspect +DATA = pg_walinspect--1.0.sql + +REGRESS = pg_walinspect + +ifdef USE_PGXS +PG_CONFIG = pg_config +PGXS := $(shell $(PG_CONFIG) --pgxs) +include $(PGXS) +else +subdir = contrib/pg_walinspect +top_builddir = ../.. +include $(top_builddir)/src/Makefile.global +include $(top_srcdir)/contrib/contrib-global.mk +endif diff --git a/contrib/pg_walinspect/pg_walinspect--1.0.sql b/contrib/pg_walinspect/pg_walinspect--1.0.sql new file mode 100644 index 0000000000..14d7642350 --- /dev/null +++ b/contrib/pg_walinspect/pg_walinspect--1.0.sql @@ -0,0 +1,95 @@ +/* contrib/pg_walinspect/pg_walinspect--1.0.sql */ + +-- complain if script is sourced in psql, rather than via CREATE EXTENSION +\echo Use "CREATE EXTENSION pg_walinspect" to load this file. \quit + +-- +-- pg_get_raw_wal_record() +-- +CREATE FUNCTION pg_get_raw_wal_record(IN in_lsn pg_lsn, + OUT start_lsn pg_lsn, + OUT end_lsn pg_lsn, + OUT prev_lsn pg_lsn, + OUT record_length int4, + OUT record bytea +) +AS 'MODULE_PATHNAME', 'pg_get_raw_wal_record' +LANGUAGE C CALLED ON NULL INPUT PARALLEL SAFE; + +REVOKE EXECUTE ON FUNCTION pg_get_raw_wal_record(pg_lsn) FROM PUBLIC; +GRANT EXECUTE ON FUNCTION pg_get_raw_wal_record(pg_lsn) TO pg_read_server_files; + +-- +-- pg_get_wal_record_info() +-- +CREATE FUNCTION pg_get_wal_record_info(IN in_lsn pg_lsn, + OUT start_lsn pg_lsn, + OUT end_lsn pg_lsn, + OUT prev_lsn pg_lsn, + OUT xid xid, + OUT resource_manager text, + OUT record_length int4, + OUT fpi_length int4, + OUT description text, + OUT block_ref text, + OUT data_length int4, + OUT data bytea +) +AS 'MODULE_PATHNAME', 'pg_get_wal_record_info' +LANGUAGE C CALLED ON NULL INPUT PARALLEL SAFE; + +REVOKE EXECUTE ON FUNCTION pg_get_wal_record_info(pg_lsn) FROM PUBLIC; +GRANT EXECUTE ON FUNCTION pg_get_wal_record_info(pg_lsn) TO pg_monitor; + +-- +-- pg_get_wal_records_info() +-- +CREATE FUNCTION pg_get_wal_records_info(IN start_lsn pg_lsn, + IN end_lsn pg_lsn DEFAULT NULL, + OUT start_lsn pg_lsn, + OUT end_lsn pg_lsn, + OUT prev_lsn pg_lsn, + OUT xid xid, + OUT resource_manager text, + OUT record_length int4, + OUT fpi_length int4, + OUT description text, + OUT block_ref text, + OUT data_length int4, + OUT data bytea +) +RETURNS SETOF record +AS 'MODULE_PATHNAME', 'pg_get_wal_records_info' +LANGUAGE C CALLED ON NULL INPUT PARALLEL SAFE; + +REVOKE EXECUTE ON FUNCTION pg_get_wal_records_info(pg_lsn, pg_lsn) FROM PUBLIC; +GRANT EXECUTE ON FUNCTION pg_get_wal_records_info(pg_lsn, pg_lsn) TO pg_monitor; + +-- +-- pg_get_wal_stats() +-- +CREATE FUNCTION pg_get_wal_stats(IN start_lsn pg_lsn, + IN end_lsn pg_lsn DEFAULT NULL, + OUT resource_manager text, + OUT count int8, + OUT count_percentage float4, + OUT record_length int8, + OUT record_length_percentage float4, + OUT fpi_length int8, + OUT fpi_length_percentage float4 + ) +RETURNS SETOF record AS $$ +SELECT resource_manager, + count(*) AS cnt, + CASE WHEN count(*) > 0 THEN (count(*) * 100 / sum(count(*)) OVER total)::numeric(5,2) ELSE 0 END AS "count_%", + sum(record_length) AS trecl, + CASE WHEN sum(record_length) > 0 THEN (sum(record_length) * 100 / sum(sum(record_length)) OVER total)::numeric(5,2) ELSE 0 END AS "trecl_%", + sum(fpi_length) AS tfpil, + CASE WHEN sum(fpi_length) > 0 THEN (sum(fpi_length) * 100 / sum(sum(fpi_length)) OVER total)::numeric(5,2) ELSE 0 END AS "tfpil_%" +FROM pg_get_wal_records_info(start_lsn, end_lsn) +GROUP BY resource_manager +WINDOW total AS (); +$$ LANGUAGE SQL CALLED ON NULL INPUT PARALLEL SAFE; + +REVOKE EXECUTE ON FUNCTION pg_get_wal_stats(pg_lsn, pg_lsn) FROM PUBLIC; +GRANT EXECUTE ON FUNCTION pg_get_wal_stats(pg_lsn, pg_lsn) TO pg_monitor; diff --git a/contrib/pg_walinspect/pg_walinspect.c b/contrib/pg_walinspect/pg_walinspect.c new file mode 100644 index 0000000000..667d9567cc --- /dev/null +++ b/contrib/pg_walinspect/pg_walinspect.c @@ -0,0 +1,594 @@ +/*------------------------------------------------------------------------- + * + * pg_walinspect.c + * Functions to inspect contents of PostgreSQL Write-Ahead Log + * + * Copyright (c) 2022, PostgreSQL Global Development Group + * + * IDENTIFICATION + * contrib/pg_walinspect/pg_walinspect.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/xlog.h" +#include "access/xlog_internal.h" +#include "access/xlogreader.h" +#include "access/xlogrecovery.h" +#include "access/xlogutils.h" +#include "funcapi.h" +#include "miscadmin.h" +#include "utils/builtins.h" +#include "utils/pg_lsn.h" + +/* + * NOTE: For any code change or issue fix here, it is highly recommended to + * give a thought about doing the same in pg_waldump tool as well. + */ + +PG_MODULE_MAGIC; + +extern void _PG_init(void); +extern void _PG_fini(void); + +PG_FUNCTION_INFO_V1(pg_get_raw_wal_record); +PG_FUNCTION_INFO_V1(pg_get_wal_record_info); +PG_FUNCTION_INFO_V1(pg_get_wal_records_info); + +static XLogRecPtr ValidateInputLSN(XLogRecPtr lsn); +static XLogRecPtr ValidateStartAndEndLSNs(XLogRecPtr start_lsn, + XLogRecPtr end_lsn); +static XLogReaderState *InitXLogReaderState(XLogRecPtr lsn, + XLogRecPtr *first_record); +static XLogRecord *ReadNextXLogRecord(XLogReaderState *xlogreader, + XLogRecPtr first_record); +static void GetXLogRecordInfo(XLogReaderState *record, XLogRecPtr lsn, + Datum *values, bool *nulls, uint32 ncols); +static void GetWALRecordsInfoInternal(FunctionCallInfo fcinfo, + XLogRecPtr start_lsn, + XLogRecPtr end_lsn); + +/* + * Module load callback. + */ +void +_PG_init(void) +{ + /* Define custom GUCs and install hooks here, if any. */ + + /* + * Have EmitWarningsOnPlaceholders("pg_walinspect"); if custom GUCs are + * defined. + */ +} + +/* + * Module unload callback. + */ +void +_PG_fini(void) +{ + /* Uninstall hooks, if any. */ +} + +/* + * Validate given LSN and return the LSN up to which the server has WAL. + */ +static XLogRecPtr +ValidateInputLSN(XLogRecPtr lsn) +{ + XLogRecPtr curr_lsn; + + /* Validate input WAL LSN. */ + if (XLogRecPtrIsInvalid(lsn)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("invalid WAL LSN"))); + + /* + * We determine the current LSN of the server similar to how page_read + * callback read_local_xlog_page does. + */ + if (!RecoveryInProgress()) + curr_lsn = GetFlushRecPtr(NULL); + else + curr_lsn = GetXLogReplayRecPtr(NULL); + + Assert(!XLogRecPtrIsInvalid(curr_lsn)); + + if (lsn >= curr_lsn) + { + /* + * GetFlushRecPtr or GetXLogReplayRecPtr gives "end+1" LSN of the last + * record flushed or replayed respectively. But let's use the LSN up + * to "end" in user facing message. + */ + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("cannot accept future input LSN"), + errdetail("Last known WAL LSN on the database system is %X/%X.", + LSN_FORMAT_ARGS(curr_lsn - 1)))); + } + + return curr_lsn; +} + +/* + * Validate given start LSN and end LSN, return the new end LSN in case user + * hasn't specified one. + */ +static XLogRecPtr +ValidateStartAndEndLSNs(XLogRecPtr start_lsn, XLogRecPtr end_lsn) +{ + XLogRecPtr curr_lsn; + + /* Validate WAL start LSN. */ + if (XLogRecPtrIsInvalid(start_lsn)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("invalid WAL start LSN"))); + + if (!RecoveryInProgress()) + curr_lsn = GetFlushRecPtr(NULL); + else + curr_lsn = GetXLogReplayRecPtr(NULL); + + if (start_lsn >= curr_lsn) + { + /* + * GetFlushRecPtr or GetXLogReplayRecPtr gives "end+1" LSN of the last + * record flushed or replayed respectively. But let's use the LSN up + * to "end" in user facing message. + */ + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("cannot accept future start LSN"), + errdetail("Last known WAL LSN on the database system is %X/%X.", + LSN_FORMAT_ARGS(curr_lsn - 1)))); + } + + /* + * If end_lsn is specified, let's ensure that it's not a future LSN i.e. + * something the database system doesn't know about. + */ + if (!XLogRecPtrIsInvalid(end_lsn) && + (end_lsn >= curr_lsn)) + { + /* + * GetFlushRecPtr or GetXLogReplayRecPtr gives "end+1" LSN of the last + * record flushed or replayed respectively. But let's use the LSN up + * to "end" in user facing message. + */ + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("cannot accept future end LSN"), + errdetail("Last known WAL LSN on the database system is %X/%X.", + LSN_FORMAT_ARGS(curr_lsn - 1)))); + } + + /* + * When end_lsn is not specified let's read up to the last WAL position + * known to be on the server. + */ + if (XLogRecPtrIsInvalid(end_lsn)) + end_lsn = curr_lsn; + + Assert(!XLogRecPtrIsInvalid(end_lsn)); + + if (start_lsn >= end_lsn) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("WAL start LSN must be less than end LSN"))); + + return end_lsn; +} + +/* + * Intialize WAL reader and identify first valid LSN. + */ +static XLogReaderState * +InitXLogReaderState(XLogRecPtr lsn, XLogRecPtr *first_record) +{ + XLogReaderState *xlogreader; + + /* + * Reading WAL below the first page of the first sgements isn't allowed. + * This is a bootstrap WAL page and the page_read callback fails to read + * it. + */ + if (lsn < XLOG_BLCKSZ) + ereport(ERROR, + (errmsg("could not read WAL at LSN %X/%X", + LSN_FORMAT_ARGS(lsn)))); + + xlogreader = XLogReaderAllocate(wal_segment_size, NULL, + XL_ROUTINE(.page_read = &read_local_xlog_page, + .segment_open = &wal_segment_open, + .segment_close = &wal_segment_close), + NULL); + + if (xlogreader == NULL) + ereport(ERROR, + (errcode(ERRCODE_OUT_OF_MEMORY), + errmsg("out of memory"), + errdetail("Failed while allocating a WAL reading processor."))); + + /* First find a valid recptr to start from. */ + *first_record = XLogFindNextRecord(xlogreader, lsn); + + if (XLogRecPtrIsInvalid(*first_record)) + ereport(ERROR, + (errmsg("could not find a valid record after %X/%X", + LSN_FORMAT_ARGS(lsn)))); + + return xlogreader; +} + +/* + * Read next WAL record. + */ +static XLogRecord * +ReadNextXLogRecord(XLogReaderState *xlogreader, XLogRecPtr first_record) +{ + XLogRecord *record; + char *errormsg; + + record = XLogReadRecord(xlogreader, &errormsg); + + if (record == NULL) + { + if (errormsg) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not read WAL at %X/%X: %s", + LSN_FORMAT_ARGS(first_record), errormsg))); + else + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not read WAL at %X/%X", + LSN_FORMAT_ARGS(first_record)))); + } + + return record; +} + +/* + * Get raw WAL record. + * + * This function emits an error if a future WAL LSN i.e. WAL LSN the database + * system doesn't know about is specified. + */ +Datum +pg_get_raw_wal_record(PG_FUNCTION_ARGS) +{ +#define PG_GET_RAW_WAL_RECORD_COLS 5 + XLogRecPtr lsn; + XLogRecord *record; + XLogRecPtr first_record; + XLogReaderState *xlogreader; + bytea *raw_record; + uint32 rec_len; + char *raw_record_data; + TupleDesc tupdesc; + Datum result; + HeapTuple tuple; + Datum values[PG_GET_RAW_WAL_RECORD_COLS]; + bool nulls[PG_GET_RAW_WAL_RECORD_COLS]; + int i = 0; + + lsn = PG_GETARG_LSN(0); + + (void) ValidateInputLSN(lsn); + + /* 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"); + + xlogreader = InitXLogReaderState(lsn, &first_record); + + Assert(xlogreader); + + record = ReadNextXLogRecord(xlogreader, first_record); + + rec_len = XLogRecGetTotalLen(xlogreader); + + Assert(rec_len > 0); + + raw_record = (bytea *) palloc(rec_len + VARHDRSZ); + SET_VARSIZE(raw_record, rec_len + VARHDRSZ); + raw_record_data = VARDATA(raw_record); + + memcpy(raw_record_data, record, rec_len); + + MemSet(values, 0, sizeof(values)); + MemSet(nulls, 0, sizeof(nulls)); + + values[i++] = LSNGetDatum(first_record); + values[i++] = LSNGetDatum(xlogreader->EndRecPtr - 1); + values[i++] = LSNGetDatum(XLogRecGetPrev(xlogreader)); + values[i++] = UInt32GetDatum(rec_len); + values[i++] = PointerGetDatum(raw_record); + + XLogReaderFree(xlogreader); + + Assert(i == PG_GET_RAW_WAL_RECORD_COLS); + + tuple = heap_form_tuple(tupdesc, values, nulls); + result = HeapTupleGetDatum(tuple); + + PG_RETURN_DATUM(result); +#undef PG_GET_RAW_WAL_RECORD_COLS +} + +/* + * Get WAL record info. + */ +static void +GetXLogRecordInfo(XLogReaderState *record, XLogRecPtr lsn, + Datum *values, bool *nulls, uint32 ncols) +{ + const char *id; + const RmgrData *desc; + uint32 fpi_len = 0; + RelFileNode rnode; + ForkNumber forknum; + BlockNumber blk; + int block_id; + StringInfoData rec_desc; + StringInfoData rec_blk_ref; + StringInfoData temp; + bytea *data; + char *main_data; + uint32 main_data_len; + int i = 0; + + desc = &RmgrTable[XLogRecGetRmid(record)]; + initStringInfo(&rec_desc); + id = desc->rm_identify(XLogRecGetInfo(record)); + + if (id == NULL) + appendStringInfo(&rec_desc, "UNKNOWN (%x) ", XLogRecGetInfo(record) & ~XLR_INFO_MASK); + else + appendStringInfo(&rec_desc, "%s ", id); + + initStringInfo(&temp); + desc->rm_desc(&temp, record); + appendStringInfo(&rec_desc, "%s", temp.data); + pfree(temp.data); + initStringInfo(&rec_blk_ref); + + /* Block references (detailed format). */ + for (block_id = 0; block_id <= record->max_block_id; block_id++) + { + if (!XLogRecHasBlockRef(record, block_id)) + continue; + + XLogRecGetBlockTag(record, block_id, &rnode, &forknum, &blk); + + if (forknum != MAIN_FORKNUM) + appendStringInfo(&rec_blk_ref, + "blkref #%u: rel %u/%u/%u fork %s blk %u", + block_id, rnode.spcNode, rnode.dbNode, + rnode.relNode, get_forkname(forknum), blk); + else + appendStringInfo(&rec_blk_ref, + "blkref #%u: rel %u/%u/%u blk %u", + block_id, rnode.spcNode, rnode.dbNode, + rnode.relNode, blk); + + if (XLogRecHasBlockImage(record, block_id)) + { + uint8 bimg_info = record->blocks[block_id].bimg_info; + + /* Calculate the amount of FPI data in the record. */ + fpi_len += record->blocks[block_id].bimg_len; + + if (BKPIMAGE_COMPRESSED(bimg_info)) + { + const char *method; + + if ((bimg_info & BKPIMAGE_COMPRESS_PGLZ) != 0) + method = "pglz"; + else if ((bimg_info & BKPIMAGE_COMPRESS_LZ4) != 0) + method = "lz4"; + else + method = "unknown"; + + appendStringInfo(&rec_blk_ref, " (FPW%s); hole: offset: %u, length: %u, " + "compression saved: %u, method: %s", + XLogRecBlockImageApply(record, block_id) ? + "" : " for WAL verification", + record->blocks[block_id].hole_offset, + record->blocks[block_id].hole_length, + BLCKSZ - + record->blocks[block_id].hole_length - + record->blocks[block_id].bimg_len, + method); + } + else + { + appendStringInfo(&rec_blk_ref, " (FPW%s); hole: offset: %u, length: %u", + XLogRecBlockImageApply(record, block_id) ? + "" : " for WAL verification", + record->blocks[block_id].hole_offset, + record->blocks[block_id].hole_length); + } + } + } + + main_data_len = XLogRecGetDataLen(record); + data = (bytea *) palloc(main_data_len + VARHDRSZ); + SET_VARSIZE(data, main_data_len + VARHDRSZ); + main_data = VARDATA(data); + memcpy(main_data, XLogRecGetData(record), main_data_len); + + values[i++] = LSNGetDatum(lsn); + values[i++] = LSNGetDatum(record->EndRecPtr - 1); + values[i++] = LSNGetDatum(XLogRecGetPrev(record)); + values[i++] = TransactionIdGetDatum(XLogRecGetXid(record)); + values[i++] = CStringGetTextDatum(desc->rm_name); + values[i++] = UInt32GetDatum(XLogRecGetTotalLen(record)); + values[i++] = UInt32GetDatum(fpi_len); + values[i++] = CStringGetTextDatum(rec_desc.data); + values[i++] = CStringGetTextDatum(rec_blk_ref.data); + values[i++] = UInt32GetDatum(main_data_len); + values[i++] = PointerGetDatum(data); + + Assert(i == ncols); +} + +/* + * Get WAL record info and data. + * + * This function emits an error if a future WAL LSN i.e. WAL LSN the database + * system doesn't know about is specified. + */ +Datum +pg_get_wal_record_info(PG_FUNCTION_ARGS) +{ +#define PG_GET_WAL_RECORD_INFO_COLS 11 + XLogRecPtr lsn; + XLogRecPtr first_record; + XLogReaderState *xlogreader; + TupleDesc tupdesc; + Datum result; + HeapTuple tuple; + Datum values[PG_GET_WAL_RECORD_INFO_COLS]; + bool nulls[PG_GET_WAL_RECORD_INFO_COLS]; + + lsn = PG_GETARG_LSN(0); + + (void) ValidateInputLSN(lsn); + + /* 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"); + + xlogreader = InitXLogReaderState(lsn, &first_record); + + Assert(xlogreader); + + (void) ReadNextXLogRecord(xlogreader, first_record); + + MemSet(values, 0, sizeof(values)); + MemSet(nulls, 0, sizeof(nulls)); + + GetXLogRecordInfo(xlogreader, first_record, values, nulls, + PG_GET_WAL_RECORD_INFO_COLS); + + XLogReaderFree(xlogreader); + + tuple = heap_form_tuple(tupdesc, values, nulls); + result = HeapTupleGetDatum(tuple); + + PG_RETURN_DATUM(result); +#undef PG_GET_WAL_RECORD_INFO_COLS +} + +/* + * Get info and data of all WAL records between start LSN and end LSN. + */ +static void +GetWALRecordsInfoInternal(FunctionCallInfo fcinfo, XLogRecPtr start_lsn, + XLogRecPtr end_lsn) +{ +#define PG_GET_WAL_RECORDS_INFO_COLS 11 + XLogRecPtr first_record; + XLogReaderState *xlogreader; + ReturnSetInfo *rsinfo; + TupleDesc tupdesc; + Tuplestorestate *tupstore; + MemoryContext per_query_ctx; + MemoryContext oldcontext; + Datum values[PG_GET_WAL_RECORDS_INFO_COLS]; + bool nulls[PG_GET_WAL_RECORDS_INFO_COLS]; + + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + /* 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); + + xlogreader = InitXLogReaderState(start_lsn, &first_record); + + Assert(xlogreader); + + MemSet(values, 0, sizeof(values)); + MemSet(nulls, 0, sizeof(nulls)); + + for (;;) + { + (void) ReadNextXLogRecord(xlogreader, first_record); + + /* + * Let's not show the record info if it is spanning more than the + * end_lsn. EndRecPtr is "end+1" of the last read record, hence + * use "end" here. + */ + if ((xlogreader->EndRecPtr - 1) <= end_lsn) + { + GetXLogRecordInfo(xlogreader, xlogreader->currRecPtr, values, nulls, + PG_GET_WAL_RECORDS_INFO_COLS); + + tuplestore_putvalues(tupstore, tupdesc, values, nulls); + } + + /* Exit loop if read up to end_lsn. */ + if (xlogreader->EndRecPtr >= end_lsn) + break; + + CHECK_FOR_INTERRUPTS(); + } + + XLogReaderFree(xlogreader); + + /* Clean up and return the tuplestore. */ + tuplestore_donestoring(tupstore); +#undef PG_GET_WAL_RECORDS_INFO_COLS +} + +/* + * Get info and data of all WAL records between start LSN and end LSN. + * + * This function emits an error if a future end WAL LSN i.e. WAL LSN the + * database system doesn't know about is specified. + * + * This function will figure out the end LSN if it's not specified. + */ +Datum +pg_get_wal_records_info(PG_FUNCTION_ARGS) +{ + XLogRecPtr start_lsn; + XLogRecPtr end_lsn; + + start_lsn = PG_GETARG_LSN(0); + end_lsn = PG_GETARG_LSN(1); + + end_lsn = ValidateStartAndEndLSNs(start_lsn, end_lsn); + + GetWALRecordsInfoInternal(fcinfo, start_lsn, end_lsn); + + PG_RETURN_VOID(); +} diff --git a/contrib/pg_walinspect/pg_walinspect.control b/contrib/pg_walinspect/pg_walinspect.control new file mode 100644 index 0000000000..017e56a2bb --- /dev/null +++ b/contrib/pg_walinspect/pg_walinspect.control @@ -0,0 +1,5 @@ +# pg_walinspect extension +comment = 'functions to inspect contents of PostgreSQL Write-Ahead Log' +default_version = '1.0' +module_pathname = '$libdir/pg_walinspect' +relocatable = true diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c index b7c06da255..1b072f9c11 100644 --- a/src/backend/access/transam/xlogreader.c +++ b/src/backend/access/transam/xlogreader.c @@ -959,13 +959,6 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr, return true; } -#ifdef FRONTEND -/* - * Functions that are currently not needed in the backend, but are better - * implemented inside xlogreader.c because of the internal facilities available - * here. - */ - /* * Find the first record with an lsn >= RecPtr. * @@ -1083,6 +1076,13 @@ err: return InvalidXLogRecPtr; } +#ifdef FRONTEND +/* + * Functions that are currently not needed in the backend, but are better + * implemented inside xlogreader.c because of the internal facilities available + * here. + */ + #endif /* FRONTEND */ /* diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c index f128050b4e..aac41a0793 100644 --- a/src/bin/pg_waldump/pg_waldump.c +++ b/src/bin/pg_waldump/pg_waldump.c @@ -26,6 +26,11 @@ #include "getopt_long.h" #include "rmgrdesc.h" +/* + * NOTE: For any code change or issue fix here, it is highly recommended to + * give a thought about doing the same in pg_walinspect contrib module as well. + */ + static const char *progname; static int WalSegSz; diff --git a/src/common/relpath.c b/src/common/relpath.c index 636c96efd3..e8e3c44eae 100644 --- a/src/common/relpath.c +++ b/src/common/relpath.c @@ -40,6 +40,24 @@ const char *const forkNames[] = { StaticAssertDecl(lengthof(forkNames) == (MAX_FORKNUM + 1), "array length mismatch"); +/* + * get_forkname - return fork name given fork number + * + * This function is defined with "extern PGDLLIMPORT ..." in the core here so + * that the loadable modules can access it. + */ +const char *const +get_forkname(ForkNumber num) +{ + /* + * As this function gets called by external modules, let's ensure that the + * fork number passed in is valid. + */ + Assert(num > InvalidForkNumber && num <= MAX_FORKNUM); + + return forkNames[num]; +} + /* * forkname_to_number - look up fork number by name * diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index 09f6464331..3e644372f9 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -31,7 +31,7 @@ extern XLogRecPtr XactLastRecEnd; extern PGDLLIMPORT XLogRecPtr XactLastCommitEnd; /* these variables are GUC parameters related to XLOG */ -extern int wal_segment_size; +extern PGDLLIMPORT int wal_segment_size; extern int min_wal_size_mb; extern int max_wal_size_mb; extern int wal_keep_size_mb; diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h index 0e94833129..8468732d76 100644 --- a/src/include/access/xlog_internal.h +++ b/src/include/access/xlog_internal.h @@ -319,7 +319,7 @@ typedef struct RmgrData struct XLogRecordBuffer *buf); } RmgrData; -extern const RmgrData RmgrTable[]; +extern PGDLLIMPORT const RmgrData RmgrTable[]; /* * Exported to support xlog switching from checkpointer diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h index 477f0efe26..d62d6ce7f8 100644 --- a/src/include/access/xlogreader.h +++ b/src/include/access/xlogreader.h @@ -276,9 +276,7 @@ extern void XLogReaderFree(XLogReaderState *state); /* Position the XLogReader to given record */ extern void XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr); -#ifdef FRONTEND extern XLogRecPtr XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr); -#endif /* FRONTEND */ /* Read the next XLog record. Returns NULL on end-of-WAL or failure */ extern struct XLogRecord *XLogReadRecord(XLogReaderState *state, diff --git a/src/include/common/relpath.h b/src/include/common/relpath.h index a4b5dc853b..3743f2e505 100644 --- a/src/include/common/relpath.h +++ b/src/include/common/relpath.h @@ -57,6 +57,7 @@ typedef enum ForkNumber #define FORKNAMECHARS 4 /* max chars for a fork name */ extern const char *const forkNames[]; +extern PGDLLIMPORT const char *const get_forkname(ForkNumber num); extern ForkNumber forkname_to_number(const char *forkName); extern int forkname_chars(const char *str, ForkNumber *fork); -- 2.25.1