passwordcheck \
pg_buffercache \
pg_freespacemap \
+ pg_logicalinspect \
pg_prewarm \
pg_stat_statements \
pg_surgery \
subdir('pg_buffercache')
subdir('pgcrypto')
subdir('pg_freespacemap')
+subdir('pg_logicalinspect')
subdir('pg_prewarm')
subdir('pgrowlocks')
subdir('pg_stat_statements')
--- /dev/null
+# Generated subdirectories
+/log/
+/results/
+/output_iso/
+/tmp_check/
+/tmp_check_iso/
--- /dev/null
+# contrib/pg_logicalinspect/Makefile
+
+MODULE_big = pg_logicalinspect
+OBJS = \
+ $(WIN32RES) \
+ pg_logicalinspect.o
+PGFILEDESC = "pg_logicalinspect - functions to inspect logical decoding components"
+
+EXTENSION = pg_logicalinspect
+DATA = pg_logicalinspect--1.0.sql
+
+EXTRA_INSTALL = contrib/test_decoding
+
+ISOLATION = logical_inspect
+
+ISOLATION_OPTS = --temp-config $(top_srcdir)/contrib/pg_logicalinspect/logicalinspect.conf
+
+# Disabled because these tests require "wal_level=logical", which
+# some installcheck users do not have (e.g. buildfarm clients).
+NO_INSTALLCHECK = 1
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/pg_logicalinspect
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
--- /dev/null
+Parsed test spec with 2 sessions
+
+starting permutation: s0_init s0_begin s0_savepoint s0_truncate s1_checkpoint s1_get_changes s0_commit s0_begin s0_insert s1_checkpoint s1_get_changes s0_commit s1_get_changes s1_get_logical_snapshot_info s1_get_logical_snapshot_meta
+step s0_init: SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding');
+?column?
+--------
+init
+(1 row)
+
+step s0_begin: BEGIN;
+step s0_savepoint: SAVEPOINT sp1;
+step s0_truncate: TRUNCATE tbl1;
+step s1_checkpoint: CHECKPOINT;
+step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
+data
+----
+(0 rows)
+
+step s0_commit: COMMIT;
+step s0_begin: BEGIN;
+step s0_insert: INSERT INTO tbl1 VALUES (1);
+step s1_checkpoint: CHECKPOINT;
+step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
+data
+---------------------------------------
+BEGIN
+table public.tbl1: TRUNCATE: (no-flags)
+COMMIT
+(3 rows)
+
+step s0_commit: COMMIT;
+step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
+data
+-------------------------------------------------------------
+BEGIN
+table public.tbl1: INSERT: val1[integer]:1 val2[integer]:null
+COMMIT
+(3 rows)
+
+step s1_get_logical_snapshot_info: SELECT info.state, info.catchange_count, array_length(info.catchange_xip,1) AS catchange_array_length, info.committed_count, array_length(info.committed_xip,1) AS committed_array_length FROM pg_ls_logicalsnapdir(), pg_get_logical_snapshot_info(name) AS info ORDER BY 2;
+state |catchange_count|catchange_array_length|committed_count|committed_array_length
+----------+---------------+----------------------+---------------+----------------------
+consistent| 0| | 2| 2
+consistent| 2| 2| 0|
+(2 rows)
+
+step s1_get_logical_snapshot_meta: SELECT COUNT(meta.*) from pg_ls_logicalsnapdir(), pg_get_logical_snapshot_meta(name) as meta;
+count
+-----
+ 2
+(1 row)
+
--- /dev/null
+wal_level = logical
--- /dev/null
+# Copyright (c) 2024, PostgreSQL Global Development Group
+
+pg_logicalinspect_sources = files('pg_logicalinspect.c')
+
+if host_system == 'windows'
+ pg_logicalinspect_sources += rc_lib_gen.process(win32ver_rc, extra_args: [
+ '--NAME', 'pg_logicalinspect',
+ '--FILEDESC', 'pg_logicalinspect - functions to inspect logical decoding components',])
+endif
+
+pg_logicalinspect = shared_module('pg_logicalinspect',
+ pg_logicalinspect_sources,
+ kwargs: contrib_mod_args + {
+ 'dependencies': contrib_mod_args['dependencies'],
+ },
+)
+contrib_targets += pg_logicalinspect
+
+install_data(
+ 'pg_logicalinspect.control',
+ 'pg_logicalinspect--1.0.sql',
+ kwargs: contrib_data_args,
+)
+
+tests += {
+ 'name': 'pg_logicalinspect',
+ 'sd': meson.current_source_dir(),
+ 'bd': meson.current_build_dir(),
+ 'isolation': {
+ 'specs': [
+ 'logical_inspect',
+ ],
+ 'regress_args': [
+ '--temp-config', files('logicalinspect.conf'),
+ ],
+ # see above
+ 'runningcheck': false,
+ },
+}
--- /dev/null
+/* contrib/pg_logicalinspect/pg_logicalinspect--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION pg_logicalinspect" to load this file. \quit
+
+--
+-- pg_get_logical_snapshot_meta()
+--
+CREATE FUNCTION pg_get_logical_snapshot_meta(IN filename text,
+ OUT magic int4,
+ OUT checksum int8,
+ OUT version int4
+)
+AS 'MODULE_PATHNAME', 'pg_get_logical_snapshot_meta'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+REVOKE EXECUTE ON FUNCTION pg_get_logical_snapshot_meta(text) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pg_get_logical_snapshot_meta(text) TO pg_read_server_files;
+
+--
+-- pg_get_logical_snapshot_info()
+--
+CREATE FUNCTION pg_get_logical_snapshot_info(IN filename text,
+ OUT state text,
+ OUT xmin xid,
+ OUT xmax xid,
+ OUT start_decoding_at pg_lsn,
+ OUT two_phase_at pg_lsn,
+ OUT initial_xmin_horizon xid,
+ OUT building_full_snapshot boolean,
+ OUT in_slot_creation boolean,
+ OUT last_serialized_snapshot pg_lsn,
+ OUT next_phase_at xid,
+ OUT committed_count int4,
+ OUT committed_xip xid[],
+ OUT catchange_count int4,
+ OUT catchange_xip xid[]
+)
+AS 'MODULE_PATHNAME', 'pg_get_logical_snapshot_info'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+REVOKE EXECUTE ON FUNCTION pg_get_logical_snapshot_info(text) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pg_get_logical_snapshot_info(text) TO pg_read_server_files;
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * pg_logicalinspect.c
+ * Functions to inspect contents of PostgreSQL logical snapshots
+ *
+ * Copyright (c) 2024, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * contrib/pg_logicalinspect/pg_logicalinspect.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "funcapi.h"
+#include "replication/snapbuild_internal.h"
+#include "utils/array.h"
+#include "utils/builtins.h"
+#include "utils/pg_lsn.h"
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(pg_get_logical_snapshot_meta);
+PG_FUNCTION_INFO_V1(pg_get_logical_snapshot_info);
+
+/* Return the description of SnapBuildState */
+static const char *
+get_snapbuild_state_desc(SnapBuildState state)
+{
+ const char *stateDesc = "unknown state";
+
+ switch (state)
+ {
+ case SNAPBUILD_START:
+ stateDesc = "start";
+ break;
+ case SNAPBUILD_BUILDING_SNAPSHOT:
+ stateDesc = "building";
+ break;
+ case SNAPBUILD_FULL_SNAPSHOT:
+ stateDesc = "full";
+ break;
+ case SNAPBUILD_CONSISTENT:
+ stateDesc = "consistent";
+ break;
+ }
+
+ return stateDesc;
+}
+
+/*
+ * Retrieve the logical snapshot file metadata.
+ */
+Datum
+pg_get_logical_snapshot_meta(PG_FUNCTION_ARGS)
+{
+#define PG_GET_LOGICAL_SNAPSHOT_META_COLS 3
+ SnapBuildOnDisk ondisk;
+ HeapTuple tuple;
+ Datum values[PG_GET_LOGICAL_SNAPSHOT_META_COLS] = {0};
+ bool nulls[PG_GET_LOGICAL_SNAPSHOT_META_COLS] = {0};
+ TupleDesc tupdesc;
+ char path[MAXPGPATH];
+ int i = 0;
+ text *filename_t = PG_GETARG_TEXT_PP(0);
+
+ /* 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");
+
+ sprintf(path, "%s/%s",
+ PG_LOGICAL_SNAPSHOTS_DIR,
+ text_to_cstring(filename_t));
+
+ /* Validate and restore the snapshot to 'ondisk' */
+ SnapBuildRestoreSnapshot(&ondisk, path, CurrentMemoryContext, false);
+
+ values[i++] = UInt32GetDatum(ondisk.magic);
+ values[i++] = Int64GetDatum((int64) ondisk.checksum);
+ values[i++] = UInt32GetDatum(ondisk.version);
+
+ Assert(i == PG_GET_LOGICAL_SNAPSHOT_META_COLS);
+
+ tuple = heap_form_tuple(tupdesc, values, nulls);
+
+ PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
+
+#undef PG_GET_LOGICAL_SNAPSHOT_META_COLS
+}
+
+Datum
+pg_get_logical_snapshot_info(PG_FUNCTION_ARGS)
+{
+#define PG_GET_LOGICAL_SNAPSHOT_INFO_COLS 14
+ SnapBuildOnDisk ondisk;
+ HeapTuple tuple;
+ Datum values[PG_GET_LOGICAL_SNAPSHOT_INFO_COLS] = {0};
+ bool nulls[PG_GET_LOGICAL_SNAPSHOT_INFO_COLS] = {0};
+ TupleDesc tupdesc;
+ char path[MAXPGPATH];
+ int i = 0;
+ text *filename_t = PG_GETARG_TEXT_PP(0);
+
+ /* 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");
+
+ sprintf(path, "%s/%s",
+ PG_LOGICAL_SNAPSHOTS_DIR,
+ text_to_cstring(filename_t));
+
+ /* Validate and restore the snapshot to 'ondisk' */
+ SnapBuildRestoreSnapshot(&ondisk, path, CurrentMemoryContext, false);
+
+ values[i++] = CStringGetTextDatum(get_snapbuild_state_desc(ondisk.builder.state));
+ values[i++] = TransactionIdGetDatum(ondisk.builder.xmin);
+ values[i++] = TransactionIdGetDatum(ondisk.builder.xmax);
+ values[i++] = LSNGetDatum(ondisk.builder.start_decoding_at);
+ values[i++] = LSNGetDatum(ondisk.builder.two_phase_at);
+ values[i++] = TransactionIdGetDatum(ondisk.builder.initial_xmin_horizon);
+ values[i++] = BoolGetDatum(ondisk.builder.building_full_snapshot);
+ values[i++] = BoolGetDatum(ondisk.builder.in_slot_creation);
+ values[i++] = LSNGetDatum(ondisk.builder.last_serialized_snapshot);
+ values[i++] = TransactionIdGetDatum(ondisk.builder.next_phase_at);
+
+ values[i++] = UInt32GetDatum(ondisk.builder.committed.xcnt);
+ if (ondisk.builder.committed.xcnt > 0)
+ {
+ Datum *arrayelems;
+
+ arrayelems = (Datum *) palloc(ondisk.builder.committed.xcnt * sizeof(Datum));
+
+ for (int j = 0; j < ondisk.builder.committed.xcnt; j++)
+ arrayelems[j] = TransactionIdGetDatum(ondisk.builder.committed.xip[j]);
+
+ values[i++] = PointerGetDatum(construct_array_builtin(arrayelems,
+ ondisk.builder.committed.xcnt,
+ XIDOID));
+ }
+ else
+ nulls[i++] = true;
+
+ values[i++] = UInt32GetDatum(ondisk.builder.catchange.xcnt);
+ if (ondisk.builder.catchange.xcnt > 0)
+ {
+ Datum *arrayelems;
+
+ arrayelems = (Datum *) palloc(ondisk.builder.catchange.xcnt * sizeof(Datum));
+
+ for (int j = 0; j < ondisk.builder.catchange.xcnt; j++)
+ arrayelems[j] = TransactionIdGetDatum(ondisk.builder.catchange.xip[j]);
+
+ values[i++] = PointerGetDatum(construct_array_builtin(arrayelems,
+ ondisk.builder.catchange.xcnt,
+ XIDOID));
+ }
+ else
+ nulls[i++] = true;
+
+ Assert(i == PG_GET_LOGICAL_SNAPSHOT_INFO_COLS);
+
+ tuple = heap_form_tuple(tupdesc, values, nulls);
+
+ PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
+
+#undef PG_GET_LOGICAL_SNAPSHOT_INFO_COLS
+}
--- /dev/null
+# pg_logicalinspect extension
+comment = 'functions to inspect logical decoding components'
+default_version = '1.0'
+module_pathname = '$libdir/pg_logicalinspect'
+relocatable = true
--- /dev/null
+# Test the pg_logicalinspect functions: that needs some permutation to
+# ensure that we are creating multiple logical snapshots and that one of them
+# contains ongoing catalogs changes.
+setup
+{
+ DROP TABLE IF EXISTS tbl1;
+ CREATE TABLE tbl1 (val1 integer, val2 integer);
+ CREATE EXTENSION pg_logicalinspect;
+}
+
+teardown
+{
+ DROP TABLE tbl1;
+ SELECT 'stop' FROM pg_drop_replication_slot('isolation_slot');
+ DROP EXTENSION pg_logicalinspect;
+}
+
+session "s0"
+setup { SET synchronous_commit=on; }
+step "s0_init" { SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding'); }
+step "s0_begin" { BEGIN; }
+step "s0_savepoint" { SAVEPOINT sp1; }
+step "s0_truncate" { TRUNCATE tbl1; }
+step "s0_insert" { INSERT INTO tbl1 VALUES (1); }
+step "s0_commit" { COMMIT; }
+
+session "s1"
+setup { SET synchronous_commit=on; }
+step "s1_checkpoint" { CHECKPOINT; }
+step "s1_get_changes" { SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0'); }
+step "s1_get_logical_snapshot_meta" { SELECT COUNT(meta.*) from pg_ls_logicalsnapdir(), pg_get_logical_snapshot_meta(name) as meta;}
+step "s1_get_logical_snapshot_info" { SELECT info.state, info.catchange_count, array_length(info.catchange_xip,1) AS catchange_array_length, info.committed_count, array_length(info.committed_xip,1) AS committed_array_length FROM pg_ls_logicalsnapdir(), pg_get_logical_snapshot_info(name) AS info ORDER BY 2; }
+
+permutation "s0_init" "s0_begin" "s0_savepoint" "s0_truncate" "s1_checkpoint" "s1_get_changes" "s0_commit" "s0_begin" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_commit" "s1_get_changes" "s1_get_logical_snapshot_info" "s1_get_logical_snapshot_meta"
&pgbuffercache;
&pgcrypto;
&pgfreespacemap;
+ &pglogicalinspect;
&pgprewarm;
&pgrowlocks;
&pgstatstatements;
<!ENTITY pgbuffercache SYSTEM "pgbuffercache.sgml">
<!ENTITY pgcrypto SYSTEM "pgcrypto.sgml">
<!ENTITY pgfreespacemap SYSTEM "pgfreespacemap.sgml">
+<!ENTITY pglogicalinspect SYSTEM "pglogicalinspect.sgml">
<!ENTITY pgprewarm SYSTEM "pgprewarm.sgml">
<!ENTITY pgrowlocks SYSTEM "pgrowlocks.sgml">
<!ENTITY pgstatstatements SYSTEM "pgstatstatements.sgml">
--- /dev/null
+<!-- doc/src/sgml/pglogicalinspect.sgml -->
+
+<sect1 id="pglogicalinspect" xreflabel="pg_logicalinspect">
+ <title>pg_logicalinspect — logical decoding components inspection</title>
+
+ <indexterm zone="pglogicalinspect">
+ <primary>pg_logicalinspect</primary>
+ </indexterm>
+
+ <para>
+ The <filename>pg_logicalinspect</filename> module provides SQL functions
+ that allow you to inspect the contents of logical decoding components. It
+ allows the inspection of serialized logical snapshots of a running
+ <productname>PostgreSQL</productname> database cluster, which is useful
+ for debugging or educational purposes.
+ </para>
+
+ <para>
+ By default, use of these functions is restricted to superusers and members of
+ the <literal>pg_read_server_files</literal> role. Access may be granted by
+ superusers to others using <command>GRANT</command>.
+ </para>
+
+ <sect2 id="pglogicalinspect-funcs">
+ <title>Functions</title>
+
+ <variablelist>
+ <varlistentry id="pglogicalinspect-funcs-pg-get-logical-snapshot-meta">
+ <term>
+ <function>pg_get_logical_snapshot_meta(filename text) returns record</function>
+ </term>
+
+ <listitem>
+ <para>
+ Gets logical snapshot metadata about a snapshot file that is located in
+ the server's <filename>pg_logical/snapshots</filename> directory.
+ The <replaceable>filename</replaceable> argument represents the snapshot
+ file name.
+ For example:
+<screen>
+postgres=# SELECT * FROM pg_ls_logicalsnapdir();
+-[ RECORD 1 ]+-----------------------
+name | 0-40796E18.snap
+size | 152
+modification | 2024-08-14 16:36:32+00
+
+postgres=# SELECT * FROM pg_get_logical_snapshot_meta('0-40796E18.snap');
+-[ RECORD 1 ]--------
+magic | 1369563137
+checksum | 1028045905
+version | 6
+
+postgres=# SELECT ss.name, meta.* FROM pg_ls_logicalsnapdir() AS ss,
+pg_get_logical_snapshot_meta(ss.name) AS meta;
+-[ RECORD 1 ]-------------
+name | 0-40796E18.snap
+magic | 1369563137
+checksum | 1028045905
+version | 6
+</screen>
+ </para>
+ <para>
+ If <replaceable>filename</replaceable> does not match a snapshot file, the
+ function raises an error.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="pglogicalinspect-funcs-pg-get-logical-snapshot-info">
+ <term>
+ <function>pg_get_logical_snapshot_info(filename text) returns record</function>
+ </term>
+
+ <listitem>
+ <para>
+ Gets logical snapshot information about a snapshot file that is located in
+ the server's <filename>pg_logical/snapshots</filename> directory.
+ The <replaceable>filename</replaceable> argument represents the snapshot
+ file name.
+ For example:
+<screen>
+postgres=# SELECT * FROM pg_ls_logicalsnapdir();
+-[ RECORD 1 ]+-----------------------
+name | 0-40796E18.snap
+size | 152
+modification | 2024-08-14 16:36:32+00
+
+postgres=# SELECT * FROM pg_get_logical_snapshot_info('0-40796E18.snap');
+-[ RECORD 1 ]------------+-----------
+state | consistent
+xmin | 751
+xmax | 751
+start_decoding_at | 0/40796AF8
+two_phase_at | 0/40796AF8
+initial_xmin_horizon | 0
+building_full_snapshot | f
+in_slot_creation | f
+last_serialized_snapshot | 0/0
+next_phase_at | 0
+committed_count | 0
+committed_xip |
+catchange_count | 2
+catchange_xip | {751,752}
+
+postgres=# SELECT ss.name, info.* FROM pg_ls_logicalsnapdir() AS ss,
+pg_get_logical_snapshot_info(ss.name) AS info;
+-[ RECORD 1 ]------------+----------------
+name | 0-40796E18.snap
+state | consistent
+xmin | 751
+xmax | 751
+start_decoding_at | 0/40796AF8
+two_phase_at | 0/40796AF8
+initial_xmin_horizon | 0
+building_full_snapshot | f
+in_slot_creation | f
+last_serialized_snapshot | 0/0
+next_phase_at | 0
+committed_count | 0
+committed_xip |
+catchange_count | 2
+catchange_xip | {751,752}
+</screen>
+ </para>
+ <para>
+ If <replaceable>filename</replaceable> does not match a snapshot file, the
+ function raises an error.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </sect2>
+
+ <sect2 id="pglogicalinspect-author">
+ <title>Author</title>
+
+ <para>
+ </para>
+ </sect2>
+
+</sect1>
}
/*
- * Restore a snapshot into 'builder' if previously one has been stored at the
- * location indicated by 'lsn'. Returns true if successful, false otherwise.
+ * Restore the logical snapshot file contents to 'ondisk'.
+ *
+ * 'context' is the memory context where the catalog modifying/committed xid
+ * will live.
+ * If 'missing_ok' is true, will not throw an error if the file is not found.
*/
-static bool
-SnapBuildRestore(SnapBuild *builder, XLogRecPtr lsn)
+bool
+SnapBuildRestoreSnapshot(SnapBuildOnDisk *ondisk, const char *path,
+ MemoryContext context, bool missing_ok)
{
- SnapBuildOnDisk ondisk;
int fd;
- char path[MAXPGPATH];
- Size sz;
pg_crc32c checksum;
-
- /* no point in loading a snapshot if we're already there */
- if (builder->state == SNAPBUILD_CONSISTENT)
- return false;
-
- sprintf(path, "%s/%X-%X.snap",
- PG_LOGICAL_SNAPSHOTS_DIR,
- LSN_FORMAT_ARGS(lsn));
+ Size sz;
fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
- if (fd < 0 && errno == ENOENT)
- return false;
- else if (fd < 0)
+ if (fd < 0)
+ {
+ if (missing_ok && errno == ENOENT)
+ return false;
+
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\": %m", path)));
+ }
/* ----
* Make sure the snapshot had been stored safely to disk, that's normally
fsync_fname(path, false);
fsync_fname(PG_LOGICAL_SNAPSHOTS_DIR, true);
-
/* read statically sized portion of snapshot */
- SnapBuildRestoreContents(fd, (char *) &ondisk, SnapBuildOnDiskConstantSize, path);
+ SnapBuildRestoreContents(fd, (char *) ondisk, SnapBuildOnDiskConstantSize, path);
- if (ondisk.magic != SNAPBUILD_MAGIC)
+ if (ondisk->magic != SNAPBUILD_MAGIC)
ereport(ERROR,
(errcode(ERRCODE_DATA_CORRUPTED),
errmsg("snapbuild state file \"%s\" has wrong magic number: %u instead of %u",
- path, ondisk.magic, SNAPBUILD_MAGIC)));
+ path, ondisk->magic, SNAPBUILD_MAGIC)));
- if (ondisk.version != SNAPBUILD_VERSION)
+ if (ondisk->version != SNAPBUILD_VERSION)
ereport(ERROR,
(errcode(ERRCODE_DATA_CORRUPTED),
errmsg("snapbuild state file \"%s\" has unsupported version: %u instead of %u",
- path, ondisk.version, SNAPBUILD_VERSION)));
+ path, ondisk->version, SNAPBUILD_VERSION)));
INIT_CRC32C(checksum);
COMP_CRC32C(checksum,
- ((char *) &ondisk) + SnapBuildOnDiskNotChecksummedSize,
+ ((char *) ondisk) + SnapBuildOnDiskNotChecksummedSize,
SnapBuildOnDiskConstantSize - SnapBuildOnDiskNotChecksummedSize);
/* read SnapBuild */
- SnapBuildRestoreContents(fd, (char *) &ondisk.builder, sizeof(SnapBuild), path);
- COMP_CRC32C(checksum, &ondisk.builder, sizeof(SnapBuild));
+ SnapBuildRestoreContents(fd, (char *) &ondisk->builder, sizeof(SnapBuild), path);
+ COMP_CRC32C(checksum, &ondisk->builder, sizeof(SnapBuild));
/* restore committed xacts information */
- if (ondisk.builder.committed.xcnt > 0)
+ if (ondisk->builder.committed.xcnt > 0)
{
- sz = sizeof(TransactionId) * ondisk.builder.committed.xcnt;
- ondisk.builder.committed.xip = MemoryContextAllocZero(builder->context, sz);
- SnapBuildRestoreContents(fd, (char *) ondisk.builder.committed.xip, sz, path);
- COMP_CRC32C(checksum, ondisk.builder.committed.xip, sz);
+ sz = sizeof(TransactionId) * ondisk->builder.committed.xcnt;
+ ondisk->builder.committed.xip = MemoryContextAllocZero(context, sz);
+ SnapBuildRestoreContents(fd, (char *) ondisk->builder.committed.xip, sz, path);
+ COMP_CRC32C(checksum, ondisk->builder.committed.xip, sz);
}
/* restore catalog modifying xacts information */
- if (ondisk.builder.catchange.xcnt > 0)
+ if (ondisk->builder.catchange.xcnt > 0)
{
- sz = sizeof(TransactionId) * ondisk.builder.catchange.xcnt;
- ondisk.builder.catchange.xip = MemoryContextAllocZero(builder->context, sz);
- SnapBuildRestoreContents(fd, (char *) ondisk.builder.catchange.xip, sz, path);
- COMP_CRC32C(checksum, ondisk.builder.catchange.xip, sz);
+ sz = sizeof(TransactionId) * ondisk->builder.catchange.xcnt;
+ ondisk->builder.catchange.xip = MemoryContextAllocZero(context, sz);
+ SnapBuildRestoreContents(fd, (char *) ondisk->builder.catchange.xip, sz, path);
+ COMP_CRC32C(checksum, ondisk->builder.catchange.xip, sz);
}
if (CloseTransientFile(fd) != 0)
FIN_CRC32C(checksum);
/* verify checksum of what we've read */
- if (!EQ_CRC32C(checksum, ondisk.checksum))
+ if (!EQ_CRC32C(checksum, ondisk->checksum))
ereport(ERROR,
(errcode(ERRCODE_DATA_CORRUPTED),
errmsg("checksum mismatch for snapbuild state file \"%s\": is %u, should be %u",
- path, checksum, ondisk.checksum)));
+ path, checksum, ondisk->checksum)));
+
+ return true;
+}
+
+/*
+ * Restore a snapshot into 'builder' if previously one has been stored at the
+ * location indicated by 'lsn'. Returns true if successful, false otherwise.
+ */
+static bool
+SnapBuildRestore(SnapBuild *builder, XLogRecPtr lsn)
+{
+ SnapBuildOnDisk ondisk;
+ char path[MAXPGPATH];
+
+ /* no point in loading a snapshot if we're already there */
+ if (builder->state == SNAPBUILD_CONSISTENT)
+ return false;
+
+ sprintf(path, "%s/%X-%X.snap",
+ PG_LOGICAL_SNAPSHOTS_DIR,
+ LSN_FORMAT_ARGS(lsn));
+
+ /* validate and restore the snapshot to 'ondisk' */
+ if (!SnapBuildRestoreSnapshot(&ondisk, path, builder->context, true))
+ return false;
/*
* ok, we now have a sensible snapshot here, figure out if it has more
elmalign = TYPALIGN_SHORT;
break;
+ case XIDOID:
+ elmlen = sizeof(TransactionId);
+ elmbyval = true;
+ elmalign = TYPALIGN_INT;
+ break;
+
default:
elog(ERROR, "type %u not supported by construct_array_builtin()", elmtype);
/* keep compiler quiet */
#include "access/xlogdefs.h"
#include "utils/snapmgr.h"
+/*
+ * Please keep get_snapbuild_state_desc() (located in the pg_logicalinspect
+ * module) updated if a change needs to be made to SnapBuildState.
+ */
typedef enum
{
/*
/* variable amount of TransactionIds follows */
} SnapBuildOnDisk;
+extern bool SnapBuildRestoreSnapshot(SnapBuildOnDisk *ondisk, const char *path,
+ MemoryContext context, bool missing_ok);
+
#endif /* SNAPBUILD_INTERNAL_H */
projects / postgresql.git / commitdiff