Define PG_LOGICAL_DIR for path pg_logical/ in data folder

This is similar to 2065ddf, but this time for pg_logical/ itself
and its contents, like the paths for snapshots, mappings or origin
checkpoints.

Author: Bertrand Drouvot
Reviewed-by: Ashutosh Bapat, Yugo Nagata, Michael Paquier
Discussion: https://postgr.es/m/ZryVvjqS9SnV1GPP@ip-10-97-1-34.eu-west-3.compute.internal

Author: michaelpq

src/backend/access/heap/rewriteheap.c

@@ -961,8 +961,8 @@ logical_rewrite_log_mapping(RewriteState state, TransactionId xid,
 			dboid = MyDatabaseId;
 
 		snprintf(path, MAXPGPATH,
-				 "pg_logical/mappings/" LOGICAL_REWRITE_FORMAT,
-				 dboid, relid,
+				 "%s/" LOGICAL_REWRITE_FORMAT,
+				 PG_LOGICAL_MAPPINGS_DIR, dboid, relid,
 				 LSN_FORMAT_ARGS(state->rs_begin_lsn),
 				 xid, GetCurrentTransactionId());
 
@@ -1081,8 +1081,8 @@ heap_xlog_logical_rewrite(XLogReaderState *r)
 	xlrec = (xl_heap_rewrite_mapping *) XLogRecGetData(r);
 
 	snprintf(path, MAXPGPATH,
-			 "pg_logical/mappings/" LOGICAL_REWRITE_FORMAT,
-			 xlrec->mapped_db, xlrec->mapped_rel,
+			 "%s/" LOGICAL_REWRITE_FORMAT,
+			 PG_LOGICAL_MAPPINGS_DIR, xlrec->mapped_db, xlrec->mapped_rel,
 			 LSN_FORMAT_ARGS(xlrec->start_lsn),
 			 xlrec->mapped_xid, XLogRecGetXid(r));
 
@@ -1158,7 +1158,7 @@ CheckPointLogicalRewriteHeap(void)
 	XLogRecPtr	redo;
 	DIR		   *mappings_dir;
 	struct dirent *mapping_de;
-	char		path[MAXPGPATH + 20];
+	char		path[MAXPGPATH + sizeof(PG_LOGICAL_MAPPINGS_DIR)];
 
 	/*
 	 * We start of with a minimum of the last redo pointer. No new decoding
@@ -1173,8 +1173,8 @@ CheckPointLogicalRewriteHeap(void)
 	if (cutoff != InvalidXLogRecPtr && redo < cutoff)
 		cutoff = redo;
 
-	mappings_dir = AllocateDir("pg_logical/mappings");
-	while ((mapping_de = ReadDir(mappings_dir, "pg_logical/mappings")) != NULL)
+	mappings_dir = AllocateDir(PG_LOGICAL_MAPPINGS_DIR);
+	while ((mapping_de = ReadDir(mappings_dir, PG_LOGICAL_MAPPINGS_DIR)) != NULL)
 	{
 		Oid			dboid;
 		Oid			relid;
@@ -1189,7 +1189,7 @@ CheckPointLogicalRewriteHeap(void)
 			strcmp(mapping_de->d_name, "..") == 0)
 			continue;
 
-		snprintf(path, sizeof(path), "pg_logical/mappings/%s", mapping_de->d_name);
+		snprintf(path, sizeof(path), "%s/%s", PG_LOGICAL_MAPPINGS_DIR, mapping_de->d_name);
 		de_type = get_dirent_type(path, mapping_de, false, DEBUG1);
 
 		if (de_type != PGFILETYPE_ERROR && de_type != PGFILETYPE_REG)
@@ -1249,5 +1249,5 @@ CheckPointLogicalRewriteHeap(void)
 	FreeDir(mappings_dir);
 
 	/* persist directory entries to disk */
-	fsync_fname("pg_logical/mappings", true);
+	fsync_fname(PG_LOGICAL_MAPPINGS_DIR, true);
 }

src/backend/replication/logical/origin.c

@@ -95,6 +95,10 @@
 #include "utils/snapmgr.h"
 #include "utils/syscache.h"
 
+/* paths for replication origin checkpoint files */
+#define PG_REPLORIGIN_CHECKPOINT_FILENAME PG_LOGICAL_DIR "/replorigin_checkpoint"
+#define PG_REPLORIGIN_CHECKPOINT_TMPFILE PG_REPLORIGIN_CHECKPOINT_FILENAME ".tmp"
+
 /*
  * Replay progress of a single remote node.
  */
@@ -572,8 +576,8 @@ ReplicationOriginShmemInit(void)
 void
 CheckPointReplicationOrigin(void)
 {
-	const char *tmppath = "pg_logical/replorigin_checkpoint.tmp";
-	const char *path = "pg_logical/replorigin_checkpoint";
+	const char *tmppath = PG_REPLORIGIN_CHECKPOINT_TMPFILE;
+	const char *path = PG_REPLORIGIN_CHECKPOINT_FILENAME;
 	int			tmpfd;
 	int			i;
 	uint32		magic = REPLICATION_STATE_MAGIC;
@@ -698,7 +702,7 @@ CheckPointReplicationOrigin(void)
 void
 StartupReplicationOrigin(void)
 {
-	const char *path = "pg_logical/replorigin_checkpoint";
+	const char *path = PG_REPLORIGIN_CHECKPOINT_FILENAME;
 	int			fd;
 	int			readBytes;
 	uint32		magic = REPLICATION_STATE_MAGIC;

src/backend/replication/logical/reorderbuffer.c

@@ -5081,7 +5081,7 @@ ApplyLogicalMappingFile(HTAB *tuplecid_data, Oid relid, const char *fname)
 	int			readBytes;
 	LogicalRewriteMappingData map;
 
-	sprintf(path, "pg_logical/mappings/%s", fname);
+	sprintf(path, "%s/%s", PG_LOGICAL_MAPPINGS_DIR, fname);
 	fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
 	if (fd < 0)
 		ereport(ERROR,
@@ -5197,8 +5197,8 @@ UpdateLogicalMappings(HTAB *tuplecid_data, Oid relid, Snapshot snapshot)
 	ListCell   *file;
 	Oid			dboid = IsSharedRelation(relid) ? InvalidOid : MyDatabaseId;
 
-	mapping_dir = AllocateDir("pg_logical/mappings");
-	while ((mapping_de = ReadDir(mapping_dir, "pg_logical/mappings")) != NULL)
+	mapping_dir = AllocateDir(PG_LOGICAL_MAPPINGS_DIR);
+	while ((mapping_de = ReadDir(mapping_dir, PG_LOGICAL_MAPPINGS_DIR)) != NULL)
 	{
 		Oid			f_dboid;
 		Oid			f_relid;

src/backend/replication/logical/snapbuild.c

@@ -1654,7 +1654,8 @@ SnapBuildSerialize(SnapBuild *builder, XLogRecPtr lsn)
 	 * unless the user used pg_resetwal or similar. If a user did so, there's
 	 * no hope continuing to decode anyway.
 	 */
-	sprintf(path, "pg_logical/snapshots/%X-%X.snap",
+	sprintf(path, "%s/%X-%X.snap",
+			PG_LOGICAL_SNAPSHOTS_DIR,
 			LSN_FORMAT_ARGS(lsn));
 
 	/*
@@ -1681,7 +1682,7 @@ SnapBuildSerialize(SnapBuild *builder, XLogRecPtr lsn)
 		 * be safely on disk.
 		 */
 		fsync_fname(path, false);
-		fsync_fname("pg_logical/snapshots", true);
+		fsync_fname(PG_LOGICAL_SNAPSHOTS_DIR, true);
 
 		builder->last_serialized_snapshot = lsn;
 		goto out;
@@ -1697,7 +1698,8 @@ SnapBuildSerialize(SnapBuild *builder, XLogRecPtr lsn)
 	elog(DEBUG1, "serializing snapshot to %s", path);
 
 	/* to make sure only we will write to this tempfile, include pid */
-	sprintf(tmppath, "pg_logical/snapshots/%X-%X.snap.%d.tmp",
+	sprintf(tmppath, "%s/%X-%X.snap.%d.tmp",
+			PG_LOGICAL_SNAPSHOTS_DIR,
 			LSN_FORMAT_ARGS(lsn), MyProcPid);
 
 	/*
@@ -1818,7 +1820,7 @@ SnapBuildSerialize(SnapBuild *builder, XLogRecPtr lsn)
 				(errcode_for_file_access(),
 				 errmsg("could not close file \"%s\": %m", tmppath)));
 
-	fsync_fname("pg_logical/snapshots", true);
+	fsync_fname(PG_LOGICAL_SNAPSHOTS_DIR, true);
 
 	/*
 	 * We may overwrite the work from some other backend, but that's ok, our
@@ -1834,7 +1836,7 @@ SnapBuildSerialize(SnapBuild *builder, XLogRecPtr lsn)
 
 	/* make sure we persist */
 	fsync_fname(path, false);
-	fsync_fname("pg_logical/snapshots", true);
+	fsync_fname(PG_LOGICAL_SNAPSHOTS_DIR, true);
 
 	/*
 	 * Now there's no way we can lose the dumped state anymore, remember this
@@ -1871,7 +1873,8 @@ SnapBuildRestore(SnapBuild *builder, XLogRecPtr lsn)
 	if (builder->state == SNAPBUILD_CONSISTENT)
 		return false;
 
-	sprintf(path, "pg_logical/snapshots/%X-%X.snap",
+	sprintf(path, "%s/%X-%X.snap",
+			PG_LOGICAL_SNAPSHOTS_DIR,
 			LSN_FORMAT_ARGS(lsn));
 
 	fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
@@ -1892,7 +1895,7 @@ SnapBuildRestore(SnapBuild *builder, XLogRecPtr lsn)
 	 * ----
 	 */
 	fsync_fname(path, false);
-	fsync_fname("pg_logical/snapshots", true);
+	fsync_fname(PG_LOGICAL_SNAPSHOTS_DIR, true);
 
 
 	/* read statically sized portion of snapshot */
@@ -2074,7 +2077,7 @@ CheckPointSnapBuild(void)
 	XLogRecPtr	redo;
 	DIR		   *snap_dir;
 	struct dirent *snap_de;
-	char		path[MAXPGPATH + 21];
+	char		path[MAXPGPATH + sizeof(PG_LOGICAL_SNAPSHOTS_DIR)];
 
 	/*
 	 * We start off with a minimum of the last redo pointer. No new
@@ -2090,8 +2093,8 @@ CheckPointSnapBuild(void)
 	if (redo < cutoff)
 		cutoff = redo;
 
-	snap_dir = AllocateDir("pg_logical/snapshots");
-	while ((snap_de = ReadDir(snap_dir, "pg_logical/snapshots")) != NULL)
+	snap_dir = AllocateDir(PG_LOGICAL_SNAPSHOTS_DIR);
+	while ((snap_de = ReadDir(snap_dir, PG_LOGICAL_SNAPSHOTS_DIR)) != NULL)
 	{
 		uint32		hi;
 		uint32		lo;
@@ -2102,7 +2105,7 @@ CheckPointSnapBuild(void)
 			strcmp(snap_de->d_name, "..") == 0)
 			continue;
 
-		snprintf(path, sizeof(path), "pg_logical/snapshots/%s", snap_de->d_name);
+		snprintf(path, sizeof(path), "%s/%s", PG_LOGICAL_SNAPSHOTS_DIR, snap_de->d_name);
 		de_type = get_dirent_type(path, snap_de, false, DEBUG1);
 
 		if (de_type != PGFILETYPE_ERROR && de_type != PGFILETYPE_REG)
@@ -2162,7 +2165,8 @@ SnapBuildSnapshotExists(XLogRecPtr lsn)
 	int			ret;
 	struct stat stat_buf;
 
-	sprintf(path, "pg_logical/snapshots/%X-%X.snap",
+	sprintf(path, "%s/%X-%X.snap",
+			PG_LOGICAL_SNAPSHOTS_DIR,
 			LSN_FORMAT_ARGS(lsn));
 
 	ret = stat(path, &stat_buf);

src/backend/utils/adt/genfile.c

@@ -690,21 +690,23 @@ pg_ls_archive_statusdir(PG_FUNCTION_ARGS)
 }
 
 /*
- * Function to return the list of files in the pg_logical/snapshots directory.
+ * Function to return the list of files in the PG_LOGICAL_SNAPSHOTS_DIR
+ * directory.
  */
 Datum
 pg_ls_logicalsnapdir(PG_FUNCTION_ARGS)
 {
-	return pg_ls_dir_files(fcinfo, "pg_logical/snapshots", false);
+	return pg_ls_dir_files(fcinfo, PG_LOGICAL_SNAPSHOTS_DIR, false);
 }
 
 /*
- * Function to return the list of files in the pg_logical/mappings directory.
+ * Function to return the list of files in the PG_LOGICAL_MAPPINGS_DIR
+ * directory.
  */
 Datum
 pg_ls_logicalmapdir(PG_FUNCTION_ARGS)
 {
-	return pg_ls_dir_files(fcinfo, "pg_logical/mappings", false);
+	return pg_ls_dir_files(fcinfo, PG_LOGICAL_MAPPINGS_DIR, false);
 }
 
 /*

src/include/replication/reorderbuffer.h

@@ -18,6 +18,11 @@
 #include "utils/snapshot.h"
 #include "utils/timestamp.h"
 
+/* paths for logical decoding data (relative to installation's $PGDATA) */
+#define PG_LOGICAL_DIR				"pg_logical"
+#define PG_LOGICAL_MAPPINGS_DIR		PG_LOGICAL_DIR "/mappings"
+#define PG_LOGICAL_SNAPSHOTS_DIR	PG_LOGICAL_DIR "/snapshots"
+
 /* GUC variables */
 extern PGDLLIMPORT int logical_decoding_work_mem;
 extern PGDLLIMPORT int debug_logical_replication_streaming;