Make logical decoding a part of the rmgr.

Add a new rmgr method, rm_decode, and use that rather than a switch
statement.

In preparation for rmgr extensibility.

Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/ed1fb2e22d15d3563ae0eb610f7b61bb15999c0a.camel%40j-davis.com
Discussion: https://postgr.es/m/20220118095332.6xtlcjoyxobv6cbk@jrouhaud

4 files changed, 43 insertions, 24 deletions

diff --git a/src/include/access/rmgr.h b/src/include/access/rmgr.h
index c9b5c56a4c6..d9b512630ca 100644
--- a/src/include/access/rmgr.h
+++ b/src/include/access/rmgr.h
@@ -19,7 +19,7 @@ typedef uint8 RmgrId;
  * Note: RM_MAX_ID must fit in RmgrId; widening that type will affect the XLOG
  * file format.
  */
-#define PG_RMGR(symname,name,redo,desc,identify,startup,cleanup,mask) \
+#define PG_RMGR(symname,name,redo,desc,identify,startup,cleanup,mask,decode) \
 	symname,
 
 typedef enum RmgrIds
diff --git a/src/include/access/rmgrlist.h b/src/include/access/rmgrlist.h
index ed751aaf039..9a74721c97c 100644
--- a/src/include/access/rmgrlist.h
+++ b/src/include/access/rmgrlist.h
@@ -25,25 +25,25 @@
  */
 
 /* symbol name, textual name, redo, desc, identify, startup, cleanup */
-PG_RMGR(RM_XLOG_ID, "XLOG", xlog_redo, xlog_desc, xlog_identify, NULL, NULL, NULL)
-PG_RMGR(RM_XACT_ID, "Transaction", xact_redo, xact_desc, xact_identify, NULL, NULL, NULL)
-PG_RMGR(RM_SMGR_ID, "Storage", smgr_redo, smgr_desc, smgr_identify, NULL, NULL, NULL)
-PG_RMGR(RM_CLOG_ID, "CLOG", clog_redo, clog_desc, clog_identify, NULL, NULL, NULL)
-PG_RMGR(RM_DBASE_ID, "Database", dbase_redo, dbase_desc, dbase_identify, NULL, NULL, NULL)
-PG_RMGR(RM_TBLSPC_ID, "Tablespace", tblspc_redo, tblspc_desc, tblspc_identify, NULL, NULL, NULL)
-PG_RMGR(RM_MULTIXACT_ID, "MultiXact", multixact_redo, multixact_desc, multixact_identify, NULL, NULL, NULL)
-PG_RMGR(RM_RELMAP_ID, "RelMap", relmap_redo, relmap_desc, relmap_identify, NULL, NULL, NULL)
-PG_RMGR(RM_STANDBY_ID, "Standby", standby_redo, standby_desc, standby_identify, NULL, NULL, NULL)
-PG_RMGR(RM_HEAP2_ID, "Heap2", heap2_redo, heap2_desc, heap2_identify, NULL, NULL, heap_mask)
-PG_RMGR(RM_HEAP_ID, "Heap", heap_redo, heap_desc, heap_identify, NULL, NULL, heap_mask)
-PG_RMGR(RM_BTREE_ID, "Btree", btree_redo, btree_desc, btree_identify, btree_xlog_startup, btree_xlog_cleanup, btree_mask)
-PG_RMGR(RM_HASH_ID, "Hash", hash_redo, hash_desc, hash_identify, NULL, NULL, hash_mask)
-PG_RMGR(RM_GIN_ID, "Gin", gin_redo, gin_desc, gin_identify, gin_xlog_startup, gin_xlog_cleanup, gin_mask)
-PG_RMGR(RM_GIST_ID, "Gist", gist_redo, gist_desc, gist_identify, gist_xlog_startup, gist_xlog_cleanup, gist_mask)
-PG_RMGR(RM_SEQ_ID, "Sequence", seq_redo, seq_desc, seq_identify, NULL, NULL, seq_mask)
-PG_RMGR(RM_SPGIST_ID, "SPGist", spg_redo, spg_desc, spg_identify, spg_xlog_startup, spg_xlog_cleanup, spg_mask)
-PG_RMGR(RM_BRIN_ID, "BRIN", brin_redo, brin_desc, brin_identify, NULL, NULL, brin_mask)
-PG_RMGR(RM_COMMIT_TS_ID, "CommitTs", commit_ts_redo, commit_ts_desc, commit_ts_identify, NULL, NULL, NULL)
-PG_RMGR(RM_REPLORIGIN_ID, "ReplicationOrigin", replorigin_redo, replorigin_desc, replorigin_identify, NULL, NULL, NULL)
-PG_RMGR(RM_GENERIC_ID, "Generic", generic_redo, generic_desc, generic_identify, NULL, NULL, generic_mask)
-PG_RMGR(RM_LOGICALMSG_ID, "LogicalMessage", logicalmsg_redo, logicalmsg_desc, logicalmsg_identify, NULL, NULL, NULL)
+PG_RMGR(RM_XLOG_ID, "XLOG", xlog_redo, xlog_desc, xlog_identify, NULL, NULL, NULL, xlog_decode)
+PG_RMGR(RM_XACT_ID, "Transaction", xact_redo, xact_desc, xact_identify, NULL, NULL, NULL, xact_decode)
+PG_RMGR(RM_SMGR_ID, "Storage", smgr_redo, smgr_desc, smgr_identify, NULL, NULL, NULL, NULL)
+PG_RMGR(RM_CLOG_ID, "CLOG", clog_redo, clog_desc, clog_identify, NULL, NULL, NULL, NULL)
+PG_RMGR(RM_DBASE_ID, "Database", dbase_redo, dbase_desc, dbase_identify, NULL, NULL, NULL, NULL)
+PG_RMGR(RM_TBLSPC_ID, "Tablespace", tblspc_redo, tblspc_desc, tblspc_identify, NULL, NULL, NULL, NULL)
+PG_RMGR(RM_MULTIXACT_ID, "MultiXact", multixact_redo, multixact_desc, multixact_identify, NULL, NULL, NULL, NULL)
+PG_RMGR(RM_RELMAP_ID, "RelMap", relmap_redo, relmap_desc, relmap_identify, NULL, NULL, NULL, NULL)
+PG_RMGR(RM_STANDBY_ID, "Standby", standby_redo, standby_desc, standby_identify, NULL, NULL, NULL, standby_decode)
+PG_RMGR(RM_HEAP2_ID, "Heap2", heap2_redo, heap2_desc, heap2_identify, NULL, NULL, heap_mask, heap2_decode)
+PG_RMGR(RM_HEAP_ID, "Heap", heap_redo, heap_desc, heap_identify, NULL, NULL, heap_mask, heap_decode)
+PG_RMGR(RM_BTREE_ID, "Btree", btree_redo, btree_desc, btree_identify, btree_xlog_startup, btree_xlog_cleanup, btree_mask, NULL)
+PG_RMGR(RM_HASH_ID, "Hash", hash_redo, hash_desc, hash_identify, NULL, NULL, hash_mask, NULL)
+PG_RMGR(RM_GIN_ID, "Gin", gin_redo, gin_desc, gin_identify, gin_xlog_startup, gin_xlog_cleanup, gin_mask, NULL)
+PG_RMGR(RM_GIST_ID, "Gist", gist_redo, gist_desc, gist_identify, gist_xlog_startup, gist_xlog_cleanup, gist_mask, NULL)
+PG_RMGR(RM_SEQ_ID, "Sequence", seq_redo, seq_desc, seq_identify, NULL, NULL, seq_mask, NULL)
+PG_RMGR(RM_SPGIST_ID, "SPGist", spg_redo, spg_desc, spg_identify, spg_xlog_startup, spg_xlog_cleanup, spg_mask, NULL)
+PG_RMGR(RM_BRIN_ID, "BRIN", brin_redo, brin_desc, brin_identify, NULL, NULL, brin_mask, NULL)
+PG_RMGR(RM_COMMIT_TS_ID, "CommitTs", commit_ts_redo, commit_ts_desc, commit_ts_identify, NULL, NULL, NULL, NULL)
+PG_RMGR(RM_REPLORIGIN_ID, "ReplicationOrigin", replorigin_redo, replorigin_desc, replorigin_identify, NULL, NULL, NULL, NULL)
+PG_RMGR(RM_GENERIC_ID, "Generic", generic_redo, generic_desc, generic_identify, NULL, NULL, generic_mask, NULL)
+PG_RMGR(RM_LOGICALMSG_ID, "LogicalMessage", logicalmsg_redo, logicalmsg_desc, logicalmsg_identify, NULL, NULL, NULL, logicalmsg_decode)
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index e27fca0cc0e..849954a8e5a 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -287,6 +287,9 @@ typedef enum
 	RECOVERY_TARGET_ACTION_SHUTDOWN
 }			RecoveryTargetAction;
 
+struct LogicalDecodingContext;
+struct XLogRecordBuffer;
+
 /*
  * Method table for resource managers.
  *
@@ -312,6 +315,8 @@ typedef struct RmgrData
 	void		(*rm_startup) (void);
 	void		(*rm_cleanup) (void);
 	void		(*rm_mask) (char *pagedata, BlockNumber blkno);
+	void		(*rm_decode) (struct LogicalDecodingContext *ctx,
+							  struct XLogRecordBuffer *buf);
 } RmgrData;
 
 extern const RmgrData RmgrTable[];
diff --git a/src/include/replication/decode.h b/src/include/replication/decode.h
index 1db73f35549..a33c2a718a7 100644
--- a/src/include/replication/decode.h
+++ b/src/include/replication/decode.h
@@ -14,7 +14,21 @@
 #include "replication/logical.h"
 #include "replication/reorderbuffer.h"
 
-void		LogicalDecodingProcessRecord(LogicalDecodingContext *ctx,
+typedef struct XLogRecordBuffer
+{
+	XLogRecPtr	origptr;
+	XLogRecPtr	endptr;
+	XLogReaderState *record;
+} XLogRecordBuffer;
+
+extern void xlog_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf);
+extern void heap_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf);
+extern void heap2_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf);
+extern void xact_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf);
+extern void standby_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf);
+extern void logicalmsg_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf);
+
+extern void	LogicalDecodingProcessRecord(LogicalDecodingContext *ctx,
 										 XLogReaderState *record);
 
 #endif