Add rmgr callback to name xlog record types for display purposes.

This is primarily useful for the upcoming pg_xlogdump --stats feature,
but also allows to remove some duplicated code in the rmgr_desc
routines.

Due to the separation and harmonization, the output of dipsplayed
records changes somewhat. But since this isn't enduser oriented
content that's ok.

It's potentially desirable to further change pg_xlogdump's display of
records. It previously wasn't possible to show the record type
separately from the description forcing it to be in the last
column. But that's better done in a separate commit.

Author: Abhijit Menon-Sen, slightly editorialized by me
Reviewed-By: Álvaro Herrera, Andres Freund, and Heikki Linnakangas
Discussion: 20140604104716.GA3989@toroid.org

19 files changed, 44 insertions, 18 deletions

diff --git a/src/include/access/clog.h b/src/include/access/clog.h
index be9b8675a4..8562631b54 100644
--- a/src/include/access/clog.h
+++ b/src/include/access/clog.h
@@ -49,5 +49,6 @@ extern void TruncateCLOG(TransactionId oldestXact);
 
 extern void clog_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void clog_desc(StringInfo buf, XLogRecord *record);
+extern const char *clog_identify(uint8 info);
 
 #endif   /* CLOG_H */
diff --git a/src/include/access/gin.h b/src/include/access/gin.h
index a0b288d957..0ebecb4140 100644
--- a/src/include/access/gin.h
+++ b/src/include/access/gin.h
@@ -74,6 +74,7 @@ extern void ginUpdateStats(Relation index, const GinStatsData *stats);
 /* ginxlog.c */
 extern void gin_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void gin_desc(StringInfo buf, XLogRecord *record);
+extern const char *gin_identify(uint8 info);
 extern void gin_xlog_startup(void);
 extern void gin_xlog_cleanup(void);
 
diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h
index 03e9903e8a..879f11351b 100644
--- a/src/include/access/gist_private.h
+++ b/src/include/access/gist_private.h
@@ -452,6 +452,7 @@ extern SplitedPageLayout *gistSplit(Relation r, Page page, IndexTuple *itup,
 /* gistxlog.c */
 extern void gist_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void gist_desc(StringInfo buf, XLogRecord *record);
+extern const char *gist_identify(uint8 info);
 extern void gist_xlog_startup(void);
 extern void gist_xlog_cleanup(void);
 
diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index ff29fea089..a81b9de0e6 100644
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -357,5 +357,6 @@ extern OffsetNumber _hash_binsearch_last(Page page, uint32 hash_value);
 /* hash.c */
 extern void hash_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void hash_desc(StringInfo buf, XLogRecord *record);
+extern const char *hash_identify(uint8 info);
 
 #endif   /* HASH_H */
diff --git a/src/include/access/heapam_xlog.h b/src/include/access/heapam_xlog.h
index 254434773e..5ac98a5baa 100644
--- a/src/include/access/heapam_xlog.h
+++ b/src/include/access/heapam_xlog.h
@@ -357,8 +357,10 @@ extern void HeapTupleHeaderAdvanceLatestRemovedXid(HeapTupleHeader tuple,
 
 extern void heap_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void heap_desc(StringInfo buf, XLogRecord *record);
+extern const char *heap_identify(uint8 info);
 extern void heap2_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void heap2_desc(StringInfo buf, XLogRecord *record);
+extern const char *heap2_identify(uint8 info);
 extern void heap_xlog_logical_rewrite(XLogRecPtr lsn, XLogRecord *r);
 
 extern XLogRecPtr log_heap_cleanup_info(RelFileNode rnode,
diff --git a/src/include/access/multixact.h b/src/include/access/multixact.h
index 8db773b1b5..b331447ade 100644
--- a/src/include/access/multixact.h
+++ b/src/include/access/multixact.h
@@ -136,6 +136,7 @@ extern void multixact_twophase_postabort(TransactionId xid, uint16 info,
 
 extern void multixact_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void multixact_desc(StringInfo buf, XLogRecord *record);
+extern const char *multixact_identify(uint8 info);
 extern char *mxid_to_string(MultiXactId multi, int nmembers,
 			   MultiXactMember *members);
 
diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h
index 9fa943f39e..90fd6d0056 100644
--- a/src/include/access/nbtree.h
+++ b/src/include/access/nbtree.h
@@ -726,5 +726,6 @@ extern void _bt_leafbuild(BTSpool *btspool, BTSpool *spool2);
  */
 extern void btree_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void btree_desc(StringInfo buf, XLogRecord *record);
+extern const char *btree_identify(uint8 info);
 
 #endif   /* NBTREE_H */
diff --git a/src/include/access/rmgr.h b/src/include/access/rmgr.h
index 1b577a2050..ff7fe62c05 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,startup,cleanup) \
+#define PG_RMGR(symname,name,redo,desc,identify,startup,cleanup) \
 	symname,
 
 typedef enum RmgrIds
diff --git a/src/include/access/rmgrlist.h b/src/include/access/rmgrlist.h
index 662fb77b42..77d4574ed1 100644
--- a/src/include/access/rmgrlist.h
+++ b/src/include/access/rmgrlist.h
@@ -25,20 +25,20 @@
  */
 
 /* symbol name, textual name, redo, desc, startup, cleanup */
-PG_RMGR(RM_XLOG_ID, "XLOG", xlog_redo, xlog_desc, NULL, NULL)
-PG_RMGR(RM_XACT_ID, "Transaction", xact_redo, xact_desc, NULL, NULL)
-PG_RMGR(RM_SMGR_ID, "Storage", smgr_redo, smgr_desc, NULL, NULL)
-PG_RMGR(RM_CLOG_ID, "CLOG", clog_redo, clog_desc, NULL, NULL)
-PG_RMGR(RM_DBASE_ID, "Database", dbase_redo, dbase_desc, NULL, NULL)
-PG_RMGR(RM_TBLSPC_ID, "Tablespace", tblspc_redo, tblspc_desc, NULL, NULL)
-PG_RMGR(RM_MULTIXACT_ID, "MultiXact", multixact_redo, multixact_desc, NULL, NULL)
-PG_RMGR(RM_RELMAP_ID, "RelMap", relmap_redo, relmap_desc, NULL, NULL)
-PG_RMGR(RM_STANDBY_ID, "Standby", standby_redo, standby_desc, NULL, NULL)
-PG_RMGR(RM_HEAP2_ID, "Heap2", heap2_redo, heap2_desc, NULL, NULL)
-PG_RMGR(RM_HEAP_ID, "Heap", heap_redo, heap_desc, NULL, NULL)
-PG_RMGR(RM_BTREE_ID, "Btree", btree_redo, btree_desc, NULL, NULL)
-PG_RMGR(RM_HASH_ID, "Hash", hash_redo, hash_desc, NULL, NULL)
-PG_RMGR(RM_GIN_ID, "Gin", gin_redo, gin_desc, gin_xlog_startup, gin_xlog_cleanup)
-PG_RMGR(RM_GIST_ID, "Gist", gist_redo, gist_desc, gist_xlog_startup, gist_xlog_cleanup)
-PG_RMGR(RM_SEQ_ID, "Sequence", seq_redo, seq_desc, NULL, NULL)
-PG_RMGR(RM_SPGIST_ID, "SPGist", spg_redo, spg_desc, spg_xlog_startup, spg_xlog_cleanup)
+PG_RMGR(RM_XLOG_ID, "XLOG", xlog_redo, xlog_desc, xlog_identify, NULL, NULL)
+PG_RMGR(RM_XACT_ID, "Transaction", xact_redo, xact_desc, xact_identify, NULL, NULL)
+PG_RMGR(RM_SMGR_ID, "Storage", smgr_redo, smgr_desc, smgr_identify, NULL, NULL)
+PG_RMGR(RM_CLOG_ID, "CLOG", clog_redo, clog_desc, clog_identify, NULL, NULL)
+PG_RMGR(RM_DBASE_ID, "Database", dbase_redo, dbase_desc, dbase_identify, NULL, NULL)
+PG_RMGR(RM_TBLSPC_ID, "Tablespace", tblspc_redo, tblspc_desc, tblspc_identify, NULL, NULL)
+PG_RMGR(RM_MULTIXACT_ID, "MultiXact", multixact_redo, multixact_desc, multixact_identify, NULL, NULL)
+PG_RMGR(RM_RELMAP_ID, "RelMap", relmap_redo, relmap_desc, relmap_identify, NULL, NULL)
+PG_RMGR(RM_STANDBY_ID, "Standby", standby_redo, standby_desc, standby_identify, NULL, NULL)
+PG_RMGR(RM_HEAP2_ID, "Heap2", heap2_redo, heap2_desc, heap2_identify, NULL, NULL)
+PG_RMGR(RM_HEAP_ID, "Heap", heap_redo, heap_desc, heap_identify, NULL, NULL)
+PG_RMGR(RM_BTREE_ID, "Btree", btree_redo, btree_desc, btree_identify, NULL, NULL)
+PG_RMGR(RM_HASH_ID, "Hash", hash_redo, hash_desc, hash_identify, NULL, NULL)
+PG_RMGR(RM_GIN_ID, "Gin", gin_redo, gin_desc, gin_identify, gin_xlog_startup, gin_xlog_cleanup)
+PG_RMGR(RM_GIST_ID, "Gist", gist_redo, gist_desc, gist_identify, gist_xlog_startup, gist_xlog_cleanup)
+PG_RMGR(RM_SEQ_ID, "Sequence", seq_redo, seq_desc, seq_identify, NULL, NULL)
+PG_RMGR(RM_SPGIST_ID, "SPGist", spg_redo, spg_desc, spg_identify, spg_xlog_startup, spg_xlog_cleanup)
diff --git a/src/include/access/spgist.h b/src/include/access/spgist.h
index 7f8655cf60..f218a83224 100644
--- a/src/include/access/spgist.h
+++ b/src/include/access/spgist.h
@@ -198,6 +198,7 @@ extern Datum spgvacuumcleanup(PG_FUNCTION_ARGS);
 /* spgxlog.c */
 extern void spg_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void spg_desc(StringInfo buf, XLogRecord *record);
+extern const char *spg_identify(uint8 info);
 extern void spg_xlog_startup(void);
 extern void spg_xlog_cleanup(void);
 
diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index 2168dc3cb5..45376b4792 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.h
@@ -256,5 +256,6 @@ extern int	xactGetCommittedChildren(TransactionId **ptr);
 
 extern void xact_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void xact_desc(StringInfo buf, XLogRecord *record);
+extern const char *xact_identify(uint8 info);
 
 #endif   /* XACT_H */
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 7d6db49893..0b7bfa5f30 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -304,6 +304,7 @@ extern Buffer RestoreBackupBlock(XLogRecPtr lsn, XLogRecord *record,
 
 extern void xlog_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void xlog_desc(StringInfo buf, XLogRecord *record);
+extern const char *xlog_identify(uint8 info);
 
 extern void issue_xlog_fsync(int fd, XLogSegNo segno);
 
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index 954114f0d5..a1452b82b8 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -239,6 +239,14 @@ struct XLogRecord;
  * This struct must be kept in sync with the PG_RMGR definition in
  * rmgr.c.
  *
+ * rm_identify must return a name for the record based on xl_info (without
+ * reference to the rmid). For example, XLOG_BTREE_VACUUM would be named
+ * "VACUUM". rm_desc can then be called to obtain additional detail for the
+ * record, if available (e.g. the last block).
+ *
+ * The return value from rm_identify is a pointer to a statically allocated
+ * buffer, and only valid until the next invocation of the callback.
+ *
  * RmgrTable[] is indexed by RmgrId values (see rmgrlist.h).
  */
 typedef struct RmgrData
@@ -246,6 +254,7 @@ typedef struct RmgrData
 	const char *rm_name;
 	void		(*rm_redo) (XLogRecPtr lsn, struct XLogRecord *rptr);
 	void		(*rm_desc) (StringInfo buf, struct XLogRecord *rptr);
+	const char *(*rm_identify) (uint8 info);
 	void		(*rm_startup) (void);
 	void		(*rm_cleanup) (void);
 } RmgrData;
diff --git a/src/include/catalog/storage_xlog.h b/src/include/catalog/storage_xlog.h
index 7081c990ad..5fc7235828 100644
--- a/src/include/catalog/storage_xlog.h
+++ b/src/include/catalog/storage_xlog.h
@@ -45,5 +45,6 @@ extern void log_smgrcreate(RelFileNode *rnode, ForkNumber forkNum);
 
 extern void smgr_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void smgr_desc(StringInfo buf, XLogRecord *record);
+extern const char *smgr_identify(uint8 info);
 
 #endif   /* STORAGE_XLOG_H */
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index c2380dca11..811713fb83 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -64,6 +64,7 @@ extern char *get_database_name(Oid dbid);
 
 extern void dbase_redo(XLogRecPtr lsn, XLogRecord *rptr);
 extern void dbase_desc(StringInfo buf, XLogRecord *rptr);
+extern const char *dbase_identify(uint8 info);
 
 extern void check_encoding_locale_matches(int encoding, const char *collate, const char *ctype);
 
diff --git a/src/include/commands/sequence.h b/src/include/commands/sequence.h
index 8819c00e81..914d155c9f 100644
--- a/src/include/commands/sequence.h
+++ b/src/include/commands/sequence.h
@@ -78,5 +78,6 @@ extern void ResetSequenceCaches(void);
 
 extern void seq_redo(XLogRecPtr lsn, XLogRecord *rptr);
 extern void seq_desc(StringInfo buf, XLogRecord *rptr);
+extern const char *seq_identify(uint8 info);
 
 #endif   /* SEQUENCE_H */
diff --git a/src/include/commands/tablespace.h b/src/include/commands/tablespace.h
index d01ae8bdf9..0f16f40e3d 100644
--- a/src/include/commands/tablespace.h
+++ b/src/include/commands/tablespace.h
@@ -57,5 +57,6 @@ extern bool directory_is_empty(const char *path);
 
 extern void tblspc_redo(XLogRecPtr lsn, XLogRecord *rptr);
 extern void tblspc_desc(StringInfo buf, XLogRecord *rptr);
+extern const char *tblspc_identify(uint8 info);
 
 #endif   /* TABLESPACE_H */
diff --git a/src/include/storage/standby.h b/src/include/storage/standby.h
index da22fd3149..1c63af521f 100644
--- a/src/include/storage/standby.h
+++ b/src/include/storage/standby.h
@@ -83,6 +83,7 @@ typedef struct xl_running_xacts
 /* Recovery handlers for the Standby Rmgr (RM_STANDBY_ID) */
 extern void standby_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void standby_desc(StringInfo buf, XLogRecord *record);
+extern const char *standby_identify(uint8 info);
 
 /*
  * Declarations for GetRunningTransactionData(). Similar to Snapshots, but
diff --git a/src/include/utils/relmapper.h b/src/include/utils/relmapper.h
index 76bcf18d5a..37937ddab8 100644
--- a/src/include/utils/relmapper.h
+++ b/src/include/utils/relmapper.h
@@ -60,5 +60,6 @@ extern void RelationMapInitializePhase3(void);
 
 extern void relmap_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void relmap_desc(StringInfo buf, XLogRecord *record);
+extern const char *relmap_identify(uint8 info);
 
 #endif   /* RELMAPPER_H */