Extens page bitmap by doubling its size

Author: knizhnik

.gitignore

@@ -34,9 +34,6 @@
 
 # Extra files
 /src/pg_crc.c
-/src/datapagemap.c
-/src/datapagemap.h
-/src/logging.h
 /src/receivelog.c
 /src/receivelog.h
 /src/streamutil.c

Makefile

@@ -7,13 +7,13 @@ OBJS = src/utils/configuration.o src/utils/json.o src/utils/logger.o \
 OBJS += src/archive.o src/backup.o src/catalog.o src/checkdb.o src/configure.o src/data.o \
 	src/delete.o src/dir.o src/fetch.o src/help.o src/init.o src/merge.o \
 	src/parsexlog.o src/ptrack.o src/pg_probackup.o src/restore.o src/show.o src/util.o \
-	src/validate.o
+	src/validate.o src/datapagemap.o
 
 # borrowed files
-OBJS += src/pg_crc.o src/datapagemap.o src/receivelog.o src/streamutil.o \
+OBJS += src/pg_crc.o src/receivelog.o src/streamutil.o \
 	src/xlogreader.o
 
-EXTRA_CLEAN = src/pg_crc.c src/datapagemap.c src/datapagemap.h \
+EXTRA_CLEAN = src/pg_crc.c \
 	src/receivelog.c src/receivelog.h src/streamutil.c src/streamutil.h \
 	src/xlogreader.c src/instr_time.h
 
@@ -34,9 +34,6 @@ ifneq (,$(wildcard $(srchome)/src/bin/pg_basebackup/walmethods.c))
 OBJS += src/walmethods.o
 EXTRA_CLEAN += src/walmethods.c src/walmethods.h
 endif
-ifneq (,$(wildcard $(srchome)/src/bin/pg_rewind/logging.h))
-EXTRA_CLEAN += src/logging.h
-endif
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config
@@ -56,16 +53,9 @@ PG_LIBS_INTERNAL = $(libpq_pgport) ${PTHREAD_CFLAGS}
 src/utils/configuration.o: src/datapagemap.h
 src/archive.o: src/instr_time.h
 src/backup.o: src/receivelog.h src/streamutil.h
-ifneq (,$(wildcard $(srchome)/src/bin/pg_rewind/logging.h))
-src/datapagemap.o: src/logging.h
-endif
 
 src/instr_time.h: $(srchome)/src/include/portability/instr_time.h
 	rm -f $@ && $(LN_S) $(srchome)/src/include/portability/instr_time.h $@
-src/datapagemap.c: $(srchome)/src/bin/pg_rewind/datapagemap.c
-	rm -f $@ && $(LN_S) $(srchome)/src/bin/pg_rewind/datapagemap.c $@
-src/datapagemap.h: $(srchome)/src/bin/pg_rewind/datapagemap.h
-	rm -f $@ && $(LN_S) $(srchome)/src/bin/pg_rewind/datapagemap.h $@
 src/pg_crc.c: $(srchome)/src/backend/utils/hash/pg_crc.c
 	rm -f $@ && $(LN_S) $(srchome)/src/backend/utils/hash/pg_crc.c $@
 src/receivelog.c: $(srchome)/src/bin/pg_basebackup/receivelog.c
@@ -82,8 +72,6 @@ src/streamutil.h: $(srchome)/src/bin/pg_basebackup/streamutil.h
 	rm -f $@ && $(LN_S) $(srchome)/src/bin/pg_basebackup/streamutil.h $@
 src/xlogreader.c: $(srchome)/src/backend/access/transam/xlogreader.c
 	rm -f $@ && $(LN_S) $(srchome)/src/backend/access/transam/xlogreader.c $@
-src/logging.h: $(srchome)/src/bin/pg_rewind/logging.h
-	rm -f $@ && $(LN_S) $(srchome)/src/bin/pg_rewind/logging.h $@
 src/walmethods.c: $(srchome)/src/bin/pg_basebackup/walmethods.c
 	rm -f $@ && $(LN_S) $(srchome)/src/bin/pg_basebackup/walmethods.c $@
 src/walmethods.h: $(srchome)/src/bin/pg_basebackup/walmethods.h

src/datapagemap.c

@@ -0,0 +1,113 @@
+/*-------------------------------------------------------------------------
+ *
+ * datapagemap.c
+ *	  A data structure for keeping track of data pages that have changed.
+ *
+ * This is a fairly simple bitmap.
+ *
+ * Copyright (c) 2013-2019, PostgreSQL Global Development Group
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres_fe.h"
+
+#include "datapagemap.h"
+
+struct datapagemap_iterator
+{
+	datapagemap_t *map;
+	BlockNumber nextblkno;
+};
+
+/*****
+ * Public functions
+ */
+
+/*
+ * Add a block to the bitmap.
+ */
+void
+datapagemap_add(datapagemap_t *map, BlockNumber blkno)
+{
+	int			offset;
+	int			bitno;
+	int			oldsize = map->bitmapsize;
+
+	offset = blkno / 8;
+	bitno = blkno % 8;
+
+	/* enlarge or create bitmap if needed */
+	if (oldsize <= offset)
+	{
+		int			newsize;
+
+		/*
+		 * The minimum to hold the new bit is offset + 1. But add some
+		 * headroom, so that we don't need to repeatedly enlarge the bitmap in
+		 * the common case that blocks are modified in order, from beginning
+		 * of a relation to the end.
+		 */
+		newsize = (oldsize == 0) ? 16 : oldsize;
+		while (newsize <= offset) {
+			newsize <<= 1;
+		}
+
+		map->bitmap = pg_realloc(map->bitmap, newsize);
+
+		/* zero out the newly allocated region */
+		memset(&map->bitmap[oldsize], 0, newsize - oldsize);
+
+		map->bitmapsize = newsize;
+	}
+
+	/* Set the bit */
+	map->bitmap[offset] |= (1 << bitno);
+}
+
+/*
+ * Start iterating through all entries in the page map.
+ *
+ * After datapagemap_iterate, call datapagemap_next to return the entries,
+ * until it returns false. After you're done, use pg_free() to destroy the
+ * iterator.
+ */
+datapagemap_iterator_t *
+datapagemap_iterate(datapagemap_t *map)
+{
+	datapagemap_iterator_t *iter;
+
+	iter = pg_malloc(sizeof(datapagemap_iterator_t));
+	iter->map = map;
+	iter->nextblkno = 0;
+
+	return iter;
+}
+
+bool
+datapagemap_next(datapagemap_iterator_t *iter, BlockNumber *blkno)
+{
+	datapagemap_t *map = iter->map;
+
+	for (;;)
+	{
+		BlockNumber blk = iter->nextblkno;
+		int			nextoff = blk / 8;
+		int			bitno = blk % 8;
+
+		if (nextoff >= map->bitmapsize)
+			break;
+
+		iter->nextblkno++;
+
+		if (map->bitmap[nextoff] & (1 << bitno))
+		{
+			*blkno = blk;
+			return true;
+		}
+	}
+
+	/* no more set bits in this bitmap. */
+	return false;
+}
+

src/datapagemap.h

@@ -0,0 +1,29 @@
+/*-------------------------------------------------------------------------
+ *
+ * datapagemap.h
+ *
+ * Copyright (c) 2013-2019, PostgreSQL Global Development Group
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef DATAPAGEMAP_H
+#define DATAPAGEMAP_H
+
+#include "storage/relfilenode.h"
+#include "storage/block.h"
+
+
+struct datapagemap
+{
+	char	   *bitmap;
+	int			bitmapsize;
+};
+
+typedef struct datapagemap datapagemap_t;
+typedef struct datapagemap_iterator datapagemap_iterator_t;
+
+extern void datapagemap_add(datapagemap_t *map, BlockNumber blkno);
+extern datapagemap_iterator_t *datapagemap_iterate(datapagemap_t *map);
+extern bool datapagemap_next(datapagemap_iterator_t *iter, BlockNumber *blkno);
+
+#endif							/* DATAPAGEMAP_H */

src/util.c

@@ -538,33 +538,7 @@ datapagemap_is_set(datapagemap_t *map, BlockNumber blkno)
 	offset = blkno / 8;
 	bitno = blkno % 8;
 
-	/* enlarge or create bitmap if needed */
-	if (map->bitmapsize <= offset)
-	{
-		int			oldsize = map->bitmapsize;
-		int			newsize;
-
-		/*
-		 * The minimum to hold the new bit is offset + 1. But add some
-		 * headroom, so that we don't need to repeatedly enlarge the bitmap in
-		 * the common case that blocks are modified in order, from beginning
-		 * of a relation to the end.
-		 */
-		newsize = offset + 1;
-		newsize += 10;
-
-		map->bitmap = pg_realloc(map->bitmap, newsize);
-
-		/* zero out the newly allocated region */
-		memset(&map->bitmap[oldsize], 0, newsize - oldsize);
-
-		map->bitmapsize = newsize;
-	}
-
-	//datapagemap_print(map);
-
-	/* check the bit */
-	return map->bitmap[offset] & (1 << bitno);
+	return (map->bitmapsize <= offset) ? false : (map->bitmap[offset] & (1 << bitno)) != 0;
 }
 
 /*