Commit the reasonably uncontroversial parts of J.R. Nield's PITR patch, to

wit: Add a header record to each WAL segment file so that it can be reliably
identified.  Avoid splitting WAL records across segment files (this is not
strictly necessary, but makes it simpler to incorporate the header records).
Make WAL entries for file creation, deletion, and truncation (as foreseen but
never implemented by Vadim).  Also, add support for making XLOG_SEG_SIZE
configurable at compile time, similarly to BLCKSZ.  Fix a couple bugs I
introduced in WAL replay during recent smgr API changes.  initdb is forced
due to changes in pg_control contents.

1 files changed, 68 insertions, 8 deletions

diff --git a/src/bin/pg_resetxlog/pg_resetxlog.c b/src/bin/pg_resetxlog/pg_resetxlog.c
index ab64c224fc..9049aed099 100644
--- a/src/bin/pg_resetxlog/pg_resetxlog.c
+++ b/src/bin/pg_resetxlog/pg_resetxlog.c
@@ -23,7 +23,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.14 2003/11/29 19:52:06 pgsql Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.15 2004/02/11 22:55:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -33,6 +33,7 @@
 #include <unistd.h>
 #include <time.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 #include <fcntl.h>
 #include <dirent.h>
 #include <locale.h>
@@ -289,7 +290,7 @@ main(int argc, char *argv[])
  * Try to read the existing pg_control file.
  *
  * This routine is also responsible for updating old pg_control versions
- * to the current format.
+ * to the current format.  (Currently we don't do anything of the sort.)
  */
 static bool
 ReadControlFile(void)
@@ -366,6 +367,8 @@ ReadControlFile(void)
 static void
 GuessControlValues(void)
 {
+	uint64		sysidentifier;
+	struct timeval tv;
 	char	   *localeptr;
 
 	/*
@@ -377,8 +380,18 @@ GuessControlValues(void)
 	ControlFile.pg_control_version = PG_CONTROL_VERSION;
 	ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 
+	/*
+	 * Create a new unique installation identifier, since we can no longer
+	 * use any old XLOG records.  See notes in xlog.c about the algorithm.
+	 */
+	gettimeofday(&tv, NULL);
+	sysidentifier = ((uint64) tv.tv_sec) << 32;
+	sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
+
+	ControlFile.system_identifier = sysidentifier;
+
 	ControlFile.checkPointCopy.redo.xlogid = 0;
-	ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogPHD;
+	ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogPHD + SizeOfXLogRecord + SizeOfXLogFHD;
 	ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 	ControlFile.checkPointCopy.ThisStartUpID = 0;
 	ControlFile.checkPointCopy.nextXid = (TransactionId) 514;	/* XXX */
@@ -393,6 +406,7 @@ GuessControlValues(void)
 
 	ControlFile.blcksz = BLCKSZ;
 	ControlFile.relseg_size = RELSEG_SIZE;
+	ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 	ControlFile.nameDataLen = NAMEDATALEN;
 	ControlFile.funcMaxArgs = FUNC_MAX_ARGS;
 #ifdef HAVE_INT64_TIMESTAMP
@@ -433,13 +447,23 @@ GuessControlValues(void)
 static void
 PrintControlValues(bool guessed)
 {
+	char		sysident_str[32];
+
 	if (guessed)
 		printf(_("Guessed pg_control values:\n\n"));
 	else
 		printf(_("pg_control values:\n\n"));
 
+	/*
+	 * Format system_identifier separately to keep platform-dependent format
+	 * code out of the translatable message string.
+	 */
+	snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
+			 ControlFile.system_identifier);
+
 	printf(_("pg_control version number:            %u\n"), ControlFile.pg_control_version);
 	printf(_("Catalog version number:               %u\n"), ControlFile.catalog_version_no);
+	printf(_("Database system identifier:           %s\n"), sysident_str);
 	printf(_("Current log file ID:                  %u\n"), ControlFile.logId);
 	printf(_("Next log file segment:                %u\n"), ControlFile.logSeg);
 	printf(_("Latest checkpoint's StartUpID:        %u\n"), ControlFile.checkPointCopy.ThisStartUpID);
@@ -472,12 +496,20 @@ RewriteControlFile(void)
 	 */
 	newXlogId = ControlFile.logId;
 	newXlogSeg = ControlFile.logSeg;
+
+	/* adjust in case we are changing segment size */
+	newXlogSeg *= ControlFile.xlog_seg_size;
+	newXlogSeg = (newXlogSeg + XLogSegSize-1) / XLogSegSize;
+
 	/* be sure we wrap around correctly at end of a logfile */
 	NextLogSeg(newXlogId, newXlogSeg);
 
+	/* Now we can force the recorded xlog seg size to the right thing. */
+	ControlFile.xlog_seg_size = XLogSegSize;
+
 	ControlFile.checkPointCopy.redo.xlogid = newXlogId;
 	ControlFile.checkPointCopy.redo.xrecoff =
-		newXlogSeg * XLogSegSize + SizeOfXLogPHD;
+		newXlogSeg * XLogSegSize + SizeOfXLogPHD + SizeOfXLogRecord + SizeOfXLogFHD;
 	ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 	ControlFile.checkPointCopy.time = time(NULL);
 
@@ -600,6 +632,7 @@ WriteEmptyXLOG(void)
 	char	   *buffer;
 	XLogPageHeader page;
 	XLogRecord *record;
+	XLogFileHeaderData *fhdr;
 	crc64		crc;
 	char		path[MAXPGPATH];
 	int			fd;
@@ -608,20 +641,47 @@ WriteEmptyXLOG(void)
 	/* Use malloc() to ensure buffer is MAXALIGNED */
 	buffer = (char *) malloc(BLCKSZ);
 	page = (XLogPageHeader) buffer;
-
-	/* Set up the first page with initial record */
 	memset(buffer, 0, BLCKSZ);
+
+	/* Set up the XLOG page header */
 	page->xlp_magic = XLOG_PAGE_MAGIC;
 	page->xlp_info = 0;
 	page->xlp_sui = ControlFile.checkPointCopy.ThisStartUpID;
 	page->xlp_pageaddr.xlogid =
 		ControlFile.checkPointCopy.redo.xlogid;
 	page->xlp_pageaddr.xrecoff =
-		ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogPHD;
+		ControlFile.checkPointCopy.redo.xrecoff -
+		(SizeOfXLogPHD + SizeOfXLogRecord + SizeOfXLogFHD);
+
+	/* Insert the file header record */
 	record = (XLogRecord *) ((char *) page + SizeOfXLogPHD);
 	record->xl_prev.xlogid = 0;
 	record->xl_prev.xrecoff = 0;
-	record->xl_xact_prev = record->xl_prev;
+	record->xl_xact_prev.xlogid = 0;
+	record->xl_xact_prev.xrecoff = 0;
+	record->xl_xid = InvalidTransactionId;
+	record->xl_len = SizeOfXLogFHD;
+	record->xl_info = XLOG_FILE_HEADER;
+	record->xl_rmid = RM_XLOG_ID;
+	fhdr = (XLogFileHeaderData *) XLogRecGetData(record);
+	fhdr->xlfhd_sysid = ControlFile.system_identifier;
+	fhdr->xlfhd_xlogid = page->xlp_pageaddr.xlogid;
+	fhdr->xlfhd_segno = page->xlp_pageaddr.xrecoff / XLogSegSize;
+	fhdr->xlfhd_seg_size = XLogSegSize;
+
+	INIT_CRC64(crc);
+	COMP_CRC64(crc, fhdr, SizeOfXLogFHD);
+	COMP_CRC64(crc, (char *) record + sizeof(crc64),
+			   SizeOfXLogRecord - sizeof(crc64));
+	FIN_CRC64(crc);
+	record->xl_crc = crc;
+
+	/* Insert the initial checkpoint record */
+	record = (XLogRecord *) ((char *) page + SizeOfXLogPHD + SizeOfXLogRecord + SizeOfXLogFHD);
+	record->xl_prev.xlogid = page->xlp_pageaddr.xlogid;
+	record->xl_prev.xrecoff = page->xlp_pageaddr.xrecoff + SizeOfXLogPHD;
+	record->xl_xact_prev.xlogid = 0;
+	record->xl_xact_prev.xrecoff = 0;
 	record->xl_xid = InvalidTransactionId;
 	record->xl_len = sizeof(CheckPoint);
 	record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;