Make use of xlog_internal.h's macros in WAL-related utilities.

Commit 179cdd0 added macros to check if a filename is a WAL segment
or other such file. However there were still some instances of the
strlen + strspn combination to check for that in WAL-related utilities
like pg_archivecleanup. Those checks can be replaced with the macros.

This patch makes use of the macros in those utilities and
which would make the code a bit easier to read.

Back-patch to 9.5.

Michael Paquier

Author: MasaoFujii

contrib/pg_standby/pg_standby.c

@@ -32,6 +32,8 @@
 
 #include "pg_getopt.h"
 
+#include "access/xlog_internal.h"
+
 const char *progname;
 
 /* Options and defaults */
@@ -57,7 +59,7 @@ char	   *restartWALFileName; /* the file from which we can restart restore */
 char	   *priorWALFileName;	/* the file we need to get from archive */
 char		WALFilePath[MAXPGPATH];		/* the file path including archive */
 char		restoreCommand[MAXPGPATH];	/* run this to restore */
-char		exclusiveCleanupFileName[MAXPGPATH];		/* the file we need to
+char		exclusiveCleanupFileName[MAXFNAMELEN];		/* the file we need to
 														 * get from archive */
 
 /*
@@ -113,11 +115,6 @@ struct stat stat_buf;
  *	folded in to later versions of this program.
  */
 
-#define XLOG_DATA_FNAME_LEN		24
-/* Reworked from access/xlog_internal.h */
-#define XLogFileName(fname, tli, log, seg)	\
-	snprintf(fname, XLOG_DATA_FNAME_LEN + 1, "%08X%08X%08X", tli, log, seg)
-
 /*
  *	Initialize allows customized commands into the warm standby program.
  *
@@ -182,10 +179,7 @@ CustomizableNextWALFileReady()
 		 * If it's a backup file, return immediately. If it's a regular file
 		 * return only if it's the right size already.
 		 */
-		if (strlen(nextWALFileName) > 24 &&
-			strspn(nextWALFileName, "0123456789ABCDEF") == 24 &&
-		strcmp(nextWALFileName + strlen(nextWALFileName) - strlen(".backup"),
-			   ".backup") == 0)
+		if (IsBackupHistoryFileName(nextWALFileName))
 		{
 			nextWALFileType = XLOG_BACKUP_LABEL;
 			return true;
@@ -261,8 +255,7 @@ CustomizableCleanupPriorWALFiles(void)
 				 * are not removed in the order they were originally written,
 				 * in case this worries you.
 				 */
-				if (strlen(xlde->d_name) == XLOG_DATA_FNAME_LEN &&
-					strspn(xlde->d_name, "0123456789ABCDEF") == XLOG_DATA_FNAME_LEN &&
+				if (IsXLogFileName(xlde->d_name) &&
 				  strcmp(xlde->d_name + 8, exclusiveCleanupFileName + 8) < 0)
 				{
 #ifdef WIN32
@@ -366,7 +359,7 @@ SetWALFileNameForCleanup(void)
 		}
 	}
 
-	XLogFileName(exclusiveCleanupFileName, tli, log, seg);
+	XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
 
 	return cleanup;
 }
@@ -740,10 +733,7 @@ main(int argc, char **argv)
 	 * Check for initial history file: always the first file to be requested
 	 * It's OK if the file isn't there - all other files need to wait
 	 */
-	if (strlen(nextWALFileName) > 8 &&
-		strspn(nextWALFileName, "0123456789ABCDEF") == 8 &&
-		strcmp(nextWALFileName + strlen(nextWALFileName) - strlen(".history"),
-			   ".history") == 0)
+	if (IsTLHistoryFileName(nextWALFileName))
 	{
 		nextWALFileType = XLOG_HISTORY;
 		if (RestoreWALFileForRecovery())

src/bin/pg_archivecleanup/pg_archivecleanup.c

@@ -21,6 +21,8 @@
 
 #include "pg_getopt.h"
 
+#include "access/xlog_internal.h"
+
 const char *progname;
 
 /* Options and defaults */
@@ -31,7 +33,7 @@ char	   *additional_ext = NULL;		/* Extension to remove from filenames */
 char	   *archiveLocation;	/* where to find the archive? */
 char	   *restartWALFileName; /* the file from which we can restart restore */
 char		WALFilePath[MAXPGPATH];		/* the file path including archive */
-char		exclusiveCleanupFileName[MAXPGPATH];		/* the oldest file we
+char		exclusiveCleanupFileName[MAXFNAMELEN];		/* the oldest file we
 														 * want to remain in
 														 * archive */
 
@@ -51,12 +53,6 @@ char		exclusiveCleanupFileName[MAXPGPATH];		/* the oldest file we
  *	folded in to later versions of this program.
  */
 
-#define XLOG_DATA_FNAME_LEN		24
-/* Reworked from access/xlog_internal.h */
-#define XLogFileName(fname, tli, log, seg)	\
-	snprintf(fname, XLOG_DATA_FNAME_LEN + 1, "%08X%08X%08X", tli, log, seg)
-#define XLOG_BACKUP_FNAME_LEN	40
-
 /*
  *	Initialize allows customized commands into the archive cleanup program.
  *
@@ -110,7 +106,7 @@ CleanupPriorWALFiles(void)
 		{
 			/*
 			 * Truncation is essentially harmless, because we skip names of
-			 * length other than XLOG_DATA_FNAME_LEN.  (In principle, one
+			 * length other than XLOG_FNAME_LEN.  (In principle, one
 			 * could use a 1000-character additional_ext and get trouble.)
 			 */
 			strlcpy(walfile, xlde->d_name, MAXPGPATH);
@@ -129,8 +125,7 @@ CleanupPriorWALFiles(void)
 			 * file. Note that this means files are not removed in the order
 			 * they were originally written, in case this worries you.
 			 */
-			if (strlen(walfile) == XLOG_DATA_FNAME_LEN &&
-				strspn(walfile, "0123456789ABCDEF") == XLOG_DATA_FNAME_LEN &&
+			if (IsXLogFileName(walfile) &&
 				strcmp(walfile + 8, exclusiveCleanupFileName + 8) < 0)
 			{
 				/*
@@ -202,13 +197,12 @@ SetWALFileNameForCleanup(void)
 	 * 000000010000000000000010.00000020.backup is after
 	 * 000000010000000000000010.
 	 */
-	if (strlen(restartWALFileName) == XLOG_DATA_FNAME_LEN &&
-		strspn(restartWALFileName, "0123456789ABCDEF") == XLOG_DATA_FNAME_LEN)
+	if (IsXLogFileName(restartWALFileName))
 	{
 		strcpy(exclusiveCleanupFileName, restartWALFileName);
 		fnameOK = true;
 	}
-	else if (strlen(restartWALFileName) == XLOG_BACKUP_FNAME_LEN)
+	else if (IsBackupHistoryFileName(restartWALFileName))
 	{
 		int			args;
 		uint32		tli = 1,
@@ -225,7 +219,7 @@ SetWALFileNameForCleanup(void)
 			 * Use just the prefix of the filename, ignore everything after
 			 * first period
 			 */
-			XLogFileName(exclusiveCleanupFileName, tli, log, seg);
+			XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
 		}
 	}
 

src/bin/pg_resetxlog/pg_resetxlog.c

@@ -261,7 +261,7 @@ main(int argc, char *argv[])
 				break;
 
 			case 'l':
-				if (strspn(optarg, "01234567890ABCDEFabcdef") != 24)
+				if (strspn(optarg, "01234567890ABCDEFabcdef") != XLOG_FNAME_LEN)
 				{
 					fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-l");
 					fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
@@ -976,8 +976,7 @@ KillExistingXLOG(void)
 
 	while (errno = 0, (xlde = readdir(xldir)) != NULL)
 	{
-		if (strlen(xlde->d_name) == 24 &&
-			strspn(xlde->d_name, "0123456789ABCDEF") == 24)
+		if (IsXLogFileName(xlde->d_name))
 		{
 			snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
 			if (unlink(path) < 0)
@@ -1027,9 +1026,9 @@ KillExistingArchiveStatus(void)
 
 	while (errno = 0, (xlde = readdir(xldir)) != NULL)
 	{
-		if (strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
-			(strcmp(xlde->d_name + 24, ".ready") == 0 ||
-			 strcmp(xlde->d_name + 24, ".done") == 0))
+		if (strspn(xlde->d_name, "0123456789ABCDEF") == XLOG_FNAME_LEN &&
+			(strcmp(xlde->d_name + XLOG_FNAME_LEN, ".ready") == 0 ||
+			 strcmp(xlde->d_name + XLOG_FNAME_LEN, ".done") == 0))
 		{
 			snprintf(path, MAXPGPATH, "%s/%s", ARCHSTATDIR, xlde->d_name);
 			if (unlink(path) < 0)

src/include/access/xlog_internal.h

@@ -137,23 +137,30 @@ typedef XLogLongPageHeaderData *XLogLongPageHeader;
  */
 #define MAXFNAMELEN		64
 
+/* Length of XLog file name */
+#define XLOG_FNAME_LEN     24
+
 #define XLogFileName(fname, tli, logSegNo)	\
 	snprintf(fname, MAXFNAMELEN, "%08X%08X%08X", tli,		\
 			 (uint32) ((logSegNo) / XLogSegmentsPerXLogId), \
 			 (uint32) ((logSegNo) % XLogSegmentsPerXLogId))
 
+#define XLogFileNameById(fname, tli, log, seg)	\
+	snprintf(fname, MAXFNAMELEN, "%08X%08X%08X", tli, log, seg)
+
 #define IsXLogFileName(fname) \
-	(strlen(fname) == 24 && strspn(fname, "0123456789ABCDEF") == 24)
+	(strlen(fname) == XLOG_FNAME_LEN && \
+	 strspn(fname, "0123456789ABCDEF") == XLOG_FNAME_LEN)
 
 /*
  * XLOG segment with .partial suffix.  Used by pg_receivexlog and at end of
  * archive recovery, when we want to archive a WAL segment but it might not
  * be complete yet.
  */
 #define IsPartialXLogFileName(fname)	\
-	(strlen(fname) == 24 + strlen(".partial") &&	\
-	 strspn(fname, "0123456789ABCDEF") == 24 &&		\
-	 strcmp((fname) + 24, ".partial") == 0)
+	(strlen(fname) == XLOG_FNAME_LEN + strlen(".partial") &&	\
+	 strspn(fname, "0123456789ABCDEF") == XLOG_FNAME_LEN &&		\
+	 strcmp((fname) + XLOG_FNAME_LEN, ".partial") == 0)
 
 #define XLogFromFileName(fname, tli, logSegNo)	\
 	do {												\
@@ -188,8 +195,8 @@ typedef XLogLongPageHeaderData *XLogLongPageHeader;
 			 (uint32) ((logSegNo) % XLogSegmentsPerXLogId), offset)
 
 #define IsBackupHistoryFileName(fname) \
-	(strlen(fname) > 24 && \
-	 strspn(fname, "0123456789ABCDEF") == 24 && \
+	(strlen(fname) > XLOG_FNAME_LEN && \
+	 strspn(fname, "0123456789ABCDEF") == XLOG_FNAME_LEN && \
 	 strcmp((fname) + strlen(fname) - strlen(".backup"), ".backup") == 0)
 
 #define BackupHistoryFilePath(path, tli, logSegNo, offset)	\