Add files to do read I/O on the cluster directory:

pg_stat_file()
	pg_read_file()
	pg_ls_dir()
	pg_reload_conf()
	pg_rotate_logfile()

Dave Page
Andreas Pflug

src/backend/postmaster/postmaster.c

@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.462 2005/08/11 21:11:44 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.463 2005/08/12 03:23:51 momjian Exp $
  *
  * NOTES
  *
@@ -3394,6 +3394,9 @@ sigusr1_handler(SIGNAL_ARGS)
 		}
 	}
 
+	if (CheckPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE) && SysLoggerPID != 0)
+	    kill(SysLoggerPID, SIGUSR1);
+
 	PG_SETMASK(&UnBlockSig);
 
 	errno = save_errno;

src/backend/postmaster/syslogger.c

@@ -18,7 +18,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/syslogger.c,v 1.18 2005/07/21 18:06:12 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/syslogger.c,v 1.19 2005/08/12 03:23:51 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -101,6 +101,7 @@ static CRITICAL_SECTION sysfileSection;
  * Flags set by interrupt handlers for later service in the main loop.
  */
 static volatile sig_atomic_t got_SIGHUP = false;
+static volatile sig_atomic_t rotation_requested = false;
 
 
 /* Local subroutines */
@@ -117,6 +118,7 @@ static void logfile_rotate(bool time_based_rotation);
 static char *logfile_getname(pg_time_t timestamp);
 static void set_next_rotation_time(void);
 static void sigHupHandler(SIGNAL_ARGS);
+static void sigUsr1Handler(SIGNAL_ARGS);
 
 
 /*
@@ -200,7 +202,7 @@ SysLoggerMain(int argc, char *argv[])
 	pqsignal(SIGQUIT, SIG_IGN);
 	pqsignal(SIGALRM, SIG_IGN);
 	pqsignal(SIGPIPE, SIG_IGN);
-	pqsignal(SIGUSR1, SIG_IGN);
+	pqsignal(SIGUSR1, sigUsr1Handler);  /* request log rotation */
 	pqsignal(SIGUSR2, SIG_IGN);
 
 	/*
@@ -235,7 +237,6 @@ SysLoggerMain(int argc, char *argv[])
 	/* main worker loop */
 	for (;;)
 	{
-		bool		rotation_requested = false;
 		bool		time_based_rotation = false;
 
 #ifndef WIN32
@@ -726,6 +727,8 @@ logfile_rotate(bool time_based_rotation)
 	char	   *filename;
 	FILE	   *fh;
 
+	rotation_requested = false;
+
 	/*
 	 * When doing a time-based rotation, invent the new logfile name based
 	 * on the planned rotation time, not current time, to avoid "slippage"
@@ -876,3 +879,10 @@ sigHupHandler(SIGNAL_ARGS)
 {
 	got_SIGHUP = true;
 }
+
+/* SIGUSR1: set flag to rotate logfile */
+static void
+sigUsr1Handler(SIGNAL_ARGS)
+{
+	rotation_requested = true;
+}

src/backend/utils/adt/Makefile

@@ -1,7 +1,7 @@
 #
 # Makefile for utils/adt
 #
-# $PostgreSQL: pgsql/src/backend/utils/adt/Makefile,v 1.58 2005/07/29 14:46:57 momjian Exp $
+# $PostgreSQL: pgsql/src/backend/utils/adt/Makefile,v 1.59 2005/08/12 03:24:08 momjian Exp $
 #
 
 subdir = src/backend/utils/adt
@@ -24,7 +24,7 @@ OBJS = acl.o arrayfuncs.o array_userfuncs.o arrayutils.o bool.o \
 	tid.o timestamp.o varbit.o varchar.o varlena.o version.o xid.o \
 	network.o mac.o inet_net_ntop.o inet_net_pton.o \
 	ri_triggers.o pg_lzcompress.o pg_locale.o formatting.o \
-	ascii.o quote.o pgstatfuncs.o encode.o dbsize.o
+	ascii.o quote.o pgstatfuncs.o encode.o dbsize.o genfile.o
 
 like.o: like.c like_match.c
 

src/backend/utils/adt/genfile.c

@@ -0,0 +1,258 @@
+/*-------------------------------------------------------------------------
+ *
+ * genfile.c
+ *
+ *
+ * Copyright (c) 2004, PostgreSQL Global Development Group
+ * 
+ * Author: Andreas Pflug <pgadmin@pse-consulting.de>
+ *
+ * IDENTIFICATION
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/genfile.c,v 1.1 2005/08/12 03:24:08 momjian Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <dirent.h>
+
+#include "utils/builtins.h"
+#include "miscadmin.h"
+#include "storage/fd.h"
+#include "catalog/pg_type.h"
+#include "funcapi.h"
+
+extern  char *Log_directory;
+
+typedef struct 
+{
+	char	*location;
+	DIR		*dirdesc;
+} directory_fctx;
+
+/*
+ * Return an absolute path. Argument may be absolute or 
+ * relative to the DataDir.
+ */
+static char *check_and_make_absolute(text *arg)
+{
+	int datadir_len = strlen(DataDir);
+	int filename_len = VARSIZE(arg) - VARHDRSZ;
+	char *filename = palloc(filename_len + 1);
+	
+	memcpy(filename, VARDATA(arg), filename_len);
+	filename[filename_len] = '\0';
+
+	canonicalize_path(filename);
+	filename_len = strlen(filename);	/* recompute */
+
+	/*
+	 *	Prevent reference to the parent directory.
+	 *	"..a.." is a valid file name though.
+	 */
+	if (strcmp(filename, "..") == 0 ||							/* beginning */
+		strncmp(filename, "../", 3) == 0 ||						/* beginning */
+		strcmp(filename, "/..") == 0 ||							/* beginning */
+		strncmp(filename, "../", 3) == 0 ||						/* beginning */
+		strstr(filename, "/../") != NULL ||						/* middle */
+		strncmp(filename + filename_len - 3, "/..", 3) == 0)	/* end */
+			ereport(ERROR,
+				  (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				   (errmsg("Reference to a parent directory (\"..\") not allowed"))));
+
+	if (is_absolute_path(filename))
+	{
+		/* The log directory might be outside our datadir, but allow it */
+	    if (is_absolute_path(Log_directory) &&
+			strncmp(filename, Log_directory, strlen(Log_directory)) == 0 &&
+			(filename[strlen(Log_directory)] == '/' ||
+			 filename[strlen(Log_directory)] == '\0'))
+			return filename;
+
+	    ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("Absolute paths not allowed"))));
+		return NULL;
+	}
+	else
+	{
+	    char *absname = palloc(datadir_len + filename_len + 2);
+		sprintf(absname, "%s/%s", DataDir, filename);
+		pfree(filename);
+		return absname;
+	}
+}
+
+
+Datum pg_read_file(PG_FUNCTION_ARGS)
+{
+	int64		bytes_to_read = PG_GETARG_INT64(2);
+	int64		seek_offset = PG_GETARG_INT64(1);
+	char 		*buf = 0;
+	size_t		nbytes;
+	FILE		*file;
+	char		*filename;
+
+	if (!superuser())
+	    ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to read files"))));
+
+	filename = check_and_make_absolute(PG_GETARG_TEXT_P(0));
+
+	if ((file = AllocateFile(filename, PG_BINARY_R)) == NULL)
+	{
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not open file %s for reading: %m", filename)));
+		PG_RETURN_NULL();
+	}
+
+	if (fseeko(file, (off_t)seek_offset,
+		(seek_offset >= 0) ? SEEK_SET : SEEK_END) != 0)
+	{
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not seek in file %s: %m", filename)));
+		PG_RETURN_NULL();
+	}
+
+	if (bytes_to_read < 0)
+	{
+		ereport(ERROR,
+			(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("length cannot be negative")));
+	}
+	
+	buf = palloc(bytes_to_read + VARHDRSZ);
+
+	nbytes = fread(VARDATA(buf), 1, bytes_to_read, file);
+
+	if (nbytes < 0)
+	{
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not read file %s: %m", filename)));
+		PG_RETURN_NULL();
+	}
+	VARATT_SIZEP(buf) = nbytes + VARHDRSZ;
+
+	pfree(filename);
+	FreeFile(file);
+	PG_RETURN_TEXT_P(buf);
+}
+
+
+Datum pg_stat_file(PG_FUNCTION_ARGS)
+{
+	AttInMetadata *attinmeta;
+	char		*filename = check_and_make_absolute(PG_GETARG_TEXT_P(0));
+	struct stat fst;
+	char		lenbuf[30], cbuf[30], abuf[30], mbuf[30], dirbuf[2];
+	char		*values[5] = {lenbuf, cbuf, abuf, mbuf, dirbuf};
+	pg_time_t	timestamp;
+	HeapTuple	tuple;
+	TupleDesc	tupdesc = CreateTemplateTupleDesc(5, false);
+
+	if (!superuser())
+	    ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to get file information"))));
+
+	TupleDescInitEntry(tupdesc, (AttrNumber) 1, "length", INT8OID, -1, 0);
+	TupleDescInitEntry(tupdesc, (AttrNumber) 2, "atime", TIMESTAMPOID, -1, 0);
+	TupleDescInitEntry(tupdesc, (AttrNumber) 3, "mtime", TIMESTAMPOID, -1, 0);
+	TupleDescInitEntry(tupdesc, (AttrNumber) 4, "ctime", TIMESTAMPOID, -1, 0);
+	TupleDescInitEntry(tupdesc, (AttrNumber) 5, "isdir", BOOLOID, -1, 0);
+	attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+	if (stat(filename, &fst) < 0)
+	{
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not stat file %s: %m", filename)));
+		PG_RETURN_NULL();
+	}
+	else
+	{
+		snprintf(lenbuf, 30, INT64_FORMAT, (int64)fst.st_size);
+
+		timestamp = fst.st_atime;
+		pg_strftime(abuf, 30, "%F %T", pg_localtime(&timestamp, global_timezone));
+
+		timestamp = fst.st_mtime;
+		pg_strftime(mbuf, 30, "%F %T", pg_localtime(&timestamp, global_timezone));
+
+		timestamp = fst.st_ctime;
+		pg_strftime(cbuf, 30, "%F %T", pg_localtime(&timestamp, global_timezone));
+
+		if (fst.st_mode & S_IFDIR)
+			strcpy(dirbuf, "t");
+		else
+			strcpy(dirbuf, "f");
+
+		tuple = BuildTupleFromCStrings(attinmeta, values);
+		pfree(filename);
+		PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
+	}
+}
+
+
+Datum pg_ls_dir(PG_FUNCTION_ARGS)
+{
+	FuncCallContext	*funcctx;
+	struct dirent	*de;
+	directory_fctx	*fctx;
+
+	if (!superuser())
+	    ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to get directory listings"))));
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		MemoryContext oldcontext;
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		fctx = palloc(sizeof(directory_fctx));
+		fctx->location = check_and_make_absolute(PG_GETARG_TEXT_P(0));
+
+		fctx->dirdesc = AllocateDir(fctx->location);
+
+		if (!fctx->dirdesc)
+		    ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("%s is not browsable: %m", fctx->location)));
+
+		funcctx->user_fctx = fctx;
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	fctx = (directory_fctx*) funcctx->user_fctx;
+
+	if (!fctx->dirdesc)  /* not a readable directory  */
+		SRF_RETURN_DONE(funcctx);
+
+	while ((de = ReadDir(fctx->dirdesc, fctx->location)) != NULL)
+	{
+		int			len = strlen(de->d_name);
+		text		*result = palloc(len + VARHDRSZ);
+
+		if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
+		    continue;
+
+		VARATT_SIZEP(result) = len + VARHDRSZ;
+		memcpy(VARDATA(result), de->d_name, len);
+
+		SRF_RETURN_NEXT(funcctx, PointerGetDatum(result));
+	}
+
+	FreeDir(fctx->dirdesc);
+	SRF_RETURN_DONE(funcctx);
+}

src/backend/utils/adt/misc.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.45 2005/07/04 04:51:50 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.46 2005/08/12 03:24:08 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,14 +21,23 @@
 #include "commands/dbcommands.h"
 #include "miscadmin.h"
 #include "storage/procarray.h"
+#include "storage/pmsignal.h"
 #include "storage/fd.h"
 #include "utils/builtins.h"
+#include "utils/elog.h"
 #include "funcapi.h"
 #include "catalog/pg_type.h"
 #include "catalog/pg_tablespace.h"
+#include "postmaster/syslogger.h"
 
 #define atooid(x)  ((Oid) strtoul((x), NULL, 10))
 
+typedef struct 
+{
+	char	*location;
+	DIR		*dirdesc;
+} directory_fctx;
+
 
 /*
  * Check if data is Null
@@ -107,6 +116,51 @@ pg_cancel_backend(PG_FUNCTION_ARGS)
 	PG_RETURN_INT32(pg_signal_backend(PG_GETARG_INT32(0), SIGINT));
 }
 
+
+Datum
+pg_reload_conf(PG_FUNCTION_ARGS)
+{
+	if (!superuser()) 
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to signal the postmaster"))));
+
+	if (kill(PostmasterPid, SIGHUP))
+	{
+		ereport(WARNING,
+				(errmsg("failed to send signal to postmaster: %m")));
+
+		PG_RETURN_INT32(0);
+	}
+
+	PG_RETURN_INT32(1);
+}
+
+
+/*
+ * Rotate log file
+ */
+Datum
+pg_rotate_logfile(PG_FUNCTION_ARGS)
+{
+	if (!superuser()) 
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to rotate log files"))));
+
+	if (!Redirect_stderr)
+	{
+	    ereport(NOTICE,
+				(errcode(ERRCODE_WARNING),
+				 errmsg("no logfile configured; rotation not supported")));
+		PG_RETURN_INT32(0);
+	}
+
+	SendPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE);
+
+	PG_RETURN_INT32(0);
+}
+
 #ifdef NOT_USED
 
 /* Disabled in 8.0 due to reliability concerns; FIXME someday */