Simplify SortTocFromFile() by removing fixed buffer-size limit.

pg_restore previously coped with overlength TOC-file lines using some
complicated logic to ignore additional bufferloads.  While this isn't
wrong, since we don't expect that the interesting part of a line would
run to more than a dozen or so bytes, it's more complex than it needs
to be.  Use a StringInfo instead of a fixed-size buffer so that we can
process long lines as single entities and thus not need the extra
logic.

Daniel Gustafsson

Discussion: https://postgr.es/m/48A4FA71-524E-41B9-953A-FD04EF36E2E7@yesql.se

src/bin/pg_dump/pg_backup_archiver.c

@@ -30,8 +30,10 @@
 #include <io.h>
 #endif
 
+#include "common/string.h"
 #include "dumputils.h"
 #include "fe_utils/string_utils.h"
+#include "lib/stringinfo.h"
 #include "libpq/libpq-fs.h"
 #include "parallel.h"
 #include "pg_backup_archiver.h"
@@ -1367,8 +1369,7 @@ SortTocFromFile(Archive *AHX)
 	ArchiveHandle *AH = (ArchiveHandle *) AHX;
 	RestoreOptions *ropt = AH->public.ropt;
 	FILE	   *fh;
-	char		buf[100];
-	bool		incomplete_line;
+	StringInfoData linebuf;
 
 	/* Allocate space for the 'wanted' array, and init it */
 	ropt->idWanted = (bool *) pg_malloc0(sizeof(bool) * AH->maxDumpId);
@@ -1378,45 +1379,33 @@ SortTocFromFile(Archive *AHX)
 	if (!fh)
 		fatal("could not open TOC file \"%s\": %m", ropt->tocFile);
 
-	incomplete_line = false;
-	while (fgets(buf, sizeof(buf), fh) != NULL)
+	initStringInfo(&linebuf);
+
+	while (pg_get_line_buf(fh, &linebuf))
 	{
-		bool		prev_incomplete_line = incomplete_line;
-		int			buflen;
 		char	   *cmnt;
 		char	   *endptr;
 		DumpId		id;
 		TocEntry   *te;
 
-		/*
-		 * Some lines in the file might be longer than sizeof(buf).  This is
-		 * no problem, since we only care about the leading numeric ID which
-		 * can be at most a few characters; but we have to skip continuation
-		 * bufferloads when processing a long line.
-		 */
-		buflen = strlen(buf);
-		if (buflen > 0 && buf[buflen - 1] == '\n')
-			incomplete_line = false;
-		else
-			incomplete_line = true;
-		if (prev_incomplete_line)
-			continue;
-
 		/* Truncate line at comment, if any */
-		cmnt = strchr(buf, ';');
+		cmnt = strchr(linebuf.data, ';');
 		if (cmnt != NULL)
+		{
 			cmnt[0] = '\0';
+			linebuf.len = cmnt - linebuf.data;
+		}
 
 		/* Ignore if all blank */
-		if (strspn(buf, " \t\r\n") == strlen(buf))
+		if (strspn(linebuf.data, " \t\r\n") == linebuf.len)
 			continue;
 
 		/* Get an ID, check it's valid and not already seen */
-		id = strtol(buf, &endptr, 10);
-		if (endptr == buf || id <= 0 || id > AH->maxDumpId ||
+		id = strtol(linebuf.data, &endptr, 10);
+		if (endptr == linebuf.data || id <= 0 || id > AH->maxDumpId ||
 			ropt->idWanted[id - 1])
 		{
-			pg_log_warning("line ignored: %s", buf);
+			pg_log_warning("line ignored: %s", linebuf.data);
 			continue;
 		}
 
@@ -1443,6 +1432,8 @@ SortTocFromFile(Archive *AHX)
 		_moveBefore(AH->toc, te);
 	}
 
+	pg_free(linebuf.data);
+
 	if (fclose(fh) != 0)
 		fatal("could not close TOC file: %m");
 }