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| author | Tom Lane <tgl@sss.pgh.pa.us> | 1999-10-19 02:34:45 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 1999-10-19 02:34:45 +0000 |
| commit | 42b991fd1f951374fb37bd1b9844faf16c74a38e (patch) | |
| tree | 6bef7e7123660b8d5cf96ca83deb3f2262910658 /src | |
| parent | d357c96789f1df4b885a555ae88d192deb15cd95 (diff) | |
| download | postgresql-42b991fd1f951374fb37bd1b9844faf16c74a38e.tar.gz postgresql-42b991fd1f951374fb37bd1b9844faf16c74a38e.zip | |
BufFileSeek's behavior at segment boundaries wasn't what
logfile.c wanted ... seems easier to fix BufFileSeek.
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/storage/file/buffile.c | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/src/backend/storage/file/buffile.c b/src/backend/storage/file/buffile.c index 452e3a187df..2dafe08c5d9 100644 --- a/src/backend/storage/file/buffile.c +++ b/src/backend/storage/file/buffile.c @@ -6,7 +6,7 @@ * Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/storage/file/buffile.c,v 1.2 1999/10/16 19:49:26 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/file/buffile.c,v 1.3 1999/10/19 02:34:45 tgl Exp $ * * NOTES: * @@ -434,8 +434,7 @@ BufFileSeek(BufFile *file, int fileno, long offset, int whence) switch (whence) { case SEEK_SET: - if (fileno < 0 || fileno >= file->numFiles || - offset < 0) + if (fileno < 0) return EOF; newFile = fileno; newOffset = offset; @@ -443,7 +442,7 @@ BufFileSeek(BufFile *file, int fileno, long offset, int whence) case SEEK_CUR: /* * Relative seek considers only the signed offset, ignoring fileno. - * Note that large offsets (> 1 gig) risk overflow. + * Note that large offsets (> 1 gig) risk overflow in this add... */ newFile = file->curFile; newOffset = (file->curOffset + file->pos) + offset; @@ -463,15 +462,6 @@ BufFileSeek(BufFile *file, int fileno, long offset, int whence) return EOF; newOffset += MAX_PHYSICAL_FILESIZE; } - if (file->isTemp) - { - while (newOffset > MAX_PHYSICAL_FILESIZE) - { - if (++newFile >= file->numFiles) - return EOF; - newOffset -= MAX_PHYSICAL_FILESIZE; - } - } if (newFile == file->curFile && newOffset >= file->curOffset && newOffset <= file->curOffset + file->nbytes) @@ -488,6 +478,29 @@ BufFileSeek(BufFile *file, int fileno, long offset, int whence) /* Otherwise, must reposition buffer, so flush any dirty data */ if (BufFileFlush(file) != 0) return EOF; + /* + * At this point and no sooner, check for seek past last segment. + * The above flush could have created a new segment, so + * checking sooner would not work (at least not with this code). + */ + if (file->isTemp) + { + /* convert seek to "start of next seg" to "end of last seg" */ + if (newFile == file->numFiles && newOffset == 0) + { + newFile--; + newOffset = MAX_PHYSICAL_FILESIZE; + } + while (newOffset > MAX_PHYSICAL_FILESIZE) + { + if (++newFile >= file->numFiles) + return EOF; + newOffset -= MAX_PHYSICAL_FILESIZE; + } + } + if (newFile >= file->numFiles) + return EOF; + /* Seek is OK! */ file->curFile = newFile; file->curOffset = newOffset; file->pos = 0; |