diff options
Diffstat (limited to 'src/backend/storage/smgr/md.c')
| -rw-r--r-- | src/backend/storage/smgr/md.c | 112 |
1 files changed, 68 insertions, 44 deletions
diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c index b30b0386af8..e4fee432205 100644 --- a/src/backend/storage/smgr/md.c +++ b/src/backend/storage/smgr/md.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.66 2000/04/10 23:41:51 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.67 2000/04/12 17:15:41 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -21,7 +21,8 @@ #include "catalog/catalog.h" #include "miscadmin.h" #include "storage/smgr.h" -#include "utils/inval.h" /* ImmediateSharedRelationCacheInvalidate() */ +#include "utils/inval.h" /* ImmediateSharedRelationCacheInvalidate() + * */ #undef DIAGNOSTIC @@ -62,17 +63,18 @@ typedef struct _MdfdVec static int Nfds = 100; /* initial/current size of Md_fdvec array */ static MdfdVec *Md_fdvec = (MdfdVec *) NULL; -static int Md_Free = -1; /* head of freelist of unused fdvec entries */ +static int Md_Free = -1; /* head of freelist of unused fdvec + * entries */ static int CurFd = 0; /* first never-used fdvec index */ static MemoryContext MdCxt; /* context for all my allocations */ /* routines declared here */ static void mdclose_fd(int fd); -static int _mdfd_getrelnfd(Relation reln); +static int _mdfd_getrelnfd(Relation reln); static MdfdVec *_mdfd_openseg(Relation reln, int segno, int oflags); static MdfdVec *_mdfd_getseg(Relation reln, int blkno); static int _mdfd_blind_getseg(char *dbname, char *relname, - Oid dbid, Oid relid, int blkno); + Oid dbid, Oid relid, int blkno); static int _fdvec_alloc(void); static void _fdvec_free(int); static BlockNumber _mdnblocks(File file, Size blcksz); @@ -140,11 +142,10 @@ mdcreate(Relation reln) * are processed. * * For cataloged relations,pg_class is guaranteed to have an unique - * record with the same relname by the unique index. - * So we are able to reuse existent files for new catloged relations. - * Currently we reuse them in the following cases. - * 1. they are empty. - * 2. they are used for Index relations and their size == BLCKSZ * 2. + * record with the same relname by the unique index. So we are able to + * reuse existent files for new catloged relations. Currently we reuse + * them in the following cases. 1. they are empty. 2. they are used + * for Index relations and their size == BLCKSZ * 2. */ if (fd < 0) @@ -162,13 +163,13 @@ mdcreate(Relation reln) return -1; if (!IsBootstrapProcessingMode()) { - bool reuse = false; - int len = FileSeek(fd, 0L, SEEK_END); + bool reuse = false; + int len = FileSeek(fd, 0L, SEEK_END); if (len == 0) reuse = true; else if (reln->rd_rel->relkind == RELKIND_INDEX && - len == BLCKSZ * 2) + len == BLCKSZ * 2) reuse = true; if (!reuse) { @@ -206,14 +207,15 @@ mdunlink(Relation reln) MdfdVec *v; MemoryContext oldcxt; - /* If the relation is already unlinked,we have nothing to do - * any more. + /* + * If the relation is already unlinked,we have nothing to do any more. */ if (reln->rd_unlinked && reln->rd_fd < 0) return SM_SUCCESS; + /* - * Force all segments of the relation to be opened, so that we - * won't miss deleting any of them. + * Force all segments of the relation to be opened, so that we won't + * miss deleting any of them. */ nblocks = mdnblocks(reln); @@ -222,9 +224,10 @@ mdunlink(Relation reln) * * NOTE: We truncate the file(s) before deleting 'em, because if other * backends are holding the files open, the unlink will fail on some - * platforms (think Microsoft). Better a zero-size file gets left around - * than a big file. Those other backends will be forced to close the - * relation by cache invalidation, but that probably hasn't happened yet. + * platforms (think Microsoft). Better a zero-size file gets left + * around than a big file. Those other backends will be forced to + * close the relation by cache invalidation, but that probably hasn't + * happened yet. */ fd = RelationGetFile(reln); if (fd < 0) /* should not happen */ @@ -237,6 +240,7 @@ mdunlink(Relation reln) for (v = &Md_fdvec[fd]; v != (MdfdVec *) NULL;) { MdfdVec *ov = v; + FileTruncate(v->mdfd_vfd, 0); FileUnlink(v->mdfd_vfd); v = v->mdfd_chain; @@ -269,7 +273,8 @@ mdunlink(Relation reln) int mdextend(Relation reln, char *buffer) { - long pos, nbytes; + long pos, + nbytes; int nblocks; MdfdVec *v; @@ -279,7 +284,7 @@ mdextend(Relation reln, char *buffer) if ((pos = FileSeek(v->mdfd_vfd, 0L, SEEK_END)) < 0) return SM_FAIL; - if (pos % BLCKSZ != 0) /* the last block is incomplete */ + if (pos % BLCKSZ != 0) /* the last block is incomplete */ { pos -= pos % BLCKSZ; if (FileSeek(v->mdfd_vfd, pos, SEEK_SET) < 0) @@ -414,6 +419,7 @@ mdclose_fd(int fd) /* if not closed already */ if (v->mdfd_vfd >= 0) { + /* * We sync the file descriptor so that we don't need to reopen * it at transaction commit to force changes to disk. (This @@ -436,6 +442,7 @@ mdclose_fd(int fd) { if (v->mdfd_vfd >= 0) { + /* * We sync the file descriptor so that we don't need to reopen * it at transaction commit to force changes to disk. (This @@ -689,9 +696,11 @@ mdnblocks(Relation reln) { int fd; MdfdVec *v; + #ifndef LET_OS_MANAGE_FILESIZE int nblocks; int segno; + #endif fd = _mdfd_getrelnfd(reln); @@ -738,13 +747,16 @@ mdtruncate(Relation reln, int nblocks) int curnblk; int fd; MdfdVec *v; + #ifndef LET_OS_MANAGE_FILESIZE MemoryContext oldcxt; int priorblocks; + #endif - /* NOTE: mdnblocks makes sure we have opened all existing segments, - * so that truncate/delete loop will get them all! + /* + * NOTE: mdnblocks makes sure we have opened all existing segments, so + * that truncate/delete loop will get them all! */ curnblk = mdnblocks(reln); if (nblocks < 0 || nblocks > curnblk) @@ -764,29 +776,34 @@ mdtruncate(Relation reln, int nblocks) if (priorblocks > nblocks) { - /* This segment is no longer wanted at all (and has already been - * unlinked from the mdfd_chain). - * We truncate the file before deleting it because if other - * backends are holding the file open, the unlink will fail on - * some platforms. Better a zero-size file gets left around than - * a big file... + + /* + * This segment is no longer wanted at all (and has already + * been unlinked from the mdfd_chain). We truncate the file + * before deleting it because if other backends are holding + * the file open, the unlink will fail on some platforms. + * Better a zero-size file gets left around than a big file... */ FileTruncate(v->mdfd_vfd, 0); FileUnlink(v->mdfd_vfd); v = v->mdfd_chain; - Assert(ov != &Md_fdvec[fd]); /* we never drop the 1st segment */ + Assert(ov != &Md_fdvec[fd]); /* we never drop the 1st + * segment */ pfree(ov); } else if (priorblocks + RELSEG_SIZE > nblocks) { - /* This is the last segment we want to keep. - * Truncate the file to the right length, and clear chain link - * that points to any remaining segments (which we shall zap). - * NOTE: if nblocks is exactly a multiple K of RELSEG_SIZE, - * we will truncate the K+1st segment to 0 length but keep it. - * This is mainly so that the right thing happens if nblocks=0. + + /* + * This is the last segment we want to keep. Truncate the file + * to the right length, and clear chain link that points to + * any remaining segments (which we shall zap). NOTE: if + * nblocks is exactly a multiple K of RELSEG_SIZE, we will + * truncate the K+1st segment to 0 length but keep it. This is + * mainly so that the right thing happens if nblocks=0. */ - int lastsegblocks = nblocks - priorblocks; + int lastsegblocks = nblocks - priorblocks; + if (FileTruncate(v->mdfd_vfd, lastsegblocks * BLCKSZ) < 0) return -1; v->mdfd_lstbcnt = lastsegblocks; @@ -795,7 +812,9 @@ mdtruncate(Relation reln, int nblocks) } else { - /* We still need this segment and 0 or more blocks beyond it, + + /* + * We still need this segment and 0 or more blocks beyond it, * so nothing to do here. */ v = v->mdfd_chain; @@ -842,7 +861,7 @@ mdcommit() continue; /* Sync the file entry */ #ifndef LET_OS_MANAGE_FILESIZE - for ( ; v != (MdfdVec *) NULL; v = v->mdfd_chain) + for (; v != (MdfdVec *) NULL; v = v->mdfd_chain) #else if (v != (MdfdVec *) NULL) #endif @@ -853,7 +872,7 @@ mdcommit() } return SM_SUCCESS; -#endif /* XLOG */ +#endif /* XLOG */ } /* @@ -865,7 +884,9 @@ mdcommit() int mdabort() { - /* We don't actually have to do anything here. fd.c will discard + + /* + * We don't actually have to do anything here. fd.c will discard * fsync-needed bits in its AtEOXact_Files() routine. */ return SM_SUCCESS; @@ -1073,8 +1094,10 @@ _mdfd_blind_getseg(char *dbname, char *relname, Oid dbid, Oid relid, { char *path; int fd; + #ifndef LET_OS_MANAGE_FILESIZE int segno; + #endif /* construct the path to the relation */ @@ -1085,7 +1108,7 @@ _mdfd_blind_getseg(char *dbname, char *relname, Oid dbid, Oid relid, segno = blkno / RELSEG_SIZE; if (segno > 0) { - char *segpath = (char *) palloc(strlen(path) + 12); + char *segpath = (char *) palloc(strlen(path) + 12); sprintf(segpath, "%s.%d", path, segno); pfree(path); @@ -1110,6 +1133,7 @@ _mdnblocks(File file, Size blcksz) long len; len = FileSeek(file, 0L, SEEK_END); - if (len < 0) return 0; /* on failure, assume file is empty */ + if (len < 0) + return 0; /* on failure, assume file is empty */ return (BlockNumber) (len / blcksz); } |