*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.12 1997/05/06 02:03:20 vadim Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.13 1997/05/22 17:08:33 vadim Exp $
*
*-------------------------------------------------------------------------
*/
*/
typedef struct _MdfdVec {
- int mdfd_vfd; /* fd number in vfd pool */
- uint16 mdfd_flags; /* clean, dirty */
- int mdfd_lstbcnt; /* most recent block count */
- struct _MdfdVec *mdfd_chain; /* for large relations */
+ int mdfd_vfd; /* fd number in vfd pool */
+ uint16 mdfd_flags; /* clean, dirty, free */
+ int mdfd_lstbcnt; /* most recent block count */
+ int mdfd_nextFree; /* next free vector */
+ struct _MdfdVec *mdfd_chain; /* for large relations */
} MdfdVec;
static int Nfds = 100;
static MdfdVec *Md_fdvec = (MdfdVec *) NULL;
+static int Md_Free = -1;
static int CurFd = 0;
static MemoryContext MdCxt;
#define MDFD_DIRTY (uint16) 0x01
+#define MDFD_FREE (uint16) 0x02
#define RELSEG_SIZE 262144 /* (2 ** 31) / 8192 -- 2GB file */
/* routines declared here */
static MdfdVec *_mdfd_openseg(Relation reln, int segno, int oflags);
static MdfdVec *_mdfd_getseg(Relation reln, int blkno, int oflag);
-static int _fdvec_ext(void);
+static int _fdvec_alloc (void);
+static void _fdvec_free (int);
static BlockNumber _mdnblocks(File file, Size blcksz);
/*
mdinit()
{
MemoryContext oldcxt;
+ int i;
MdCxt = (MemoryContext) CreateGlobalMemory("MdSmgr");
if (MdCxt == (MemoryContext) NULL)
if (Md_fdvec == (MdfdVec *) NULL)
return (SM_FAIL);
- memset(Md_fdvec, 0, Nfds * sizeof(MdfdVec));
+ memset(Md_fdvec, 0, Nfds * sizeof(MdfdVec));
+
+ /* Set free list */
+ for (i = 0; i < Nfds; i++ )
+ {
+ Md_fdvec[i].mdfd_nextFree = i + 1;
+ Md_fdvec[i].mdfd_flags = MDFD_FREE;
+ }
+ Md_Free = 0;
+ Md_fdvec[Nfds - 1].mdfd_nextFree = -1;
return (SM_SUCCESS);
}
if ( fd < 0 )
return (-1);
}
+
+ vfd = _fdvec_alloc ();
+ if ( vfd < 0 )
+ return (-1);
- if (CurFd >= Nfds) {
- if (_fdvec_ext() == SM_FAIL)
- return (-1);
- }
-
- Md_fdvec[CurFd].mdfd_vfd = fd;
- Md_fdvec[CurFd].mdfd_flags = (uint16) 0;
- Md_fdvec[CurFd].mdfd_chain = (MdfdVec *) NULL;
- Md_fdvec[CurFd].mdfd_lstbcnt = 0;
-
- vfd = CurFd++;
+ Md_fdvec[vfd].mdfd_vfd = fd;
+ Md_fdvec[vfd].mdfd_flags = (uint16) 0;
+ Md_fdvec[vfd].mdfd_chain = (MdfdVec *) NULL;
+ Md_fdvec[vfd].mdfd_lstbcnt = 0;
return (vfd);
}
Md_fdvec[fd].mdfd_flags = (uint16) 0;
oldcxt = MemoryContextSwitchTo(MdCxt);
- for (v = &Md_fdvec[fd]; v != (MdfdVec *) NULL; ) {
+ for (v = &Md_fdvec[fd]; v != (MdfdVec *) NULL; )
+ {
+ FileUnlink(v->mdfd_vfd);
ov = v;
v = v->mdfd_chain;
if (ov != &Md_fdvec[fd])
Md_fdvec[fd].mdfd_chain = (MdfdVec *) NULL;
(void) MemoryContextSwitchTo(oldcxt);
+ _fdvec_free (fd);
+
return (SM_SUCCESS);
}
int fd;
int vfd;
- if (CurFd >= Nfds) {
- if (_fdvec_ext() == SM_FAIL)
- return (-1);
- }
-
path = relpath(&(reln->rd_rel->relname.data[0]));
fd = FileNameOpenFile(path, O_RDWR, 0600);
if (fd < 0)
fd = FileNameOpenFile(path, O_RDWR|O_CREAT|O_EXCL, 0600);
- Md_fdvec[CurFd].mdfd_vfd = fd;
- Md_fdvec[CurFd].mdfd_flags = (uint16) 0;
- Md_fdvec[CurFd].mdfd_chain = (MdfdVec *) NULL;
- Md_fdvec[CurFd].mdfd_lstbcnt = _mdnblocks(fd, BLCKSZ);
+ vfd = _fdvec_alloc ();
+ if ( vfd < 0 )
+ return (-1);
+
+ Md_fdvec[vfd].mdfd_vfd = fd;
+ Md_fdvec[vfd].mdfd_flags = (uint16) 0;
+ Md_fdvec[vfd].mdfd_chain = (MdfdVec *) NULL;
+ Md_fdvec[vfd].mdfd_lstbcnt = _mdnblocks(fd, BLCKSZ);
#ifdef DIAGNOSTIC
- if (Md_fdvec[CurFd].mdfd_lstbcnt > RELSEG_SIZE)
+ if (Md_fdvec[vfd].mdfd_lstbcnt > RELSEG_SIZE)
elog(FATAL, "segment too big on relopen!");
#endif
- vfd = CurFd++;
-
return (vfd);
}
/*
- * mdclose() -- Close the specified relation.
+ * mdclose() -- Close the specified relation
+ *
+ * AND FREE fd vector! It may be re-used for other relation!
+ * reln should be flushed from cache after closing !..
*
* Returns SM_SUCCESS or SM_FAIL with errno set as appropriate.
*/
mdclose(Relation reln)
{
int fd;
- MdfdVec *v;
+ MdfdVec *v, *ov;
+ MemoryContext oldcxt;
fd = RelationGetFile(reln);
- for (v = &Md_fdvec[fd]; v != (MdfdVec *) NULL; v = v->mdfd_chain) {
-
- /* may be closed already */
- if (v->mdfd_vfd < 0)
- continue;
-
- /*
- * We sync the file descriptor so that we don't need to reopen it at
- * transaction commit to force changes to disk.
- */
-
- FileSync(v->mdfd_vfd);
- FileClose(v->mdfd_vfd);
-
- /* mark this file descriptor as clean in our private table */
- v->mdfd_flags &= ~MDFD_DIRTY;
+ oldcxt = MemoryContextSwitchTo(MdCxt);
+ for (v = &Md_fdvec[fd]; v != (MdfdVec *) NULL; )
+ {
+ /* 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.
+ */
+
+ FileSync(v->mdfd_vfd);
+ FileClose(v->mdfd_vfd);
+
+ /* mark this file descriptor as clean in our private table */
+ v->mdfd_flags &= ~MDFD_DIRTY;
+ }
+ /* Now free vector */
+ ov = v;
+ v = v->mdfd_chain;
+ if (ov != &Md_fdvec[fd])
+ pfree(ov);
}
+ (void) MemoryContextSwitchTo(oldcxt);
+ Md_fdvec[fd].mdfd_chain = (MdfdVec *) NULL;
+
+ _fdvec_free (fd);
+
return (SM_SUCCESS);
}
}
/*
- * _fdvec_ext() -- Extend the md file descriptor vector.
+ * _fdvec_alloc () -- grab a free (or new) md file descriptor vector.
*
- * The file descriptor vector must be large enough to hold at least
- * 'fd' entries.
*/
static
-int _fdvec_ext()
+int _fdvec_alloc ()
{
MdfdVec *nvec;
+ int fdvec, i;
MemoryContext oldcxt;
+
+ if ( Md_Free >= 0 ) /* get from free list */
+ {
+ fdvec = Md_Free;
+ Md_Free = Md_fdvec[fdvec].mdfd_nextFree;
+ Assert ( Md_fdvec[fdvec].mdfd_flags == MDFD_FREE );
+ Md_fdvec[fdvec].mdfd_flags = 0;
+ if ( fdvec >= CurFd )
+ {
+ Assert ( fdvec == CurFd );
+ CurFd++;
+ }
+ return (fdvec);
+ }
+ /* Must allocate more room */
+
+ if ( Nfds != CurFd )
+ elog (FATAL, "_fdvec_alloc error");
+
Nfds *= 2;
oldcxt = MemoryContextSwitchTo(MdCxt);
nvec = (MdfdVec *) palloc(Nfds * sizeof(MdfdVec));
memset(nvec, 0, Nfds * sizeof(MdfdVec));
- memmove(nvec, (char *) Md_fdvec, (Nfds / 2) * sizeof(MdfdVec));
+ memmove(nvec, (char *) Md_fdvec, CurFd * sizeof(MdfdVec));
pfree(Md_fdvec);
(void) MemoryContextSwitchTo(oldcxt);
Md_fdvec = nvec;
- return (SM_SUCCESS);
+ /* Set new free list */
+ for (i = CurFd; i < Nfds; i++ )
+ {
+ Md_fdvec[i].mdfd_nextFree = i + 1;
+ Md_fdvec[i].mdfd_flags = MDFD_FREE;
+ }
+ Md_fdvec[Nfds - 1].mdfd_nextFree = -1;
+ Md_Free = CurFd + 1;
+
+ fdvec = CurFd;
+ CurFd++;
+ Md_fdvec[fdvec].mdfd_flags = 0;
+
+ return (fdvec);
+}
+
+/*
+ * _fdvec_free () -- free md file descriptor vector.
+ *
+ */
+static
+void _fdvec_free (int fdvec)
+{
+
+ Assert ( Md_Free < 0 || Md_fdvec[Md_Free].mdfd_flags == MDFD_FREE );
+ Md_fdvec[fdvec].mdfd_nextFree = Md_Free;
+ Md_fdvec[fdvec].mdfd_flags = MDFD_FREE;
+ Md_Free = fdvec;
+
}
static MdfdVec *
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