* Known contributors to this file:
* Dave Pare, 1989
* Steve McClure, 2000
- * Markus Armbruster, 2005-2006
+ * Markus Armbruster, 2005-2008
*/
#include <config.h>
static int ef_realloc_cache(struct empfile *, int);
static int fillcache(struct empfile *, int);
+static int do_read(struct empfile *, void *, int, int);
static int do_write(struct empfile *, void *, int, int);
+static unsigned get_seqno(struct empfile *, int);
+static void new_seqno(struct empfile *, void *);
static void do_blank(struct empfile *, void *, int, int);
/*
* Open the file-backed table TYPE (EF_SECTOR, ...).
* HOW are flags to control operation. Naturally, immutable flags are
* not permitted.
+ * If NELT is non-negative, the table must have that many elements.
* Return non-zero on success, zero on failure.
* You must call ef_close() before the next ef_open().
*/
int
-ef_open(int type, int how)
+ef_open(int type, int how, int nelt)
{
struct empfile *ep;
struct flock lock;
return 0;
}
ep->fids = fsiz / ep->size;
+ if (nelt >= 0 && nelt != ep->fids) {
+ logerror("Can't open %s (got %d records instead of %d)",
+ ep->file, ep->fids, nelt);
+ close(fd);
+ return 0;
+ }
/* allocate cache */
if (ep->flags & EFF_STATIC) {
ep->cache = NULL;
}
if (close(ep->fd) < 0) {
- logerror("Error closing %s (%s)", ep->name, strerror(errno));
+ logerror("Error closing %s (%s)", ep->file, strerror(errno));
retval = 0;
}
ep->fd = -1;
/*
* Flush table TYPE (EF_SECTOR, ...) to disk.
- * Does nothing if the table is privately mapped.
+ * Do nothing if the table is privately mapped.
+ * Update timestamps of written elements if table is EFF_TYPED.
* Return non-zero on success, zero on failure.
*/
int
* allowed only with EFF_MEM. Assume the whole cash is dirty
* then.
*/
- if (ep->flags & EFF_MEM)
- return do_write(ep, ep->cache, ep->baseid, ep->cids) >= 0;
+ if (ep->flags & EFF_MEM) {
+ if (do_write(ep, ep->cache, ep->baseid, ep->cids) < 0)
+ return 0;
+ }
return 1;
}
}
/*
- * Fill cache of EP with elements starting at ID.
+ * Fill cache of file-backed EP with elements starting at ID.
* If any were read, return their number.
* Else return -1 and leave the cache unchanged.
*/
static int
-fillcache(struct empfile *ep, int start)
+fillcache(struct empfile *ep, int id)
+{
+ int ret;
+
+ if (CANT_HAPPEN(!ep->cache))
+ return -1;
+
+ ret = do_read(ep, ep->cache, id, MIN(ep->csize, ep->fids - id));
+ if (ret >= 0) {
+ /* cache changed */
+ ep->baseid = id;
+ ep->cids = ret;
+ }
+ return ret;
+}
+
+static int
+do_read(struct empfile *ep, void *buf, int id, int count)
{
int n, ret;
char *p;
- if (CANT_HAPPEN(ep->fd < 0 || !ep->cache))
+ if (CANT_HAPPEN(ep->fd < 0 || id < 0 || count < 0))
return -1;
- if (lseek(ep->fd, start * ep->size, SEEK_SET) == (off_t)-1) {
- logerror("Error seeking %s (%s)", ep->file, strerror(errno));
+ if (lseek(ep->fd, id * ep->size, SEEK_SET) == (off_t)-1) {
+ logerror("Error seeking %s to elt %d (%s)",
+ ep->file, id, strerror(errno));
return -1;
}
- p = ep->cache;
- n = ep->csize * ep->size;
+ p = buf;
+ n = count * ep->size;
while (n > 0) {
ret = read(ep->fd, p, n);
if (ret < 0) {
- if (errno != EAGAIN) {
- logerror("Error reading %s (%s)", ep->file, strerror(errno));
+ if (errno != EINTR) {
+ logerror("Error reading %s elt %d (%s)",
+ ep->file,
+ id + (int)((p - (char *)buf) / ep->size),
+ strerror(errno));
break;
}
} else if (ret == 0) {
+ logerror("Unexpected EOF reading %s elt %d",
+ ep->file, id + (int)((p - (char *)buf) / ep->size));
break;
} else {
p += ret;
}
}
- if (p == ep->cache)
- return -1; /* nothing read, old cache still ok */
-
- ep->baseid = start;
- ep->cids = (p - ep->cache) / ep->size;
- return ep->cids;
+ return (p - (char *)buf) / ep->size;
}
/*
- * Write COUNT elements from BUF to EP, starting at ID.
- * Return 0 on success, -1 on error.
+ * Write COUNT elements starting at ID from BUF to file-backed EP.
+ * Update the timestamp if the table is EFF_TYPED.
+ * Don't actually write if table is privately mapped.
+ * Return 0 on success, -1 on error (file may be corrupt then).
*/
static int
do_write(struct empfile *ep, void *buf, int id, int count)
{
- int n, ret;
+ int i, n, ret;
char *p;
+ struct emptypedstr *elt;
+ time_t now;
- if (CANT_HAPPEN(ep->fd < 0 || (ep->flags & EFF_PRIVATE)
- || id < 0 || count < 0))
+ if (CANT_HAPPEN(ep->fd < 0 || id < 0 || count < 0))
return -1;
+ if (ep->flags & EFF_TYPED) {
+ now = ep->flags & EFF_NOTIME ? (time_t)-1 : time(NULL);
+ for (i = 0; i < count; i++) {
+ /*
+ * TODO Oopses here could be due to bad data corruption.
+ * Fail instead of attempting to recover?
+ */
+ elt = (struct emptypedstr *)((char *)buf + i * ep->size);
+ if (CANT_HAPPEN(elt->ef_type != ep->uid))
+ elt->ef_type = ep->uid;
+ if (CANT_HAPPEN(elt->uid != id + i))
+ elt->uid = id + i;
+ if (now != (time_t)-1)
+ elt->timestamp = now;
+ }
+ }
+
+ if (ep->flags & EFF_PRIVATE)
+ return 0;
+
if (lseek(ep->fd, id * ep->size, SEEK_SET) == (off_t)-1) {
- logerror("Error seeking %s (%s)", ep->file, strerror(errno));
+ logerror("Error seeking %s to elt %d (%s)",
+ ep->file, id, strerror(errno));
return -1;
}
while (n > 0) {
ret = write(ep->fd, p, n);
if (ret < 0) {
- if (errno != EAGAIN) {
- logerror("Error writing %s (%s)", ep->file, strerror(errno));
- /* FIXME if this extended file, truncate back to old size */
+ if (errno != EINTR) {
+ logerror("Error writing %s elt %d (%s)",
+ ep->file,
+ id + (int)((p - (char *)buf) / ep->size),
+ strerror(errno));
return -1;
}
} else {
/*
* Write element ID into table TYPE from buffer FROM.
* FIXME pass buffer size!
+ * Update timestamp in FROM if table is EFF_TYPED.
* If table is file-backed and not privately mapped, write through
* cache straight to disk.
* Cannot write beyond the end of fully cached table (flags & EFF_MEM).
ep->prewrite(id, from);
if (CANT_HAPPEN((ep->flags & EFF_MEM) ? id >= ep->fids : id > ep->fids))
return 0; /* not implemented */
- if (!(ep->flags & EFF_PRIVATE)) {
+ new_seqno(ep, from);
+ if (ep->fd >= 0) {
if (do_write(ep, from, id, 1) < 0)
return 0;
}
return 1;
}
+/*
+ * Change element id.
+ * BUF is an element of table TYPE.
+ * ID is its new element ID.
+ * If table is EFF_TYPED, change id and sequence number stored in BUF.
+ * Else do nothing.
+ */
+void
+ef_set_uid(int type, void *buf, int uid)
+{
+ struct emptypedstr *elt;
+ struct empfile *ep;
+
+ if (ef_check(type) < 0)
+ return;
+ ep = &empfile[type];
+ if (!(ep->flags & EFF_TYPED))
+ return;
+ elt = buf;
+ if (elt->uid == uid)
+ return;
+ elt->uid = uid;
+ elt->seqno = get_seqno(ep, uid);
+}
+
+/*
+ * Return sequence number of element ID in table EP.
+ * Return zero if table is not EFF_TYPED (it has no sequence number
+ * then).
+ */
+static unsigned
+get_seqno(struct empfile *ep, int id)
+{
+ struct emptypedstr *elt;
+
+ if (!(ep->flags & EFF_TYPED))
+ return 0;
+ if (id < 0 || id >= ep->fids)
+ return 0;
+ if (id >= ep->baseid && id < ep->baseid + ep->cids)
+ elt = (void *)(ep->cache + (id - ep->baseid) * ep->size);
+ else {
+ /* need a buffer, steal last cache slot */
+ if (ep->cids == ep->csize)
+ ep->cids--;
+ elt = (void *)(ep->cache + ep->cids * ep->size);
+ if (do_read(ep, elt, id, 1) < 0)
+ return 0; /* deep trouble */
+ }
+ return elt->seqno;
+}
+
+/*
+ * Increment sequence number in BUF, which is about to be written to EP.
+ * Do nothing if table is not EFF_TYPED (it has no sequence number
+ * then).
+ */
+static void
+new_seqno(struct empfile *ep, void *buf)
+{
+ struct emptypedstr *elt = buf;
+ unsigned old_seqno;
+
+ if (!(ep->flags & EFF_TYPED))
+ return;
+ old_seqno = get_seqno(ep, elt->uid);
+ if (CANT_HAPPEN(old_seqno != elt->seqno))
+ old_seqno = MAX(old_seqno, elt->seqno);
+ elt->seqno = old_seqno + 1;
+}
+
/*
* Extend table TYPE by COUNT elements.
* Any pointers obtained from ef_ptr() become invalid.
{
struct empfile *ep;
char *p;
- int i, id;
+ int need_sentinel, i, id;
if (ef_check(type) < 0)
return 0;
id = ep->fids;
if (ep->flags & EFF_MEM) {
- if (id + count > ep->csize) {
+ need_sentinel = (ep->flags & EFF_SENTINEL) != 0;
+ if (id + count + need_sentinel > ep->csize) {
if (ep->flags & EFF_STATIC) {
logerror("Can't extend %s beyond %d elements",
- ep->file, ep->csize);
+ ep->name, ep->csize - need_sentinel);
return 0;
}
- if (!ef_realloc_cache(ep, id + count)) {
+ if (!ef_realloc_cache(ep, id + count + need_sentinel)) {
logerror("Can't extend %s to %d elements (%s)",
- ep->file, id + count, strerror(errno));
+ ep->name, id + count, strerror(errno));
return 0;
}
}
p = ep->cache + id * ep->size;
do_blank(ep, p, id, count);
- if (ep->fd >= 0 && !(ep->flags & EFF_PRIVATE)) {
+ if (ep->fd >= 0) {
if (do_write(ep, p, id, count) < 0)
return 0;
}
- ep->cids += count;
+ if (need_sentinel)
+ memset(ep->cache + (id + count) * ep->size, 0, ep->size);
+ ep->cids = id + count;
} else {
/* need a buffer, steal last cache slot */
if (ep->cids == ep->csize)
return 0;
}
}
- ep->fids += count;
+ ep->fids = id + count;
return 1;
}
+/*
+ * Initialize element ID for EP in BUF.
+ * FIXME pass buffer size!
+ */
+void
+ef_blank(int type, int id, void *buf)
+{
+ struct empfile *ep;
+ struct emptypedstr *elt;
+
+ if (ef_check(type) < 0)
+ return;
+ ep = &empfile[type];
+ do_blank(ep, buf, id, 1);
+ if (ep->flags & EFF_TYPED) {
+ elt = buf;
+ elt->seqno = get_seqno(ep, elt->uid);
+ }
+}
+
/*
* Initialize COUNT elements of EP in BUF, starting with element ID.
*/
}
}
+/*
+ * Truncate table TYPE to COUNT elements.
+ * Any pointers obtained from ef_ptr() become invalid.
+ * Return non-zero on success, zero on failure.
+ */
+int
+ef_truncate(int type, int count)
+{
+ struct empfile *ep;
+ int need_sentinel;
+
+ if (ef_check(type) < 0)
+ return 0;
+ ep = &empfile[type];
+ if (CANT_HAPPEN(count < 0 || count > ep->fids))
+ return 0;
+
+ if (ep->fd >= 0 && !(ep->flags & EFF_PRIVATE)) {
+ if (ftruncate(ep->fd, count * ep->size) < 0) {
+ logerror("Can't truncate %s to %d elements (%s)",
+ ep->file, count, strerror(errno));
+ return 0;
+ }
+ }
+ ep->fids = count;
+
+ if (ep->flags & EFF_MEM) {
+ need_sentinel = (ep->flags & EFF_SENTINEL) != 0;
+ if (!(ep->flags & EFF_STATIC)) {
+ if (!ef_realloc_cache(ep, count + need_sentinel)) {
+ logerror("Can't shrink %s cache after truncate (%s)",
+ ep->name, strerror(errno));
+ /* continue with unshrunk cache */
+ }
+ }
+ if (need_sentinel)
+ memset(ep->cache + count * ep->size, 0, ep->size);
+ ep->cids = count;
+ } else {
+ if (ep->baseid >= count)
+ ep->cids = 0;
+ else if (ep->cids > count - ep->baseid)
+ ep->cids = count - ep->baseid;
+ }
+
+ return 1;
+}
+
struct castr *
ef_cadef(int type)
{
}
/*
- * Ensure file-backed table contains ID.
+ * Ensure table contains element ID.
* If necessary, extend it in steps of COUNT elements.
* Return non-zero on success, zero on failure.
*/
projects / empserver / blobdiff