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);
/*
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;
*/
static int
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, id * ep->size, SEEK_SET) == (off_t)-1) {
return -1;
}
- p = ep->cache;
- n = MIN(ep->csize, ep->fids - id) * ep->size;
+ p = buf;
+ n = count * ep->size;
while (n > 0) {
ret = read(ep->fd, p, n);
if (ret < 0) {
if (errno != EINTR) {
logerror("Error reading %s elt %d (%s)",
ep->file,
- id + (int)((p - ep->cache) / ep->size),
+ 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 - ep->cache) / ep->size));
+ 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 = id;
- ep->cids = (p - ep->cache) / ep->size;
- return ep->cids;
+ return (p - (char *)buf) / ep->size;
}
/*
ep->prewrite(id, from);
if (CANT_HAPPEN((ep->flags & EFF_MEM) ? id >= ep->fids : id > ep->fids))
return 0; /* not implemented */
+ 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;
}
}
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;
}
void
ef_blank(int type, int id, void *buf)
{
+ struct empfile *ep;
+ struct emptypedstr *elt;
+
if (ef_check(type) < 0)
return;
- do_blank(&empfile[type], buf, id, 1);
+ ep = &empfile[type];
+ do_blank(ep, buf, id, 1);
+ if (ep->flags & EFF_TYPED) {
+ elt = buf;
+ elt->seqno = get_seqno(ep, elt->uid);
+ }
}
/*
ef_truncate(int type, int count)
{
struct empfile *ep;
+ int need_sentinel;
if (ef_check(type) < 0)
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)) {
- logerror("Can't shrink cache after truncate");
+ 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)
}
/*
- * 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