/*
* Empire - A multi-player, client/server Internet based war game.
- * Copyright (C) 1986-2008, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ * Copyright (C) 1986-2009, Dave Pare, Jeff Bailey, Thomas Ruschak,
* Ken Stevens, Steve McClure
*
* This program is free software; you can redistribute it and/or modify
* ---
*
* file.c: Operations on Empire tables (`files' for historical reasons)
- *
+ *
* Known contributors to this file:
* Dave Pare, 1989
* Steve McClure, 2000
static int ef_realloc_cache(struct empfile *, int);
static int fillcache(struct empfile *, int);
-static int do_write(struct empfile *, void *, int, int, time_t);
+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 must_be_fresh(struct empfile *, void *);
static void do_blank(struct empfile *, void *, int, int);
+static int ef_check(int);
+
+static unsigned ef_generation;
/*
* Open the file-backed table TYPE (EF_SECTOR, ...).
}
}
+ if (ep->onresize && ep->onresize(type) < 0)
+ return 0;
return 1;
}
return 1;
}
+/*
+ * Open the table TYPE as view of table BASE.
+ * Return non-zero on success, zero on failure.
+ * Beware: views work only as long as BASE doesn't change size!
+ * You must call ef_close(TYPE) before closing BASE.
+ */
+int
+ef_open_view(int type, int base)
+{
+ struct empfile *ep;
+
+ if (CANT_HAPPEN(!EF_IS_VIEW(type)))
+ return -1;
+ ep = &empfile[type];
+ if (CANT_HAPPEN(!(ef_flags(base) & EFF_MEM)))
+ return -1;
+
+ ep->cache = empfile[base].cache;
+ ep->csize = empfile[base].csize;
+ ep->flags |= EFF_MEM;
+ ep->baseid = empfile[base].baseid;
+ ep->cids = empfile[base].cids;
+ ep->fids = empfile[base].fids;
+ return 0;
+}
+
/*
* Close the file-backed table TYPE (EF_SECTOR, ...).
* Return non-zero on success, zero on failure.
ef_close(int type)
{
struct empfile *ep;
- int retval;
+ int retval = 1;
- retval = ef_flush(type);
+ if (ef_check(type) < 0)
+ return 0;
ep = &empfile[type];
- ep->flags &= EFF_IMMUTABLE;
- if (!(ep->flags & EFF_STATIC)) {
- free(ep->cache);
+
+ if (EF_IS_VIEW(type))
ep->cache = NULL;
+ else {
+ if (!ef_flush(type))
+ retval = 0;
+ ep->flags &= EFF_IMMUTABLE;
+ if (!(ep->flags & EFF_STATIC)) {
+ free(ep->cache);
+ ep->cache = NULL;
+ }
+ if (close(ep->fd) < 0) {
+ logerror("Error closing %s (%s)", ep->file, strerror(errno));
+ retval = 0;
+ }
+ ep->fd = -1;
}
- if (close(ep->fd) < 0) {
- logerror("Error closing %s (%s)", ep->name, strerror(errno));
+ ep->baseid = ep->cids = ep->fids = 0;
+ if (ep->onresize && ep->onresize(type) < 0)
retval = 0;
- }
- ep->fd = -1;
return retval;
}
/*
- * Flush table TYPE (EF_SECTOR, ...) to disk.
- * Does nothing if the table is privately mapped.
+ * Flush file-backed table TYPE (EF_SECTOR, ...) to its backing file.
+ * 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
* then.
*/
if (ep->flags & EFF_MEM) {
- if (do_write(ep, ep->cache, ep->baseid, ep->cids, time(NULL)) < 0)
+ if (do_write(ep, ep->cache, ep->baseid, ep->cids) < 0)
return 0;
}
ef_read(int type, int id, void *into)
{
struct empfile *ep;
- void *from;
+ void *cachep;
if (ef_check(type) < 0)
return 0;
return 0;
if (ep->flags & EFF_MEM) {
- from = ep->cache + id * ep->size;
+ cachep = ep->cache + id * ep->size;
} else {
if (ep->baseid + ep->cids <= id || ep->baseid > id) {
if (fillcache(ep, id) < 1)
return 0;
}
- from = ep->cache + (id - ep->baseid) * ep->size;
+ cachep = ep->cache + (id - ep->baseid) * ep->size;
}
- memcpy(into, from, ep->size);
+ memcpy(into, cachep, ep->size);
+ ef_mark_fresh(type, into);
if (ep->postread)
ep->postread(id, into);
*/
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;
}
/*
* Write COUNT elements starting at ID from BUF to file-backed EP.
- * Set the timestamp to NOW if the table has those.
+ * 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, time_t now)
+do_write(struct empfile *ep, void *buf, int id, int count)
{
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.
elt->ef_type = ep->uid;
if (CANT_HAPPEN(elt->uid != id + i))
elt->uid = id + i;
- elt->timestamp = now;
+ 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 to elt %d (%s)",
ep->file, id, strerror(errno));
/*
* 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).
ef_write(int type, int id, void *from)
{
struct empfile *ep;
- char *to;
+ char *cachep;
if (ef_check(type) < 0)
return 0;
ep = &empfile[type];
if (CANT_HAPPEN((ep->flags & (EFF_MEM | EFF_PRIVATE)) == EFF_PRIVATE))
return 0;
- if (ep->prewrite)
- ep->prewrite(id, from);
if (CANT_HAPPEN((ep->flags & EFF_MEM) ? id >= ep->fids : id > ep->fids))
return 0; /* not implemented */
- if (ep->fd >= 0 && !(ep->flags & EFF_PRIVATE)) {
- if (do_write(ep, from, id, 1, time(NULL)) < 0)
- return 0;
- }
- if (id >= ep->baseid && id < ep->baseid + ep->cids) {
- /* update the cache if necessary */
- to = ep->cache + (id - ep->baseid) * ep->size;
- if (to != from)
- memcpy(to, from, ep->size);
- }
+ new_seqno(ep, from);
if (id >= ep->fids) {
/* write beyond end of file extends it, take note */
ep->fids = id + 1;
+ if (ep->onresize && ep->onresize(type) < 0)
+ return 0;
}
+ if (id >= ep->baseid && id < ep->baseid + ep->cids) {
+ cachep = ep->cache + (id - ep->baseid) * ep->size;
+ if (cachep != from)
+ must_be_fresh(ep, from);
+ } else
+ cachep = NULL;
+ if (ep->prewrite)
+ ep->prewrite(id, cachep, from);
+ if (ep->fd >= 0) {
+ if (do_write(ep, from, id, 1) < 0)
+ return 0;
+ }
+ if (cachep && cachep != from) /* update the cache if necessary */
+ memcpy(cachep, from, ep->size);
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;
+}
+
+void
+ef_make_stale(void)
+{
+ ef_generation++;
+}
+
+void
+ef_mark_fresh(int type, void *buf)
+{
+ struct empfile *ep;
+
+ if (ef_check(type) < 0)
+ return;
+ ep = &empfile[type];
+ if (!(ep->flags & EFF_TYPED))
+ return;
+ ((struct emptypedstr *)buf)->generation = ef_generation;
+}
+
+static void
+must_be_fresh(struct empfile *ep, void *buf)
+{
+ struct emptypedstr *elt = buf;
+
+ if (!(ep->flags & EFF_TYPED))
+ return;
+ CANT_HAPPEN(elt->generation != ef_generation);
+}
+
/*
* Extend table TYPE by COUNT elements.
* Any pointers obtained from ef_ptr() become invalid.
{
struct empfile *ep;
char *p;
- int i, id;
- time_t now = time(NULL);
+ int need_sentinel, i, id;
- if (ef_check(type) < 0)
+ if (ef_check(type) < 0 || CANT_HAPPEN(EF_IS_VIEW(type)))
return 0;
ep = &empfile[type];
if (CANT_HAPPEN(count < 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 (do_write(ep, p, id, count, now) < 0)
+ 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)
p = ep->cache + ep->cids * ep->size;
for (i = 0; i < count; i++) {
do_blank(ep, p, id + i, 1);
- if (do_write(ep, p, id + i, 1, now) < 0)
+ if (do_write(ep, p, id + i, 1) < 0)
return 0;
}
}
- ep->fids += count;
+ ep->fids = id + count;
+ if (ep->onresize && ep->onresize(type) < 0)
+ return 0;
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_mark_fresh(type, buf);
}
/*
struct emptypedstr *elt;
memset(buf, 0, count * ep->size);
- if (ep->flags & EFF_TYPED) {
- for (i = 0; i < count; i++) {
- elt = (struct emptypedstr *)((char *)buf + i * ep->size);
+ for (i = 0; i < count; i++) {
+ elt = (struct emptypedstr *)((char *)buf + i * ep->size);
+ if (ep->flags & EFF_TYPED) {
elt->ef_type = ep->uid;
elt->uid = id + i;
}
+ if (ep->oninit)
+ ep->oninit(elt);
}
}
ef_truncate(int type, int count)
{
struct empfile *ep;
+ int need_sentinel;
- if (ef_check(type) < 0)
+ if (ef_check(type) < 0 || CANT_HAPPEN(EF_IS_VIEW(type)))
return 0;
ep = &empfile[type];
if (CANT_HAPPEN(count < 0 || count > ep->fids))
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)
ep->cids = count - ep->baseid;
}
+ if (ep->onresize && ep->onresize(type) < 0)
+ return 0;
return 1;
}
struct castr *
ef_cadef(int type)
{
+ if (ef_check(type) < 0)
+ return NULL;
return empfile[type].cadef;
}
int
ef_nelem(int type)
{
+ if (ef_check(type) < 0)
+ return 0;
return empfile[type].fids;
}
int
ef_flags(int type)
{
+ if (ef_check(type) < 0)
+ return 0;
return empfile[type].flags;
}
time_t
ef_mtime(int type)
{
+ if (ef_check(type) < 0)
+ return 0;
if (empfile[type].fd <= 0)
return 0;
return fdate(empfile[type].fd);
return empfile[type].name;
}
-int
+static int
ef_check(int type)
{
if (CANT_HAPPEN((unsigned)type >= EF_MAX))
}
/*
- * 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