/* cache.c: cache management
*
* Copyright (C) 2006 Lars Hjemli
*
* Licensed under GNU General Public License v2
* (see COPYING for full license text)
*
*
* The cache is just a directory structure where each file is a cache slot,
* and each filename is based on the hash of some key (e.g. the cgit url).
* Each file contains the full key followed by the cached content for that
* key.
*
*/
#include "cgit.h"
#include "cache.h"
#define CACHE_BUFSIZE (1024 * 4)
struct cache_slot {
const char *key;
int keylen;
int ttl;
cache_fill_fn fn;
void *cbdata;
int cache_fd;
int lock_fd;
const char *cache_name;
const char *lock_name;
int match;
struct stat cache_st;
struct stat lock_st;
int bufsize;
char buf[CACHE_BUFSIZE];
};
/* Open an existing cache slot and fill the cache buffer with
* (part of) the content of the cache file. Return 0 on success
* and errno otherwise.
*/
static int open_slot(struct cache_slot *slot)
{
char *bufz;
int bufkeylen = -1;
slot->cache_fd = open(slot->cache_name, O_RDONLY);
if (slot->cache_fd == -1)
return errno;
if (fstat(slot->cache_fd, &slot->cache_st))
return errno;
slot->bufsize = xread(slot->cache_fd, slot->buf, sizeof(slot->buf));
if (slot->bufsize < 0)
return errno;
bufz = memchr(slot->buf, 0, slot->bufsize);
if (bufz)
bufkeylen = bufz - slot->buf;
slot->match = bufkeylen == slot->keylen &&
!memcmp(slot->key, slot->buf, bufkeylen + 1);
return 0;
}
/* Close the active cache slot */
static int close_slot(struct cache_slot *slot)
{
int err = 0;
if (slot->cache_fd > 0) {
if (close(slot->cache_fd))
err = errno;
else
slot->cache_fd = -1;
}
return err;
}
/* Print the content of the active cache slot (but skip the key). */
static int print_slot(struct cache_slot *slot)
{
ssize_t i, j;
i = lseek(slot->cache_fd, slot->keylen + 1, SEEK_SET);
if (i != slot->keylen + 1)
return errno;
do {
i = j = xread(slot->cache_fd, slot->buf, sizeof(slot->buf));
if (i > 0)
j = xwrite(STDOUT_FILENO, slot->buf, i);
} while (i > 0 && j == i);
if (i < 0 || j != i)
return errno;
else
return 0;
}
/* Check if the slot has expired */
static int is_expired(struct cache_slot *slot)
{
if (slot->ttl < 0)
return 0;
else
return slot->cache_st.st_mtime + slot->ttl * 60 < time(NULL);
}
/* Check if the slot has been modified since we opened it.
* NB: If stat() fails, we pretend the file is modified.
*/
static int is_modified(struct cache_slot *slot)
{
struct stat st;
if (stat(slot->cache_name, &st))
return 1;
return (st.st_ino != slot->cache_st.st_ino ||
st.st_mtime != slot->cache_st.st_mtime ||
st.st_size != slot->cache_st.st_size);
}
/* Close an open lockfile */
static int close_lock(struct cache_slot *slot)
{
int err = 0;
if (slot->lock_fd > 0) {
if (close(slot->lock_fd))
err = errno;
else
slot->lock_fd = -1;
}
return err;
}
/* Create a lockfile used to store the generated content for a cache
* slot, and write the slot key + \0 into it.
* Returns 0 on success and errno otherwise.
*/
static int lock_slot(struct cache_slot *slot)
{
slot->lock_fd = open(slot->lock_name, O_RDWR | O_CREAT | O_EXCL,
S_IRUSR | S_IWUSR);
if (slot->lock_fd == -1)
return errno;
if (xwrite(slot->lock_fd, slot->key, slot->keylen + 1) < 0)
return errno;
return 0;
}
/* Release the current lockfile. If `replace_old_slot` is set the
* lockfile replaces the old cache slot, otherwise the lockfile is
* just deleted.
*/
static int unlock_slot(struct cache_slot *slot, i
#ifndef UI_STATS_H#define UI_STATS_H#include"cgit.h"structcgit_period{constcharcode;constchar*name;intmax_periods;intcount;/* Convert a tm value to the first day in the period */void(