gitweb.ps.run Git - ps-cgit/blob - cache.c

   1 /* cache.c: cache management
   2  *
   3  * Copyright (C) 2006 Lars Hjemli
   4  *
   5  * Licensed under GNU General Public License v2
   6  *   (see COPYING for full license text)
   7  */
   8
   9 #include "cgit.h"
  10
  11 const int NOLOCK = -1;
  12
  13 void cache_prepare(struct cacheitem *item)
  14 {
  15         if (!cgit_query_repo) {
  16                 item->name = xstrdup(fmt("%s/index.html", cgit_cache_root));
  17                 item->ttl = cgit_cache_root_ttl;
  18         } else if (!cgit_query_page) {
  19                 item->name = xstrdup(fmt("%s/%s/index.html", cgit_cache_root,
  20                            cgit_query_repo));
  21                 item->ttl = cgit_cache_repo_ttl;
  22         } else {
  23                 item->name = xstrdup(fmt("%s/%s/%s/%s.html", cgit_cache_root,
  24                            cgit_query_repo, cgit_query_page,
  25                            cgit_querystring));
  26                 if (cgit_query_has_symref)
  27                         item->ttl = cgit_cache_dynamic_ttl;
  28                 else if (cgit_query_has_sha1)
  29                         item->ttl = cgit_cache_static_ttl;
  30                 else
  31                         item->ttl = cgit_cache_repo_ttl;
  32         }
  33 }
  34
  35 int cache_exist(struct cacheitem *item)
  36 {
  37         if (stat(item->name, &item->st)) {
  38                 item->st.st_mtime = 0;
  39                 return 0;
  40         }
  41         return 1;
  42 }
  43
  44 int cache_create_dirs()
  45 {
  46         char *path;
  47
  48         if (!cgit_query_repo)
  49                 return 0;
  50
  51         path = fmt("%s/%s", cgit_cache_root, cgit_query_repo);
  52         if (mkdir(path, S_IRWXU) && errno!=EEXIST)
  53                 return 0;
  54
  55         if (cgit_query_page) {
  56                 path = fmt("%s/%s/%s", cgit_cache_root, cgit_query_repo,
  57                            cgit_query_page);
  58                 if (mkdir(path, S_IRWXU) && errno!=EEXIST)
  59                         return 0;
  60         }
  61         return 1;
  62 }
  63
  64 int cache_lock(struct cacheitem *item)
  65 {
  66         int ret;
  67         char *lockfile = fmt("%s.lock", item->name);
  68
  69  top:
  70         item->fd = open(lockfile, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR|S_IWUSR);
  71         if (item->fd == NOLOCK && errno == ENOENT && cache_create_dirs())
  72                 goto top;
  73         if (item->fd == NOLOCK && errno == EEXIST) {
  74                 struct stat st;
  75                 time_t t;
  76                 if (stat(lockfile, &st))
  77                         return ret;
  78                 t = time(NULL);
  79                 if (t-st.st_mtime > cgit_cache_max_create_time &&
  80                     !unlink(lockfile))
  81                         goto top;
  82                 return 0;
  83         }
  84         return (item->fd > 0);
  85 }
  86
  87 int cache_unlock(struct cacheitem *item)
  88 {
  89         close(item->fd);
  90         return (rename(fmt("%s.lock", item->name), item->name) == 0);
  91 }
  92
  93 int cache_expired(struct cacheitem *item)
  94 {
  95         if (item->ttl < 0)
  96                 return 0;
  97         return item->st.st_mtime + item->ttl * 60 < time(NULL);
  98 }