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 int cache_lookup(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         if (stat(item->name, &item->st)) {
  34                 item->st.st_mtime = 0;
  35                 return 0;
  36         }
  37         return 1;
  38 }
  39
  40 int cache_create_dirs()
  41 {
  42         char *path;
  43
  44         if (!cgit_query_repo)
  45                 return 0;
  46
  47         path = fmt("%s/%s", cgit_cache_root, cgit_query_repo);
  48         if (mkdir(path, S_IRWXU) && errno!=EEXIST)
  49                 return 0;
  50
  51         if (cgit_query_page) {
  52                 path = fmt("%s/%s/%s", cgit_cache_root, cgit_query_repo,
  53                            cgit_query_page);
  54                 if (mkdir(path, S_IRWXU) && errno!=EEXIST)
  55                         return 0;
  56         }
  57         return 1;
  58 }
  59
  60 int cache_lock(struct cacheitem *item)
  61 {
  62         int ret;
  63         char *lockfile = fmt("%s.lock", item->name);
  64
  65  top:
  66         item->fd = open(lockfile, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR|S_IWUSR);
  67         if (item->fd == NOLOCK && errno == ENOENT && cache_create_dirs())
  68                 goto top;
  69         if (item->fd == NOLOCK && errno == EEXIST) {
  70                 struct stat st;
  71                 time_t t;
  72                 if (stat(lockfile, &st))
  73                         return ret;
  74                 t = time(NULL);
  75                 if (t-st.st_mtime > cgit_cache_max_create_time &&
  76                     !unlink(lockfile))
  77                         goto top;
  78                 return 0;
  79         }
  80         return (item->fd > 0);
  81 }
  82
  83 int cache_unlock(struct cacheitem *item)
  84 {
  85         close(item->fd);
  86         return (rename(fmt("%s.lock", item->name), item->name) == 0);
  87 }
  88
  89 int cache_expired(struct cacheitem *item)
  90 {
  91         if (item->ttl < 0)
  92                 return 0;
  93         return item->st.st_mtime + item->ttl * 60 < time(NULL);
  94 }