src/mod_magnet_cache.c

   1 #include "first.h"
   2
   3 #include "mod_magnet_cache.h"
   4 #include "stat_cache.h"
   5
   6 #include <stdlib.h>
   7 #include <time.h>
   8
   9 #include <lualib.h>
  10 #include <lauxlib.h>
  11
  12 static script *script_init() {
  13         script *sc;
  14
  15         sc = calloc(1, sizeof(*sc));
  16         sc->name = buffer_init();
  17         sc->etag = buffer_init();
  18
  19         return sc;
  20 }
  21
  22 static void script_free(script *sc) {
  23         if (!sc) return;
  24
  25         lua_pop(sc->L, 1); /* the function copy */
  26
  27         buffer_free(sc->name);
  28         buffer_free(sc->etag);
  29
  30         lua_close(sc->L);
  31
  32         free(sc);
  33 }
  34
  35 script_cache *script_cache_init() {
  36         script_cache *p;
  37
  38         p = calloc(1, sizeof(*p));
  39
  40         return p;
  41 }
  42
  43 void script_cache_free(script_cache *p) {
  44         size_t i;
  45
  46         if (!p) return;
  47
  48         for (i = 0; i < p->used; i++) {
  49                 script_free(p->ptr[i]);
  50         }
  51
  52         free(p->ptr);
  53
  54         free(p);
  55 }
  56
  57 lua_State *script_cache_get_script(server *srv, connection *con, script_cache *cache, buffer *name) {
  58         size_t i;
  59         script *sc = NULL;
  60         stat_cache_entry *sce;
  61
  62         for (i = 0; i < cache->used; i++) {
  63                 sc = cache->ptr[i];
  64
  65                 if (buffer_is_equal(name, sc->name)) {
  66                         sc->last_used = time(NULL);
  67
  68                         /* oops, the script failed last time */
  69
  70                         if (lua_gettop(sc->L) == 0) break;
  71                         force_assert(lua_gettop(sc->L) == 1);
  72
  73                         if (HANDLER_ERROR == stat_cache_get_entry(srv, con, sc->name, &sce)) {
  74                                 lua_pop(sc->L, 1); /* pop the old function */
  75                                 break;
  76                         }
  77
  78                         if (!buffer_is_equal(sce->etag, sc->etag)) {
  79                                 /* the etag is outdated, reload the function */
  80                                 lua_pop(sc->L, 1);
  81                                 break;
  82                         }
  83
  84                         force_assert(lua_isfunction(sc->L, -1));
  85
  86                         return sc->L;
  87                 }
  88
  89                 sc = NULL;
  90         }
  91
  92         /* if the script was script already loaded but either got changed or
  93          * failed to load last time */
  94         if (sc == NULL) {
  95                 sc = script_init();
  96
  97                 if (cache->size == 0) {
  98                         cache->size = 16;
  99                         cache->ptr = malloc(cache->size * sizeof(*(cache->ptr)));
 100                 } else if (cache->used == cache->size) {
 101                         cache->size += 16;
 102                         cache->ptr = realloc(cache->ptr, cache->size * sizeof(*(cache->ptr)));
 103                 }
 104
 105                 cache->ptr[cache->used++] = sc;
 106
 107                 buffer_copy_buffer(sc->name, name);
 108
 109                 sc->L = luaL_newstate();
 110                 luaL_openlibs(sc->L);
 111         }
 112
 113         sc->last_used = time(NULL);
 114
 115         if (0 != luaL_loadfile(sc->L, name->ptr)) {
 116                 /* oops, an error, return it */
 117                 return sc->L;
 118         }
 119
 120         if (HANDLER_GO_ON == stat_cache_get_entry(srv, con, sc->name, &sce)) {
 121                 buffer_copy_buffer(sc->etag, sce->etag);
 122         }
 123
 124         force_assert(lua_isfunction(sc->L, -1));
 125
 126         return sc->L;
 127 }