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 #include <assert.h>
   9
  10 #ifdef HAVE_LUA_H
  11 #include <lualib.h>
  12 #include <lauxlib.h>
  13
  14 static script *script_init() {
  15         script *sc;
  16
  17         sc = calloc(1, sizeof(*sc));
  18         sc->name = buffer_init();
  19         sc->etag = buffer_init();
  20
  21         return sc;
  22 }
  23
  24 static void script_free(script *sc) {
  25         if (!sc) return;
  26
  27         lua_pop(sc->L, 1); /* the function copy */
  28
  29         buffer_free(sc->name);
  30         buffer_free(sc->etag);
  31
  32         lua_close(sc->L);
  33
  34         free(sc);
  35 }
  36
  37 script_cache *script_cache_init() {
  38         script_cache *p;
  39
  40         p = calloc(1, sizeof(*p));
  41
  42         return p;
  43 }
  44
  45 void script_cache_free(script_cache *p) {
  46         size_t i;
  47
  48         if (!p) return;
  49
  50         for (i = 0; i < p->used; i++) {
  51                 script_free(p->ptr[i]);
  52         }
  53
  54         free(p->ptr);
  55
  56         free(p);
  57 }
  58
  59 lua_State *script_cache_get_script(server *srv, connection *con, script_cache *cache, buffer *name) {
  60         size_t i;
  61         script *sc = NULL;
  62         stat_cache_entry *sce;
  63
  64         for (i = 0; i < cache->used; i++) {
  65                 sc = cache->ptr[i];
  66
  67                 if (buffer_is_equal(name, sc->name)) {
  68                         sc->last_used = time(NULL);
  69
  70                         /* oops, the script failed last time */
  71
  72                         if (lua_gettop(sc->L) == 0) break;
  73                         force_assert(lua_gettop(sc->L) == 1);
  74
  75                         if (HANDLER_ERROR == stat_cache_get_entry(srv, con, sc->name, &sce)) {
  76                                 lua_pop(sc->L, 1); /* pop the old function */
  77                                 break;
  78                         }
  79
  80                         if (!buffer_is_equal(sce->etag, sc->etag)) {
  81                                 /* the etag is outdated, reload the function */
  82                                 lua_pop(sc->L, 1);
  83                                 break;
  84                         }
  85
  86                         force_assert(lua_isfunction(sc->L, -1));
  87
  88                         return sc->L;
  89                 }
  90
  91                 sc = NULL;
  92         }
  93
  94         /* if the script was script already loaded but either got changed or
  95          * failed to load last time */
  96         if (sc == NULL) {
  97                 sc = script_init();
  98
  99                 if (cache->size == 0) {
 100                         cache->size = 16;
 101                         cache->ptr = malloc(cache->size * sizeof(*(cache->ptr)));
 102                 } else if (cache->used == cache->size) {
 103                         cache->size += 16;
 104                         cache->ptr = realloc(cache->ptr, cache->size * sizeof(*(cache->ptr)));
 105                 }
 106
 107                 cache->ptr[cache->used++] = sc;
 108
 109                 buffer_copy_buffer(sc->name, name);
 110
 111                 sc->L = luaL_newstate();
 112                 luaL_openlibs(sc->L);
 113         }
 114
 115         sc->last_used = time(NULL);
 116
 117         if (0 != luaL_loadfile(sc->L, name->ptr)) {
 118                 /* oops, an error, return it */
 119                 return sc->L;
 120         }
 121
 122         if (HANDLER_GO_ON == stat_cache_get_entry(srv, con, sc->name, &sce)) {
 123                 buffer_copy_buffer(sc->etag, sce->etag);
 124         }
 125
 126         force_assert(lua_isfunction(sc->L, -1));
 127
 128         return sc->L;
 129 }
 130
 131 #endif