1 #include "mod_magnet_cache.h"
2 #include "stat_cache.h"
3
4 #include <stdlib.h>
5 #include <time.h>
6 #include <assert.h>
7
8 #ifdef HAVE_LUA_H
9 #include <lualib.h>
10 #include <lauxlib.h>
11
script_init()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
script_free(script * sc)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
script_cache_init()35 script_cache *script_cache_init() {
36 script_cache *p;
37
38 p = calloc(1, sizeof(*p));
39
40 return p;
41 }
42
script_cache_free(script_cache * p)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
script_cache_get_script(server * srv,connection * con,script_cache * cache,buffer * name)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
72 if (HANDLER_ERROR == stat_cache_get_entry(srv, con, sc->name, &sce)) {
73 lua_pop(sc->L, 1); /* pop the old function */
74 break;
75 }
76
77 if (!buffer_is_equal(sce->etag, sc->etag)) {
78 /* the etag is outdated, reload the function */
79 lua_pop(sc->L, 1);
80 break;
81 }
82
83 assert(lua_isfunction(sc->L, -1));
84 lua_pushvalue(sc->L, -1); /* copy the function-reference */
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_string_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
118 return sc->L;
119 }
120
121 if (HANDLER_GO_ON == stat_cache_get_entry(srv, con, sc->name, &sce)) {
122 buffer_copy_string_buffer(sc->etag, sce->etag);
123 }
124
125 /**
126 * pcall() needs the function on the stack
127 *
128 * as pcall() will pop the script from the stack when done, we have to
129 * duplicate it here
130 */
131 assert(lua_isfunction(sc->L, -1));
132 lua_pushvalue(sc->L, -1); /* copy the function-reference */
133
134 return sc->L;
135 }
136
137 #endif
138