Imported Upstream version 1.4.12upstream/1.4.12

1 files changed, 137 insertions, 0 deletions

diff --git a/src/mod_magnet_cache.c b/src/mod_magnet_cache.c
new file mode 100644
index 0000000..e2f5d84
--- /dev/null
+++ b/src/mod_magnet_cache.c
@@ -0,0 +1,137 @@
+#include <stdlib.h>
+#include <time.h>
+#include <assert.h>
+
+#include "mod_magnet_cache.h"
+#include "stat_cache.h"
+
+#ifdef HAVE_LUA_H
+#include <lualib.h>
+#include <lauxlib.h>
+
+script *script_init() {
+	script *sc;
+
+	sc = calloc(1, sizeof(*sc));
+	sc->name = buffer_init();
+	sc->etag = buffer_init();
+
+	return sc;
+}
+
+void script_free(script *sc) {
+	if (!sc) return;
+
+	lua_pop(sc->L, 1); /* the function copy */
+
+	buffer_free(sc->name);
+	buffer_free(sc->etag);
+
+	lua_close(sc->L);
+
+	free(sc);
+}
+
+script_cache *script_cache_init() {
+	script_cache *p;
+	
+	p = calloc(1, sizeof(*p));
+
+	return p;
+}
+
+void script_cache_free(script_cache *p) {
+	size_t i;
+
+	if (!p) return;
+
+	for (i = 0; i < p->used; i++) {
+		script_free(p->ptr[i]);
+	}
+
+	free(p->ptr);
+
+	free(p);
+}
+
+lua_State *script_cache_get_script(server *srv, connection *con, script_cache *cache, buffer *name) {
+	size_t i;
+	script *sc = NULL;
+	stat_cache_entry *sce;
+
+	for (i = 0; i < cache->used; i++) {
+		sc = cache->ptr[i];
+
+		if (buffer_is_equal(name, sc->name)) {
+			sc->last_used = time(NULL);
+
+			/* oops, the script failed last time */
+
+			if (lua_gettop(sc->L) == 0) break;
+
+			if (HANDLER_ERROR == stat_cache_get_entry(srv, con, sc->name, &sce)) {
+				lua_pop(sc->L, 1); /* pop the old function */
+				break;
+			}
+
+			if (!buffer_is_equal(sce->etag, sc->etag)) {
+				/* the etag is outdated, reload the function */
+				lua_pop(sc->L, 1);
+				break;
+			}
+
+			assert(lua_isfunction(sc->L, -1));
+			lua_pushvalue(sc->L, -1); /* copy the function-reference */
+
+			return sc->L;
+		}
+
+		sc = NULL;
+	}
+
+	/* if the script was script already loaded but either got changed or 
+	 * failed to load last time */
+	if (sc == NULL) {
+		sc = script_init();
+
+		if (cache->size == 0) {
+			cache->size = 16;
+			cache->ptr = malloc(cache->size * sizeof(*(cache->ptr)));
+		} else if (cache->used == cache->size) {
+			cache->size += 16;
+			cache->ptr = realloc(cache->ptr, cache->size * sizeof(*(cache->ptr)));
+		}
+
+		cache->ptr[cache->used++] = sc;
+	
+		buffer_copy_string_buffer(sc->name, name);
+
+		sc->L = luaL_newstate();
+		luaL_openlibs(sc->L);
+	}
+
+	sc->last_used = time(NULL);
+
+	if (0 != luaL_loadfile(sc->L, name->ptr)) {
+		/* oops, an error, return it */
+
+		return sc->L;
+	}
+
+	if (HANDLER_GO_ON == stat_cache_get_entry(srv, con, sc->name, &sce)) {
+		buffer_copy_string_buffer(sc->etag, sce->etag);
+	}
+
+	/**
+	 * pcall() needs the function on the stack
+	 *
+	 * as pcall() will pop the script from the stack when done, we have to
+	 * duplicate it here
+	 */
+	assert(lua_isfunction(sc->L, -1));
+	lua_pushvalue(sc->L, -1); /* copy the function-reference */
+
+	return sc->L;
+}
+
+#endif