split cookie cache keeping into separate file

daemon/cookie_cache.c

@@ -0,0 +1,80 @@
+#include <time.h>
+#include <glib.h>
+#include "cookie_cache.h"
+#include "aux.h"
+#include "poller.h"
+
+static const char *cookie_in_use = "MAGIC";
+
+static inline void cookie_cache_state_init(struct cookie_cache_state *s) {
+	s->cookies = g_hash_table_new(g_str_hash, g_str_equal);
+	s->chunks = g_string_chunk_new(4 * 1024);
+}
+
+void cookie_cache_init(struct cookie_cache *c) {
+	cookie_cache_state_init(&c->current);
+	cookie_cache_state_init(&c->old);
+	c->swap_time = poller_now;
+	mutex_init(&c->lock);
+	cond_init(&c->cond);
+}
+
+/* lock must be held */
+static void __cookie_cache_check_swap(struct cookie_cache *c) {
+	if (poller_now - c->swap_time >= 30) {
+		g_hash_table_remove_all(c->old.cookies);
+#if GLIB_CHECK_VERSION(2,14,0)
+		g_string_chunk_clear(c->old.chunks);
+		swap_ptrs(&c->old.chunks, &c->current.chunks);
+#else
+		g_string_chunk_free(c->old.chunks);
+		c->old.chunks = c->current.chunks;
+		c->current.chunks = g_string_chunk_new(4 * 1024);
+#endif
+		swap_ptrs(&c->old.cookies, &c->current.cookies);
+		c->swap_time = poller_now;
+	}
+}
+
+char *cookie_cache_lookup(struct cookie_cache *c, const char *s) {
+	char *ret;
+
+	mutex_lock(&c->lock);
+
+	__cookie_cache_check_swap(c);
+
+restart:
+	/* XXX better hashing */
+	ret = g_hash_table_lookup(c->current.cookies, s);
+	if (!ret)
+		ret = g_hash_table_lookup(c->old.cookies, s);
+	if (ret) {
+		if (ret == cookie_in_use) {
+			/* another thread is working on this right now */
+			cond_wait(&c->cond, &c->lock);
+			goto restart;
+		}
+		mutex_unlock(&c->lock);
+		return ret;
+	}
+	g_hash_table_replace(c->current.cookies, (void *) s, (void *) cookie_in_use);
+	mutex_unlock(&c->lock);
+	return NULL;
+}
+
+void cookie_cache_insert(struct cookie_cache *c, const char *s, const char *r, int len) {
+	mutex_lock(&c->lock);
+	g_hash_table_replace(c->current.cookies, g_string_chunk_insert(c->current.chunks, s),
+		g_string_chunk_insert_len(c->current.chunks, r, (len >= 0) ? len : strlen(r)));
+	g_hash_table_remove(c->old.cookies, s);
+	cond_broadcast(&c->cond);
+	mutex_unlock(&c->lock);
+}
+
+void cookie_cache_remove(struct cookie_cache *c, const char *s) {
+	mutex_lock(&c->lock);
+	g_hash_table_remove(c->current.cookies, s);
+	g_hash_table_remove(c->old.cookies, s);
+	cond_broadcast(&c->cond);
+	mutex_unlock(&c->lock);
+}

daemon/cookie_cache.h

@@ -0,0 +1,25 @@
+#ifndef _COOKIE_CACHE_H_
+#define _COOKIE_CACHE_H_
+
+#include <time.h>
+#include <glib.h>
+#include "aux.h"
+
+struct cookie_cache_state {
+	GHashTable *cookies;
+	GStringChunk *chunks;
+};
+
+struct cookie_cache {
+	mutex_t lock;
+	cond_t cond;
+	struct cookie_cache_state current, old;
+	time_t swap_time;
+};
+
+void cookie_cache_init(struct cookie_cache *);
+char *cookie_cache_lookup(struct cookie_cache *, const char *);
+void cookie_cache_insert(struct cookie_cache *, const char *, const char *, int);
+void cookie_cache_remove(struct cookie_cache *, const char *);
+
+#endif