From 86fcd13dd9a012fe22ef98b187dd3eab15198bf6 Mon Sep 17 00:00:00 2001
From: "roberto@goyle" <roberto@goyle>
Date: Fri, 18 Feb 2011 19:31:58 +0100
Subject: [PATCH] structure for future response caching

---
 cache.c   |  4 +++-
 uwsgi.h   |  5 ++++-
 writers.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+), 2 deletions(-)
 create mode 100644 writers.c

diff --git a/cache.c b/cache.c
index ac8858ec..6b012bec 100644
--- a/cache.c
+++ b/cache.c
@@ -57,6 +57,7 @@ char *uwsgi_cache_get(char *key, uint16_t keylen, uint64_t *valsize) {
 	uint64_t index = uwsgi_cache_get_index(key, keylen);
 
 	if (index) {
+		if (uwsgi.cache_items[index].flags & UWSGI_CACHE_FLAG_UNGETTABLE) return NULL;
 		*valsize = uwsgi.cache_items[index].valsize;
 		uwsgi.cache_items[index].hits++;
 		return uwsgi.cache+(index*uwsgi.cache_blocksize);
@@ -104,7 +105,7 @@ int uwsgi_cache_del(char *key, uint16_t keylen) {
 	return ret;
 }
 
-int uwsgi_cache_set(char *key, uint16_t keylen, char *val, uint64_t vallen, uint64_t expires) {
+int uwsgi_cache_set(char *key, uint16_t keylen, char *val, uint64_t vallen, uint64_t expires, uint16_t flags) {
 
 	uint64_t index = 0, last_index = 0 ;
 
@@ -141,6 +142,7 @@ int uwsgi_cache_set(char *key, uint16_t keylen, char *val, uint64_t vallen, uint
 		uci->expires = expires;
 		uci->djbhash = djb33x_hash(key, keylen);
 		uci->hits = 0;
+		uci->flags = flags;
 		memcpy(uci->key, key, keylen);
 		memcpy(uwsgi.cache+(index*uwsgi.cache_blocksize), val, vallen);
 
diff --git a/uwsgi.h b/uwsgi.h
index e915f424..52b37122 100644
--- a/uwsgi.h
+++ b/uwsgi.h
@@ -193,6 +193,9 @@ extern int pivot_root(const char * new_root, const char * put_old);
 #endif
 
 #define UWSGI_CACHE_MAX_KEY_SIZE 2048
+#define UWSGI_CACHE_FLAG_UNGETTABLE	0x0001
+
+#define uwsgi_cache_update_start(x, y, z) uwsgi_cache_set(x, y, "", 0, CACHE_FLAG_UNGETTABLE)
 
 union uwsgi_sockaddr {
 	struct sockaddr     sa;
@@ -242,7 +245,7 @@ struct uwsgi_queue_item {
 // maintain alignment here !!!
 struct uwsgi_cache_item {
 	// unused
-	uint16_t	unused;
+	uint16_t	flags;
 	// size of the key
 	uint16_t	keysize;
 	// djb hash of the key
diff --git a/writers.c b/writers.c
new file mode 100644
index 00000000..db97282f
--- /dev/null
+++ b/writers.c
@@ -0,0 +1,51 @@
+// uWSGI writer
+
+void simple_writer_init(struct wsgi_request *wsgi_req) {}
+void simple_writer_end(struct wsgi_request *wsgi_req) {}
+
+ssize_t simple_writer(struct wsgi_request *wsgi_req, char *buf, size_t len) {
+
+	return write(wsgi_req->poll.fd, buf, len);
+
+}
+
+void cache_writer_init(struct wsgi_request *wsgi_req) {
+	if (wsgi_req->cache_it) {
+		// lock cache write
+		if (uwsgi_cache_update_start(wsgi_req->uri, wsgi_req->uri_len)) {
+			uwsgi_log("unable to write data to uwsgi cache\n");
+			wsgi_req->cache_it = 0;
+		}
+	}
+}
+
+ssize_t cache_writer(struct wsgi_request *wsgi_req, char *buf, size_t len) {
+
+	if (wsgi_req->cache_it) {
+		// lock cache write
+		if (uwsgi_cache_update(wsgi_req->uri, wsgi_req->uri_len, buf, len, wsgi_req->cache_expires)) {
+			uwsgi_log("unable to write data to uwsgi cache\n");
+			uwsgi_cache_del(sgi_req->uri, wsgi_req->uri_len);
+		}
+		// unlock cache
+	}
+	return write(wsgi_req->poll.fd, buf, len);
+}
+
+void cache_writer_end(struct wsgi_request *wsgi_req) {
+
+	if (wsgi_req->cache_it) {
+		// finish cache update (lock write it)
+		uwsgi_cache_update_finalize(wsgi_req->uri, wsgi_req->uri_len);
+	}
+}
+
+void memcached_writer_init(struct wsgi_request *wsgi_req) {
+	//open connection to memcached and create entry
+}
+
+void memcached_writer_end(struct wsgi_request *wsgi_req) {
+	// close connection with memcached
+}
+ssize_t memcached_writer(struct wsgi_request *wsgi_req, char *buf, size_t len) {
+}