generic backends

include/lighttpd/backends.h

@@ -0,0 +1,106 @@
+#ifndef _LIGHTTPD_BACKENDS_H_
+#define _LIGHTTPD_BACKENDS_H_
+
+#include <lighttpd/base.h>
+
+enum liBackendResult {
+	LI_BACKEND_SUCCESS, /* got a connection */
+	LI_BACKEND_WAIT, /* establishing new connection, or waiting for a free slot */
+	LI_BACKEND_TIMEOUT /* wait timed out, no free slots available */
+};
+
+typedef enum liBackendResult liBackendResult;
+typedef struct liBackendCallbacks liBackendCallbacks;
+typedef struct liBackendWait liBackendWait;
+typedef struct liBackendConnection liBackendConnection;
+typedef struct liBackendPool liBackendPool;
+typedef struct liBackendConfig liBackendConfig;
+
+typedef void (*liBackendConnectionThreadCB)(liBackendPool *bpool, liWorker *wrk, liBackendConnection *bcon);
+typedef void (*liBackendCB)(liBackendPool *bpool);
+
+
+struct liBackendConnection {
+	/* must not keep a loop ref while the connection is not actively used,
+	 * get and put will do ref/unref if the watcher is active */
+	ev_io watcher;
+	gpointer data;
+};
+
+/* states: [start]  ->(new)->   [INACTIVE]  ->(detach)->   [detached]  ->(attach)->   [INACTIVE]   ->get->   [active]   ->put->   [INACTIVE]   ->(close)->   [done] */
+/* the backend pool might be locked while the callbacks are running, but don't rely on it */
+struct liBackendCallbacks {
+	/* for moving connection between threads */
+	liBackendConnectionThreadCB detach_thread_cb;
+	liBackendConnectionThreadCB attach_thread_cb;
+
+	/* for initializing/shutdown */
+	liBackendConnectionThreadCB new_cb;
+	liBackendConnectionThreadCB close_cb;
+
+	/* free pool config */
+	liBackendCB free_cb;
+};
+
+
+struct liBackendPool {
+	/* READ ONLY CONFIGURATION DATA */
+	const liBackendConfig *config;
+};
+
+struct liBackendConfig {
+	const liBackendCallbacks *callbacks;
+
+	liSocketAddress sock_addr;
+
+	/* >0: real limit for current connections + pendings connects
+	 * <0: unlimited connections, absolute value limits the number of pending connects per worker
+	 * =0: no limit
+	 *
+	 * if there is no limit (i.e. <= 0), backend connections won't be moved between threads
+	 */
+	int max_connections;
+
+	/* how long we wait on keep-alive connections. 0: no keep-alive;
+	 * also used for new connection we didn't use
+	 */
+	guint idle_timeout;
+
+	/* how long we wait for connect to succeed, must be > 0; when connect fails the pool gets "disabled". */
+	guint connect_timeout;
+
+	/* how long a vrequest is allowed to wait for a connect  before we return an error. if pool gets disabled all requests fail.
+	 * if a pending connect is assigned to a vrequest wait_timeout is not active.
+	 */
+	guint wait_timeout;
+
+	/* how long the pool stays disabled. even if this is 0, all vrequests will receive an error on disable */
+	guint disable_time;
+
+	/* max requests per connection. -1: unlimited */
+	int max_requests;
+
+	/* if enabled, the backend.watcher will be set to internal callback and EV_READ while the connection
+	 * is not used by a vrequest;
+	 *   if it sees input data it will log an error and close it, and if it sees eof it will
+	 *   close it too
+	 * if you disable this you should have to handle this yourself
+	 */
+	gboolean watch_for_close;
+};
+
+LI_API liBackendPool* li_backend_pool_new(const liBackendConfig *config);
+LI_API void li_backend_pool_free(liBackendPool *bpool);
+
+LI_API liBackendResult li_backend_get(liVRequest *vr, liBackendPool *bpool, liBackendConnection **pbcon, liBackendWait **pbwait);
+LI_API void li_backend_wait_stop(liVRequest *vr, liBackendPool *bpool, liBackendWait **pbwait);
+
+/* set bcon->fd = -1 if you closed the connection after an error */
+LI_API void li_backend_put(liWorker *wrk, liBackendPool *bpool, liBackendConnection *bcon, gboolean closecon); /* if closecon == TRUE or bcon->watcher.fd == -1 the connection gets removed */
+
+/* if an idle connections gets closed; bcon must be INACTIVE (i.e. not detached and not active).
+ * call in worker that bcon is attached to.
+ */
+LI_API void li_backend_connection_closed(liBackendPool *bpool, liBackendConnection *bcon);
+
+#endif

src/CMakeLists.txt

@@ -205,6 +205,7 @@ SET(LIGHTTPD_SHARED_SRC
 	angel_fake.c
 	actions.c
 	base_lua.c
+	backends.c
 	chunk.c
 	chunk_parser.c
 	collect.c

src/main/Makefile.am

@@ -9,6 +9,7 @@ lighttpd_shared_src= \
 	angel_fake.c \
 	actions.c \
 	base_lua.c \
+	backends.c \
 	chunk.c \
 	chunk_parser.c \
 	collect.c \

src/main/wscript

@@ -22,6 +22,7 @@ def build(bld):
 		angel.c
 		angel_fake.c
 		base_lua.c
+		backends.c
 		chunk.c
 		chunk_parser.c
 		collect.c