proxy: initial commit.

See BUILD for compilation details.

See t/startfile.lua for configuration examples.

(see also https://github.com/memcached/memcached-proxylibs for
extensions, config libraries, more examples)

NOTE: io_uring mode is _not stable_, will crash.

As of this commit it is not recommended to run the proxy in production.
If you are interested please let us know, as we are actively stabilizing
for production use.

1 files changed, 29 insertions, 2 deletions

diff --git a/memcached.h b/memcached.h
index 12385db..b7d4ad5 100644
--- a/memcached.h
+++ b/memcached.h
@@ -223,7 +223,10 @@ enum bin_substates {
 enum protocol {
     ascii_prot = 3, /* arbitrary value. */
     binary_prot,
-    negotiating_prot /* Discovering the protocol */
+    negotiating_prot, /* Discovering the protocol */
+#ifdef PROXY
+    proxy_prot,
+#endif
 };
 
 enum network_transport {
@@ -329,6 +332,12 @@ struct slab_stats {
     X(badcrc_from_extstore)
 #endif
 
+#ifdef PROXY
+#define PROXY_THREAD_STATS_FIELDS \
+    X(proxy_conn_requests) \
+    X(proxy_conn_errors)
+#endif
+
 /**
  * Stats stored per-thread.
  */
@@ -339,6 +348,9 @@ struct thread_stats {
 #ifdef EXTSTORE
     EXTSTORE_THREAD_STATS_FIELDS
 #endif
+#ifdef PROXY
+    PROXY_THREAD_STATS_FIELDS
+#endif
 #undef X
     struct slab_stats slab_stats[MAX_NUMBER_OF_SLAB_CLASSES];
     uint64_t lru_hits[POWER_LARGEST];
@@ -501,6 +513,11 @@ struct settings {
 #endif
     int num_napi_ids;   /* maximum number of NAPI IDs */
     char *memory_file;  /* warm restart memory file path */
+#ifdef PROXY
+    bool proxy_enabled;
+    char *proxy_startfile; /* lua file to run when workers start */
+    void *proxy_ctx; /* proxy's state context */
+#endif
 };
 
 extern struct stats stats;
@@ -628,6 +645,7 @@ typedef struct {
 
 #define IO_QUEUE_NONE 0
 #define IO_QUEUE_EXTSTORE 1
+#define IO_QUEUE_PROXY 2
 
 typedef struct _io_pending_t io_pending_t;
 typedef struct io_queue_s io_queue_t;
@@ -690,7 +708,12 @@ typedef struct {
     char   *ssl_wbuf;
 #endif
     int napi_id;                /* napi id associated with this thread */
-
+#ifdef PROXY
+    void *L;
+    void *proxy_hooks;
+    void *proxy_stats;
+    // TODO: add ctx object so we can attach to queue.
+#endif
 } LIBEVENT_THREAD;
 
 /**
@@ -905,6 +928,9 @@ extern int daemonize(int nochdir, int noclose);
 void memcached_thread_init(int nthreads, void *arg);
 void redispatch_conn(conn *c);
 void timeout_conn(conn *c);
+#ifdef PROXY
+void proxy_reload_notify(LIBEVENT_THREAD *t);
+#endif
 void return_io_pending(io_pending_t *io);
 void dispatch_conn_new(int sfd, enum conn_states init_state, int event_flags, int read_buffer_size,
     enum network_transport transport, void *ssl);
@@ -945,6 +971,7 @@ void STATS_UNLOCK(void);
 void threadlocal_stats_reset(void);
 void threadlocal_stats_aggregate(struct thread_stats *stats);
 void slab_stats_aggregate(struct thread_stats *stats, struct slab_stats *out);
+LIBEVENT_THREAD *get_worker_thread(int id);
 
 /* Stat processing functions */
 void append_stat(const char *name, ADD_STAT add_stats, conn *c,