Initial version.

src/nxt_cache.h

@@ -0,0 +1,122 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) NGINX, Inc.
+ */
+
+#ifndef _NXT_CACHE_INCLUDED_
+#define _NXT_CACHE_INCLUDED_
+
+
+typedef struct nxt_cache_query_s       nxt_cache_query_t;
+typedef struct nxt_cache_query_wait_s  nxt_cache_query_wait_t;
+
+
+typedef struct {
+    uint32_t                  shared;        /* 1 bit */
+    nxt_thread_spinlock_t     lock;
+
+    nxt_lvlhsh_t              lvlhsh;
+    const nxt_lvlhsh_proto_t  *proto;
+    void                      *pool;
+
+    nxt_queue_t               expiry_queue;
+
+    nxt_queue_t               free_nodes;
+    uint32_t                  nfree_nodes;
+
+    uint32_t                  nfree_query_wait;
+    nxt_cache_query_wait_t    *free_query_wait;
+
+    uint64_t                  start_time;
+
+    /* STUB: use nxt_lvlhsh_proto_t */
+    void                      *(*alloc)(void *data, size_t size);
+    void                      (*free)(void *data, void *p);
+    void                      *data;
+
+    nxt_work_handler_t        delete_handler;
+} nxt_cache_t;
+
+
+typedef struct {
+    u_char                    *key_data;
+
+    uint16_t                  key_len;       /* 16 bits */
+    uint8_t                   uses;          /* 8 bits */
+    uint8_t                   updating:1;
+    uint8_t                   deleted:1;
+
+    uint32_t                  count;
+
+    /* Times relative to the cache->start_time. */
+    uint32_t                  expiry;
+    uint32_t                  accessed;
+
+    nxt_off_t                 size;
+
+    nxt_queue_link_t          link;
+
+    nxt_cache_query_wait_t    *waiting;
+} nxt_cache_node_t;
+
+
+struct nxt_cache_query_wait_s {
+    nxt_cache_query_t         *query;
+    nxt_cache_query_wait_t    *next;
+
+    uint8_t                   busy;          /* 1 bit */
+    uint8_t                   deleted;       /* 1 bit */
+
+    nxt_pid_t                 pid;
+    nxt_event_engine_t        *engine;
+    nxt_work_handler_t        handler;
+    nxt_cache_t               *cache;
+};
+
+
+typedef struct {
+    nxt_work_handler_t        nocache_handler;
+    nxt_work_handler_t        ready_handler;
+    nxt_work_handler_t        stale_handler;
+    nxt_work_handler_t        update_stale_handler;
+    nxt_work_handler_t        update_handler;
+    nxt_work_handler_t        timeout_handler;
+    nxt_work_handler_t        error_handler;
+} nxt_cache_query_state_t;
+
+
+struct nxt_cache_query_s {
+    u_char                    *key_data;
+
+    uint16_t                  key_len;       /* 16 bits */
+#if (NXT_64_BIT)
+    uint8_t                   hold;          /* 1 bit */
+    uint8_t                   use_stale;     /* 1 bit */
+    uint8_t                   update_stale;  /* 1 bit */
+    uint8_t                   stale;         /* 1 bit */
+#else
+    uint8_t                   hold:1;
+    uint8_t                   use_stale:1;
+    uint8_t                   update_stale:1;
+    uint8_t                   stale:1;
+#endif
+
+    nxt_cache_node_t          *node;
+    nxt_cache_query_t         *next;
+    nxt_cache_query_state_t   *state;
+
+    nxt_time_t                now;
+
+    nxt_msec_t                timeout;
+    nxt_event_timer_t         timer;
+};
+
+
+NXT_EXPORT void nxt_cache_init(nxt_cache_t *cache);
+NXT_EXPORT void nxt_cache_query(nxt_cache_t *cache, nxt_cache_query_t *q);
+NXT_EXPORT void nxt_cache_release(nxt_cache_t *cache, nxt_cache_query_t *q);
+NXT_EXPORT nxt_int_t nxt_cache_update(nxt_cache_t *cache, nxt_cache_query_t *q);
+
+
+#endif /* _NXT_CACHE_INCLUDED_ */