new file mode 100644
--- /dev/null
+++ b/src/http/ngx_http_cache.h
@@ -0,0 +1,131 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#ifndef _NGX_HTTP_CACHE_H_INCLUDED_
+#define _NGX_HTTP_CACHE_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+
+
+/*
+ * The 7 uses before an allocation.
+ * We can use maximum 7 bits, i.e up to the 127 uses.
+ */
+#define NGX_HTTP_CACHE_LAZY_ALLOCATION_BITS  3
+
+typedef struct {
+    uint32_t         crc;
+    ngx_str_t        key;
+    time_t           accessed;
+
+    unsigned         refs:20;    /* 1048576 references */
+
+    unsigned         count:NGX_HTTP_CACHE_LAZY_ALLOCATION_BITS;
+
+    unsigned         deleted:1;
+    unsigned         expired:1;
+    unsigned         memory:1;
+    unsigned         mmap:1;
+    unsigned         notify:1;
+
+    ngx_fd_t         fd;
+#if (NGX_USE_HTTP_FILE_CACHE_UNIQ)
+    ngx_file_uniq_t  uniq;       /* no needed with kqueue */
+#endif
+    time_t           last_modified;
+    time_t           updated;
+
+    union {
+        off_t        size;
+        ngx_str_t    value;
+    } data;
+} ngx_http_cache_t;
+
+
+typedef struct {
+    time_t       expires;
+    time_t       last_modified;
+    time_t       date;
+    off_t        length;
+    size_t       key_len;
+    char         key[1];
+} ngx_http_cache_header_t;
+
+
+#define NGX_HTTP_CACHE_HASH   7
+#define NGX_HTTP_CACHE_NELTS  4
+
+typedef struct {
+    ngx_http_cache_t         *elts;
+    size_t                    hash;
+    size_t                    nelts;
+    time_t                    life;
+    time_t                    update;
+#if (NGX_THREADS)
+    ngx_mutex_t               mutex;
+#endif
+    ngx_pool_t               *pool;
+} ngx_http_cache_hash_t;
+
+
+typedef struct {
+    ngx_http_cache_hash_t    *hash;
+    ngx_http_cache_t         *cache;
+    ngx_file_t                file;
+    ngx_str_t                 key;
+    uint32_t                  crc;
+    u_char                    md5[16];
+    ngx_path_t               *path;
+    ngx_buf_t                *buf;
+    time_t                    expires;
+    time_t                    last_modified;
+    time_t                    date;
+    off_t                     length;
+    ssize_t                   header_size;
+    size_t                    file_start;
+    ngx_log_t                *log;
+} ngx_http_cache_ctx_t;
+
+
+
+#define NGX_HTTP_CACHE_STALE     1
+#define NGX_HTTP_CACHE_AGED      2
+#define NGX_HTTP_CACHE_THE_SAME  3
+
+
+ngx_http_cache_t *ngx_http_cache_get(ngx_http_cache_hash_t *cache,
+                                     ngx_http_cleanup_t *cleanup,
+                                     ngx_str_t *key, uint32_t *crc);
+
+ngx_http_cache_t *ngx_http_cache_alloc(ngx_http_cache_hash_t *hash,
+                                       ngx_http_cache_t *cache,
+                                       ngx_http_cleanup_t *cleanup,
+                                       ngx_str_t *key, uint32_t crc,
+                                       ngx_str_t *value, ngx_log_t *log);
+void ngx_http_cache_free(ngx_http_cache_t *cache,
+                         ngx_str_t *key, ngx_str_t *value, ngx_log_t *log);
+void ngx_http_cache_lock(ngx_http_cache_hash_t *hash, ngx_http_cache_t *cache);
+void ngx_http_cache_unlock(ngx_http_cache_hash_t *hash,
+                           ngx_http_cache_t *cache, ngx_log_t *log);
+
+int ngx_http_cache_get_file(ngx_http_request_t *r, ngx_http_cache_ctx_t *ctx);
+int ngx_http_cache_open_file(ngx_http_cache_ctx_t *ctx, ngx_file_uniq_t uniq);
+int ngx_http_cache_update_file(ngx_http_request_t *r,ngx_http_cache_ctx_t *ctx,
+                               ngx_str_t *temp_file);
+
+int ngx_http_send_cached(ngx_http_request_t *r);
+
+
+int ngx_garbage_collector_http_cache_handler(ngx_gc_t *gc, ngx_str_t *name,
+                                             ngx_dir_t *dir);
+
+char *ngx_http_set_cache_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
+
+
+#endif /* _NGX_HTTP_CACHE_H_INCLUDED_ */