new file mode 100644
--- /dev/null
+++ b/src/http/modules/proxy/ngx_http_proxy_cache.c
@@ -0,0 +1,629 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+#include <ngx_http_proxy_handler.h>
+
+
+static int ngx_http_proxy_process_cached_response(ngx_http_proxy_ctx_t *p,
+                                                  int rc);
+static int ngx_http_proxy_process_cached_header(ngx_http_proxy_ctx_t *p);
+static void ngx_http_proxy_cache_look_complete_request(ngx_http_proxy_ctx_t *p);
+
+
+int ngx_http_proxy_get_cached_response(ngx_http_proxy_ctx_t *p)
+{
+    char                            *last;
+    ngx_http_request_t              *r;
+    ngx_http_proxy_cache_t          *c;
+    ngx_http_proxy_upstream_conf_t  *u;
+
+    r = p->request;
+
+    if (!(c = ngx_pcalloc(r->pool, sizeof(ngx_http_proxy_cache_t)))) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    p->cache = c;
+
+    c->ctx.file.fd = NGX_INVALID_FILE;
+    c->ctx.file.log = r->connection->log;
+    c->ctx.path = p->lcf->cache_path;
+
+    u = p->lcf->upstream;
+
+    c->ctx.key.len = u->url.len + r->uri.len - u->location->len + r->args.len;
+    if (!(c->ctx.key.data = ngx_palloc(r->pool, c->ctx.key.len + 1))) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    last = ngx_cpymem(c->ctx.key.data, u->url.data, u->url.len);
+
+    last = ngx_cpymem(last, r->uri.data + u->location->len,
+                      r->uri.len - u->location->len);
+
+    if (r->args.len > 0) {
+        *(last++) = '?';
+        last = ngx_cpymem(last, r->args.data, r->args.len);
+    }
+    *last = '\0';
+
+    p->header_in = ngx_create_temp_hunk(r->pool, p->lcf->header_buffer_size);
+    if (p->header_in == NULL) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+    p->header_in->tag = (ngx_hunk_tag_t) &ngx_http_proxy_module;
+
+    c->ctx.buf = p->header_in; 
+    c->ctx.log = r->connection->log;
+
+    return ngx_http_proxy_process_cached_response(p,
+                                          ngx_http_cache_get_file(r, &c->ctx));
+}
+
+
+static int ngx_http_proxy_process_cached_response(ngx_http_proxy_ctx_t *p,
+                                                  int rc)
+{
+    if (rc == NGX_OK) {
+        p->state->cache_state = NGX_HTTP_PROXY_CACHE_HIT;
+        p->header_in->pos = p->header_in->start + p->cache->ctx.header_size;
+
+        if (ngx_http_proxy_process_cached_header(p) == NGX_ERROR) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        p->valid_header_in = 1;
+
+        return ngx_http_proxy_send_cached_response(p);
+    }
+
+    if (rc == NGX_HTTP_CACHE_STALE) {
+        p->state->cache_state = NGX_HTTP_PROXY_CACHE_EXPR;
+
+    } else if (rc == NGX_HTTP_CACHE_AGED) {
+        p->state->cache_state = NGX_HTTP_PROXY_CACHE_AGED;
+    }
+
+    if (rc == NGX_HTTP_CACHE_STALE || rc == NGX_HTTP_CACHE_AGED) {
+        p->state->expired = ngx_time() - p->cache->ctx.expires;
+        p->header_in->pos = p->header_in->start + p->cache->ctx.header_size;
+
+        if (ngx_http_proxy_process_cached_header(p) == NGX_ERROR) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        p->header_in->pos = p->header_in->start + p->cache->ctx.header_size;
+        p->header_in->last = p->header_in->pos;
+
+        p->stale = 1;
+        p->valid_header_in = 1;
+
+    } else if (rc == NGX_DECLINED) {
+        p->state->cache_state = NGX_HTTP_PROXY_CACHE_MISS;
+        p->header_in->pos = p->header_in->start + p->cache->ctx.header_size;
+        p->header_in->last = p->header_in->pos;
+    }
+
+    if (p->lcf->busy_lock) {
+        p->try_busy_lock = 1;
+
+        p->header_in->pos = p->header_in->start;
+        p->header_in->last = p->header_in->start;
+
+        p->busy_lock.time = 0;
+        p->busy_lock.event = p->request->connection->read;
+        p->busy_lock.event_handler = ngx_http_proxy_busy_lock_handler;
+        p->busy_lock.md5 = p->cache->ctx.md5;
+
+        ngx_http_proxy_cache_busy_lock(p);
+        return NGX_DONE;
+    }
+
+    return ngx_http_proxy_request_upstream(p);
+}
+
+
+static int ngx_http_proxy_process_cached_header(ngx_http_proxy_ctx_t *p)
+{
+    int                      rc, i;
+    ngx_table_elt_t         *h;
+    ngx_http_request_t      *r;
+    ngx_http_proxy_cache_t  *c;
+
+    rc = ngx_http_proxy_parse_status_line(p);
+
+    c = p->cache;
+    r = p->request;
+
+    if (rc == NGX_AGAIN) {
+        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                      "\"proxy_header_buffer_size\" "
+                      "is too small to read header from \"%s\"",
+                      c->ctx.file.name.data);
+        return NGX_ERROR;
+    }
+
+    if (rc == NGX_HTTP_PROXY_PARSE_NO_HEADER) {
+        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                      "no valid HTTP/1.0 header in \"%s\"",
+                      c->ctx.file.name.data);
+        return NGX_ERROR;
+    }
+
+    /* rc == NGX_OK */
+
+    c->status = p->status;
+    c->status_line.len = p->status_end - p->status_start;
+    c->status_line.data = ngx_palloc(r->pool, c->status_line.len + 1);
+    if (c->status_line.data == NULL) {
+        return NGX_ERROR;
+    }
+
+    /* reset for the possible parsing the upstream header */
+
+    p->status = 0;
+    p->status_count = 0;
+
+    ngx_cpystrn(c->status_line.data, p->status_start, c->status_line.len + 1);
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "http cache status %d \"%s\"", 
+                   c->status, c->status_line.data);
+
+    /* TODO: ngx_init_table */
+    c->headers_in.headers = ngx_create_table(r->pool, 20);
+
+    for ( ;; ) {
+        rc = ngx_http_parse_header_line(r, p->header_in);
+
+        if (rc == NGX_OK) {
+
+            /* a header line has been parsed successfully */
+
+            h = ngx_http_add_header(&c->headers_in, ngx_http_proxy_headers_in);
+            if (h == NULL) {
+                return NGX_ERROR;
+            }
+
+            h->key.len = r->header_name_end - r->header_name_start;
+            h->value.len = r->header_end - r->header_start;
+
+            h->key.data = ngx_palloc(r->pool,
+                                     h->key.len + 1 + h->value.len + 1);
+            if (h->key.data == NULL) {
+                return NGX_ERROR;
+            }
+
+            h->value.data = h->key.data + h->key.len + 1;
+            ngx_cpystrn(h->key.data, r->header_name_start, h->key.len + 1);
+            ngx_cpystrn(h->value.data, r->header_start, h->value.len + 1);
+
+            for (i = 0; ngx_http_proxy_headers_in[i].name.len != 0; i++) {
+                if (ngx_http_proxy_headers_in[i].name.len != h->key.len) {
+                    continue;
+                }
+
+                if (ngx_strcasecmp(ngx_http_proxy_headers_in[i].name.data,
+                                                             h->key.data) == 0)
+                {
+                    *((ngx_table_elt_t **) ((char *) &c->headers_in
+                                   + ngx_http_proxy_headers_in[i].offset)) = h;
+                    break;
+                }
+            }
+
+            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                           "http cache header: \"%s: %s\"",
+                           h->key.data, h->value.data);
+
+            continue;
+
+        } else if (rc == NGX_HTTP_PARSE_HEADER_DONE) {
+
+            /* a whole header has been parsed successfully */
+
+            ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                           "http cache header done");
+
+            c->ctx.file_start = p->header_in->pos - p->header_in->start;
+
+            return NGX_OK;
+
+        } else if (rc == NGX_HTTP_PARSE_INVALID_HEADER) {
+
+            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                          "invalid header in \"%s\"",
+                          c->ctx.file.name.data);
+            return NGX_ERROR;
+        }
+
+        /* rc == NGX_AGAIN || rc == NGX_HTTP_PARSE_TOO_LONG_HEADER */
+
+        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                      "\"proxy_header_buffer_size\" "
+                      "is too small to read header from \"%s\"",
+                      c->ctx.file.name.data);
+        return NGX_ERROR;
+    }
+}
+
+
+void ngx_http_proxy_cache_busy_lock(ngx_http_proxy_ctx_t *p)
+{
+    int  rc, ft_type;
+
+    rc = ngx_http_busy_lock_cachable(p->lcf->busy_lock, &p->busy_lock,
+                                     p->try_busy_lock);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, p->request->connection->log, 0,
+                   "http cache busy lock cachable: %d", rc);
+
+    if (rc == NGX_OK) {
+        if (p->try_busy_lock) {
+            p->busy_locked = 1;
+            p->header_in->pos = p->header_in->start + p->cache->ctx.header_size;
+            p->header_in->last = p->header_in->pos;
+
+            ngx_http_proxy_request_upstream(p);
+            return;
+        }
+
+        ngx_http_proxy_cache_look_complete_request(p);
+        return;
+    }
+
+    p->try_busy_lock = 0;
+
+    if (p->cache->ctx.file.fd != NGX_INVALID_FILE
+        && !p->cache->ctx.file.info_valid)
+    {
+        if (ngx_fd_info(p->cache->ctx.file.fd, &p->cache->ctx.file.info)
+                                                             == NGX_FILE_ERROR)
+        {
+            ngx_log_error(NGX_LOG_CRIT, p->request->connection->log, ngx_errno,
+                          ngx_fd_info_n " \"%s\" failed",
+                          p->cache->ctx.file.name.data);
+            ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return;
+        }
+
+        p->cache->ctx.file.info_valid = 1;
+    }
+
+    if (rc == NGX_AGAIN) {
+
+        if ((ngx_event_flags & (NGX_USE_CLEAR_EVENT|NGX_HAVE_KQUEUE_EVENT))
+            && !p->request->connection->write->active)
+        {
+            /*
+             * kqueue allows to detect when client closes prematurely
+             * connection
+             */
+
+            p->request->connection->write->event_handler =
+                                        ngx_http_proxy_check_broken_connection;
+
+            if (ngx_add_event(p->request->connection->write, NGX_WRITE_EVENT,
+                                                NGX_CLEAR_EVENT) == NGX_ERROR)
+            {
+                ngx_http_proxy_finalize_request(p,
+                                                NGX_HTTP_INTERNAL_SERVER_ERROR);
+                return;
+            }
+        }
+
+        return;
+    }
+
+    ngx_http_busy_unlock(p->lcf->busy_lock, &p->busy_lock);
+
+    if (rc == NGX_DONE) {
+        ft_type = NGX_HTTP_PROXY_FT_BUSY_LOCK;
+
+    } else {
+        /* rc == NGX_ERROR */
+        ft_type = NGX_HTTP_PROXY_FT_MAX_WAITING;
+    }
+    
+    if (p->stale && (p->lcf->use_stale & ft_type)) {
+        ngx_http_proxy_finalize_request(p,
+                                        ngx_http_proxy_send_cached_response(p));
+        return;
+    }
+    
+    p->state->status = NGX_HTTP_SERVICE_UNAVAILABLE;
+    ngx_http_proxy_finalize_request(p, NGX_HTTP_SERVICE_UNAVAILABLE);
+}
+
+
+static void ngx_http_proxy_cache_look_complete_request(ngx_http_proxy_ctx_t *p)
+{
+    int                    rc;
+    ngx_http_cache_ctx_t  *ctx;
+
+    if (!(ctx = ngx_pcalloc(p->request->pool, sizeof(ngx_http_cache_ctx_t)))) {
+        ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        return;
+    }
+
+    *ctx = p->cache->ctx;
+
+    rc = ngx_http_cache_open_file(ctx, ngx_file_uniq(&p->cache->ctx.file.info));
+
+    if (rc == NGX_DECLINED || rc == NGX_HTTP_CACHE_THE_SAME) {
+        p->try_busy_lock = 1;
+        p->busy_lock.time = 0;
+        ngx_http_proxy_cache_busy_lock(p);
+        return;
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, p->request->connection->log, 0,
+                   "http cache old fd:%d, new fd:%d",
+                   p->cache->ctx.file.fd, ctx->file.fd);
+
+    if (p->cache->ctx.file.fd != NGX_INVALID_FILE) {
+        if (ngx_close_file(p->cache->ctx.file.fd) == NGX_FILE_ERROR) {
+            ngx_log_error(NGX_LOG_ALERT, p->request->connection->log, ngx_errno,
+                          ngx_close_file_n " \"%s\" failed",
+                          p->cache->ctx.file.name.data);
+        }
+    }
+
+    p->cache->ctx = *ctx;
+
+    p->status = 0;
+    p->status_count = 0;
+
+    ngx_http_proxy_finalize_request(p,
+                                ngx_http_proxy_process_cached_response(p, rc));
+}
+
+
+int ngx_http_proxy_send_cached_response(ngx_http_proxy_ctx_t *p)
+{
+    int                  rc, len, i;
+    off_t                rest;
+    ngx_hunk_t          *h0, *h1;
+    ngx_chain_t          out[2];
+    ngx_http_request_t  *r;
+
+    r = p->request;
+
+    r->headers_out.status = p->cache->status;
+
+#if 0
+    r->headers_out.content_length_n = -1;
+    r->headers_out.content_length = NULL;
+#endif
+
+    /* copy an cached header to r->headers_out */
+    
+    if (ngx_http_proxy_copy_header(p, &p->cache->headers_in) == NGX_ERROR) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    /* we need to allocate all before the header would be sent */
+
+    len = p->header_in->end - (p->header_in->start + p->cache->ctx.file_start);
+
+    h0 = NULL;
+    h1 = NULL;
+
+    if (len) {
+        if (!((h0 = ngx_calloc_hunk(r->pool)))) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        if (!((h0->file = ngx_pcalloc(r->pool, sizeof(ngx_file_t))))) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+    }
+
+    if (len < p->cache->ctx.length) {
+        if (!((h1 = ngx_calloc_hunk(r->pool)))) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        if (!((h1->file = ngx_pcalloc(r->pool, sizeof(ngx_file_t))))) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+    }
+
+    rc = ngx_http_send_header(r);
+
+    /* NEEDED ??? */ p->header_sent = 1;
+
+    if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
+        return rc;
+    }
+
+    rest = p->cache->ctx.length;
+
+    if (len) {
+        if (p->valid_header_in) {
+            h0->pos = p->header_in->start + p->cache->ctx.file_start;
+
+            if (len > p->cache->ctx.length) {
+                h0->last = h0->pos + p->cache->ctx.length;
+
+            } else {
+                h0->last = p->header_in->end;
+            }
+
+            h0->type = NGX_HUNK_IN_MEMORY|NGX_HUNK_TEMP;
+        }
+
+        h0->type |= NGX_HUNK_FILE;
+        h0->file_pos = p->cache->ctx.file_start;
+
+        h0->file->fd = p->cache->ctx.file.fd;
+        h0->file->log = r->connection->log;
+
+        if (len > p->cache->ctx.length) {
+            h0->file_last = h0->file_pos + p->cache->ctx.length;
+            rest = 0;
+
+        } else {
+            h0->file_last = h0->file_pos + len;
+            rest -= len;
+        }
+
+        out[0].hunk = h0;
+        out[0].next = &out[1];
+        i = 0;
+
+    } else {
+        i = -1;
+    }
+
+    if (rest) {
+        h1->file_pos = p->cache->ctx.file_start + len;
+        h1->file_last = h1->file_pos + rest;
+        h1->type = NGX_HUNK_FILE;
+
+        h1->file->fd = p->cache->ctx.file.fd;
+        h1->file->log = r->connection->log;
+
+        out[++i].hunk = h1;
+    }
+
+    out[i].next = NULL;
+    if (!r->main) {
+        out[i].hunk->type |= NGX_HUNK_LAST;
+    }
+
+    r->file.fd = p->cache->ctx.file.fd;
+
+    return ngx_http_output_filter(r, out);
+}
+
+
+int ngx_http_proxy_is_cachable(ngx_http_proxy_ctx_t *p)
+{
+    time_t                        date, last_modified, expires, t;
+    ngx_http_proxy_headers_in_t  *h;
+
+    switch (p->upstream->status) {
+    case NGX_HTTP_OK:
+    case NGX_HTTP_MOVED_PERMANENTLY:
+    case NGX_HTTP_MOVED_TEMPORARILY:
+        break;
+
+#if 0
+    case NGX_HTTP_NOT_MODIFIED:
+        return 1;
+#endif
+
+    default:
+        return 0;
+    }
+
+    h = &p->upstream->headers_in;
+
+    date = NGX_ERROR;
+    if (h->date) {
+        date = ngx_http_parse_time(h->date->value.data, h->date->value.len);
+    }
+    if (date == NGX_ERROR) {
+        date = ngx_time();
+    }
+    p->cache->ctx.date = date;
+
+    last_modified = NGX_ERROR;
+    if (h->last_modified) {
+        last_modified = ngx_http_parse_time(h->last_modified->value.data,
+                                            h->last_modified->value.len);
+        p->cache->ctx.last_modified = last_modified;
+    }
+
+    if (h->x_accel_expires) {
+        expires = ngx_atoi(h->x_accel_expires->value.data,
+                           h->x_accel_expires->value.len);
+        if (expires != NGX_ERROR) {
+            p->state->reason = NGX_HTTP_PROXY_CACHE_XAE;
+            p->state->expires = expires;
+            p->cache->ctx.expires = date + expires;
+            return (expires > 0);
+        }
+    }
+
+    if (!p->lcf->ignore_expires) {
+
+        /* TODO: Cache-Control: no-cache, max-age= */
+
+        if (h->expires) {
+            expires = ngx_http_parse_time(h->expires->value.data,
+                                          h->expires->value.len);
+            if (expires != NGX_ERROR) {
+                p->state->reason = NGX_HTTP_PROXY_CACHE_EXP;
+                p->state->expires = expires - date;
+                p->cache->ctx.expires = expires;
+                return (date < expires);
+            }
+        }
+    }
+
+    if (p->upstream->status == NGX_HTTP_MOVED_PERMANENTLY) {
+        p->state->reason = NGX_HTTP_PROXY_CACHE_MVD;
+        p->state->expires = /* STUB: 1 hour */ 60 * 60;
+        p->cache->ctx.expires = /* STUB: 1 hour */ 60 * 60;
+        return 1;
+    }
+
+    if (p->upstream->status == NGX_HTTP_MOVED_TEMPORARILY) {
+        return 1;
+    }
+
+    if (last_modified != NGX_ERROR && p->lcf->lm_factor > 0) {
+
+        /* FIXME: time_t == int_64_t, we can use fpu */ 
+
+        p->state->reason = NGX_HTTP_PROXY_CACHE_LMF;
+        t = (time_t)
+              ((((int64_t) (date - last_modified)) * p->lcf->lm_factor) / 100);
+        p->state->expires = t;
+        p->cache->ctx.expires = ngx_time() + t;
+        return 1;
+    }
+
+    if (p->lcf->default_expires > 0) {
+        p->state->reason = NGX_HTTP_PROXY_CACHE_PDE;
+        p->state->expires = p->lcf->default_expires;
+        p->cache->ctx.expires = ngx_time() + p->lcf->default_expires;
+        return 1;
+    }
+
+    return 0;
+}
+
+
+int ngx_http_proxy_update_cache(ngx_http_proxy_ctx_t *p)
+{
+    ngx_event_pipe_t  *ep;
+
+    if (p->cache == NULL) {
+        return NGX_OK;
+    }
+
+    ep = p->upstream->event_pipe;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, p->request->connection->log, 0,
+                   "http cache update len: " OFF_T_FMT ":" OFF_T_FMT,
+                   p->cache->ctx.length, ep->read_length);
+
+    if (p->cache->ctx.length == -1) {
+        /* TODO: test rc */
+        ngx_write_file(&ep->temp_file->file,
+                       (char *) &ep->read_length, sizeof(off_t),
+                       offsetof(ngx_http_cache_header_t, length));
+    }
+
+    return ngx_http_cache_update_file(p->request, &p->cache->ctx,
+                                      &ep->temp_file->file.name);
+}