Nginx配置缓存 多域名时分域名配置缓存

相信很多人有已经从apache之类的web服务器转到Nginx了，然而Nginx除了单纯的web服务器用途外，可以当做反向代理服务器使用，配合proxy_cache功能基本可以代替squid了。

1. 编译安装Nginx

./configure --user=www --group=www --prefix=/opt/nginx --with-http_stub_status_module --with-http_ssl_module
make && make install
2. nginx.conf配置文件如下：
user  www www;
worker_processes 8;
error_log  /opt/nginx/logs/nginx_error.log  crit;
pid        /opt/nginx/nginx.pid;

#Specifies the value for maximum file descriptors that can be opened by this process.
worker_rlimit_nofile 65535;

events
{
use epoll;
worker_connections 65535;
}

http
{
include       mime.types;
default_type  application/octet-stream;

charset  utf-8;

server_names_hash_bucket_size 128;
client_header_buffer_size 32k;
large_client_header_buffers 4 32k;
client_max_body_size 300m;

sendfile on;
tcp_nopush     on;

keepalive_timeout 60;

tcp_nodelay on;

client_body_buffer_size  512k;
proxy_connect_timeout    5;
proxy_read_timeout       60;
proxy_send_timeout       5;
proxy_buffer_size        16k;
proxy_buffers            4 64k;
proxy_busy_buffers_size 128k;
proxy_temp_file_write_size 128k;

gzip on;
gzip_min_length  1k;
gzip_buffers     4 16k;
gzip_http_version 1.1;
gzip_comp_level 2;
gzip_types       text/plain application/x-javascript text/css application/xml;
gzip_vary on;

#注：proxy_temp_path和proxy_cache_path指定的路径必须在同一分区
proxy_temp_path   /data/proxy_temp_dir;
#设置Web缓存区名称为cache_one，内存缓存空间大小为200MB，1天没有被访问的内容自动清除，硬盘缓存空间大小为30GB。
proxy_cache_path  /data/proxy_cache_dir  levels=1:2   keys_zone=cache_one:200m inactive=1d max_size=30g;

upstream backend_server {
server   192.168.8.43:80 weight=1 max_fails=2 fail_timeout=30s;
server   192.168.8.44:80 weight=1 max_fails=2 fail_timeout=30s;
server   192.168.8.45:80 weight=1 max_fails=2 fail_timeout=30s;
}

server
{
listen       80;
server_name  *.yourdomain.com;
index index.html index.htm;
root  /data/htdocs/www;

location /
{
#如果后端的服务器返回502、504、执行超时等错误，自动将请求转发到upstream负载均衡池中的另一台服务器，实现故障转移。
proxy_next_upstream http_502 http_504 error timeout invalid_header;
proxy_cache cache_one;
#对不同的HTTP状态码设置不同的缓存时间
proxy_cache_valid  200 304 12h;
#以域名、URI、参数组合成Web缓存的Key值，Nginx根据Key值哈希，存储缓存内容到二级缓存目录内
proxy_cache_key $host$uri$is_args$args;
proxy_set_header Host  $host;
proxy_set_header X-Forwarded-For  $remote_addr;
proxy_pass http://backend_server;
expires      1d;
}

#扩展名以.php、.jsp、.cgi结尾的动态应用程序不缓存。
location ~ .*＼.(php|jsp|cgi)?$
{
proxy_set_header Host  $host;
proxy_set_header X-Forwarded-For  $remote_addr;
proxy_pass http://backend_server;
}

access_log  off;
}
}

3. 接下来启动nginx吧

 

/opt/nginx/sbin/nginx
4. 能否将缓存按照域名分文件夹存放？
由于我们的运营的是一个网站集群，所以子站是通过域名泛解析解析到本机的，所以希望能否按照域名存放，便于整站清理缓存。比如：a.youdomain.com/a/b3/…. ,b.youdomain.com/b/ae/….,这样的目录结构。但是研究了很久nginx配置方式，并没有发现相关的设置。于是想到自己来改写nginx源代码，涉及到的文件是src/http/ngx_http_file_cache.c文件。
以下函数的改写是基于 nginx0.8.55的。
ngx_http_file_cache_name函数改写如下：
static ngx_int_t
ngx_http_file_cache_name(ngx_http_request_t *r, ngx_path_t *path)
{
    u_char            *p;
    ngx_http_cache_t  *c;
    size_t            pathlen;

    c = r->cache;
    //added by Lingter
    pathlen = path->name.len;
   
    ngx_http_file_cache_domain(r,path);
   
      c->file.name.len = path->name.len + 1 + path->len
                       + 2 * NGX_HTTP_CACHE_KEY_LEN;
      c->file.name.data = ngx_pnalloc(r->pool, c->file.name.len + 1);
     
    if (c->file.name.data == NULL) {
            return NGX_ERROR;
    }

    ngx_memcpy(c->file.name.data, path->name.data, path->name.len);

    p = c->file.name.data + path->name.len + 1 + path->len;
    p = ngx_hex_dump(p, c->key, NGX_HTTP_CACHE_KEY_LEN);
    *p = '＼0';
   
    ngx_create_hashed_filename(path, c->file.name.data, c->file.name.len);
    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
               "cache file: ＼"%s＼"", c->file.name.data);
   
    path->name.len = pathlen;
   
    return NGX_OK;
}
上一段代码中加入了一个新的函数ngx_http_file_cache_domain的调用。
先申明一下函数定义：

static ngx_int_t ngx_http_file_cache_domain(ngx_http_request_t *r,
ngx_path_t *path);

具体函数内容：
//added by Lingter
static ngx_int_t ngx_http_file_cache_domain(ngx_http_request_t *r,ngx_path_t *path)
{
    ngx_http_cache_t    *c;
    u_char              *pathname,*pos;
    size_t              i;
    ngx_str_t           *key,domain;
   
    c = r->cache;
    key = c->keys.elts;

    domain.len  = key[0].len;
    domain.data = ngx_pstrdup(r->pool,& key[0]);
    pos = (u_char *) ngx_strchr(domain.data,'/');
    if(pos){
        *pos = '＼0';
        domain.len = ngx_strlen(domain.data);
       
        pathname = path->name.data;
        i = path->name.len+1;
        pathname[i-1] = '/';
        ngx_memcpy(&pathname[i],domain.data,domain.len);
        path->name.len = i + domain.len;
    }
    return NGX_OK;
}

实际上上面的代码仅仅是找出key中的第一个出现字符’/'的地方，并且将/前的字符串作为域名拼接到缓存路径里去。
由于本人不会C语言，所以写得比较粗糙，但是基本实现了这一需求。

看看最终的成果吧：

最后补充全部代码

/*
 * Copyright (C) Igor Sysoev
 */

#include
#include
#include
#include

static ngx_int_t ngx_http_file_cache_read(ngx_http_request_t *r,
    ngx_http_cache_t *c);
static ssize_t ngx_http_file_cache_aio_read(ngx_http_request_t *r,
    ngx_http_cache_t *c);
#if (NGX_HAVE_FILE_AIO)
static void ngx_http_cache_aio_event_handler(ngx_event_t *ev);
#endif
static ngx_int_t ngx_http_file_cache_exists(ngx_http_file_cache_t *cache,
    ngx_http_cache_t *c);
static ngx_int_t ngx_http_file_cache_domain(ngx_http_request_t *r,
  ngx_path_t *path);
static ngx_int_t ngx_http_file_cache_name(ngx_http_request_t *r,
    ngx_path_t *path);
static ngx_http_file_cache_node_t *
    ngx_http_file_cache_lookup(ngx_http_file_cache_t *cache, u_char *key);
static void ngx_http_file_cache_rbtree_insert_value(ngx_rbtree_node_t *temp,
    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
static void ngx_http_file_cache_cleanup(void *data);
static time_t ngx_http_file_cache_forced_expire(ngx_http_file_cache_t *cache);
static time_t ngx_http_file_cache_expire(ngx_http_file_cache_t *cache);
static void ngx_http_file_cache_delete(ngx_http_file_cache_t *cache,
    ngx_queue_t *q, u_char *name);
static ngx_int_t
    ngx_http_file_cache_manager_sleep(ngx_http_file_cache_t *cache);
static ngx_int_t ngx_http_file_cache_noop(ngx_tree_ctx_t *ctx,
    ngx_str_t *path);
static ngx_int_t ngx_http_file_cache_manage_file(ngx_tree_ctx_t *ctx,
    ngx_str_t *path);
static ngx_int_t ngx_http_file_cache_add_file(ngx_tree_ctx_t *ctx,
    ngx_str_t *path);
static ngx_int_t ngx_http_file_cache_add(ngx_http_file_cache_t *cache,
    ngx_http_cache_t *c);
static ngx_int_t ngx_http_file_cache_delete_file(ngx_tree_ctx_t *ctx,
    ngx_str_t *path);

ngx_str_t  ngx_http_cache_status[] = {
    ngx_string("MISS"),
    ngx_string("BYPASS"),
    ngx_string("EXPIRED"),
    ngx_string("STALE"),
    ngx_string("UPDATING"),
    ngx_string("HIT")
};

static u_char  ngx_http_file_cache_key[] = { LF, 'K', 'E', 'Y', ':', ' ' };

static ngx_int_t
ngx_http_file_cache_init(ngx_shm_zone_t *shm_zone, void *data)
{
    ngx_http_file_cache_t  *ocache = data;

    size_t                  len;
    ngx_uint_t              n;
    ngx_http_file_cache_t  *cache;

    cache = shm_zone->data;

    if (ocache) {
        if (ngx_strcmp(cache->path->name.data, ocache->path->name.data) != 0) {
            ngx_log_error(NGX_LOG_EMERG, shm_zone->shm.log, 0,
                          "cache "%V" uses the "%V" cache path "
                          "while previously it used the "%V" cache path",
                          &shm_zone->shm.name, &cache->path->name,
                          &ocache->path->name);

            return NGX_ERROR;
        }

        for (n = 0; n < 3; n++) {
            if (cache->path->level[n] != ocache->path->level[n]) {
                ngx_log_error(NGX_LOG_EMERG, shm_zone->shm.log, 0,
                              "cache "%V" had previously different levels",
                              &shm_zone->shm.name);
                return NGX_ERROR;
            }
        }

        cache->sh = ocache->sh;

        cache->shpool = ocache->shpool;
        cache->bsize = ocache->bsize;

        cache->max_size /= cache->bsize;

        if (!cache->sh->cold || cache->sh->loading) {
            cache->path->loader = NULL;
        }

        return NGX_OK;
    }

    cache->shpool = (ngx_slab_pool_t *) shm_zone->shm.addr;

    if (shm_zone->shm.exists) {
        cache->sh = cache->shpool->data;
        cache->bsize = ngx_fs_bsize(cache->path->name.data);

        return NGX_OK;
    }

    cache->sh = ngx_slab_alloc(cache->shpool, sizeof(ngx_http_file_cache_sh_t));
    if (cache->sh == NULL) {
        return NGX_ERROR;
    }

    cache->shpool->data = cache->sh;

    ngx_rbtree_init(&cache->sh->rbtree, &cache->sh->sentinel,
                    ngx_http_file_cache_rbtree_insert_value);

    ngx_queue_init(&cache->sh->queue);

    cache->sh->cold = 1;
    cache->sh->loading = 0;
    cache->sh->size = 0;

    cache->bsize = ngx_fs_bsize(cache->path->name.data);

    cache->max_size /= cache->bsize;

    len = sizeof(" in cache keys zone """) + shm_zone->shm.name.len;

    cache->shpool->log_ctx = ngx_slab_alloc(cache->shpool, len);
    if (cache->shpool->log_ctx == NULL) {
        return NGX_ERROR;
    }

    ngx_sprintf(cache->shpool->log_ctx, " in cache keys zone "%V"%Z",
                &shm_zone->shm.name);

    return NGX_OK;
}

ngx_int_t
ngx_http_file_cache_new(ngx_http_request_t *r)
{
    ngx_http_cache_t  *c;

    c = ngx_pcalloc(r->pool, sizeof(ngx_http_cache_t));
    if (c == NULL) {
        return NGX_ERROR;
    }

    if (ngx_array_init(&c->keys, r->pool, 4, sizeof(ngx_str_t)) != NGX_OK) {
        return NGX_ERROR;
    }

    r->cache = c;
    c->file.log = r->connection->log;
    c->file.fd = NGX_INVALID_FILE;

    return NGX_OK;
}

ngx_int_t
ngx_http_file_cache_create(ngx_http_request_t *r)
{
    ngx_http_cache_t       *c;
    ngx_pool_cleanup_t     *cln;
    ngx_http_file_cache_t  *cache;

    ngx_http_file_cache_create_key(r);

    c = r->cache;
    cache = c->file_cache;

    cln = ngx_pool_cleanup_add(r->pool, 0);
    if (cln == NULL) {
        return NGX_ERROR;
    }

    if (ngx_http_file_cache_exists(cache, c) == NGX_ERROR) {
        return NGX_ERROR;
    }

    cln->handler = ngx_http_file_cache_cleanup;
    cln->data = c;

    if (ngx_http_file_cache_name(r, cache->path) != NGX_OK) {
        return NGX_ERROR;
    }

    return NGX_OK;
}

void
ngx_http_file_cache_create_key(ngx_http_request_t *r)
{
    size_t             len;
    ngx_str_t         *key;
    ngx_uint_t         i;
    ngx_md5_t          md5;
    ngx_http_cache_t  *c;

    c = r->cache;

    len = 0;

    ngx_crc32_init(c->crc32);
    ngx_md5_init(&md5);

    key = c->keys.elts;
    for (i = 0; i < c->keys.nelts; i++) {
        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "http cache key: "%V"", &key[i]);

        len += key[i].len;
        ngx_crc32_update(&c->crc32, key[i].data, key[i].len);
        ngx_md5_update(&md5, key[i].data, key[i].len);
    }

    c->header_start = sizeof(ngx_http_file_cache_header_t)
                      + sizeof(ngx_http_file_cache_key) + len + 1;
   
    ngx_crc32_final(c->crc32);
    ngx_md5_final(c->key, &md5);
}

ngx_int_t
ngx_http_file_cache_open(ngx_http_request_t *r)
{
    ngx_int_t                  rc, rv;
    ngx_uint_t                 cold, test;
    ngx_http_cache_t          *c;
    ngx_pool_cleanup_t        *cln;
    ngx_open_file_info_t       of;
    ngx_http_file_cache_t     *cache;
    ngx_http_core_loc_conf_t  *clcf;

    c = r->cache;

    if (c->buf) {
        return ngx_http_file_cache_read(r, c);
    }

    cache = c->file_cache;

    cln = ngx_pool_cleanup_add(r->pool, 0);
    if (cln == NULL) {
        return NGX_ERROR;
    }

    rc = ngx_http_file_cache_exists(cache, c);

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http file cache exists: %i e:%d", rc, c->exists);

    if (rc == NGX_ERROR) {
        return rc;
    }

    cln->handler = ngx_http_file_cache_cleanup;
    cln->data = c;

    if (rc == NGX_AGAIN) {
        return NGX_HTTP_CACHE_SCARCE;
    }

    cold = cache->sh->cold;

    if (rc == NGX_OK) {

        if (c->error) {
            return c->error;
        }

        c->temp_file = 1;
        test = c->exists ? 1 : 0;
        rv = NGX_DECLINED;

    } else { /* rc == NGX_DECLINED */

        if (c->min_uses > 1) {

            if (!cold) {
                return NGX_HTTP_CACHE_SCARCE;
            }

            test = 1;
            rv = NGX_HTTP_CACHE_SCARCE;

        } else {
            c->temp_file = 1;
            test = cold ? 1 : 0;
            rv = NGX_DECLINED;
        }
    }

    if (ngx_http_file_cache_name(r, cache->path) != NGX_OK) {
        return NGX_ERROR;
    }

    if (!test) {
        return NGX_DECLINED;
    }

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    ngx_memzero(&of, sizeof(ngx_open_file_info_t));

    of.uniq = c->uniq;
    of.valid = clcf->open_file_cache_valid;
    of.min_uses = clcf->open_file_cache_min_uses;
    of.events = clcf->open_file_cache_events;
    of.directio = NGX_OPEN_FILE_DIRECTIO_OFF;
    of.read_ahead = clcf->read_ahead;

    if (ngx_open_cached_file(clcf->open_file_cache, &c->file.name, &of, r->pool)
        != NGX_OK)
    {
        switch (of.err) {

        case 0:
            return NGX_ERROR;

        case NGX_ENOENT:
        case NGX_ENOTDIR:
            return rv;

        default:
            ngx_log_error(NGX_LOG_CRIT, r->connection->log, of.err,
                          ngx_open_file_n " "%s" failed", c->file.name.data);
            return NGX_ERROR;
        }
    }

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http file cache fd: %d", of.fd);

    c->file.fd = of.fd;
    c->file.log = r->connection->log;
    c->uniq = of.uniq;
    c->length = of.size;

    c->buf = ngx_create_temp_buf(r->pool, c->body_start);
    if (c->buf == NULL) {
        return NGX_ERROR;
    }

    return ngx_http_file_cache_read(r, c);
}

static ngx_int_t
ngx_http_file_cache_read(ngx_http_request_t *r, ngx_http_cache_t *c)
{
    time_t                         now;
    ssize_t                        n;
    ngx_int_t                      rc;
    ngx_http_file_cache_t         *cache;
    ngx_http_file_cache_header_t  *h;

    n = ngx_http_file_cache_aio_read(r, c);

    if (n < 0) {
        return n;
    }

    if ((size_t) n < c->header_start) {
        ngx_log_error(NGX_LOG_CRIT, r->connection->log, 0,
                      "cache file "%s" is too small", c->file.name.data);
        return NGX_ERROR;
    }

    h = (ngx_http_file_cache_header_t *) c->buf->pos;

    if (h->crc32 != c->crc32) {
        ngx_log_error(NGX_LOG_CRIT, r->connection->log, 0,
                      "cache file "%s" has md5 collision", c->file.name.data);
        return NGX_DECLINED;
    }

    c->buf->last += n;

    c->valid_sec = h->valid_sec;
    c->last_modified = h->last_modified;
    c->date = h->date;
    c->valid_msec = h->valid_msec;
    c->header_start = h->header_start;
    c->body_start = h->body_start;

    r->cached = 1;

    cache = c->file_cache;

    if (cache->sh->cold) {

        ngx_shmtx_lock(&cache->shpool->mutex);

        if (!c->node->exists) {
            c->node->uses = 1;
            c->node->body_start = c->body_start;
            c->node->exists = 1;
            c->node->uniq = c->uniq;

            cache->sh->size += (c->length + cache->bsize - 1) / cache->bsize;
        }

        ngx_shmtx_unlock(&cache->shpool->mutex);
    }

    now = ngx_time();

    if (c->valid_sec < now) {

        ngx_shmtx_lock(&cache->shpool->mutex);

        if (c->node->updating) {
            rc = NGX_HTTP_CACHE_UPDATING;

        } else {
            c->node->updating = 1;
            c->updating = 1;
            rc = NGX_HTTP_CACHE_STALE;
        }

        ngx_shmtx_unlock(&cache->shpool->mutex);

        ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "http file cache expired: %i %T %T",
                       rc, c->valid_sec, now);

        return rc;
    }

    return NGX_OK;
}

static ssize_t
ngx_http_file_cache_aio_read(ngx_http_request_t *r, ngx_http_cache_t *c)
{
#if (NGX_HAVE_FILE_AIO)
    ssize_t                    n;
    ngx_http_core_loc_conf_t  *clcf;

    if (!ngx_file_aio) {
        goto noaio;
    }

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    if (!clcf->aio) {
        goto noaio;
    }
    n = ngx_file_aio_read(&c->file, c->buf->pos, c->body_start, 0, r->pool);

    if (n != NGX_AGAIN) {
        return n;
    }

    c->file.aio->data = r;
    c->file.aio->handler = ngx_http_cache_aio_event_handler;

    r->main->blocked++;
    r->aio = 1;

    return NGX_AGAIN;

noaio:

#endif

    return ngx_read_file(&c->file, c->buf->pos, c->body_start, 0);
}

#if (NGX_HAVE_FILE_AIO)

static void
ngx_http_cache_aio_event_handler(ngx_event_t *ev)
{
    ngx_event_aio_t     *aio;
    ngx_http_request_t  *r;

    aio = ev->data;
    r = aio->data;

    r->main->blocked--;
    r->aio = 0;

    r->connection->write->handler(r->connection->write);
}

#endif

static ngx_int_t
ngx_http_file_cache_exists(ngx_http_file_cache_t *cache, ngx_http_cache_t *c)
{
    ngx_int_t                    rc;
    ngx_http_file_cache_node_t  *fcn;

    ngx_shmtx_lock(&cache->shpool->mutex);

    fcn = ngx_http_file_cache_lookup(cache, c->key);

    if (fcn) {
        ngx_queue_remove(&fcn->queue);

        fcn->uses++;
        fcn->count++;

        if (fcn->error) {

            if (fcn->valid_sec < ngx_time()) {
                goto renew;
            }

            rc = NGX_OK;

            goto done;
        }

        if (fcn->exists) {

            c->exists = fcn->exists;
            c->body_start = fcn->body_start;

            rc = NGX_OK;

            goto done;
        }

        if (fcn->uses >= c->min_uses) {

            c->exists = fcn->exists;
            c->body_start = fcn->body_start;

            rc = NGX_OK;

        } else {
            rc = NGX_AGAIN;
        }

        goto done;
    }

    fcn = ngx_slab_alloc_locked(cache->shpool,
                                sizeof(ngx_http_file_cache_node_t));
    if (fcn == NULL) {
        ngx_shmtx_unlock(&cache->shpool->mutex);

        (void) ngx_http_file_cache_forced_expire(cache);

        ngx_shmtx_lock(&cache->shpool->mutex);

        fcn = ngx_slab_alloc_locked(cache->shpool,
                                    sizeof(ngx_http_file_cache_node_t));
        if (fcn == NULL) {
            rc = NGX_ERROR;
            goto failed;
        }
    }

    ngx_memcpy((u_char *) &fcn->node.key, c->key, sizeof(ngx_rbtree_key_t));

    ngx_memcpy(fcn->key, &c->key[sizeof(ngx_rbtree_key_t)],
               NGX_HTTP_CACHE_KEY_LEN - sizeof(ngx_rbtree_key_t));

    ngx_rbtree_insert(&cache->sh->rbtree, &fcn->node);

    fcn->uses = 1;
    fcn->count = 1;
    fcn->updating = 0;
    fcn->deleting = 0;

renew:

    rc = NGX_DECLINED;

    fcn->valid_msec = 0;
    fcn->error = 0;
    fcn->exists = 0;
    fcn->valid_sec = 0;
    fcn->uniq = 0;
    fcn->body_start = 0;
    fcn->length = 0;

done:

    fcn->expire = ngx_time() + cache->inactive;

    ngx_queue_insert_head(&cache->sh->queue, &fcn->queue);

    c->uniq = fcn->uniq;
    c->error = fcn->error;
    c->node = fcn;

failed:

    ngx_shmtx_unlock(&cache->shpool->mutex);

    return rc;
}

static ngx_int_t ngx_http_file_cache_domain(ngx_http_request_t *r,ngx_path_t *path)
{
    ngx_http_cache_t    *c;
    u_char              *pathname,*pos;
    size_t              i;
    ngx_str_t           *key,domain;
   
    c = r->cache;
    key = c->keys.elts;

    domain.len  = key[0].len;
    domain.data = ngx_pstrdup(r->pool,& key[0]);
    pos = (u_char *) ngx_strchr(domain.data,'/');
    if(pos){
        *pos = '';
        domain.len = ngx_strlen(domain.data);
       
        pathname = path->name.data;
        i = path->name.len+1;
        pathname[i-1] = '/';
        ngx_memcpy(&pathname[i],domain.data,domain.len);
        path->name.len = i + domain.len;
    }
    return NGX_OK;
}

static ngx_int_t
ngx_http_file_cache_name(ngx_http_request_t *r, ngx_path_t *path)
{
    u_char            *p;
    ngx_http_cache_t  *c;
    size_t           pathlen;

    c = r->cache;
    pathlen = path->name.len;

    ngx_http_file_cache_domain(r,path);
   
   c->file.name.len = path->name.len + 1 + path->len
                       + 2 * NGX_HTTP_CACHE_KEY_LEN;
   c->file.name.data = ngx_pnalloc(r->pool, c->file.name.len + 1);
  
    if (c->file.name.data == NULL) {
   return NGX_ERROR;
    }

    ngx_memcpy(c->file.name.data, path->name.data, path->name.len);

    p = c->file.name.data + path->name.len + 1 + path->len;
    p = ngx_hex_dump(p, c->key, NGX_HTTP_CACHE_KEY_LEN);
    *p = '';
   
    ngx_create_hashed_filename(path, c->file.name.data, c->file.name.len);
    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
            "cache file: "%s"", c->file.name.data);
   
    path->name.len = pathlen;
   
    return NGX_OK;
}

static ngx_http_file_cache_node_t *
ngx_http_file_cache_lookup(ngx_http_file_cache_t *cache, u_char *key)
{
    ngx_int_t                    rc;
    ngx_rbtree_key_t             node_key;
    ngx_rbtree_node_t           *node, *sentinel;
    ngx_http_file_cache_node_t  *fcn;

    ngx_memcpy((u_char *) &node_key, key, sizeof(ngx_rbtree_key_t));

    node = cache->sh->rbtree.root;
    sentinel = cache->sh->rbtree.sentinel;

    while (node != sentinel) {

        if (node_key < node->key) {
            node = node->left;
            continue;
        }

        if (node_key > node->key) {
            node = node->right;
            continue;
        }

        /* node_key == node->key */

        do {
            fcn = (ngx_http_file_cache_node_t *) node;

            rc = ngx_memcmp(&key[sizeof(ngx_rbtree_key_t)], fcn->key,
                            NGX_HTTP_CACHE_KEY_LEN - sizeof(ngx_rbtree_key_t));

            if (rc == 0) {
                return fcn;
            }

            node = (rc < 0) ? node->left : node->right;

        } while (node != sentinel && node_key == node->key);

        break;
    }

    /* not found */

    return NULL;
}

static void
ngx_http_file_cache_rbtree_insert_value(ngx_rbtree_node_t *temp,
    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
{
    ngx_rbtree_node_t           **p;
    ngx_http_file_cache_node_t   *cn, *cnt;

    for ( ;; ) {

        if (node->key < temp->key) {

            p = &temp->left;

        } else if (node->key > temp->key) {

            p = &temp->right;

        } else { /* node->key == temp->key */

            cn = (ngx_http_file_cache_node_t *) node;
            cnt = (ngx_http_file_cache_node_t *) temp;

            p = (ngx_memcmp(cn->key, cnt->key,
                            NGX_HTTP_CACHE_KEY_LEN - sizeof(ngx_rbtree_key_t))
                 < 0)
                    ? &temp->left : &temp->right;
        }

        if (*p == sentinel) {
            break;
        }

        temp = *p;
    }

    *p = node;
    node->parent = temp;
    node->left = sentinel;
    node->right = sentinel;
    ngx_rbt_red(node);
}

void
ngx_http_file_cache_set_header(ngx_http_request_t *r, u_char *buf)
{
    ngx_http_file_cache_header_t  *h = (ngx_http_file_cache_header_t *) buf;

    u_char            *p;
    ngx_str_t         *key;
    ngx_uint_t         i;
    ngx_http_cache_t  *c;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http file cache set header");

    c = r->cache;

    h->valid_sec = c->valid_sec;
    h->last_modified = c->last_modified;
    h->date = c->date;
    h->crc32 = c->crc32;
    h->valid_msec = (u_short) c->valid_msec;
    h->header_start = (u_short) c->header_start;
    h->body_start = (u_short) c->body_start;

    p = buf + sizeof(ngx_http_file_cache_header_t);

    p = ngx_cpymem(p, ngx_http_file_cache_key, sizeof(ngx_http_file_cache_key));

    key = c->keys.elts;
    for (i = 0; i < c->keys.nelts; i++) {
        p = ngx_copy(p, key[i].data, key[i].len);
    }

    *p = LF;
}

void
ngx_http_file_cache_update(ngx_http_request_t *r, ngx_temp_file_t *tf)
{
    off_t                   size, length;
    ngx_int_t               rc;
    ngx_file_uniq_t         uniq;
    ngx_file_info_t         fi;
    ngx_http_cache_t        *c;
    ngx_ext_rename_file_t   ext;
    ngx_http_file_cache_t  *cache;

    c = r->cache;

    if (c->updated) {
        return;
    }

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http file cache update");

    c->updated = 1;
    c->updating = 0;

    cache = c->file_cache;

    uniq = 0;
    length = 0;

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http file cache rename: "%s" to "%s"",
                   tf->file.name.data, c->file.name.data);

    ext.access = NGX_FILE_OWNER_ACCESS;
    ext.path_access = NGX_FILE_OWNER_ACCESS;
    ext.time = -1;
    ext.create_path = 1;
    ext.delete_file = 1;
    ext.log = r->connection->log;

    rc = ngx_ext_rename_file(&tf->file.name, &c->file.name, &ext);

    if (rc == NGX_OK) {

        if (ngx_fd_info(tf->file.fd, &fi) == NGX_FILE_ERROR) {
            ngx_log_error(NGX_LOG_CRIT, r->connection->log, ngx_errno,
                          ngx_fd_info_n " "%s" failed", tf->file.name.data);

            rc = NGX_ERROR;

        } else {
            uniq = ngx_file_uniq(&fi);
            length = ngx_file_size(&fi);
        }
    }

    size = (length + cache->bsize - 1) / cache->bsize;

    ngx_shmtx_lock(&cache->shpool->mutex);

    c->node->count--;
    c->node->uniq = uniq;
    c->node->body_start = c->body_start;

    size = size - (c->node->length + cache->bsize - 1) / cache->bsize;

    c->node->length = length;

    cache->sh->size += size;

    if (rc == NGX_OK) {
        c->node->exists = 1;
    }

    c->node->updating = 0;

    ngx_shmtx_unlock(&cache->shpool->mutex);
}

ngx_int_t
ngx_http_cache_send(ngx_http_request_t *r)
{
    ngx_int_t          rc;
    ngx_buf_t         *b;
    ngx_chain_t        out;
    ngx_http_cache_t  *c;

    c = r->cache;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                  "http file cache send: %s", c->file.name.data);

    /* we need to allocate all before the header would be sent */

    b = ngx_pcalloc(r->pool, sizeof(ngx_buf_t));
    if (b == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    b->file = ngx_pcalloc(r->pool, sizeof(ngx_file_t));
    if (b->file == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    r->header_only = (c->length - c->body_start) == 0;

    rc = ngx_http_send_header(r);

    if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
        return rc;
    }

    b->file_pos = c->body_start;
    b->file_last = c->length;

    b->in_file = 1;
    b->last_buf = (r == r->main) ? 1: 0;
    b->last_in_chain = 1;

    b->file->fd = c->file.fd;
    b->file->name = c->file.name;
    b->file->log = r->connection->log;

    out.buf = b;
    out.next = NULL;

    return ngx_http_output_filter(r, &out);
}

void
ngx_http_file_cache_free(ngx_http_cache_t *c, ngx_temp_file_t *tf)
{
    ngx_http_file_cache_t       *cache;
    ngx_http_file_cache_node_t  *fcn;

    if (c->updated) {
        return;
    }

    cache = c->file_cache;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->file.log, 0,
                   "http file cache free, fd: %d", c->file.fd);

    ngx_shmtx_lock(&cache->shpool->mutex);

    fcn = c->node;
    fcn->count--;

    if (c->updating) {
        fcn->updating = 0;
    }

    if (c->error) {
        fcn->error = c->error;

        if (c->valid_sec) {
            fcn->valid_sec = c->valid_sec;
            fcn->valid_msec = c->valid_msec;
        }

    } else if (!fcn->exists && fcn->count == 0 && c->min_uses == 1) {
        ngx_queue_remove(&fcn->queue);
        ngx_rbtree_delete(&cache->sh->rbtree, &fcn->node);
        ngx_slab_free_locked(cache->shpool, fcn);
        c->node = NULL;
    }

    ngx_shmtx_unlock(&cache->shpool->mutex);

    c->updated = 1;
    c->updating = 0;

    if (c->temp_file) {
        if (tf && tf->file.fd != NGX_INVALID_FILE) {
            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->file.log, 0,
                           "http file cache incomplete: "%s"",
                           tf->file.name.data);

            if (ngx_delete_file(tf->file.name.data) == NGX_FILE_ERROR) {
                ngx_log_error(NGX_LOG_CRIT, c->file.log, ngx_errno,
                              ngx_delete_file_n " "%s" failed",
                              tf->file.name.data);
            }
        }
    }
}

static void
ngx_http_file_cache_cleanup(void *data)
{
    ngx_http_cache_t  *c = data;

    if (c->updated) {
        return;
    }

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->file.log, 0,
                   "http file cache cleanup");

    if (c->updating) {
        ngx_log_error(NGX_LOG_ALERT, c->file.log, 0,
                      "stalled cache updating, error:%ui", c->error);
    }

    ngx_http_file_cache_free(c, NULL);
}

static time_t
ngx_http_file_cache_forced_expire(ngx_http_file_cache_t *cache)
{
    u_char                      *name;
    size_t                       len;
    time_t                       wait;
    ngx_uint_t                   tries;
    ngx_path_t                  *path;
    ngx_queue_t                 *q;
    ngx_http_file_cache_node_t  *fcn;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
                   "http file cache forced expire");

    path = cache->path;
    len = path->name.len + 1 + path->len + 2 * NGX_HTTP_CACHE_KEY_LEN;

    name = ngx_alloc(len + 1, ngx_cycle->log);
    if (name == NULL) {
        return 10;
    }

    ngx_memcpy(name, path->name.data, path->name.len);

    wait = 10;
    tries = 20;

    ngx_shmtx_lock(&cache->shpool->mutex);

    for (q = ngx_queue_last(&cache->sh->queue);
         q != ngx_queue_sentinel(&cache->sh->queue);
         q = ngx_queue_prev(q))
    {
        fcn = ngx_queue_data(q, ngx_http_file_cache_node_t, queue);

        ngx_log_debug6(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
                  "http file cache forced expire: #%d %d %02xd%02xd%02xd%02xd",
                  fcn->count, fcn->exists,
                  fcn->key[0], fcn->key[1], fcn->key[2], f