read_ahead

diff --git a/src/core/ngx_open_file_cache.c b/src/core/ngx_open_file_cache.c
index 5f6e0b2..6aa66fd 100644
--- a/src/core/ngx_open_file_cache.c
+++ b/src/core/ngx_open_file_cache.c

@@ -17,6 +17,9 @@
  */
 
 
+#define NGX_MIN_READ_AHEAD  (128 * 1024)
+
+
 static void ngx_open_file_cache_cleanup(void *data);
 static ngx_int_t ngx_open_and_stat_file(u_char *name, ngx_open_file_info_t *of,
     ngx_log_t *log);
@@ -524,6 +527,13 @@
     } else {
         of->fd = fd;
 
+        if (of->read_ahead && ngx_file_size(&fi) > NGX_MIN_READ_AHEAD) {
+            if (ngx_read_ahead(fd, of->read_ahead) == NGX_ERROR) {
+                ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
+                              ngx_read_ahead_n " \"%s\" failed", name);
+            }
+        }
+
         if (of->directio <= ngx_file_size(&fi)) {
             if (ngx_directio_on(fd) == NGX_FILE_ERROR) {
                 ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,

diff --git a/src/core/ngx_open_file_cache.h b/src/core/ngx_open_file_cache.h
index f059d6b..f56dfcc 100644
--- a/src/core/ngx_open_file_cache.h
+++ b/src/core/ngx_open_file_cache.h

@@ -21,6 +21,7 @@
     time_t                   mtime;
     off_t                    size;
     off_t                    directio;
+    size_t                   read_ahead;
 
     ngx_err_t                err;
     char                    *failed;

diff --git a/src/http/modules/ngx_http_flv_module.c b/src/http/modules/ngx_http_flv_module.c
index 2afeb28..995ac83 100644
--- a/src/http/modules/ngx_http_flv_module.c
+++ b/src/http/modules/ngx_http_flv_module.c

@@ -106,6 +106,7 @@
 
     ngx_memzero(&of, sizeof(ngx_open_file_info_t));
 
+    of.read_ahead = clcf->read_ahead;
     of.directio = clcf->directio;
     of.valid = clcf->open_file_cache_valid;
     of.min_uses = clcf->open_file_cache_min_uses;

diff --git a/src/http/modules/ngx_http_gzip_static_module.c b/src/http/modules/ngx_http_gzip_static_module.c
index 8080d9c..25ab64c 100644
--- a/src/http/modules/ngx_http_gzip_static_module.c
+++ b/src/http/modules/ngx_http_gzip_static_module.c

@@ -124,6 +124,7 @@
 
     ngx_memzero(&of, sizeof(ngx_open_file_info_t));
 
+    of.read_ahead = clcf->read_ahead;
     of.directio = clcf->directio;
     of.valid = clcf->open_file_cache_valid;
     of.min_uses = clcf->open_file_cache_min_uses;

diff --git a/src/http/modules/ngx_http_index_module.c b/src/http/modules/ngx_http_index_module.c
index b58aa97..fe2a121 100644
--- a/src/http/modules/ngx_http_index_module.c
+++ b/src/http/modules/ngx_http_index_module.c

@@ -205,6 +205,7 @@
 
         ngx_memzero(&of, sizeof(ngx_open_file_info_t));
 
+        of.read_ahead = clcf->read_ahead;
         of.directio = clcf->directio;
         of.valid = clcf->open_file_cache_valid;
         of.min_uses = clcf->open_file_cache_min_uses;

diff --git a/src/http/modules/ngx_http_static_module.c b/src/http/modules/ngx_http_static_module.c
index bc46b84..6743e76 100644
--- a/src/http/modules/ngx_http_static_module.c
+++ b/src/http/modules/ngx_http_static_module.c

@@ -91,6 +91,7 @@
 
     ngx_memzero(&of, sizeof(ngx_open_file_info_t));
 
+    of.read_ahead = clcf->read_ahead;
     of.directio = clcf->directio;
     of.valid = clcf->open_file_cache_valid;
     of.min_uses = clcf->open_file_cache_min_uses;

diff --git a/src/http/modules/perl/nginx.xs b/src/http/modules/perl/nginx.xs
index 077cf0d..8a20c43 100644
--- a/src/http/modules/perl/nginx.xs
+++ b/src/http/modules/perl/nginx.xs

@@ -648,6 +648,7 @@
 
     ngx_memzero(&of, sizeof(ngx_open_file_info_t));
 
+    of.read_ahead = clcf->read_ahead;
     of.directio = clcf->directio;
     of.valid = clcf->open_file_cache_valid;
     of.min_uses = clcf->open_file_cache_min_uses;

diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index 19d0881..9c00206 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c

@@ -408,6 +408,13 @@
 
 #endif
 
+    { ngx_string("read_ahead"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_size_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_core_loc_conf_t, read_ahead),
+      NULL },
+
     { ngx_string("directio"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
       ngx_http_core_directio,
@@ -2957,6 +2964,7 @@
 #if (NGX_HAVE_FILE_AIO)
     lcf->aio = NGX_CONF_UNSET;
 #endif
+    lcf->read_ahead = NGX_CONF_UNSET_SIZE;
     lcf->directio = NGX_CONF_UNSET;
     lcf->directio_alignment = NGX_CONF_UNSET;
     lcf->tcp_nopush = NGX_CONF_UNSET;
@@ -3158,6 +3166,7 @@
 #if (NGX_HAVE_FILE_AIO)
     ngx_conf_merge_value(conf->aio, prev->aio, 0);
 #endif
+    ngx_conf_merge_size_value(conf->read_ahead, prev->read_ahead, 0);
     ngx_conf_merge_off_value(conf->directio, prev->directio,
                               NGX_MAX_OFF_T_VALUE);
     ngx_conf_merge_off_value(conf->directio_alignment, prev->directio_alignment,

diff --git a/src/http/ngx_http_core_module.h b/src/http/ngx_http_core_module.h
index 9946c4f..9d585e4 100644
--- a/src/http/ngx_http_core_module.h
+++ b/src/http/ngx_http_core_module.h

@@ -332,6 +332,7 @@
     size_t        limit_rate;              /* limit_rate */
     size_t        limit_rate_after;        /* limit_rate_after */
     size_t        sendfile_max_chunk;      /* sendfile_max_chunk */
+    size_t        read_ahead;              /* read_ahead */
 
     ngx_msec_t    client_body_timeout;     /* client_body_timeout */
     ngx_msec_t    send_timeout;            /* send_timeout */

diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index ca333fc..4caca91 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c

@@ -281,6 +281,7 @@
     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)

diff --git a/src/http/ngx_http_script.c b/src/http/ngx_http_script.c
index a92b199..f793457 100644
--- a/src/http/ngx_http_script.c
+++ b/src/http/ngx_http_script.c

@@ -1407,6 +1407,7 @@
 
     ngx_memzero(&of, sizeof(ngx_open_file_info_t));
 
+    of.read_ahead = clcf->read_ahead;
     of.directio = clcf->directio;
     of.valid = clcf->open_file_cache_valid;
     of.min_uses = clcf->open_file_cache_min_uses;

diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index 993ce8f..832dbbe 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h

@@ -254,6 +254,28 @@
 #define ngx_unlock_fd_n          "fcntl(F_SETLK, F_UNLCK)"
 
 
+#if (NGX_HAVE_F_READAHEAD)
+
+#define NGX_HAVE_READ_AHEAD      1
+
+#define ngx_read_ahead(fd, n)    fcntl(fd, F_READAHEAD, (int) n)
+#define ngx_read_ahead_n         "fcntl(fd, F_READAHEAD)"
+
+#elif (NGX_HAVE_POSIX_FADVISE)
+
+#define NGX_HAVE_READ_AHEAD      1
+
+#define ngx_read_ahead(fd, n)    posix_fadvise(fd, 0, 0, POSIX_FADV_SEQUENTIAL)
+#define ngx_read_ahead_n         "posix_fadvise(POSIX_FADV_SEQUENTIAL)"
+
+#else
+
+#define ngx_read_ahead(fd, n)    0
+#define ngx_read_ahead_n         "ngx_read_ahead_n"
+
+#endif
+
+
 #if (NGX_HAVE_O_DIRECT)
 
 ngx_int_t ngx_directio_on(ngx_fd_t fd);

diff --git a/src/os/win32/ngx_files.c b/src/os/win32/ngx_files.c
index 70cab2f..3bb79b8 100644
--- a/src/os/win32/ngx_files.c
+++ b/src/os/win32/ngx_files.c

@@ -477,6 +477,13 @@
 
 
 ngx_int_t
+ngx_read_ahead(ngx_fd_t fd, size_t n)
+{
+    return ~NGX_FILE_ERROR;
+}
+
+
+ngx_int_t
 ngx_directio_on(ngx_fd_t fd)
 {
     return ~NGX_FILE_ERROR;

diff --git a/src/os/win32/ngx_files.h b/src/os/win32/ngx_files.h
index 950bd98..605eee8 100644
--- a/src/os/win32/ngx_files.h
+++ b/src/os/win32/ngx_files.h

@@ -232,6 +232,8 @@
 ssize_t ngx_write_chain_to_file(ngx_file_t *file, ngx_chain_t *ce,
     off_t offset, ngx_pool_t *pool);
 
+ngx_int_t ngx_read_ahead(ngx_fd_t fd, size_t n);
+#define ngx_read_ahead_n            "ngx_read_ahead_n"
 
 ngx_int_t ngx_directio_on(ngx_fd_t fd);
 #define ngx_directio_on_n           "ngx_directio_on_n"