read_ahead

3 files changed, 31 insertions, 0 deletions

diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index 993ce8f93..832dbbe0f 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h
@@ -254,6 +254,28 @@ ngx_err_t ngx_unlock_fd(ngx_fd_t fd);
 #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 70cab2f1c..3bb79b89e 100644
--- a/src/os/win32/ngx_files.c
+++ b/src/os/win32/ngx_files.c
@@ -477,6 +477,13 @@ ngx_de_link_info(u_char *name, ngx_dir_t *dir)
 
 
 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 950bd98a2..605eee85e 100644
--- a/src/os/win32/ngx_files.h
+++ b/src/os/win32/ngx_files.h
@@ -232,6 +232,8 @@ ssize_t ngx_write_file(ngx_file_t *file, u_char *buf, size_t size,
 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"