Factorize code to map a file into memory.

[apps/pfixtools.git] / common / file.c

diff --git a/common/file.c b/common/file.c
new file mode 100644 (file)
index 0000000..dd6fc91
--- /dev/null
+++ b/common/file.c
@@ -0,0 +1,102 @@
+/******************************************************************************/
+/*          pfixtools: a collection of postfix related tools                  */
+/*          ~~~~~~~~~                                                         */
+/*  ________________________________________________________________________  */
+/*                                                                            */
+/*  Redistribution and use in source and binary forms, with or without        */
+/*  modification, are permitted provided that the following conditions        */
+/*  are met:                                                                  */
+/*                                                                            */
+/*  1. Redistributions of source code must retain the above copyright         */
+/*     notice, this list of conditions and the following disclaimer.          */
+/*  2. Redistributions in binary form must reproduce the above copyright      */
+/*     notice, this list of conditions and the following disclaimer in the    */
+/*     documentation and/or other materials provided with the distribution.   */
+/*  3. The names of its contributors may not be used to endorse or promote    */
+/*     products derived from this software without specific prior written     */
+/*     permission.                                                            */
+/*                                                                            */
+/*  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND   */
+/*  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE     */
+/*  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR        */
+/*  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS    */
+/*  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR    */
+/*  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF      */
+/*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS  */
+/*  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN   */
+/*  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)   */
+/*  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF    */
+/*  THE POSSIBILITY OF SUCH DAMAGE.                                           */
+/******************************************************************************/
+
+/*
+ * Copyright © 2008 Florent Bruneau
+ */
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include "file.h"
+
+file_map_t *file_map_new(const char *file, bool memlock)
+{
+    file_map_t *map = p_new(file_map_t, 1);
+    if (!file_map_open(map, file, memlock)) {
+        p_delete(&map);
+        return NULL;
+    }
+    return map;
+}
+
+void file_map_delete(file_map_t **map)
+{
+    if (*map) {
+        file_map_close(*map);
+        p_delete(map);
+    }
+}
+
+bool file_map_open(file_map_t *map, const char *file, bool memlock)
+{
+    struct stat st;
+    int fd;
+
+    fd = open(file, O_RDONLY, 0000);
+    if (fd < 0) {
+        UNIXERR("open");
+        return false;
+    }
+
+    if (fstat(fd, &st) < 0) {
+        UNIXERR("fstat");
+        close(fd);
+        return false;
+    }
+
+    map->map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+    if (map->map == MAP_FAILED) {
+        UNIXERR("mmap");
+        close(fd);
+        map->map = NULL;
+        return false;
+    }
+    close(fd);
+
+    map->end = map->map + st.st_size;
+    map->locked = memlock && mlock(map->map, st.st_size) == 0;
+    return true;
+}
+
+void file_map_close(file_map_t *map)
+{
+    if (!map->map) {
+        return;
+    }
+    if (map->locked) {
+        munlock(map->map, map->end - map->map);
+    }
+    munmap((void*)map->map, map->end - map->map);
+    map->map = NULL;
+    map->end = NULL;
+    map->locked = false;
+}