From f768ac2c4a17c81033eca5d1cbc2fc490a4e737c Mon Sep 17 00:00:00 2001
From: Ali Gholami Rudi <ali@rudi.ir>
Date: Thu, 5 Mar 2009 10:22:50 +0330
Subject: [PATCH] quran: use mmap() instead of read()

---
 quran.c | 27 ++++++++-------------------
 quran.h |  1 +
 2 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/quran.c b/quran.c
index 3e8c305..e4713e5 100644
--- a/quran.c
+++ b/quran.c
@@ -1,4 +1,5 @@
 #include <fcntl.h>
+#include <sys/mman.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
@@ -7,29 +8,14 @@
 #include "util.h"
 #include "quran.h"
 
-static size_t file_size(char *path)
+static size_t file_size(int fd)
 {
 	struct stat st;
-	if (!stat(path, &st))
+	if (!fstat(fd, &st))
 		return st.st_size;
 	return 0;
 }
 
-static char *file_read(char *path)
-{
-	char *buf;
-	int fd;
-	int c = 0;
-	int n = 0;
-	size_t size = file_size(path);
-	buf = xmalloc(size);
-	fd = open(path, O_RDONLY);
-	while ((c = read(fd, buf + n, size - n)) > 0)
-		n += c;
-	close(fd);
-	return buf;
-}
-
 static int newlines(char *s)
 {
 	int n;
@@ -43,7 +29,9 @@ struct quran *quran_alloc(char *path)
 	int nayas;
 	struct quran *quran = xmalloc(sizeof(struct quran));
 	memset(quran, 0, sizeof(quran));
-	quran->text = file_read(path);
+	quran->fd = open(path, O_RDONLY);
+	quran->text = mmap(NULL, file_size(quran->fd), PROT_READ,
+			   MAP_SHARED, quran->fd, 0);
 	nayas = newlines(quran->text);
 	quran->ayas = xmalloc(sizeof(quran->ayas) * nayas);
 	quran->ayas[0] = quran->text;
@@ -65,8 +53,9 @@ void quran_aya(struct quran *quran, char *buf, size_t len, int aya)
 
 void quran_free(struct quran *quran)
 {
+	munmap(quran->text, file_size(quran->fd));
+	close(quran->fd);
 	free(quran->ayas);
-	free(quran->text);
 	free(quran);
 }
 
diff --git a/quran.h b/quran.h
index a56731f..f951300 100644
--- a/quran.h
+++ b/quran.h
@@ -4,6 +4,7 @@
 #define NSURA		114
 
 struct quran {
+	int fd;
 	char *text;
 	char **ayas;
 };
-- 
2.11.4.GIT