X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=sha1_file.c;h=66308ede85c2dad6b184fb74a7215b06a173d8f7;hb=dd97f850c3fc049f4f0d8b1fd252d54bc1ba6994;hp=eee3598bb75e2199045b823f007e7933c0fb9cfe;hpb=706bc531a19f268bb03dda7551929dee20172548;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index eee3598b..66308ede 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -11,6 +11,16 @@
 
 const char *sha1_file_directory = NULL;
 
+#ifndef O_NOATIME
+#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
+#define O_NOATIME 01000000
+#else
+#define O_NOATIME 0
+#endif
+#endif
+
+static unsigned int sha1_file_open_flag = O_NOATIME;
+
 static unsigned hexval(char c)
 {
 	if (c >= '0' && c <= '9')
@@ -96,13 +106,26 @@ int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, con
 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 {
 	char *filename = sha1_file_name(sha1);
-	int fd = open(filename, O_RDONLY);
 	struct stat st;
 	void *map;
+	int fd;
 
+	fd = open(filename, O_RDONLY | sha1_file_open_flag);
 	if (fd < 0) {
-		perror(filename);
-		return NULL;
+		/* See if it works without O_NOATIME */
+		switch (sha1_file_open_flag) {
+		default:
+			fd = open(filename, O_RDONLY);
+			if (fd >= 0)
+				break;
+		/* Fallthrough */
+		case 0:
+			perror(filename);
+			return NULL;
+		}
+
+		/* If it failed once, it will probably fail again. Stop using O_NOATIME */
+		sha1_file_open_flag = 0;
 	}
 	if (fstat(fd, &st) < 0) {
 		close(fd);
@@ -166,6 +189,46 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
 	return NULL;
 }
 
+void *read_tree_with_tree_or_commit_sha1(const unsigned char *sha1,
+					 unsigned long *size,
+					 unsigned char *tree_sha1_return)
+{
+	char type[20];
+	void *buffer;
+	unsigned long isize;
+	int was_commit = 0;
+	unsigned char tree_sha1[20];
+
+	buffer = read_sha1_file(sha1, type, &isize);
+
+	/* 
+	 * We might have read a commit instead of a tree, in which case
+	 * we parse out the tree_sha1 and attempt to read from there.
+	 * (buffer + 5) is because the tree sha1 is always at offset 5
+	 * in a commit record ("tree ").
+	 */
+	if (buffer &&
+	    !strcmp(type, "commit") &&
+	    !get_sha1_hex(buffer + 5, tree_sha1)) {
+		free(buffer);
+		buffer = read_sha1_file(tree_sha1, type, &isize);
+		was_commit = 1;
+	}
+
+	/*
+	 * Now do we have something and if so is it a tree?
+	 */
+	if (!buffer || strcmp(type, "tree")) {
+		free(buffer);
+		return NULL;
+	}
+
+	*size = isize;
+	if (tree_sha1_return)
+		memcpy(tree_sha1_return, was_commit ? tree_sha1 : sha1, 20);
+	return buffer;
+}
+
 int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
 {
 	int size;