X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=sha1_file.c;h=66308ede85c2dad6b184fb74a7215b06a173d8f7;hb=65bc81d6fef619d7aadc5c7116be52860539f17a;hp=40c00b77d0e52b31dda1696f10026fe6f92bc082;hpb=d98b46f8d9a3daf965a39f8c0089c1401e0081ee;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index 40c00b77..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;
@@ -173,12 +236,30 @@ int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
 	z_stream stream;
 	unsigned char sha1[20];
 	SHA_CTX c;
+	char *filename;
+	int fd;
 
 	/* Sha1.. */
 	SHA1_Init(&c);
 	SHA1_Update(&c, buf, len);
 	SHA1_Final(sha1, &c);
 
+	if (returnsha1)
+		memcpy(returnsha1, sha1, 20);
+
+	filename = sha1_file_name(sha1);
+	fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
+	if (fd < 0) {
+		if (errno != EEXIST)
+			return -1;
+
+		/*
+		 * We might do collision checking here, but we'd need to
+		 * uncompress the old file and check it. Later.
+		 */
+		return 0;
+	}
+
 	/* Set it up */
 	memset(&stream, 0, sizeof(stream));
 	deflateInit(&stream, Z_BEST_COMPRESSION);
@@ -195,10 +276,10 @@ int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
 	deflateEnd(&stream);
 	size = stream.total_out;
 
-	if (write_sha1_buffer(sha1, compressed, size) < 0)
-		return -1;
-	if (returnsha1)
-		memcpy(returnsha1, sha1, 20);
+	if (write(fd, compressed, size) != size)
+		die("unable to write file");
+	close(fd);
+		
 	return 0;
 }