X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=sha1_file.c;h=edbf9f9a84602c9d7b0f8064a943bdc83344c728;hb=d6db01075b65da2b8584a0450619390893aae103;hp=bd68783a409473ba7cdfb4d68b8f4466d13d507a;hpb=ace1534d6f3a710ed82e7e27ba1fe77c0c278695;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index bd68783a..edbf9f9a 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -7,7 +7,9 @@
  * creation etc.
  */
 #include <stdarg.h>
+#include <limits.h>
 #include "cache.h"
+#include "delta.h"
 
 #ifndef O_NOATIME
 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
@@ -43,7 +45,7 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 	return 0;
 }
 
-int get_sha1_file(const char *path, unsigned char *result)
+static int get_sha1_file(const char *path, unsigned char *result)
 {
 	char buffer[60];
 	int fd = open(path, O_RDONLY);
@@ -58,6 +60,38 @@ int get_sha1_file(const char *path, unsigned char *result)
 	return get_sha1_hex(buffer, result);
 }
 
+static char *git_dir, *git_object_dir, *git_index_file;
+static void setup_git_env(void)
+{
+	git_dir = gitenv(GIT_DIR_ENVIRONMENT);
+	if (!git_dir)
+		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
+	git_object_dir = gitenv(DB_ENVIRONMENT);
+	if (!git_object_dir) {
+		git_object_dir = xmalloc(strlen(git_dir) + 9);
+		sprintf(git_object_dir, "%s/objects", git_dir);
+	}
+	git_index_file = gitenv(INDEX_ENVIRONMENT);
+	if (!git_index_file) {
+		git_index_file = xmalloc(strlen(git_dir) + 7);
+		sprintf(git_index_file, "%s/index", git_dir);
+	}
+}
+
+char *get_object_directory(void)
+{
+	if (!git_object_dir)
+		setup_git_env();
+	return git_object_dir;
+}
+
+char *get_index_file(void)
+{
+	if (!git_index_file)
+		setup_git_env();
+	return git_index_file;
+}
+
 int get_sha1(const char *str, unsigned char *sha1)
 {
 	static char pathname[PATH_MAX];
@@ -69,15 +103,16 @@ int get_sha1(const char *str, unsigned char *sha1)
 		"refs/snap",
 		NULL
 	};
-	const char *gitdir;
 	const char **p;
 
 	if (!get_sha1_hex(str, sha1))
 		return 0;
 
-	gitdir = ".git";
+	if (!git_dir)
+		setup_git_env();
 	for (p = prefix; *p; p++) {
-		snprintf(pathname, sizeof(pathname), "%s/%s/%s", gitdir, *p, str);
+		snprintf(pathname, sizeof(pathname), "%s/%s/%s",
+			 git_dir, *p, str);
 		if (!get_sha1_file(pathname, sha1))
 			return 0;
 	}
@@ -119,7 +154,7 @@ static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
  *
  * Also note that this returns the location for creating.  Reading
  * SHA1 file can happen from any alternate directory listed in the
- * SHA1_FILE_DIRECTORIES environment variable if it is not found in
+ * DB_ENVIRONMENT environment variable if it is not found in
  * the primary object database.
  */
 char *sha1_file_name(const unsigned char *sha1)
@@ -127,7 +162,7 @@ char *sha1_file_name(const unsigned char *sha1)
 	static char *name, *base;
 
 	if (!base) {
-		char *sha1_file_directory = get_object_directory();
+		const char *sha1_file_directory = get_object_directory();
 		int len = strlen(sha1_file_directory);
 		base = xmalloc(len + 60);
 		memcpy(base, sha1_file_directory, len);
@@ -140,20 +175,40 @@ char *sha1_file_name(const unsigned char *sha1)
 	return base;
 }
 
-static struct alternate_object_database
-{
+static struct alternate_object_database {
 	char *base;
 	char *name;
 } *alt_odb;
 
+/*
+ * Prepare alternate object database registry.
+ * alt_odb points at an array of struct alternate_object_database.
+ * This array is terminated with an element that has both its base
+ * and name set to NULL.  alt_odb[n] comes from n'th non-empty
+ * element from colon separated ALTERNATE_DB_ENVIRONMENT environment
+ * variable, and its base points at a statically allocated buffer
+ * that contains "/the/directory/corresponding/to/.git/objects/...",
+ * while its name points just after the slash at the end of
+ * ".git/objects/" in the example above, and has enough space to hold
+ * 40-byte hex SHA1, an extra slash for the first level indirection,
+ * and the terminating NUL.
+ * This function allocates the alt_odb array and all the strings
+ * pointed by base fields of the array elements with one xmalloc();
+ * the string pool immediately follows the array.
+ */
 static void prepare_alt_odb(void)
 {
 	int pass, totlen, i;
-	void *buf;
 	const char *cp, *last;
-	char *op = 0;
-	const char *alt = getenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
-
+	char *op = NULL;
+	const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
+
+	/* The first pass counts how large an area to allocate to
+	 * hold the entire alt_odb structure, including array of
+	 * structs and path buffers for them.  The second pass fills
+	 * the structure and prepares the path buffers for use by
+	 * fill_sha1_path().
+	 */
 	for (totlen = pass = 0; pass < 2; pass++) {
 		last = alt;
 		i = 0;
@@ -181,8 +236,8 @@ static void prepare_alt_odb(void)
 		} while (*cp);
 		if (pass)
 			break;
-		alt_odb = buf = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
-		alt_odb[i].base = alt_odb[i].name = 0;
+		alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
+		alt_odb[i].base = alt_odb[i].name = NULL;
 		op = (char*)(&alt_odb[i+1]);
 	}
 }
@@ -259,13 +314,13 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l
 	int ret, bytes;
 	z_stream stream;
 	char buffer[8192];
-	char *buf;
+	unsigned char *buf;
 
 	/* Get the data stream */
 	memset(&stream, 0, sizeof(stream));
 	stream.next_in = map;
 	stream.avail_in = mapsize;
-	stream.next_out = buffer;
+	stream.next_out = (unsigned char *)buffer;
 	stream.avail_out = sizeof(buffer);
 
 	inflateInit(&stream);
@@ -299,13 +354,26 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
 	if (map) {
 		buf = unpack_sha1_file(map, mapsize, type, size);
 		munmap(map, mapsize);
+		if (buf && !strcmp(type, "delta")) {
+			void *ref = NULL, *delta = buf;
+			unsigned long ref_size, delta_size = *size;
+			buf = NULL;
+			if (delta_size > 20)
+				ref = read_sha1_file(delta, type, &ref_size);
+			if (ref)
+				buf = patch_delta(ref, ref_size,
+						  delta+20, delta_size-20, 
+						  size);
+			free(delta);
+			free(ref);
+		}
 		return buf;
 	}
 	return NULL;
 }
 
 void *read_object_with_reference(const unsigned char *sha1,
-				 const unsigned char *required_type,
+				 const char *required_type,
 				 unsigned long *size,
 				 unsigned char *actual_sha1_return)
 {
@@ -349,20 +417,20 @@ void *read_object_with_reference(const unsigned char *sha1,
 	}
 }
 
-int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
 	int size;
-	char *compressed;
+	unsigned char *compressed;
 	z_stream stream;
 	unsigned char sha1[20];
 	SHA_CTX c;
 	char *filename;
 	static char tmpfile[PATH_MAX];
-	char hdr[50];
+	unsigned char hdr[50];
 	int fd, hdrlen, ret;
 
 	/* Generate the header */
-	hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
+	hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
 
 	/* Sha1.. */
 	SHA1_Init(&c);
@@ -411,7 +479,7 @@ int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned cha
 	stream.next_in = hdr;
 	stream.avail_in = hdrlen;
 	while (deflate(&stream, 0) == Z_OK)
-		/* nothing */
+		/* nothing */;
 
 	/* Then the data itself.. */
 	stream.next_in = buf;
@@ -425,6 +493,7 @@ int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned cha
 		die("unable to write file");
 	fchmod(fd, 0444);
 	close(fd);
+	free(compressed);
 
 	ret = link(tmpfile, filename);
 	if (ret < 0) {
@@ -461,8 +530,8 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd)
 	int local;
 	z_stream stream;
 	unsigned char real_sha1[20];
-	char buf[4096];
-	char discard[4096];
+	unsigned char buf[4096];
+	unsigned char discard[4096];
 	int ret;
 	SHA_CTX c;