Commit bad68ec9 authored by Junio C Hamano's avatar Junio C Hamano

index: make the index file format extensible.

... and move the cache-tree data into it.
Signed-off-by: default avatarJunio C Hamano <junkio@cox.net>
parent dd0c34c4
......@@ -12,10 +12,6 @@
#include "quote.h"
#include "blob.h"
static unsigned char active_cache_sha1[20];
static struct cache_tree *active_cache_tree;
// --check turns on checking that the working tree matches the
// files that are being modified, but doesn't apply the patch
// --stat does just a diffstat, and doesn't actually apply
......@@ -1919,9 +1915,8 @@ static int apply_patch(int fd, const char *filename)
if (write_index)
newfd = hold_index_file_for_update(&cache_file, get_index_file());
if (check_index) {
if (read_cache_1(active_cache_sha1) < 0)
if (read_cache() < 0)
die("unable to read index file");
active_cache_tree = read_cache_tree(active_cache_sha1);
}
if ((check || apply) && check_patch_list(list) < 0)
......@@ -1931,11 +1926,9 @@ static int apply_patch(int fd, const char *filename)
write_out_results(list, skipped_patch);
if (write_index) {
if (write_cache_1(newfd, active_cache, active_nr,
active_cache_sha1) ||
if (write_cache(newfd, active_cache, active_nr) ||
commit_index_file(&cache_file))
die("Unable to write new cachefile");
write_cache_tree(active_cache_sha1, active_cache_tree);
}
if (show_index_info)
......
......@@ -11,16 +11,18 @@ struct cache_tree *cache_tree(void)
return it;
}
void cache_tree_free(struct cache_tree *it)
void cache_tree_free(struct cache_tree **it_p)
{
int i;
struct cache_tree *it = *it_p;
if (!it)
return;
for (i = 0; i < it->subtree_nr; i++)
cache_tree_free(it->down[i]->cache_tree);
cache_tree_free(&it->down[i]->cache_tree);
free(it->down);
free(it);
*it_p = NULL;
}
static struct cache_tree_sub *find_subtree(struct cache_tree *it,
......@@ -78,7 +80,7 @@ void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
break;
}
if (i < it->subtree_nr) {
cache_tree_free(it->down[i]->cache_tree);
cache_tree_free(&it->down[i]->cache_tree);
free(it->down[i]);
/* 0 1 2 3 4 5
* ^ ^subtree_nr = 6
......@@ -159,13 +161,27 @@ static void discard_unused_subtrees(struct cache_tree *it)
if (s->used)
down[dst++] = s;
else {
cache_tree_free(s->cache_tree);
cache_tree_free(&s->cache_tree);
free(s);
it->subtree_nr--;
}
}
}
int cache_tree_fully_valid(struct cache_tree *it)
{
int i;
if (!it)
return 0;
if (it->entry_count < 0 || !has_sha1_file(it->sha1))
return 0;
for (i = 0; i < it->subtree_nr; i++) {
if (!cache_tree_fully_valid(it->down[i]->cache_tree))
return 0;
}
return 1;
}
static int update_one(struct cache_tree *it,
struct cache_entry **cache,
int entries,
......@@ -354,19 +370,15 @@ static void *write_one(struct cache_tree *it,
return buffer;
}
static void *cache_tree_write(const unsigned char *cache_sha1,
struct cache_tree *root,
unsigned long *offset_p)
void *cache_tree_write(struct cache_tree *root, unsigned long *size_p)
{
char path[PATH_MAX];
unsigned long size = 8192;
char *buffer = xmalloc(size);
/* the cache checksum of the corresponding index file. */
memcpy(buffer, cache_sha1, 20);
*offset_p = 20;
*size_p = 0;
path[0] = 0;
return write_one(root, path, 0, buffer, &size, offset_p);
return write_one(root, path, 0, buffer, &size, size_p);
}
static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
......@@ -439,81 +451,13 @@ static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
return it;
free_return:
cache_tree_free(it);
cache_tree_free(&it);
return NULL;
}
static struct cache_tree *cache_tree_read(unsigned char *sha1,
const char *buffer,
unsigned long size)
struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
{
/* check the cache-tree matches the index */
if (memcmp(buffer, sha1, 20))
return NULL; /* checksum mismatch */
if (buffer[20])
if (buffer[0])
return NULL; /* not the whole tree */
buffer += 20;
size -= 20;
return read_one(&buffer, &size);
}
struct cache_tree *read_cache_tree(unsigned char *sha1)
{
int fd;
struct stat st;
char path[PATH_MAX];
unsigned long size = 0;
void *map;
struct cache_tree *it;
sprintf(path, "%s.aux", get_index_file());
fd = open(path, O_RDONLY);
if (fd < 0)
return cache_tree();
if (fstat(fd, &st))
return cache_tree();
size = st.st_size;
map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
if (map == MAP_FAILED)
return cache_tree();
it = cache_tree_read(sha1, map, size);
munmap(map, size);
if (!it)
return cache_tree();
return it;
}
int write_cache_tree(const unsigned char *sha1, struct cache_tree *root)
{
char path[PATH_MAX];
unsigned long size = 0;
void *buf, *buffer;
int fd, ret = -1;
sprintf(path, "%s.aux", get_index_file());
if (!root) {
unlink(path);
return -1;
}
fd = open(path, O_WRONLY|O_CREAT, 0666);
if (fd < 0)
return -1;
buffer = buf = cache_tree_write(sha1, root, &size);
while (size) {
int written = xwrite(fd, buf, size);
if (written <= 0)
goto fail;
buf += written;
size -= written;
}
ret = 0;
fail:
close(fd);
free(buffer);
if (ret)
unlink(path);
return ret;
}
......@@ -18,12 +18,13 @@ struct cache_tree {
};
struct cache_tree *cache_tree(void);
void cache_tree_free(struct cache_tree *);
void cache_tree_free(struct cache_tree **);
void cache_tree_invalidate_path(struct cache_tree *, const char *);
int write_cache_tree(const unsigned char *, struct cache_tree *);
struct cache_tree *read_cache_tree(unsigned char *);
int cache_tree_update(struct cache_tree *, struct cache_entry **, int, int);
void *cache_tree_write(struct cache_tree *root, unsigned long *size_p);
struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
int cache_tree_fully_valid(struct cache_tree *);
int cache_tree_update(struct cache_tree *, struct cache_entry **, int, int);
#endif
......@@ -114,6 +114,7 @@ static inline unsigned int create_ce_mode(unsigned int mode)
extern struct cache_entry **active_cache;
extern unsigned int active_nr, active_alloc, active_cache_changed;
extern struct cache_tree *active_cache_tree;
#define GIT_DIR_ENVIRONMENT "GIT_DIR"
#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
......@@ -138,11 +139,8 @@ extern const char *prefix_filename(const char *prefix, int len, const char *path
#define alloc_nr(x) (((x)+16)*3/2)
/* Initialize and use the cache information */
extern int read_cache_1(unsigned char *);
extern int write_cache_1(int, struct cache_entry **, int, unsigned char *);
extern int read_cache(void);
extern int write_cache(int, struct cache_entry **, int);
extern int write_cache(int newfd, struct cache_entry **cache, int entries);
extern int cache_name_pos(const char *name, int namelen);
#define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */
#define ADD_CACHE_OK_TO_REPLACE 2 /* Ok to replace file/directory */
......
......@@ -39,6 +39,7 @@
#include "cache.h"
#include "strbuf.h"
#include "quote.h"
#include "cache-tree.h"
#define CHECKOUT_ALL 4
static const char *prefix;
......
......@@ -2,12 +2,11 @@
#include "tree.h"
#include "cache-tree.h"
static unsigned char active_cache_sha1[20];
static struct cache_tree *active_cache_tree;
static void dump_cache_tree(struct cache_tree *it, const char *pfx)
{
int i;
if (!it)
return;
if (it->entry_count < 0)
printf("%-40s %s\n", "invalid", pfx);
else
......@@ -24,9 +23,8 @@ static void dump_cache_tree(struct cache_tree *it, const char *pfx)
int main(int ac, char **av)
{
if (read_cache_1(active_cache_sha1) < 0)
if (read_cache() < 0)
die("unable to read index file");
active_cache_tree = read_cache_tree(active_cache_sha1);
dump_cache_tree(active_cache_tree, "");
return 0;
}
......@@ -4,11 +4,26 @@
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
#include "cache-tree.h"
/* Index extensions.
*
* The first letter should be 'A'..'Z' for extensions that are not
* necessary for a correct operation (i.e. optimization data).
* When new extensions are added that _needs_ to be understood in
* order to correctly interpret the index file, pick character that
* is outside the range, to cause the reader to abort.
*/
#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
struct cache_entry **active_cache = NULL;
static time_t index_file_timestamp;
unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
struct cache_tree *active_cache_tree = NULL;
/*
* This only updates the "non-critical" parts of the directory
* cache, ie the parts that aren't tracked by GIT, and only used
......@@ -496,12 +511,10 @@ int add_cache_entry(struct cache_entry *ce, int option)
return 0;
}
static int verify_hdr(struct cache_header *hdr, unsigned long size, unsigned char *sha1)
static int verify_hdr(struct cache_header *hdr, unsigned long size)
{
SHA_CTX c;
unsigned char sha1_buf[20];
if (!sha1)
sha1 = sha1_buf;
unsigned char sha1[20];
if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
return error("bad signature");
......@@ -515,7 +528,23 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size, unsigned cha
return 0;
}
int read_cache_1(unsigned char *cache_sha1)
static int read_index_extension(const char *ext, void *data, unsigned long sz)
{
switch (CACHE_EXT(ext)) {
case CACHE_EXT_TREE:
active_cache_tree = cache_tree_read(data, sz);
break;
default:
if (*ext < 'A' || 'Z' < *ext)
return error("index uses %.4s extension, which we do not understand",
ext);
fprintf(stderr, "ignoring %.4s extension\n", ext);
break;
}
return 0;
}
int read_cache(void)
{
int fd, i;
struct stat st;
......@@ -549,7 +578,7 @@ int read_cache_1(unsigned char *cache_sha1)
die("index file mmap failed (%s)", strerror(errno));
hdr = map;
if (verify_hdr(hdr, size, cache_sha1) < 0)
if (verify_hdr(hdr, size) < 0)
goto unmap;
active_nr = ntohl(hdr->hdr_entries);
......@@ -563,6 +592,22 @@ int read_cache_1(unsigned char *cache_sha1)
active_cache[i] = ce;
}
index_file_timestamp = st.st_mtime;
while (offset <= size - 20 - 8) {
/* After an array of active_nr index entries,
* there can be arbitrary number of extended
* sections, each of which is prefixed with
* extension name (4-byte) and section length
* in 4-byte network byte order.
*/
unsigned long extsize;
memcpy(&extsize, map + offset + 4, 4);
extsize = ntohl(extsize);
if (read_index_extension(map + offset,
map + offset + 8, extsize) < 0)
goto unmap;
offset += 8;
offset += extsize;
}
return active_nr;
unmap:
......@@ -597,7 +642,18 @@ static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
return 0;
}
static int ce_flush(SHA_CTX *context, int fd, unsigned char *sha1)
static int write_index_ext_header(SHA_CTX *context, int fd,
unsigned long ext, unsigned long sz)
{
ext = htonl(ext);
sz = htonl(sz);
if ((ce_write(context, fd, &ext, 4) < 0) ||
(ce_write(context, fd, &sz, 4) < 0))
return -1;
return 0;
}
static int ce_flush(SHA_CTX *context, int fd)
{
unsigned int left = write_buffer_len;
......@@ -614,8 +670,7 @@ static int ce_flush(SHA_CTX *context, int fd, unsigned char *sha1)
}
/* Append the SHA1 signature at the end */
SHA1_Final(sha1, context);
memcpy(write_buffer + left, sha1, 20);
SHA1_Final(write_buffer + left, context);
left += 20;
if (write(fd, write_buffer, left) != left)
return -1;
......@@ -666,14 +721,11 @@ static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
}
}
int write_cache_1(int newfd, struct cache_entry **cache, int entries,
unsigned char *cache_sha1)
int write_cache(int newfd, struct cache_entry **cache, int entries)
{
SHA_CTX c;
struct cache_header hdr;
int i, removed;
int status;
unsigned char sha1[20];
for (i = removed = 0; i < entries; i++)
if (!cache[i]->ce_mode)
......@@ -697,18 +749,19 @@ int write_cache_1(int newfd, struct cache_entry **cache, int entries,
if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
return -1;
}
status = ce_flush(&c, newfd, sha1);
if (cache_sha1)
memcpy(cache_sha1, sha1, 20);
return status;
}
int read_cache(void)
{
return read_cache_1(NULL);
}
int write_cache(int newfd, struct cache_entry **cache, int entries)
{
return write_cache_1(newfd, cache, entries, NULL);
/* Write extension data here */
if (active_cache_tree) {
unsigned long sz;
void *data = cache_tree_write(active_cache_tree, &sz);
if (data &&
!write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sz) &&
!ce_write(&c, newfd, data, sz))
;
else {
free(data);
return -1;
}
}
return ce_flush(&c, newfd);
}
......@@ -9,6 +9,7 @@
#include "object.h"
#include "tree.h"
#include "cache-tree.h"
#include <sys/time.h>
#include <signal.h>
......@@ -828,6 +829,7 @@ int main(int argc, char **argv)
}
unpack_trees(fn);
cache_tree_free(&active_cache_tree);
if (write_cache(newfd, active_cache, active_nr) ||
commit_index_file(&cache_file))
die("unable to write new index file");
......
......@@ -6,12 +6,8 @@
#include "cache.h"
#include "strbuf.h"
#include "quote.h"
#include "tree.h"
#include "cache-tree.h"
static unsigned char active_cache_sha1[20];
static struct cache_tree *active_cache_tree;
/*
* Default to not allowing changes to the list of files. The
* tool doesn't actually care, but this makes it harder to add
......@@ -501,10 +497,9 @@ int main(int argc, const char **argv)
if (newfd < 0)
die("unable to create new cachefile");
entries = read_cache_1(active_cache_sha1);
entries = read_cache();
if (entries < 0)
die("cache corrupted");
active_cache_tree = read_cache_tree(active_cache_sha1);
for (i = 1 ; i < argc; i++) {
const char *path = argv[i];
......@@ -630,11 +625,9 @@ int main(int argc, const char **argv)
}
}
if (active_cache_changed) {
if (write_cache_1(newfd, active_cache, active_nr,
active_cache_sha1) ||
if (write_cache(newfd, active_cache, active_nr) ||
commit_index_file(&cache_file))
die("Unable to write new cachefile");
write_cache_tree(active_cache_sha1, active_cache_tree);
}
return has_errors ? 1 : 0;
......
......@@ -7,21 +7,20 @@
#include "tree.h"
#include "cache-tree.h"
static unsigned char active_cache_sha1[20];
static struct cache_tree *active_cache_tree;
static int missing_ok = 0;
static const char write_tree_usage[] = "git-write-tree [--missing-ok]";
static struct cache_file cache_file;
int main(int argc, char **argv)
{
int entries;
int entries, was_valid, newfd;
setup_git_directory();
entries = read_cache_1(active_cache_sha1);
active_cache_tree = read_cache_tree(active_cache_sha1);
newfd = hold_index_file_for_update(&cache_file, get_index_file());
entries = read_cache();
if (argc == 2) {
if (!strcmp(argv[1], "--missing-ok"))
missing_ok = 1;
......@@ -35,11 +34,26 @@ int main(int argc, char **argv)
if (entries < 0)
die("git-write-tree: error reading cache");
if (cache_tree_update(active_cache_tree, active_cache, active_nr,
missing_ok))
die("git-write-tree: error building trees");
write_cache_tree(active_cache_sha1, active_cache_tree);
if (!active_cache_tree)
active_cache_tree = cache_tree();
was_valid = cache_tree_fully_valid(active_cache_tree);
if (!was_valid) {
if (cache_tree_update(active_cache_tree,
active_cache, active_nr,
missing_ok) < 0)
die("git-write-tree: error building trees");
if (0 <= newfd) {
if (!write_cache(newfd, active_cache, active_nr))
commit_index_file(&cache_file);
}
/* Not being able to write is fine -- we are only interested
* in updating the cache-tree part, and if the next caller
* ends up using the old index with unupdated cache-tree part
* it misses the work we did here, but that is just a
* performance penalty and not a big deal.
*/
}
printf("%s\n", sha1_to_hex(active_cache_tree->sha1));
return 0;
}
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