untracked cache: save to an index extension

Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Nguyễn Thái Ngọc Duy 2015-03-08 17:12:33 +07:00 committed by Junio C Hamano
parent be0d9d5323
commit 83c094ad0d
5 changed files with 213 additions and 0 deletions

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@ -233,3 +233,61 @@ Git index format
The remaining index entries after replaced ones will be added to the
final index. These added entries are also sorted by entry name then
stage.
== Untracked cache
Untracked cache saves the untracked file list and necessary data to
verify the cache. The signature for this extension is { 'U', 'N',
'T', 'R' }.
The extension starts with
- Stat data of $GIT_DIR/info/exclude. See "Index entry" section from
ctime field until "file size".
- Stat data of core.excludesfile
- 32-bit dir_flags (see struct dir_struct)
- 160-bit SHA-1 of $GIT_DIR/info/exclude. Null SHA-1 means the file
does not exist.
- 160-bit SHA-1 of core.excludesfile. Null SHA-1 means the file does
not exist.
- NUL-terminated string of per-dir exclude file name. This usually
is ".gitignore".
- The number of following directory blocks, variable width
encoding. If this number is zero, the extension ends here with a
following NUL.
- A number of directory blocks in depth-first-search order, each
consists of
- The number of untracked entries, variable width encoding.
- The number of sub-directory blocks, variable width encoding.
- The directory name terminated by NUL.
- A number of untrached file/dir names terminated by NUL.
The remaining data of each directory block is grouped by type:
- An ewah bitmap, the n-th bit marks whether the n-th directory has
valid untracked cache entries.
- An ewah bitmap, the n-th bit records "check-only" bit of
read_directory_recursive() for the n-th directory.
- An ewah bitmap, the n-th bit indicates whether SHA-1 and stat data
is valid for the n-th directory and exists in the next data.
- An array of stat data. The n-th data corresponds with the n-th
"one" bit in the previous ewah bitmap.
- An array of SHA-1. The n-th SHA-1 corresponds with the n-th "one" bit
in the previous ewah bitmap.
- One NUL.

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@ -291,6 +291,8 @@ static inline unsigned int canon_mode(unsigned int mode)
#define SPLIT_INDEX_ORDERED (1 << 6)
struct split_index;
struct untracked_cache;
struct index_state {
struct cache_entry **cache;
unsigned int version;
@ -304,6 +306,7 @@ struct index_state {
struct hashmap name_hash;
struct hashmap dir_hash;
unsigned char sha1[20];
struct untracked_cache *untracked;
};
extern struct index_state the_index;

139
dir.c
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@ -12,6 +12,8 @@
#include "refs.h"
#include "wildmatch.h"
#include "pathspec.h"
#include "varint.h"
#include "ewah/ewok.h"
struct path_simplify {
int len;
@ -2144,3 +2146,140 @@ void clear_directory(struct dir_struct *dir)
}
strbuf_release(&dir->basebuf);
}
struct ondisk_untracked_cache {
struct stat_data info_exclude_stat;
struct stat_data excludes_file_stat;
uint32_t dir_flags;
unsigned char info_exclude_sha1[20];
unsigned char excludes_file_sha1[20];
char exclude_per_dir[FLEX_ARRAY];
};
#define ouc_size(len) (offsetof(struct ondisk_untracked_cache, exclude_per_dir) + len + 1)
struct write_data {
int index; /* number of written untracked_cache_dir */
struct ewah_bitmap *check_only; /* from untracked_cache_dir */
struct ewah_bitmap *valid; /* from untracked_cache_dir */
struct ewah_bitmap *sha1_valid; /* set if exclude_sha1 is not null */
struct strbuf out;
struct strbuf sb_stat;
struct strbuf sb_sha1;
};
static void stat_data_to_disk(struct stat_data *to, const struct stat_data *from)
{
to->sd_ctime.sec = htonl(from->sd_ctime.sec);
to->sd_ctime.nsec = htonl(from->sd_ctime.nsec);
to->sd_mtime.sec = htonl(from->sd_mtime.sec);
to->sd_mtime.nsec = htonl(from->sd_mtime.nsec);
to->sd_dev = htonl(from->sd_dev);
to->sd_ino = htonl(from->sd_ino);
to->sd_uid = htonl(from->sd_uid);
to->sd_gid = htonl(from->sd_gid);
to->sd_size = htonl(from->sd_size);
}
static void write_one_dir(struct untracked_cache_dir *untracked,
struct write_data *wd)
{
struct stat_data stat_data;
struct strbuf *out = &wd->out;
unsigned char intbuf[16];
unsigned int intlen, value;
int i = wd->index++;
/*
* untracked_nr should be reset whenever valid is clear, but
* for safety..
*/
if (!untracked->valid) {
untracked->untracked_nr = 0;
untracked->check_only = 0;
}
if (untracked->check_only)
ewah_set(wd->check_only, i);
if (untracked->valid) {
ewah_set(wd->valid, i);
stat_data_to_disk(&stat_data, &untracked->stat_data);
strbuf_add(&wd->sb_stat, &stat_data, sizeof(stat_data));
}
if (!is_null_sha1(untracked->exclude_sha1)) {
ewah_set(wd->sha1_valid, i);
strbuf_add(&wd->sb_sha1, untracked->exclude_sha1, 20);
}
intlen = encode_varint(untracked->untracked_nr, intbuf);
strbuf_add(out, intbuf, intlen);
/* skip non-recurse directories */
for (i = 0, value = 0; i < untracked->dirs_nr; i++)
if (untracked->dirs[i]->recurse)
value++;
intlen = encode_varint(value, intbuf);
strbuf_add(out, intbuf, intlen);
strbuf_add(out, untracked->name, strlen(untracked->name) + 1);
for (i = 0; i < untracked->untracked_nr; i++)
strbuf_add(out, untracked->untracked[i],
strlen(untracked->untracked[i]) + 1);
for (i = 0; i < untracked->dirs_nr; i++)
if (untracked->dirs[i]->recurse)
write_one_dir(untracked->dirs[i], wd);
}
void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked)
{
struct ondisk_untracked_cache *ouc;
struct write_data wd;
unsigned char varbuf[16];
int len = 0, varint_len;
if (untracked->exclude_per_dir)
len = strlen(untracked->exclude_per_dir);
ouc = xmalloc(sizeof(*ouc) + len + 1);
stat_data_to_disk(&ouc->info_exclude_stat, &untracked->ss_info_exclude.stat);
stat_data_to_disk(&ouc->excludes_file_stat, &untracked->ss_excludes_file.stat);
hashcpy(ouc->info_exclude_sha1, untracked->ss_info_exclude.sha1);
hashcpy(ouc->excludes_file_sha1, untracked->ss_excludes_file.sha1);
ouc->dir_flags = htonl(untracked->dir_flags);
memcpy(ouc->exclude_per_dir, untracked->exclude_per_dir, len + 1);
strbuf_add(out, ouc, ouc_size(len));
free(ouc);
ouc = NULL;
if (!untracked->root) {
varint_len = encode_varint(0, varbuf);
strbuf_add(out, varbuf, varint_len);
return;
}
wd.index = 0;
wd.check_only = ewah_new();
wd.valid = ewah_new();
wd.sha1_valid = ewah_new();
strbuf_init(&wd.out, 1024);
strbuf_init(&wd.sb_stat, 1024);
strbuf_init(&wd.sb_sha1, 1024);
write_one_dir(untracked->root, &wd);
varint_len = encode_varint(wd.index, varbuf);
strbuf_add(out, varbuf, varint_len);
strbuf_addbuf(out, &wd.out);
ewah_serialize_strbuf(wd.valid, out);
ewah_serialize_strbuf(wd.check_only, out);
ewah_serialize_strbuf(wd.sha1_valid, out);
strbuf_addbuf(out, &wd.sb_stat);
strbuf_addbuf(out, &wd.sb_sha1);
strbuf_addch(out, '\0'); /* safe guard for string lists */
ewah_free(wd.valid);
ewah_free(wd.check_only);
ewah_free(wd.sha1_valid);
strbuf_release(&wd.out);
strbuf_release(&wd.sb_stat);
strbuf_release(&wd.sb_sha1);
}

1
dir.h
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@ -298,4 +298,5 @@ static inline int dir_path_match(const struct dir_entry *ent,
has_trailing_dir);
}
void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked);
#endif

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@ -39,6 +39,7 @@ static struct cache_entry *refresh_cache_entry(struct cache_entry *ce,
#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
#define CACHE_EXT_LINK 0x6c696e6b /* "link" */
#define CACHE_EXT_UNTRACKED 0x554E5452 /* "UNTR" */
/* changes that can be kept in $GIT_DIR/index (basically all extensions) */
#define EXTMASK (RESOLVE_UNDO_CHANGED | CACHE_TREE_CHANGED | \
@ -2047,6 +2048,17 @@ static int do_write_index(struct index_state *istate, int newfd,
if (err)
return -1;
}
if (!strip_extensions && istate->untracked) {
struct strbuf sb = STRBUF_INIT;
write_untracked_extension(&sb, istate->untracked);
err = write_index_ext_header(&c, newfd, CACHE_EXT_UNTRACKED,
sb.len) < 0 ||
ce_write(&c, newfd, sb.buf, sb.len) < 0;
strbuf_release(&sb);
if (err)
return -1;
}
if (ce_flush(&c, newfd, istate->sha1) || fstat(newfd, &st))
return -1;