Revision 4f22b1015d4203ccdf2b66f27ee5946504342ace authored by Jeff King on 24 February 2012, 22:10:17 UTC, committed by Junio C Hamano on 24 February 2012, 22:18:20 UTC
Because git's object format requires us to specify the number of bytes in the object in its header, we must know the size before streaming a blob into the object database. This is not a problem when adding a regular file, as we can get the size from stat(). However, when filters are in use (such as autocrlf, or the ident, filter, or eol gitattributes), we have no idea what the ultimate size will be. The current code just punts on the whole issue and ignores filter configuration entirely for files larger than core.bigfilethreshold. This can generate confusing results if you use filters for large binary files, as the filter will suddenly stop working as the file goes over a certain size. Rather than try to handle unknown input sizes with streaming, this patch just turns off the streaming optimization when filters are in use. This has a slight performance regression in a very specific case: if you have autocrlf on, but no gitattributes, a large binary file will avoid the streaming code path because we don't know beforehand whether it will need conversion or not. But if you are handling large binary files, you should be marking them as such via attributes (or at least not using autocrlf, and instead marking your text files as such). And the flip side is that if you have a large _non_-binary file, there is a correctness improvement; before we did not apply the conversion at all. The first half of the new t1051 script covers these failures on input. The second half tests the matching output code paths. These already work correctly, and do not need any adjustment. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 4c3b57b
entry.c
#include "cache.h"
#include "blob.h"
#include "dir.h"
#include "streaming.h"
static void create_directories(const char *path, int path_len,
const struct checkout *state)
{
char *buf = xmalloc(path_len + 1);
int len = 0;
while (len < path_len) {
do {
buf[len] = path[len];
len++;
} while (len < path_len && path[len] != '/');
if (len >= path_len)
break;
buf[len] = 0;
/*
* For 'checkout-index --prefix=<dir>', <dir> is
* allowed to be a symlink to an existing directory,
* and we set 'state->base_dir_len' below, such that
* we test the path components of the prefix with the
* stat() function instead of the lstat() function.
*/
if (has_dirs_only_path(buf, len, state->base_dir_len))
continue; /* ok, it is already a directory. */
/*
* If this mkdir() would fail, it could be that there
* is already a symlink or something else exists
* there, therefore we then try to unlink it and try
* one more time to create the directory.
*/
if (mkdir(buf, 0777)) {
if (errno == EEXIST && state->force &&
!unlink_or_warn(buf) && !mkdir(buf, 0777))
continue;
die_errno("cannot create directory at '%s'", buf);
}
}
free(buf);
}
static void remove_subtree(const char *path)
{
DIR *dir = opendir(path);
struct dirent *de;
char pathbuf[PATH_MAX];
char *name;
if (!dir)
die_errno("cannot opendir '%s'", path);
strcpy(pathbuf, path);
name = pathbuf + strlen(path);
*name++ = '/';
while ((de = readdir(dir)) != NULL) {
struct stat st;
if (is_dot_or_dotdot(de->d_name))
continue;
strcpy(name, de->d_name);
if (lstat(pathbuf, &st))
die_errno("cannot lstat '%s'", pathbuf);
if (S_ISDIR(st.st_mode))
remove_subtree(pathbuf);
else if (unlink(pathbuf))
die_errno("cannot unlink '%s'", pathbuf);
}
closedir(dir);
if (rmdir(path))
die_errno("cannot rmdir '%s'", path);
}
static int create_file(const char *path, unsigned int mode)
{
mode = (mode & 0100) ? 0777 : 0666;
return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
}
static void *read_blob_entry(struct cache_entry *ce, unsigned long *size)
{
enum object_type type;
void *new = read_sha1_file(ce->sha1, &type, size);
if (new) {
if (type == OBJ_BLOB)
return new;
free(new);
}
return NULL;
}
static int open_output_fd(char *path, struct cache_entry *ce, int to_tempfile)
{
int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;
if (to_tempfile) {
strcpy(path, symlink
? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");
return mkstemp(path);
} else {
return create_file(path, !symlink ? ce->ce_mode : 0666);
}
}
static int fstat_output(int fd, const struct checkout *state, struct stat *st)
{
/* use fstat() only when path == ce->name */
if (fstat_is_reliable() &&
state->refresh_cache && !state->base_dir_len) {
fstat(fd, st);
return 1;
}
return 0;
}
static int streaming_write_entry(struct cache_entry *ce, char *path,
struct stream_filter *filter,
const struct checkout *state, int to_tempfile,
int *fstat_done, struct stat *statbuf)
{
struct git_istream *st;
enum object_type type;
unsigned long sz;
int result = -1;
ssize_t kept = 0;
int fd = -1;
st = open_istream(ce->sha1, &type, &sz, filter);
if (!st)
return -1;
if (type != OBJ_BLOB)
goto close_and_exit;
fd = open_output_fd(path, ce, to_tempfile);
if (fd < 0)
goto close_and_exit;
for (;;) {
char buf[1024 * 16];
ssize_t wrote, holeto;
ssize_t readlen = read_istream(st, buf, sizeof(buf));
if (!readlen)
break;
if (sizeof(buf) == readlen) {
for (holeto = 0; holeto < readlen; holeto++)
if (buf[holeto])
break;
if (readlen == holeto) {
kept += holeto;
continue;
}
}
if (kept && lseek(fd, kept, SEEK_CUR) == (off_t) -1)
goto close_and_exit;
else
kept = 0;
wrote = write_in_full(fd, buf, readlen);
if (wrote != readlen)
goto close_and_exit;
}
if (kept && (lseek(fd, kept - 1, SEEK_CUR) == (off_t) -1 ||
write(fd, "", 1) != 1))
goto close_and_exit;
*fstat_done = fstat_output(fd, state, statbuf);
close_and_exit:
close_istream(st);
if (0 <= fd)
result = close(fd);
if (result && 0 <= fd)
unlink(path);
return result;
}
static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
{
unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
int fd, ret, fstat_done = 0;
char *new;
struct strbuf buf = STRBUF_INIT;
unsigned long size;
size_t wrote, newsize = 0;
struct stat st;
if (ce_mode_s_ifmt == S_IFREG) {
struct stream_filter *filter = get_stream_filter(path, ce->sha1);
if (filter &&
!streaming_write_entry(ce, path, filter,
state, to_tempfile,
&fstat_done, &st))
goto finish;
}
switch (ce_mode_s_ifmt) {
case S_IFREG:
case S_IFLNK:
new = read_blob_entry(ce, &size);
if (!new)
return error("unable to read sha1 file of %s (%s)",
path, sha1_to_hex(ce->sha1));
if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
ret = symlink(new, path);
free(new);
if (ret)
return error("unable to create symlink %s (%s)",
path, strerror(errno));
break;
}
/*
* Convert from git internal format to working tree format
*/
if (ce_mode_s_ifmt == S_IFREG &&
convert_to_working_tree(ce->name, new, size, &buf)) {
free(new);
new = strbuf_detach(&buf, &newsize);
size = newsize;
}
fd = open_output_fd(path, ce, to_tempfile);
if (fd < 0) {
free(new);
return error("unable to create file %s (%s)",
path, strerror(errno));
}
wrote = write_in_full(fd, new, size);
if (!to_tempfile)
fstat_done = fstat_output(fd, state, &st);
close(fd);
free(new);
if (wrote != size)
return error("unable to write file %s", path);
break;
case S_IFGITLINK:
if (to_tempfile)
return error("cannot create temporary subproject %s", path);
if (mkdir(path, 0777) < 0)
return error("cannot create subproject directory %s", path);
break;
default:
return error("unknown file mode for %s in index", path);
}
finish:
if (state->refresh_cache) {
if (!fstat_done)
lstat(ce->name, &st);
fill_stat_cache_info(ce, &st);
}
return 0;
}
/*
* This is like 'lstat()', except it refuses to follow symlinks
* in the path, after skipping "skiplen".
*/
static int check_path(const char *path, int len, struct stat *st, int skiplen)
{
const char *slash = path + len;
while (path < slash && *slash != '/')
slash--;
if (!has_dirs_only_path(path, slash - path, skiplen)) {
errno = ENOENT;
return -1;
}
return lstat(path, st);
}
int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
{
static char path[PATH_MAX + 1];
struct stat st;
int len = state->base_dir_len;
if (topath)
return write_entry(ce, topath, state, 1);
memcpy(path, state->base_dir, len);
strcpy(path + len, ce->name);
len += ce_namelen(ce);
if (!check_path(path, len, &st, state->base_dir_len)) {
unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
if (!changed)
return 0;
if (!state->force) {
if (!state->quiet)
fprintf(stderr, "%s already exists, no checkout\n", path);
return -1;
}
/*
* We unlink the old file, to get the new one with the
* right permissions (including umask, which is nasty
* to emulate by hand - much easier to let the system
* just do the right thing)
*/
if (S_ISDIR(st.st_mode)) {
/* If it is a gitlink, leave it alone! */
if (S_ISGITLINK(ce->ce_mode))
return 0;
if (!state->force)
return error("%s is a directory", path);
remove_subtree(path);
} else if (unlink(path))
return error("unable to unlink old '%s' (%s)", path, strerror(errno));
} else if (state->not_new)
return 0;
create_directories(path, len, state);
return write_entry(ce, path, state, 0);
}
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