mirror of
https://github.com/git/git
synced 2024-08-25 10:45:59 +00:00
![Nguyễn Thái Ngọc Duy](/assets/img/avatar_default.png)
This is because all other places do "xx > big_file_threshold" Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
547 lines
12 KiB
C
547 lines
12 KiB
C
/*
|
|
* Copyright (c) 2011, Google Inc.
|
|
*/
|
|
#include "cache.h"
|
|
#include "streaming.h"
|
|
|
|
enum input_source {
|
|
stream_error = -1,
|
|
incore = 0,
|
|
loose = 1,
|
|
pack_non_delta = 2
|
|
};
|
|
|
|
typedef int (*open_istream_fn)(struct git_istream *,
|
|
struct object_info *,
|
|
const unsigned char *,
|
|
enum object_type *);
|
|
typedef int (*close_istream_fn)(struct git_istream *);
|
|
typedef ssize_t (*read_istream_fn)(struct git_istream *, char *, size_t);
|
|
|
|
struct stream_vtbl {
|
|
close_istream_fn close;
|
|
read_istream_fn read;
|
|
};
|
|
|
|
#define open_method_decl(name) \
|
|
int open_istream_ ##name \
|
|
(struct git_istream *st, struct object_info *oi, \
|
|
const unsigned char *sha1, \
|
|
enum object_type *type)
|
|
|
|
#define close_method_decl(name) \
|
|
int close_istream_ ##name \
|
|
(struct git_istream *st)
|
|
|
|
#define read_method_decl(name) \
|
|
ssize_t read_istream_ ##name \
|
|
(struct git_istream *st, char *buf, size_t sz)
|
|
|
|
/* forward declaration */
|
|
static open_method_decl(incore);
|
|
static open_method_decl(loose);
|
|
static open_method_decl(pack_non_delta);
|
|
static struct git_istream *attach_stream_filter(struct git_istream *st,
|
|
struct stream_filter *filter);
|
|
|
|
|
|
static open_istream_fn open_istream_tbl[] = {
|
|
open_istream_incore,
|
|
open_istream_loose,
|
|
open_istream_pack_non_delta,
|
|
};
|
|
|
|
#define FILTER_BUFFER (1024*16)
|
|
|
|
struct filtered_istream {
|
|
struct git_istream *upstream;
|
|
struct stream_filter *filter;
|
|
char ibuf[FILTER_BUFFER];
|
|
char obuf[FILTER_BUFFER];
|
|
int i_end, i_ptr;
|
|
int o_end, o_ptr;
|
|
int input_finished;
|
|
};
|
|
|
|
struct git_istream {
|
|
const struct stream_vtbl *vtbl;
|
|
unsigned long size; /* inflated size of full object */
|
|
git_zstream z;
|
|
enum { z_unused, z_used, z_done, z_error } z_state;
|
|
|
|
union {
|
|
struct {
|
|
char *buf; /* from read_object() */
|
|
unsigned long read_ptr;
|
|
} incore;
|
|
|
|
struct {
|
|
void *mapped;
|
|
unsigned long mapsize;
|
|
char hdr[32];
|
|
int hdr_avail;
|
|
int hdr_used;
|
|
} loose;
|
|
|
|
struct {
|
|
struct packed_git *pack;
|
|
off_t pos;
|
|
} in_pack;
|
|
|
|
struct filtered_istream filtered;
|
|
} u;
|
|
};
|
|
|
|
int close_istream(struct git_istream *st)
|
|
{
|
|
int r = st->vtbl->close(st);
|
|
free(st);
|
|
return r;
|
|
}
|
|
|
|
ssize_t read_istream(struct git_istream *st, void *buf, size_t sz)
|
|
{
|
|
return st->vtbl->read(st, buf, sz);
|
|
}
|
|
|
|
static enum input_source istream_source(const unsigned char *sha1,
|
|
enum object_type *type,
|
|
struct object_info *oi)
|
|
{
|
|
unsigned long size;
|
|
int status;
|
|
|
|
oi->sizep = &size;
|
|
status = sha1_object_info_extended(sha1, oi);
|
|
if (status < 0)
|
|
return stream_error;
|
|
*type = status;
|
|
|
|
switch (oi->whence) {
|
|
case OI_LOOSE:
|
|
return loose;
|
|
case OI_PACKED:
|
|
if (!oi->u.packed.is_delta && big_file_threshold < size)
|
|
return pack_non_delta;
|
|
/* fallthru */
|
|
default:
|
|
return incore;
|
|
}
|
|
}
|
|
|
|
struct git_istream *open_istream(const unsigned char *sha1,
|
|
enum object_type *type,
|
|
unsigned long *size,
|
|
struct stream_filter *filter)
|
|
{
|
|
struct git_istream *st;
|
|
struct object_info oi;
|
|
const unsigned char *real = lookup_replace_object(sha1);
|
|
enum input_source src = istream_source(real, type, &oi);
|
|
|
|
if (src < 0)
|
|
return NULL;
|
|
|
|
st = xmalloc(sizeof(*st));
|
|
if (open_istream_tbl[src](st, &oi, real, type)) {
|
|
if (open_istream_incore(st, &oi, real, type)) {
|
|
free(st);
|
|
return NULL;
|
|
}
|
|
}
|
|
if (st && filter) {
|
|
/* Add "&& !is_null_stream_filter(filter)" for performance */
|
|
struct git_istream *nst = attach_stream_filter(st, filter);
|
|
if (!nst)
|
|
close_istream(st);
|
|
st = nst;
|
|
}
|
|
|
|
*size = st->size;
|
|
return st;
|
|
}
|
|
|
|
|
|
/*****************************************************************
|
|
*
|
|
* Common helpers
|
|
*
|
|
*****************************************************************/
|
|
|
|
static void close_deflated_stream(struct git_istream *st)
|
|
{
|
|
if (st->z_state == z_used)
|
|
git_inflate_end(&st->z);
|
|
}
|
|
|
|
|
|
/*****************************************************************
|
|
*
|
|
* Filtered stream
|
|
*
|
|
*****************************************************************/
|
|
|
|
static close_method_decl(filtered)
|
|
{
|
|
free_stream_filter(st->u.filtered.filter);
|
|
return close_istream(st->u.filtered.upstream);
|
|
}
|
|
|
|
static read_method_decl(filtered)
|
|
{
|
|
struct filtered_istream *fs = &(st->u.filtered);
|
|
size_t filled = 0;
|
|
|
|
while (sz) {
|
|
/* do we already have filtered output? */
|
|
if (fs->o_ptr < fs->o_end) {
|
|
size_t to_move = fs->o_end - fs->o_ptr;
|
|
if (sz < to_move)
|
|
to_move = sz;
|
|
memcpy(buf + filled, fs->obuf + fs->o_ptr, to_move);
|
|
fs->o_ptr += to_move;
|
|
sz -= to_move;
|
|
filled += to_move;
|
|
continue;
|
|
}
|
|
fs->o_end = fs->o_ptr = 0;
|
|
|
|
/* do we have anything to feed the filter with? */
|
|
if (fs->i_ptr < fs->i_end) {
|
|
size_t to_feed = fs->i_end - fs->i_ptr;
|
|
size_t to_receive = FILTER_BUFFER;
|
|
if (stream_filter(fs->filter,
|
|
fs->ibuf + fs->i_ptr, &to_feed,
|
|
fs->obuf, &to_receive))
|
|
return -1;
|
|
fs->i_ptr = fs->i_end - to_feed;
|
|
fs->o_end = FILTER_BUFFER - to_receive;
|
|
continue;
|
|
}
|
|
|
|
/* tell the filter to drain upon no more input */
|
|
if (fs->input_finished) {
|
|
size_t to_receive = FILTER_BUFFER;
|
|
if (stream_filter(fs->filter,
|
|
NULL, NULL,
|
|
fs->obuf, &to_receive))
|
|
return -1;
|
|
fs->o_end = FILTER_BUFFER - to_receive;
|
|
if (!fs->o_end)
|
|
break;
|
|
continue;
|
|
}
|
|
fs->i_end = fs->i_ptr = 0;
|
|
|
|
/* refill the input from the upstream */
|
|
if (!fs->input_finished) {
|
|
fs->i_end = read_istream(fs->upstream, fs->ibuf, FILTER_BUFFER);
|
|
if (fs->i_end < 0)
|
|
break;
|
|
if (fs->i_end)
|
|
continue;
|
|
}
|
|
fs->input_finished = 1;
|
|
}
|
|
return filled;
|
|
}
|
|
|
|
static struct stream_vtbl filtered_vtbl = {
|
|
close_istream_filtered,
|
|
read_istream_filtered,
|
|
};
|
|
|
|
static struct git_istream *attach_stream_filter(struct git_istream *st,
|
|
struct stream_filter *filter)
|
|
{
|
|
struct git_istream *ifs = xmalloc(sizeof(*ifs));
|
|
struct filtered_istream *fs = &(ifs->u.filtered);
|
|
|
|
ifs->vtbl = &filtered_vtbl;
|
|
fs->upstream = st;
|
|
fs->filter = filter;
|
|
fs->i_end = fs->i_ptr = 0;
|
|
fs->o_end = fs->o_ptr = 0;
|
|
fs->input_finished = 0;
|
|
ifs->size = -1; /* unknown */
|
|
return ifs;
|
|
}
|
|
|
|
/*****************************************************************
|
|
*
|
|
* Loose object stream
|
|
*
|
|
*****************************************************************/
|
|
|
|
static read_method_decl(loose)
|
|
{
|
|
size_t total_read = 0;
|
|
|
|
switch (st->z_state) {
|
|
case z_done:
|
|
return 0;
|
|
case z_error:
|
|
return -1;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (st->u.loose.hdr_used < st->u.loose.hdr_avail) {
|
|
size_t to_copy = st->u.loose.hdr_avail - st->u.loose.hdr_used;
|
|
if (sz < to_copy)
|
|
to_copy = sz;
|
|
memcpy(buf, st->u.loose.hdr + st->u.loose.hdr_used, to_copy);
|
|
st->u.loose.hdr_used += to_copy;
|
|
total_read += to_copy;
|
|
}
|
|
|
|
while (total_read < sz) {
|
|
int status;
|
|
|
|
st->z.next_out = (unsigned char *)buf + total_read;
|
|
st->z.avail_out = sz - total_read;
|
|
status = git_inflate(&st->z, Z_FINISH);
|
|
|
|
total_read = st->z.next_out - (unsigned char *)buf;
|
|
|
|
if (status == Z_STREAM_END) {
|
|
git_inflate_end(&st->z);
|
|
st->z_state = z_done;
|
|
break;
|
|
}
|
|
if (status != Z_OK && status != Z_BUF_ERROR) {
|
|
git_inflate_end(&st->z);
|
|
st->z_state = z_error;
|
|
return -1;
|
|
}
|
|
}
|
|
return total_read;
|
|
}
|
|
|
|
static close_method_decl(loose)
|
|
{
|
|
close_deflated_stream(st);
|
|
munmap(st->u.loose.mapped, st->u.loose.mapsize);
|
|
return 0;
|
|
}
|
|
|
|
static struct stream_vtbl loose_vtbl = {
|
|
close_istream_loose,
|
|
read_istream_loose,
|
|
};
|
|
|
|
static open_method_decl(loose)
|
|
{
|
|
st->u.loose.mapped = map_sha1_file(sha1, &st->u.loose.mapsize);
|
|
if (!st->u.loose.mapped)
|
|
return -1;
|
|
if (unpack_sha1_header(&st->z,
|
|
st->u.loose.mapped,
|
|
st->u.loose.mapsize,
|
|
st->u.loose.hdr,
|
|
sizeof(st->u.loose.hdr)) < 0) {
|
|
git_inflate_end(&st->z);
|
|
munmap(st->u.loose.mapped, st->u.loose.mapsize);
|
|
return -1;
|
|
}
|
|
|
|
parse_sha1_header(st->u.loose.hdr, &st->size);
|
|
st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1;
|
|
st->u.loose.hdr_avail = st->z.total_out;
|
|
st->z_state = z_used;
|
|
|
|
st->vtbl = &loose_vtbl;
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*****************************************************************
|
|
*
|
|
* Non-delta packed object stream
|
|
*
|
|
*****************************************************************/
|
|
|
|
static read_method_decl(pack_non_delta)
|
|
{
|
|
size_t total_read = 0;
|
|
|
|
switch (st->z_state) {
|
|
case z_unused:
|
|
memset(&st->z, 0, sizeof(st->z));
|
|
git_inflate_init(&st->z);
|
|
st->z_state = z_used;
|
|
break;
|
|
case z_done:
|
|
return 0;
|
|
case z_error:
|
|
return -1;
|
|
case z_used:
|
|
break;
|
|
}
|
|
|
|
while (total_read < sz) {
|
|
int status;
|
|
struct pack_window *window = NULL;
|
|
unsigned char *mapped;
|
|
|
|
mapped = use_pack(st->u.in_pack.pack, &window,
|
|
st->u.in_pack.pos, &st->z.avail_in);
|
|
|
|
st->z.next_out = (unsigned char *)buf + total_read;
|
|
st->z.avail_out = sz - total_read;
|
|
st->z.next_in = mapped;
|
|
status = git_inflate(&st->z, Z_FINISH);
|
|
|
|
st->u.in_pack.pos += st->z.next_in - mapped;
|
|
total_read = st->z.next_out - (unsigned char *)buf;
|
|
unuse_pack(&window);
|
|
|
|
if (status == Z_STREAM_END) {
|
|
git_inflate_end(&st->z);
|
|
st->z_state = z_done;
|
|
break;
|
|
}
|
|
if (status != Z_OK && status != Z_BUF_ERROR) {
|
|
git_inflate_end(&st->z);
|
|
st->z_state = z_error;
|
|
return -1;
|
|
}
|
|
}
|
|
return total_read;
|
|
}
|
|
|
|
static close_method_decl(pack_non_delta)
|
|
{
|
|
close_deflated_stream(st);
|
|
return 0;
|
|
}
|
|
|
|
static struct stream_vtbl pack_non_delta_vtbl = {
|
|
close_istream_pack_non_delta,
|
|
read_istream_pack_non_delta,
|
|
};
|
|
|
|
static open_method_decl(pack_non_delta)
|
|
{
|
|
struct pack_window *window;
|
|
enum object_type in_pack_type;
|
|
|
|
st->u.in_pack.pack = oi->u.packed.pack;
|
|
st->u.in_pack.pos = oi->u.packed.offset;
|
|
window = NULL;
|
|
|
|
in_pack_type = unpack_object_header(st->u.in_pack.pack,
|
|
&window,
|
|
&st->u.in_pack.pos,
|
|
&st->size);
|
|
unuse_pack(&window);
|
|
switch (in_pack_type) {
|
|
default:
|
|
return -1; /* we do not do deltas for now */
|
|
case OBJ_COMMIT:
|
|
case OBJ_TREE:
|
|
case OBJ_BLOB:
|
|
case OBJ_TAG:
|
|
break;
|
|
}
|
|
st->z_state = z_unused;
|
|
st->vtbl = &pack_non_delta_vtbl;
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*****************************************************************
|
|
*
|
|
* In-core stream
|
|
*
|
|
*****************************************************************/
|
|
|
|
static close_method_decl(incore)
|
|
{
|
|
free(st->u.incore.buf);
|
|
return 0;
|
|
}
|
|
|
|
static read_method_decl(incore)
|
|
{
|
|
size_t read_size = sz;
|
|
size_t remainder = st->size - st->u.incore.read_ptr;
|
|
|
|
if (remainder <= read_size)
|
|
read_size = remainder;
|
|
if (read_size) {
|
|
memcpy(buf, st->u.incore.buf + st->u.incore.read_ptr, read_size);
|
|
st->u.incore.read_ptr += read_size;
|
|
}
|
|
return read_size;
|
|
}
|
|
|
|
static struct stream_vtbl incore_vtbl = {
|
|
close_istream_incore,
|
|
read_istream_incore,
|
|
};
|
|
|
|
static open_method_decl(incore)
|
|
{
|
|
st->u.incore.buf = read_sha1_file_extended(sha1, type, &st->size, 0);
|
|
st->u.incore.read_ptr = 0;
|
|
st->vtbl = &incore_vtbl;
|
|
|
|
return st->u.incore.buf ? 0 : -1;
|
|
}
|
|
|
|
|
|
/****************************************************************
|
|
* Users of streaming interface
|
|
****************************************************************/
|
|
|
|
int stream_blob_to_fd(int fd, unsigned const char *sha1, struct stream_filter *filter,
|
|
int can_seek)
|
|
{
|
|
struct git_istream *st;
|
|
enum object_type type;
|
|
unsigned long sz;
|
|
ssize_t kept = 0;
|
|
int result = -1;
|
|
|
|
st = open_istream(sha1, &type, &sz, filter);
|
|
if (!st)
|
|
return result;
|
|
if (type != OBJ_BLOB)
|
|
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 (can_seek && 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;
|
|
result = 0;
|
|
|
|
close_and_exit:
|
|
close_istream(st);
|
|
return result;
|
|
}
|