mirror/git
1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-11-19 21:44:22 +01:00
Code

[PATCH] Parallelize pulling by ssh

Browse Source 
This causes ssh-pull to request objects in prefetch() and read then in
fetch(), such that it reduces the unpipelined round-trip time.

This also makes sha1_write_from_fd() support having a buffer of data
which it accidentally read from the fd after the object; this was
formerly not a problem, because it would always get a short read at
the end of an object, because the next object had not been
requested. This is no longer true.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
barkalow@iabervon.org 2005-08-02 19:46:29 -04:00 committed by Junio C Hamano
parent 1e8be59d14
commit 70b9829ea7
3 changed files with 57 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
cache.h
View File

@ -198,7 +198,8 @@ extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned l
/* Read a tree into the cache */
extern int read_tree(void *buffer, unsigned long size, int stage, const char **paths);
extern int write_sha1_from_fd(const unsigned char *sha1, int fd);
extern int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
size_t bufsize, size_t *bufposn);
extern int write_sha1_to_fd(int fd, const unsigned char *sha1);
extern int has_sha1_pack(const unsigned char *sha1);

37
sha1_file.c
View File

@ -1389,14 +1389,14 @@ int write_sha1_to_fd(int fd, const unsigned char *sha1)
return 0;
}
int write_sha1_from_fd(const unsigned char *sha1, int fd)
int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
size_t bufsize, size_t *bufposn)
{
char *filename = sha1_file_name(sha1);
int local;
z_stream stream;
unsigned char real_sha1[20];
unsigned char buf[4096];
unsigned char discard[4096];
int ret;
SHA_CTX c;
@ -1414,7 +1414,24 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd)
do {
ssize_t size;
size = read(fd, buf, 4096);
if (*bufposn) {
stream.avail_in = *bufposn;
stream.next_in = buffer;
do {
stream.next_out = discard;
stream.avail_out = sizeof(discard);
ret = inflate(&stream, Z_SYNC_FLUSH);
SHA1_Update(&c, discard, sizeof(discard) -
stream.avail_out);
} while (stream.avail_in && ret == Z_OK);
write(local, buffer, *bufposn - stream.avail_in);
memmove(buffer, buffer + *bufposn - stream.avail_in,
stream.avail_in);
*bufposn = stream.avail_in;
if (ret != Z_OK)
break;
}
size = read(fd, buffer + *bufposn, bufsize - *bufposn);
if (size <= 0) {
close(local);
unlink(filename);
@ -1423,18 +1440,8 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd)
perror("Reading from connection");
return -1;
}
write(local, buf, size);
stream.avail_in = size;
stream.next_in = buf;
do {
stream.next_out = discard;
stream.avail_out = sizeof(discard);
ret = inflate(&stream, Z_SYNC_FLUSH);
SHA1_Update(&c, discard, sizeof(discard) -
stream.avail_out);
} while (stream.avail_in && ret == Z_OK);
} while (ret == Z_OK);
*bufposn += size;
} while (1);
inflateEnd(&stream);
close(local);

41
ssh-pull.c
View File

@ -10,24 +10,49 @@ static int fd_out;
static unsigned char remote_version = 0;
static unsigned char local_version = 1;
ssize_t force_write(int fd, void *buffer, size_t length)
{
ssize_t ret = 0;
while (ret < length) {
ssize_t size = write(fd, buffer + ret, length - ret);
if (size < 0) {
return size;
}
if (size == 0) {
return ret;
}
ret += size;
}
return ret;
}
void prefetch(unsigned char *sha1)
{
char type = 'o';
force_write(fd_out, &type, 1);
force_write(fd_out, sha1, 20);
//memcpy(requested + 20 * prefetches++, sha1, 20);
}
static char conn_buf[4096];
static size_t conn_buf_posn = 0;
int fetch(unsigned char *sha1)
{
int ret;
signed char remote;
char type = 'o';
if (has_sha1_file(sha1))
return 0;
write(fd_out, &type, 1);
write(fd_out, sha1, 20);
if (read(fd_in, &remote, 1) < 1)
return -1;
if (conn_buf_posn) {
remote = conn_buf[0];
memmove(conn_buf, conn_buf + 1, --conn_buf_posn);
} else {
if (read(fd_in, &remote, 1) < 1)
return -1;
}
//fprintf(stderr, "Got %d\n", remote);
if (remote < 0)
return remote;
ret = write_sha1_from_fd(sha1, fd_in);
ret = write_sha1_from_fd(sha1, fd_in, conn_buf, 4096, &conn_buf_posn);
if (!ret)
pull_say("got %s\n", sha1_to_hex(sha1));
return ret;