git/builtin/upload-archive.c

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/*
* Copyright (c) 2006 Franck Bui-Huu
*/
#include "builtin.h"
#include "archive.h"
#include "path.h"
#include "pkt-line.h"
#include "sideband.h"
#include "repository.h"
#include "run-command.h"
#include "strvec.h"
static const char upload_archive_usage[] =
"git upload-archive <repository>";
static const char deadchild[] =
"git upload-archive: archiver died with error";
#define MAX_ARGS (64)
int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix)
{
struct strvec sent_argv = STRVEC_INIT;
const char *arg_cmd = "argument ";
if (argc != 2 || !strcmp(argv[1], "-h"))
usage(upload_archive_usage);
if (!enter_repo(argv[1], 0))
die("'%s' does not appear to be a git repository", argv[1]);
init_archivers();
/* put received options in sent_argv[] */
strvec_push(&sent_argv, "git-upload-archive");
for (;;) {
pkt-line: provide a LARGE_PACKET_MAX static buffer Most of the callers of packet_read_line just read into a static 1000-byte buffer (callers which handle arbitrary binary data already use LARGE_PACKET_MAX). This works fine in practice, because: 1. The only variable-sized data in these lines is a ref name, and refs tend to be a lot shorter than 1000 characters. 2. When sending ref lines, git-core always limits itself to 1000 byte packets. However, the only limit given in the protocol specification in Documentation/technical/protocol-common.txt is LARGE_PACKET_MAX; the 1000 byte limit is mentioned only in pack-protocol.txt, and then only describing what we write, not as a specific limit for readers. This patch lets us bump the 1000-byte limit to LARGE_PACKET_MAX. Even though git-core will never write a packet where this makes a difference, there are two good reasons to do this: 1. Other git implementations may have followed protocol-common.txt and used a larger maximum size. We don't bump into it in practice because it would involve very long ref names. 2. We may want to increase the 1000-byte limit one day. Since packets are transferred before any capabilities, it's difficult to do this in a backwards-compatible way. But if we bump the size of buffer the readers can handle, eventually older versions of git will be obsolete enough that we can justify bumping the writers, as well. We don't have plans to do this anytime soon, but there is no reason not to start the clock ticking now. Just bumping all of the reading bufs to LARGE_PACKET_MAX would waste memory. Instead, since most readers just read into a temporary buffer anyway, let's provide a single static buffer that all callers can use. We can further wrap this detail away by having the packet_read_line wrapper just use the buffer transparently and return a pointer to the static storage. That covers most of the cases, and the remaining ones already read into their own LARGE_PACKET_MAX buffers. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20 20:02:57 +00:00
char *buf = packet_read_line(0, NULL);
if (!buf)
break; /* got a flush */
if (sent_argv.nr > MAX_ARGS)
die("Too many options (>%d)", MAX_ARGS - 1);
if (!starts_with(buf, arg_cmd))
die("'argument' token or flush expected");
strvec_push(&sent_argv, buf + strlen(arg_cmd));
}
/* parse all options sent by the client */
return write_archive(sent_argv.nr, sent_argv.v, prefix,
the_repository, NULL, 1);
}
__attribute__((format (printf, 1, 2)))
static void error_clnt(const char *fmt, ...)
{
struct strbuf buf = STRBUF_INIT;
va_list params;
va_start(params, fmt);
strbuf_vaddf(&buf, fmt, params);
va_end(params);
send_sideband(1, 3, buf.buf, buf.len, LARGE_PACKET_MAX);
die("sent error to the client: %s", buf.buf);
}
static ssize_t process_input(int child_fd, int band)
{
char buf[16384];
ssize_t sz = read(child_fd, buf, sizeof(buf));
if (sz < 0) {
if (errno != EAGAIN && errno != EINTR)
error_clnt("read error: %s\n", strerror(errno));
return sz;
}
send_sideband(1, band, buf, sz, LARGE_PACKET_MAX);
return sz;
}
int cmd_upload_archive(int argc, const char **argv, const char *prefix)
{
struct child_process writer = CHILD_PROCESS_INIT;
builtins: annotate always-empty prefix parameters It's usually a bad idea for a builtin's cmd_foo() to ignore the "prefix" argument it gets, as it needs to prepend that string when accessing any paths given by the user. But if a builtin does not ask for the git wrapper to run repository setup (via the RUN_SETUP or RUN_SETUP_GENTLY flags), then we know the prefix will always be NULL (it is adjusting for the chdir() done during repo setup, but there cannot be one if we did not set up the repo). In those cases it's OK to ignore "prefix", but it's worth annotating for a few reasons: 1. It serves as documentation to somebody reading the code about what we expect. 2. If the flags in git.c ever change, the run-time assertion may help detect the problem (though only if the command is run from a subdirectory of the repository). 3. It notes to the compiler that we are OK ignoring "prefix". In particular, this silences -Wunused-parameter. It _could_ also help the compiler generate better code (because it will know the prefix is NULL), but in practice this is quite unlikely to matter. Note that I've only added this annotation to commands which triggered -Wunused-parameter. It would be correct to add it to any builtin which doesn't ask for RUN_SETUP, but most of the rest of them do the sensible thing with "prefix" by passing it to parse_options(). So they're much more likely to just work if they ever switched to RUN_SETUP, and aren't worth annotating. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 20:55:17 +00:00
BUG_ON_NON_EMPTY_PREFIX(prefix);
if (argc == 2 && !strcmp(argv[1], "-h"))
usage(upload_archive_usage);
/*
* Set up sideband subprocess.
*
* We (parent) monitor and read from child, sending its fd#1 and fd#2
* multiplexed out to our fd#1. If the child dies, we tell the other
* end over channel #3.
*/
writer.out = writer.err = -1;
writer.git_cmd = 1;
strvec_push(&writer.args, "upload-archive--writer");
strvec_pushv(&writer.args, argv + 1);
if (start_command(&writer)) {
int err = errno;
packet_write_fmt(1, "NACK unable to spawn subprocess\n");
die("upload-archive: %s", strerror(err));
}
packet_write_fmt(1, "ACK\n");
packet_flush(1);
while (1) {
struct pollfd pfd[2];
pfd[0].fd = writer.out;
pfd[0].events = POLLIN;
pfd[1].fd = writer.err;
pfd[1].events = POLLIN;
if (poll(pfd, 2, -1) < 0) {
if (errno != EINTR) {
error_errno("poll failed resuming");
sleep(1);
}
continue;
}
if (pfd[1].revents & POLLIN)
/* Status stream ready */
if (process_input(pfd[1].fd, 2))
continue;
if (pfd[0].revents & POLLIN)
/* Data stream ready */
if (process_input(pfd[0].fd, 1))
continue;
if (finish_command(&writer))
error_clnt("%s", deadchild);
packet_flush(1);
break;
}
return 0;
}