git/transport-helper.c
Junio C Hamano b361888dd5 thread-utils.h: simplify the inclusion
All files that include this header file use the same four line
incantation:

    #ifndef NO_PTHREADS
    #include <pthread.h>
    #include "thread-utils.h"
    #endif

Move the responsibility for that gymnastics to the header file from the
files that include it.  This approach makes it easier to later declare new
services that are related to threading in thread-utils.h and have them
available to all the threading code.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-12-10 12:58:06 -08:00

1177 lines
28 KiB
C

#include "cache.h"
#include "transport.h"
#include "quote.h"
#include "run-command.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "quote.h"
#include "remote.h"
#include "string-list.h"
#include "thread-utils.h"
static int debug;
struct helper_data
{
const char *name;
struct child_process *helper;
FILE *out;
unsigned fetch : 1,
import : 1,
export : 1,
option : 1,
push : 1,
connect : 1,
no_disconnect_req : 1;
/* These go from remote name (as in "list") to private name */
struct refspec *refspecs;
int refspec_nr;
/* Transport options for fetch-pack/send-pack (should one of
* those be invoked).
*/
struct git_transport_options transport_options;
};
static void sendline(struct helper_data *helper, struct strbuf *buffer)
{
if (debug)
fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
!= buffer->len)
die_errno("Full write to remote helper failed");
}
static int recvline_fh(FILE *helper, struct strbuf *buffer)
{
strbuf_reset(buffer);
if (debug)
fprintf(stderr, "Debug: Remote helper: Waiting...\n");
if (strbuf_getline(buffer, helper, '\n') == EOF) {
if (debug)
fprintf(stderr, "Debug: Remote helper quit.\n");
exit(128);
}
if (debug)
fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
return 0;
}
static int recvline(struct helper_data *helper, struct strbuf *buffer)
{
return recvline_fh(helper->out, buffer);
}
static void xchgline(struct helper_data *helper, struct strbuf *buffer)
{
sendline(helper, buffer);
recvline(helper, buffer);
}
static void write_constant(int fd, const char *str)
{
if (debug)
fprintf(stderr, "Debug: Remote helper: -> %s", str);
if (write_in_full(fd, str, strlen(str)) != strlen(str))
die_errno("Full write to remote helper failed");
}
const char *remove_ext_force(const char *url)
{
if (url) {
const char *colon = strchr(url, ':');
if (colon && colon[1] == ':')
return colon + 2;
}
return url;
}
static void do_take_over(struct transport *transport)
{
struct helper_data *data;
data = (struct helper_data *)transport->data;
transport_take_over(transport, data->helper);
fclose(data->out);
free(data);
}
static struct child_process *get_helper(struct transport *transport)
{
struct helper_data *data = transport->data;
struct strbuf buf = STRBUF_INIT;
struct child_process *helper;
const char **refspecs = NULL;
int refspec_nr = 0;
int refspec_alloc = 0;
int duped;
int code;
if (data->helper)
return data->helper;
helper = xcalloc(1, sizeof(*helper));
helper->in = -1;
helper->out = -1;
helper->err = 0;
helper->argv = xcalloc(4, sizeof(*helper->argv));
strbuf_addf(&buf, "git-remote-%s", data->name);
helper->argv[0] = strbuf_detach(&buf, NULL);
helper->argv[1] = transport->remote->name;
helper->argv[2] = remove_ext_force(transport->url);
helper->git_cmd = 0;
helper->silent_exec_failure = 1;
code = start_command(helper);
if (code < 0 && errno == ENOENT)
die("Unable to find remote helper for '%s'", data->name);
else if (code != 0)
exit(code);
data->helper = helper;
data->no_disconnect_req = 0;
/*
* Open the output as FILE* so strbuf_getline() can be used.
* Do this with duped fd because fclose() will close the fd,
* and stuff like taking over will require the fd to remain.
*/
duped = dup(helper->out);
if (duped < 0)
die_errno("Can't dup helper output fd");
data->out = xfdopen(duped, "r");
write_constant(helper->in, "capabilities\n");
while (1) {
const char *capname;
int mandatory = 0;
recvline(data, &buf);
if (!*buf.buf)
break;
if (*buf.buf == '*') {
capname = buf.buf + 1;
mandatory = 1;
} else
capname = buf.buf;
if (debug)
fprintf(stderr, "Debug: Got cap %s\n", capname);
if (!strcmp(capname, "fetch"))
data->fetch = 1;
else if (!strcmp(capname, "option"))
data->option = 1;
else if (!strcmp(capname, "push"))
data->push = 1;
else if (!strcmp(capname, "import"))
data->import = 1;
else if (!strcmp(capname, "export"))
data->export = 1;
else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
ALLOC_GROW(refspecs,
refspec_nr + 1,
refspec_alloc);
refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
} else if (!strcmp(capname, "connect")) {
data->connect = 1;
} else if (!strcmp(buf.buf, "gitdir")) {
struct strbuf gitdir = STRBUF_INIT;
strbuf_addf(&gitdir, "gitdir %s\n", get_git_dir());
sendline(data, &gitdir);
strbuf_release(&gitdir);
} else if (mandatory) {
die("Unknown mandatory capability %s. This remote "
"helper probably needs newer version of Git.\n",
capname);
}
}
if (refspecs) {
int i;
data->refspec_nr = refspec_nr;
data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
for (i = 0; i < refspec_nr; i++) {
free((char *)refspecs[i]);
}
free(refspecs);
}
strbuf_release(&buf);
if (debug)
fprintf(stderr, "Debug: Capabilities complete.\n");
return data->helper;
}
static int disconnect_helper(struct transport *transport)
{
struct helper_data *data = transport->data;
struct strbuf buf = STRBUF_INIT;
if (data->helper) {
if (debug)
fprintf(stderr, "Debug: Disconnecting.\n");
if (!data->no_disconnect_req) {
strbuf_addf(&buf, "\n");
sendline(data, &buf);
}
close(data->helper->in);
close(data->helper->out);
fclose(data->out);
finish_command(data->helper);
free((char *)data->helper->argv[0]);
free(data->helper->argv);
free(data->helper);
data->helper = NULL;
}
return 0;
}
static const char *unsupported_options[] = {
TRANS_OPT_UPLOADPACK,
TRANS_OPT_RECEIVEPACK,
TRANS_OPT_THIN,
TRANS_OPT_KEEP
};
static const char *boolean_options[] = {
TRANS_OPT_THIN,
TRANS_OPT_KEEP,
TRANS_OPT_FOLLOWTAGS
};
static int set_helper_option(struct transport *transport,
const char *name, const char *value)
{
struct helper_data *data = transport->data;
struct strbuf buf = STRBUF_INIT;
int i, ret, is_bool = 0;
get_helper(transport);
if (!data->option)
return 1;
for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
if (!strcmp(name, unsupported_options[i]))
return 1;
}
for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
if (!strcmp(name, boolean_options[i])) {
is_bool = 1;
break;
}
}
strbuf_addf(&buf, "option %s ", name);
if (is_bool)
strbuf_addstr(&buf, value ? "true" : "false");
else
quote_c_style(value, &buf, NULL, 0);
strbuf_addch(&buf, '\n');
xchgline(data, &buf);
if (!strcmp(buf.buf, "ok"))
ret = 0;
else if (!prefixcmp(buf.buf, "error")) {
ret = -1;
} else if (!strcmp(buf.buf, "unsupported"))
ret = 1;
else {
warning("%s unexpectedly said: '%s'", data->name, buf.buf);
ret = 1;
}
strbuf_release(&buf);
return ret;
}
static void standard_options(struct transport *t)
{
char buf[16];
int n;
int v = t->verbose;
set_helper_option(t, "progress", t->progress ? "true" : "false");
n = snprintf(buf, sizeof(buf), "%d", v + 1);
if (n >= sizeof(buf))
die("impossibly large verbosity value");
set_helper_option(t, "verbosity", buf);
}
static int release_helper(struct transport *transport)
{
struct helper_data *data = transport->data;
free_refspec(data->refspec_nr, data->refspecs);
data->refspecs = NULL;
disconnect_helper(transport);
free(transport->data);
return 0;
}
static int fetch_with_fetch(struct transport *transport,
int nr_heads, struct ref **to_fetch)
{
struct helper_data *data = transport->data;
int i;
struct strbuf buf = STRBUF_INIT;
standard_options(transport);
for (i = 0; i < nr_heads; i++) {
const struct ref *posn = to_fetch[i];
if (posn->status & REF_STATUS_UPTODATE)
continue;
strbuf_addf(&buf, "fetch %s %s\n",
sha1_to_hex(posn->old_sha1), posn->name);
}
strbuf_addch(&buf, '\n');
sendline(data, &buf);
while (1) {
recvline(data, &buf);
if (!prefixcmp(buf.buf, "lock ")) {
const char *name = buf.buf + 5;
if (transport->pack_lockfile)
warning("%s also locked %s", data->name, name);
else
transport->pack_lockfile = xstrdup(name);
}
else if (!buf.len)
break;
else
warning("%s unexpectedly said: '%s'", data->name, buf.buf);
}
strbuf_release(&buf);
return 0;
}
static int get_importer(struct transport *transport, struct child_process *fastimport)
{
struct child_process *helper = get_helper(transport);
memset(fastimport, 0, sizeof(*fastimport));
fastimport->in = helper->out;
fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
fastimport->argv[0] = "fast-import";
fastimport->argv[1] = "--quiet";
fastimport->git_cmd = 1;
return start_command(fastimport);
}
static int get_exporter(struct transport *transport,
struct child_process *fastexport,
const char *export_marks,
const char *import_marks,
struct string_list *revlist_args)
{
struct child_process *helper = get_helper(transport);
int argc = 0, i;
memset(fastexport, 0, sizeof(*fastexport));
/* we need to duplicate helper->in because we want to use it after
* fastexport is done with it. */
fastexport->out = dup(helper->in);
fastexport->argv = xcalloc(4 + revlist_args->nr, sizeof(*fastexport->argv));
fastexport->argv[argc++] = "fast-export";
if (export_marks)
fastexport->argv[argc++] = export_marks;
if (import_marks)
fastexport->argv[argc++] = import_marks;
for (i = 0; i < revlist_args->nr; i++)
fastexport->argv[argc++] = revlist_args->items[i].string;
fastexport->git_cmd = 1;
return start_command(fastexport);
}
static int fetch_with_import(struct transport *transport,
int nr_heads, struct ref **to_fetch)
{
struct child_process fastimport;
struct helper_data *data = transport->data;
int i;
struct ref *posn;
struct strbuf buf = STRBUF_INIT;
get_helper(transport);
if (get_importer(transport, &fastimport))
die("Couldn't run fast-import");
for (i = 0; i < nr_heads; i++) {
posn = to_fetch[i];
if (posn->status & REF_STATUS_UPTODATE)
continue;
strbuf_addf(&buf, "import %s\n", posn->name);
sendline(data, &buf);
strbuf_reset(&buf);
}
disconnect_helper(transport);
finish_command(&fastimport);
free(fastimport.argv);
fastimport.argv = NULL;
for (i = 0; i < nr_heads; i++) {
char *private;
posn = to_fetch[i];
if (posn->status & REF_STATUS_UPTODATE)
continue;
if (data->refspecs)
private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
else
private = strdup(posn->name);
read_ref(private, posn->old_sha1);
free(private);
}
strbuf_release(&buf);
return 0;
}
static int process_connect_service(struct transport *transport,
const char *name, const char *exec)
{
struct helper_data *data = transport->data;
struct strbuf cmdbuf = STRBUF_INIT;
struct child_process *helper;
int r, duped, ret = 0;
FILE *input;
helper = get_helper(transport);
/*
* Yes, dup the pipe another time, as we need unbuffered version
* of input pipe as FILE*. fclose() closes the underlying fd and
* stream buffering only can be changed before first I/O operation
* on it.
*/
duped = dup(helper->out);
if (duped < 0)
die_errno("Can't dup helper output fd");
input = xfdopen(duped, "r");
setvbuf(input, NULL, _IONBF, 0);
/*
* Handle --upload-pack and friends. This is fire and forget...
* just warn if it fails.
*/
if (strcmp(name, exec)) {
r = set_helper_option(transport, "servpath", exec);
if (r > 0)
warning("Setting remote service path not supported by protocol.");
else if (r < 0)
warning("Invalid remote service path.");
}
if (data->connect)
strbuf_addf(&cmdbuf, "connect %s\n", name);
else
goto exit;
sendline(data, &cmdbuf);
recvline_fh(input, &cmdbuf);
if (!strcmp(cmdbuf.buf, "")) {
data->no_disconnect_req = 1;
if (debug)
fprintf(stderr, "Debug: Smart transport connection "
"ready.\n");
ret = 1;
} else if (!strcmp(cmdbuf.buf, "fallback")) {
if (debug)
fprintf(stderr, "Debug: Falling back to dumb "
"transport.\n");
} else
die("Unknown response to connect: %s",
cmdbuf.buf);
exit:
fclose(input);
return ret;
}
static int process_connect(struct transport *transport,
int for_push)
{
struct helper_data *data = transport->data;
const char *name;
const char *exec;
name = for_push ? "git-receive-pack" : "git-upload-pack";
if (for_push)
exec = data->transport_options.receivepack;
else
exec = data->transport_options.uploadpack;
return process_connect_service(transport, name, exec);
}
static int connect_helper(struct transport *transport, const char *name,
const char *exec, int fd[2])
{
struct helper_data *data = transport->data;
/* Get_helper so connect is inited. */
get_helper(transport);
if (!data->connect)
die("Operation not supported by protocol.");
if (!process_connect_service(transport, name, exec))
die("Can't connect to subservice %s.", name);
fd[0] = data->helper->out;
fd[1] = data->helper->in;
return 0;
}
static int fetch(struct transport *transport,
int nr_heads, struct ref **to_fetch)
{
struct helper_data *data = transport->data;
int i, count;
if (process_connect(transport, 0)) {
do_take_over(transport);
return transport->fetch(transport, nr_heads, to_fetch);
}
count = 0;
for (i = 0; i < nr_heads; i++)
if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
count++;
if (!count)
return 0;
if (data->fetch)
return fetch_with_fetch(transport, nr_heads, to_fetch);
if (data->import)
return fetch_with_import(transport, nr_heads, to_fetch);
return -1;
}
static int push_refs_with_push(struct transport *transport,
struct ref *remote_refs, int flags)
{
int force_all = flags & TRANSPORT_PUSH_FORCE;
int mirror = flags & TRANSPORT_PUSH_MIRROR;
struct helper_data *data = transport->data;
struct strbuf buf = STRBUF_INIT;
struct child_process *helper;
struct ref *ref;
helper = get_helper(transport);
if (!data->push)
return 1;
for (ref = remote_refs; ref; ref = ref->next) {
if (!ref->peer_ref && !mirror)
continue;
/* Check for statuses set by set_ref_status_for_push() */
switch (ref->status) {
case REF_STATUS_REJECT_NONFASTFORWARD:
case REF_STATUS_UPTODATE:
continue;
default:
; /* do nothing */
}
if (force_all)
ref->force = 1;
strbuf_addstr(&buf, "push ");
if (!ref->deletion) {
if (ref->force)
strbuf_addch(&buf, '+');
if (ref->peer_ref)
strbuf_addstr(&buf, ref->peer_ref->name);
else
strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
}
strbuf_addch(&buf, ':');
strbuf_addstr(&buf, ref->name);
strbuf_addch(&buf, '\n');
}
if (buf.len == 0)
return 0;
standard_options(transport);
if (flags & TRANSPORT_PUSH_DRY_RUN) {
if (set_helper_option(transport, "dry-run", "true") != 0)
die("helper %s does not support dry-run", data->name);
}
strbuf_addch(&buf, '\n');
sendline(data, &buf);
ref = remote_refs;
while (1) {
char *refname, *msg;
int status;
recvline(data, &buf);
if (!buf.len)
break;
if (!prefixcmp(buf.buf, "ok ")) {
status = REF_STATUS_OK;
refname = buf.buf + 3;
} else if (!prefixcmp(buf.buf, "error ")) {
status = REF_STATUS_REMOTE_REJECT;
refname = buf.buf + 6;
} else
die("expected ok/error, helper said '%s'\n", buf.buf);
msg = strchr(refname, ' ');
if (msg) {
struct strbuf msg_buf = STRBUF_INIT;
const char *end;
*msg++ = '\0';
if (!unquote_c_style(&msg_buf, msg, &end))
msg = strbuf_detach(&msg_buf, NULL);
else
msg = xstrdup(msg);
strbuf_release(&msg_buf);
if (!strcmp(msg, "no match")) {
status = REF_STATUS_NONE;
free(msg);
msg = NULL;
}
else if (!strcmp(msg, "up to date")) {
status = REF_STATUS_UPTODATE;
free(msg);
msg = NULL;
}
else if (!strcmp(msg, "non-fast forward")) {
status = REF_STATUS_REJECT_NONFASTFORWARD;
free(msg);
msg = NULL;
}
}
if (ref)
ref = find_ref_by_name(ref, refname);
if (!ref)
ref = find_ref_by_name(remote_refs, refname);
if (!ref) {
warning("helper reported unexpected status of %s", refname);
continue;
}
if (ref->status != REF_STATUS_NONE) {
/*
* Earlier, the ref was marked not to be pushed, so ignore the ref
* status reported by the remote helper if the latter is 'no match'.
*/
if (status == REF_STATUS_NONE)
continue;
}
ref->status = status;
ref->remote_status = msg;
}
strbuf_release(&buf);
return 0;
}
static int push_refs_with_export(struct transport *transport,
struct ref *remote_refs, int flags)
{
struct ref *ref;
struct child_process *helper, exporter;
struct helper_data *data = transport->data;
char *export_marks = NULL, *import_marks = NULL;
struct string_list revlist_args = STRING_LIST_INIT_NODUP;
struct strbuf buf = STRBUF_INIT;
helper = get_helper(transport);
write_constant(helper->in, "export\n");
recvline(data, &buf);
if (debug)
fprintf(stderr, "Debug: Got export_marks '%s'\n", buf.buf);
if (buf.len) {
struct strbuf arg = STRBUF_INIT;
strbuf_addstr(&arg, "--export-marks=");
strbuf_addbuf(&arg, &buf);
export_marks = strbuf_detach(&arg, NULL);
}
recvline(data, &buf);
if (debug)
fprintf(stderr, "Debug: Got import_marks '%s'\n", buf.buf);
if (buf.len) {
struct strbuf arg = STRBUF_INIT;
strbuf_addstr(&arg, "--import-marks=");
strbuf_addbuf(&arg, &buf);
import_marks = strbuf_detach(&arg, NULL);
}
strbuf_reset(&buf);
for (ref = remote_refs; ref; ref = ref->next) {
char *private;
unsigned char sha1[20];
if (!data->refspecs)
continue;
private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
if (private && !get_sha1(private, sha1)) {
strbuf_addf(&buf, "^%s", private);
string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
}
string_list_append(&revlist_args, ref->name);
}
if (get_exporter(transport, &exporter,
export_marks, import_marks, &revlist_args))
die("Couldn't run fast-export");
data->no_disconnect_req = 1;
finish_command(&exporter);
disconnect_helper(transport);
return 0;
}
static int push_refs(struct transport *transport,
struct ref *remote_refs, int flags)
{
struct helper_data *data = transport->data;
if (process_connect(transport, 1)) {
do_take_over(transport);
return transport->push_refs(transport, remote_refs, flags);
}
if (!remote_refs) {
fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
"Perhaps you should specify a branch such as 'master'.\n");
return 0;
}
if (data->push)
return push_refs_with_push(transport, remote_refs, flags);
if (data->export)
return push_refs_with_export(transport, remote_refs, flags);
return -1;
}
static int has_attribute(const char *attrs, const char *attr) {
int len;
if (!attrs)
return 0;
len = strlen(attr);
for (;;) {
const char *space = strchrnul(attrs, ' ');
if (len == space - attrs && !strncmp(attrs, attr, len))
return 1;
if (!*space)
return 0;
attrs = space + 1;
}
}
static struct ref *get_refs_list(struct transport *transport, int for_push)
{
struct helper_data *data = transport->data;
struct child_process *helper;
struct ref *ret = NULL;
struct ref **tail = &ret;
struct ref *posn;
struct strbuf buf = STRBUF_INIT;
helper = get_helper(transport);
if (process_connect(transport, for_push)) {
do_take_over(transport);
return transport->get_refs_list(transport, for_push);
}
if (data->push && for_push)
write_str_in_full(helper->in, "list for-push\n");
else
write_str_in_full(helper->in, "list\n");
while (1) {
char *eov, *eon;
recvline(data, &buf);
if (!*buf.buf)
break;
eov = strchr(buf.buf, ' ');
if (!eov)
die("Malformed response in ref list: %s", buf.buf);
eon = strchr(eov + 1, ' ');
*eov = '\0';
if (eon)
*eon = '\0';
*tail = alloc_ref(eov + 1);
if (buf.buf[0] == '@')
(*tail)->symref = xstrdup(buf.buf + 1);
else if (buf.buf[0] != '?')
get_sha1_hex(buf.buf, (*tail)->old_sha1);
if (eon) {
if (has_attribute(eon + 1, "unchanged")) {
(*tail)->status |= REF_STATUS_UPTODATE;
read_ref((*tail)->name, (*tail)->old_sha1);
}
}
tail = &((*tail)->next);
}
if (debug)
fprintf(stderr, "Debug: Read ref listing.\n");
strbuf_release(&buf);
for (posn = ret; posn; posn = posn->next)
resolve_remote_symref(posn, ret);
return ret;
}
int transport_helper_init(struct transport *transport, const char *name)
{
struct helper_data *data = xcalloc(sizeof(*data), 1);
data->name = name;
if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
debug = 1;
transport->data = data;
transport->set_option = set_helper_option;
transport->get_refs_list = get_refs_list;
transport->fetch = fetch;
transport->push_refs = push_refs;
transport->disconnect = release_helper;
transport->connect = connect_helper;
transport->smart_options = &(data->transport_options);
return 0;
}
/*
* Linux pipes can buffer 65536 bytes at once (and most platforms can
* buffer less), so attempt reads and writes with up to that size.
*/
#define BUFFERSIZE 65536
/* This should be enough to hold debugging message. */
#define PBUFFERSIZE 8192
/* Print bidirectional transfer loop debug message. */
static void transfer_debug(const char *fmt, ...)
{
va_list args;
char msgbuf[PBUFFERSIZE];
static int debug_enabled = -1;
if (debug_enabled < 0)
debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
if (!debug_enabled)
return;
va_start(args, fmt);
vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
va_end(args);
fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
}
/* Stream state: More data may be coming in this direction. */
#define SSTATE_TRANSFERING 0
/*
* Stream state: No more data coming in this direction, flushing rest of
* data.
*/
#define SSTATE_FLUSHING 1
/* Stream state: Transfer in this direction finished. */
#define SSTATE_FINISHED 2
#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
/* Unidirectional transfer. */
struct unidirectional_transfer {
/* Source */
int src;
/* Destination */
int dest;
/* Is source socket? */
int src_is_sock;
/* Is destination socket? */
int dest_is_sock;
/* Transfer state (TRANSFERING/FLUSHING/FINISHED) */
int state;
/* Buffer. */
char buf[BUFFERSIZE];
/* Buffer used. */
size_t bufuse;
/* Name of source. */
const char *src_name;
/* Name of destination. */
const char *dest_name;
};
/* Closes the target (for writing) if transfer has finished. */
static void udt_close_if_finished(struct unidirectional_transfer *t)
{
if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
t->state = SSTATE_FINISHED;
if (t->dest_is_sock)
shutdown(t->dest, SHUT_WR);
else
close(t->dest);
transfer_debug("Closed %s.", t->dest_name);
}
}
/*
* Tries to read read data from source into buffer. If buffer is full,
* no data is read. Returns 0 on success, -1 on error.
*/
static int udt_do_read(struct unidirectional_transfer *t)
{
ssize_t bytes;
if (t->bufuse == BUFFERSIZE)
return 0; /* No space for more. */
transfer_debug("%s is readable", t->src_name);
bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
errno != EINTR) {
error("read(%s) failed: %s", t->src_name, strerror(errno));
return -1;
} else if (bytes == 0) {
transfer_debug("%s EOF (with %i bytes in buffer)",
t->src_name, t->bufuse);
t->state = SSTATE_FLUSHING;
} else if (bytes > 0) {
t->bufuse += bytes;
transfer_debug("Read %i bytes from %s (buffer now at %i)",
(int)bytes, t->src_name, (int)t->bufuse);
}
return 0;
}
/* Tries to write data from buffer into destination. If buffer is empty,
* no data is written. Returns 0 on success, -1 on error.
*/
static int udt_do_write(struct unidirectional_transfer *t)
{
size_t bytes;
if (t->bufuse == 0)
return 0; /* Nothing to write. */
transfer_debug("%s is writable", t->dest_name);
bytes = write(t->dest, t->buf, t->bufuse);
if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
errno != EINTR) {
error("write(%s) failed: %s", t->dest_name, strerror(errno));
return -1;
} else if (bytes > 0) {
t->bufuse -= bytes;
if (t->bufuse)
memmove(t->buf, t->buf + bytes, t->bufuse);
transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
(int)bytes, t->dest_name, (int)t->bufuse);
}
return 0;
}
/* State of bidirectional transfer loop. */
struct bidirectional_transfer_state {
/* Direction from program to git. */
struct unidirectional_transfer ptg;
/* Direction from git to program. */
struct unidirectional_transfer gtp;
};
static void *udt_copy_task_routine(void *udt)
{
struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
while (t->state != SSTATE_FINISHED) {
if (STATE_NEEDS_READING(t->state))
if (udt_do_read(t))
return NULL;
if (STATE_NEEDS_WRITING(t->state))
if (udt_do_write(t))
return NULL;
if (STATE_NEEDS_CLOSING(t->state))
udt_close_if_finished(t);
}
return udt; /* Just some non-NULL value. */
}
#ifndef NO_PTHREADS
/*
* Join thread, with apporiate errors on failure. Name is name for the
* thread (for error messages). Returns 0 on success, 1 on failure.
*/
static int tloop_join(pthread_t thread, const char *name)
{
int err;
void *tret;
err = pthread_join(thread, &tret);
if (!tret) {
error("%s thread failed", name);
return 1;
}
if (err) {
error("%s thread failed to join: %s", name, strerror(err));
return 1;
}
return 0;
}
/*
* Spawn the transfer tasks and then wait for them. Returns 0 on success,
* -1 on failure.
*/
static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
{
pthread_t gtp_thread;
pthread_t ptg_thread;
int err;
int ret = 0;
err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
&s->gtp);
if (err)
die("Can't start thread for copying data: %s", strerror(err));
err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
&s->ptg);
if (err)
die("Can't start thread for copying data: %s", strerror(err));
ret |= tloop_join(gtp_thread, "Git to program copy");
ret |= tloop_join(ptg_thread, "Program to git copy");
return ret;
}
#else
/* Close the source and target (for writing) for transfer. */
static void udt_kill_transfer(struct unidirectional_transfer *t)
{
t->state = SSTATE_FINISHED;
/*
* Socket read end left open isn't a disaster if nobody
* attempts to read from it (mingw compat headers do not
* have SHUT_RD)...
*
* We can't fully close the socket since otherwise gtp
* task would first close the socket it sends data to
* while closing the ptg file descriptors.
*/
if (!t->src_is_sock)
close(t->src);
if (t->dest_is_sock)
shutdown(t->dest, SHUT_WR);
else
close(t->dest);
}
/*
* Join process, with apporiate errors on failure. Name is name for the
* process (for error messages). Returns 0 on success, 1 on failure.
*/
static int tloop_join(pid_t pid, const char *name)
{
int tret;
if (waitpid(pid, &tret, 0) < 0) {
error("%s process failed to wait: %s", name, strerror(errno));
return 1;
}
if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
error("%s process failed", name);
return 1;
}
return 0;
}
/*
* Spawn the transfer tasks and then wait for them. Returns 0 on success,
* -1 on failure.
*/
static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
{
pid_t pid1, pid2;
int ret = 0;
/* Fork thread #1: git to program. */
pid1 = fork();
if (pid1 < 0)
die_errno("Can't start thread for copying data");
else if (pid1 == 0) {
udt_kill_transfer(&s->ptg);
exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
}
/* Fork thread #2: program to git. */
pid2 = fork();
if (pid2 < 0)
die_errno("Can't start thread for copying data");
else if (pid2 == 0) {
udt_kill_transfer(&s->gtp);
exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
}
/*
* Close both streams in parent as to not interfere with
* end of file detection and wait for both tasks to finish.
*/
udt_kill_transfer(&s->gtp);
udt_kill_transfer(&s->ptg);
ret |= tloop_join(pid1, "Git to program copy");
ret |= tloop_join(pid2, "Program to git copy");
return ret;
}
#endif
/*
* Copies data from stdin to output and from input to stdout simultaneously.
* Additionally filtering through given filter. If filter is NULL, uses
* identity filter.
*/
int bidirectional_transfer_loop(int input, int output)
{
struct bidirectional_transfer_state state;
/* Fill the state fields. */
state.ptg.src = input;
state.ptg.dest = 1;
state.ptg.src_is_sock = (input == output);
state.ptg.dest_is_sock = 0;
state.ptg.state = SSTATE_TRANSFERING;
state.ptg.bufuse = 0;
state.ptg.src_name = "remote input";
state.ptg.dest_name = "stdout";
state.gtp.src = 0;
state.gtp.dest = output;
state.gtp.src_is_sock = 0;
state.gtp.dest_is_sock = (input == output);
state.gtp.state = SSTATE_TRANSFERING;
state.gtp.bufuse = 0;
state.gtp.src_name = "stdin";
state.gtp.dest_name = "remote output";
return tloop_spawnwait_tasks(&state);
}