#include "diff.h"
#include "revision.h"
#include "quote.h"
+#include "remote.h"
+#include "string-list.h"
+#include "thread-utils.h"
-struct helper_data
-{
+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;
+ 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");
+}
+
+static 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->out = -1;
helper->err = 0;
helper->argv = xcalloc(4, sizeof(*helper->argv));
- strbuf_addf(&buf, "remote-%s", data->name);
+ strbuf_addf(&buf, "git-remote-%s", data->name);
helper->argv[0] = strbuf_detach(&buf, NULL);
helper->argv[1] = transport->remote->name;
- helper->argv[2] = transport->url;
- helper->git_cmd = 1;
- if (start_command(helper))
- die("Unable to run helper: git %s", helper->argv[0]);
+ 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_str_in_full(helper->in, "capabilities\n");
+ write_constant(helper->in, "capabilities\n");
- data->out = xfdopen(helper->out, "r");
while (1) {
- if (strbuf_getline(&buf, data->out, '\n') == EOF)
- exit(128); /* child died, message supplied already */
+ const char *capname;
+ int mandatory = 0;
+ recvline(data, &buf);
if (!*buf.buf)
break;
- if (!strcmp(buf.buf, "fetch"))
+
+ 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;
- if (!strcmp(buf.buf, "option"))
+ else if (!strcmp(capname, "option"))
data->option = 1;
- if (!strcmp(buf.buf, "push"))
+ 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) {
- write_str_in_full(data->helper->in, "\n");
+ 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);
data->helper = NULL;
}
- free(data);
return 0;
}
const char *name, const char *value)
{
struct helper_data *data = transport->data;
- struct child_process *helper = get_helper(transport);
struct strbuf buf = STRBUF_INIT;
int i, ret, is_bool = 0;
+ get_helper(transport);
+
if (!data->option)
return 1;
quote_c_style(value, &buf, NULL, 0);
strbuf_addch(&buf, '\n');
- if (write_in_full(helper->in, buf.buf, buf.len) != buf.len)
- die_errno("cannot send option to %s", data->name);
-
- strbuf_reset(&buf);
- if (strbuf_getline(&buf, data->out, '\n') == EOF)
- exit(128); /* child died, message supplied already */
+ xchgline(data, &buf);
if (!strcmp(buf.buf, "ok"))
ret = 0;
char buf[16];
int n;
int v = t->verbose;
- int no_progress = v < 0 || (!t->progress && !isatty(1));
- set_helper_option(t, "progress", !no_progress ? "true" : "false");
+ set_helper_option(t, "progress", t->progress ? "true" : "false");
n = snprintf(buf, sizeof(buf), "%d", v + 1);
if (n >= sizeof(buf))
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, const struct ref **to_fetch)
+ int nr_heads, struct ref **to_fetch)
{
struct helper_data *data = transport->data;
int i;
}
strbuf_addch(&buf, '\n');
- if (write_in_full(data->helper->in, buf.buf, buf.len) != buf.len)
- die_errno("cannot send fetch to %s", data->name);
+ sendline(data, &buf);
while (1) {
- strbuf_reset(&buf);
- if (strbuf_getline(&buf, data->out, '\n') == EOF)
- exit(128); /* child died, message supplied already */
+ recvline(data, &buf);
if (!prefixcmp(buf.buf, "lock ")) {
const char *name = buf.buf + 5;
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, const struct ref **to_fetch)
+ 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))
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(struct transport *transport,
+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;
- if (!remote_refs)
- return 0;
-
- helper = get_helper(transport);
+ get_helper(transport);
if (!data->push)
return 1;
for (ref = remote_refs; ref; ref = ref->next) {
- if (ref->peer_ref)
- hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
- else if (!mirror)
+ if (!ref->peer_ref && !mirror)
continue;
- ref->deletion = is_null_sha1(ref->new_sha1);
- if (!ref->deletion &&
- !hashcmp(ref->old_sha1, ref->new_sha1)) {
- ref->status = REF_STATUS_UPTODATE;
+ /* 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)
if (buf.len == 0)
return 0;
- transport->verbose = flags & TRANSPORT_PUSH_VERBOSE ? 1 : 0;
standard_options(transport);
if (flags & TRANSPORT_PUSH_DRY_RUN) {
}
strbuf_addch(&buf, '\n');
- if (write_in_full(helper->in, buf.buf, buf.len) != buf.len)
- exit(128);
+ sendline(data, &buf);
ref = remote_refs;
while (1) {
char *refname, *msg;
int status;
- strbuf_reset(&buf);
- if (strbuf_getline(&buf, data->out, '\n') == EOF)
- exit(128); /* child died, message supplied already */
+ recvline(data, &buf);
if (!buf.len)
break;
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;
}
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;
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
while (1) {
char *eov, *eon;
- if (strbuf_getline(&buf, data->out, '\n') == EOF)
- exit(128); /* child died, message supplied already */
+ recvline(data, &buf);
if (!*buf.buf)
break;
(*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)
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 = disconnect_helper;
+ 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)
+{
+ ssize_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(>p_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);
+}