Daniel Barkalowtransport_get() can call transport_native_helper_init() to have list and fetch-ref operations handled by running a separate program as:
git remote-<something> <remote> [<url>]
This program then accepts, on its stdin, "list" and "fetch <hex> <name>" commands; the former prints out a list of available refs and either their hashes or what they are symreefs to, while the latter fetches them into the local object database and prints a newline when done.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org> --- dscho: it turned out that disconnect...() is a method defined to return int.
Documentation/git-remote-helpers.txt | 72 +++++++++++++++ Makefile | 1 + transport-helper.c | 168 ++++++++++++++++++++++++++++++++++ transport.h | 3 + 4 files changed, 244 insertions(+), 0 deletions(-) create mode 100644 Documentation/git-remote-helpers.txt create mode 100644 transport-helper.c
Show changes to 4 files +244 −0
Documentation/git-remote-helpers.txt, Makefile, transport-helper.c, transport.h
diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt new file mode 100644 index 0000000..86a9c3f --- /dev/null +++ b/Documentation/git-remote-helpers.txt @@ -0,0 +1,72 @@ +git-remote-helpers(1) +===================== + +NAME +---- +git-remote-helpers - Helper programs for interoperation with remote git + +SYNOPSIS +-------- +'git remote-<transport>' <remote> + +DESCRIPTION +----------- + +These programs are normally not used directly by end users, but are +invoked by various git programs that interact with remote repositories +when the repository they would operate on will be accessed using +transport code not linked into the main git binary. Various particular +helper programs will behave as documented here. + +COMMANDS +-------- + +Commands are given by the caller on the helper's standard input, one per line. + +'capabilities':: + Lists the capabilities of the helper, one per line, ending + with a blank line. + +'list':: + Lists the refs, one per line, in the format "<value> <name> + [<attr> ...]". The value may be a hex sha1 hash, "@<dest>" for + a symref, or "?" to indicate that the helper could not get the + value of the ref. A space-separated list of attributes follows + the name; unrecognized attributes are ignored. After the + complete list, outputs a blank line. + +'fetch' <sha1> <name>:: + Fetches the given object, writing the necessary objects to the + database. Outputs a blank line when the fetch is + complete. Only objects which were reported in the ref list + with a sha1 may be fetched this way. ++ +Supported if the helper has the "fetch" capability. + +If a fatal error occurs, the program writes the error message to +stderr and exits. The caller should expect that a suitable error +message has been printed if the child closes the connection without +completing a valid response for the current command. + +Additional commands may be supported, as may be determined from +capabilities reported by the helper. + +CAPABILITIES +------------ + +'fetch':: + This helper supports the 'fetch' command, with the object + specified using a sha1 or ref name as specified. + +REF LIST ATTRIBUTES +------------------- + +None are defined yet, but the caller must accept any which are supplied. + +Documentation +------------- +Documentation by Daniel Barkalow. + +GIT +--- +Part of the linkgit:git[1] suite diff --git a/Makefile b/Makefile index daf4296..504646a 100644 --- a/Makefile +++ b/Makefile @@ -549,6 +549,7 @@ LIB_OBJS += symlinks.o LIB_OBJS += tag.o LIB_OBJS += trace.o LIB_OBJS += transport.o +LIB_OBJS += transport-helper.o LIB_OBJS += tree-diff.o LIB_OBJS += tree.o LIB_OBJS += tree-walk.o diff --git a/transport-helper.c b/transport-helper.c new file mode 100644 index 0000000..a879bc6 --- /dev/null +++ b/transport-helper.c @@ -0,0 +1,168 @@ +#include "cache.h" +#include "transport.h" + +#include "run-command.h" +#include "commit.h" +#include "diff.h" +#include "revision.h" + +struct helper_data +{ + const char *name; + struct child_process *helper; + unsigned fetch : 1; +}; + +static struct child_process *get_helper(struct transport *transport) +{ + struct helper_data *data = transport->data; + struct strbuf buf = STRBUF_INIT; + struct child_process *helper; + FILE *file; + + 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, "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]); + data->helper = helper; + + write_in_full(data->helper->in, "capabilities\n", 13); + file = xfdopen(helper->out, "r"); + while (1) { + if (strbuf_getline(&buf, file, '\n') == EOF) + exit(128); /* child died, message supplied already */ + + if (!*buf.buf) + break; + if (!strcmp(buf.buf, "fetch")) + data->fetch = 1; + } + return data->helper; +} + +static int disconnect_helper(struct transport *transport) +{ + struct helper_data *data = transport->data; + if (data->helper) { + write_in_full(data->helper->in, "\n", 1); + close(data->helper->in); + finish_command(data->helper); + free((char *)data->helper->argv[0]); + free(data->helper->argv); + free(data->helper); + data->helper = NULL; + } + return 0; +} + +static int fetch(struct transport *transport, + int nr_heads, const struct ref **to_fetch) +{ + struct helper_data *data = transport->data; + struct child_process *helper; + const struct ref *posn; + struct strbuf buf = STRBUF_INIT; + int i, count; + FILE *file; + + count = 0; + for (i = 0; i < nr_heads; i++) { + posn = to_fetch[i]; + if (posn->status & REF_STATUS_UPTODATE) + continue; + count++; + } + + if (!count) + return 0; + + helper = get_helper(transport); + + if (!data->fetch) + return -1; + + file = xfdopen(helper->out, "r"); + for (i = 0; i < nr_heads; i++) { + posn = to_fetch[i]; + if (posn->status & REF_STATUS_UPTODATE) + continue; + write_in_full(helper->in, "fetch ", 6); + write_in_full(helper->in, sha1_to_hex(posn->old_sha1), 40); + write_in_full(helper->in, " ", 1); + write_in_full(helper->in, posn->name, strlen(posn->name)); + write_in_full(helper->in, "\n", 1); + if (strbuf_getline(&buf, file, '\n') == EOF) + exit(128); /* child died, message supplied already */ + } + return 0; +} + +static struct ref *get_refs_list(struct transport *transport, int for_push) +{ + struct child_process *helper; + struct ref *ret = NULL; + struct ref **tail = &ret; + struct ref *posn; + struct strbuf buf = STRBUF_INIT; + FILE *file; + + helper = get_helper(transport); + write_in_full(helper->in, "list\n", 5); + + file = xfdopen(helper->out, "r"); + while (1) { + char *eov, *eon; + if (strbuf_getline(&buf, file, '\n') == EOF) + exit(128); /* child died, message supplied already */ + + 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); + tail = &((*tail)->next); + strbuf_reset(&buf); + } + strbuf_release(&buf); + + for (posn = ret; posn; posn = posn->next) + resolve_remote_symref(posn, ret); + + return ret; +} + +int transport_native_helper_init(struct transport *transport) +{ + struct helper_data *data = xmalloc(sizeof(*data)); + char *eom = strchr(transport->url, ':'); + if (!eom) + return -1; + data->helper = NULL; + data->name = xstrndup(transport->url, eom - transport->url); + transport->data = data; + transport->get_refs_list = get_refs_list; + transport->fetch = fetch; + transport->disconnect = disconnect_helper; + return 0; +} diff --git a/transport.h b/transport.h index 51b5397..fff9d8c 100644 --- a/transport.h +++ b/transport.h @@ -77,4 +77,7 @@ void transport_unlock_pack(struct transport *transport); int transport_disconnect(struct transport *transport); char *transport_anonymize_url(const char *url); +/* Transport methods defined outside transport.c */ +int transport_native_helper_init(struct transport *transport); + #endif
-- 1.6.4.rc3.25.gd5eff.dirty
