From fa8c097cc9b416283ae4c1c1507909ff207b7f60 Mon Sep 17 00:00:00 2001 From: Ilari Liusvaara Date: Wed, 9 Dec 2009 17:26:32 +0200 Subject: [PATCH] Support remote helpers implementing smart transports Signed-off-by: Ilari Liusvaara Signed-off-by: Junio C Hamano --- Documentation/git-remote-helpers.txt | 25 +++++- transport-helper.c | 124 +++++++++++++++++++++++++-- 2 files changed, 142 insertions(+), 7 deletions(-) diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt index 20a05fe9d..4685a898f 100644 --- a/Documentation/git-remote-helpers.txt +++ b/Documentation/git-remote-helpers.txt @@ -93,6 +93,20 @@ Supported if the helper has the "push" capability. + Supported if the helper has the "import" capability. +'connect' :: + Connects to given service. Standard input and standard output + of helper are connected to specified service (git prefix is + included in service name so e.g. fetching uses 'git-upload-pack' + as service) on remote side. Valid replies to this command are + empty line (connection established), 'fallback' (no smart + transport support, fall back to dumb transports) and just + exiting with error message printed (can't connect, don't + bother trying to fall back). After line feed terminating the + positive (empty) response, the output of service starts. After + the connection ends, the remote helper exits. ++ +Supported if the helper has the "connect" 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 @@ -126,6 +140,9 @@ CAPABILITIES all, it must cover all refs reported by the list command; if it is not used, it is effectively "*:*" +'connect':: + This helper supports the 'connect' command. + REF LIST ATTRIBUTES ------------------- @@ -168,9 +185,15 @@ OPTIONS but don't actually change any repository data. For most helpers this only applies to the 'push', if supported. +'option servpath ':: + Set service path (--upload-pack, --receive-pack etc.) for + next connect. Remote helper MAY support this option. Remote + helper MUST NOT rely on this option being set before + connect request occurs. + Documentation ------------- -Documentation by Daniel Barkalow. +Documentation by Daniel Barkalow and Ilari Liusvaara GIT --- diff --git a/transport-helper.c b/transport-helper.c index 97eed6cbf..50b3bac0c 100644 --- a/transport-helper.c +++ b/transport-helper.c @@ -18,7 +18,9 @@ struct helper_data unsigned fetch : 1, import : 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; @@ -37,12 +39,12 @@ static void sendline(struct helper_data *helper, struct strbuf *buffer) die_errno("Full write to remote helper failed"); } -static int recvline(struct helper_data *helper, struct strbuf *buffer) +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->out, '\n') == EOF) { + if (strbuf_getline(buffer, helper, '\n') == EOF) { if (debug) fprintf(stderr, "Debug: Remote helper quit.\n"); exit(128); @@ -53,6 +55,11 @@ static int recvline(struct helper_data *helper, struct strbuf *buffer) 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); @@ -77,6 +84,15 @@ const char *remove_ext_force(const char *url) 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; @@ -103,12 +119,12 @@ static struct child_process *get_helper(struct transport *transport) if (start_command(helper)) die("Unable to run helper: git %s", helper->argv[0]); 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) @@ -146,6 +162,8 @@ static struct child_process *get_helper(struct transport *transport) refspec_nr + 1, refspec_alloc); refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec ")); + } else if (!strcmp(capname, "connect")) { + data->connect = 1; } else if (mandatory) { die("Unknown madatory capability %s. This remote " "helper probably needs newer version of Git.\n", @@ -175,8 +193,10 @@ static int disconnect_helper(struct transport *transport) if (data->helper) { if (debug) fprintf(stderr, "Debug: Disconnecting.\n"); - strbuf_addf(&buf, "\n"); - sendline(data, &buf); + if (!data->no_disconnect_req) { + strbuf_addf(&buf, "\n"); + sendline(data, &buf); + } close(data->helper->in); close(data->helper->out); fclose(data->out); @@ -370,12 +390,94 @@ static int fetch_with_import(struct transport *transport, 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 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)) @@ -403,6 +505,11 @@ static int push_refs(struct transport *transport, struct child_process *helper; struct ref *ref; + if (process_connect(transport, 1)) { + do_take_over(transport); + return transport->push_refs(transport, remote_refs, flags); + } + if (!remote_refs) return 0; @@ -543,6 +650,11 @@ static struct ref *get_refs_list(struct transport *transport, int for_push) 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 -- 2.26.2