remote-helpers: Support custom transport options

Some transports, like the native pack transport implemented by
fetch-pack, support useful features like depth or include tags.
These should be exposed if the underlying helper knows how to
use them.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index e44d821c7b92bbb0d030060ae3ecdba45a830be9..1133f047bfaf85dd8ec1098d65bccbbf8cfcfee0 100644 (file)
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -35,6 +35,16 @@ Commands are given by the caller on the helper's standard input, one per line.
        the name; unrecognized attributes are ignored. After the
        complete list, outputs a blank line.
 
+'option' <name> <value>::
+       Set the transport helper option <name> to <value>.  Outputs a
+       single line containing one of 'ok' (option successfully set),
+       'unsupported' (option not recognized) or 'error <msg>'
+       (option <name> is supported but <value> is not correct
+       for it).  Options should be set before other commands,
+       and may how those commands behave.
++
+Supported if the helper has the "option" capability.
+
 'fetch' <sha1> <name>::
        Fetches the given object, writing the necessary objects
        to the database.  Fetch commands are sent in a batch, one
@@ -63,11 +73,39 @@ CAPABILITIES
 'fetch'::
        This helper supports the 'fetch' command.
 
+'option'::
+       This helper supports the option command.
+
 REF LIST ATTRIBUTES
 -------------------
 
 None are defined yet, but the caller must accept any which are supplied.
 
+OPTIONS
+-------
+'option verbosity' <N>::
+       Change the level of messages displayed by the helper.
+       When N is 0 the end-user has asked the process to be
+       quiet, and the helper should produce only error output.
+       N of 1 is the default level of verbosity, higher values
+       of N correspond to the number of -v flags passed on the
+       command line.
+
+'option progress' \{'true'|'false'\}::
+       Enable (or disable) progress messages displayed by the
+       transport helper during a command.
+
+'option depth' <depth>::
+       Deepen the history of a shallow repository.
+
+'option followtags' \{'true'|'false'\}::
+       If enabled the helper should automatically fetch annotated
+       tag objects if the object the tag points at was transferred
+       during the fetch command.  If the tag is not fetched by
+       the helper a second fetch command will usually be sent to
+       ask for the tag specifically.  Some helpers may be able to
+       use this option to avoid a second network connection.
+
 Documentation
 -------------
 Documentation by Daniel Barkalow.

diff --git a/remote-curl.c b/remote-curl.c
index 22cd5c5fd2a64b0ed4f6a74b38598bbcd2072efa..0951f116153409a1d5462865954ac60b15a0bdd5 100644 (file)
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -9,12 +9,61 @@ static struct remote *remote;
 static const char *url;
 static struct walker *walker;
 
+struct options {
+       int verbosity;
+       unsigned long depth;
+       unsigned progress : 1,
+               followtags : 1;
+};
+static struct options options;
+
 static void init_walker(void)
 {
        if (!walker)
                walker = get_http_walker(url, remote);
 }
 
+static int set_option(const char *name, const char *value)
+{
+       if (!strcmp(name, "verbosity")) {
+               char *end;
+               int v = strtol(value, &end, 10);
+               if (value == end || *end)
+                       return -1;
+               options.verbosity = v;
+               return 0;
+       }
+       else if (!strcmp(name, "progress")) {
+               if (!strcmp(value, "true"))
+                       options.progress = 1;
+               else if (!strcmp(value, "false"))
+                       options.progress = 0;
+               else
+                       return -1;
+               return 1 /* TODO implement later */;
+       }
+       else if (!strcmp(name, "depth")) {
+               char *end;
+               unsigned long v = strtoul(value, &end, 10);
+               if (value == end || *end)
+                       return -1;
+               options.depth = v;
+               return 1 /* TODO implement later */;
+       }
+       else if (!strcmp(name, "followtags")) {
+               if (!strcmp(value, "true"))
+                       options.followtags = 1;
+               else if (!strcmp(value, "false"))
+                       options.followtags = 0;
+               else
+                       return -1;
+               return 1 /* TODO implement later */;
+       }
+       else {
+               return 1 /* unsupported */;
+       }
+}
+
 static struct ref *get_refs(void)
 {
        struct strbuf buffer = STRBUF_INIT;
@@ -99,7 +148,7 @@ static int fetch_dumb(int nr_heads, struct ref **to_fetch)
        walker->get_all = 1;
        walker->get_tree = 1;
        walker->get_history = 1;
-       walker->get_verbosely = 0;
+       walker->get_verbosely = options.verbosity >= 3;
        walker->get_recover = 0;
        ret = walker_fetch(walker, nr_heads, targets, NULL, NULL);
 
@@ -173,6 +222,9 @@ int main(int argc, const char **argv)
                return 1;
        }
 
+       options.verbosity = 1;
+       options.progress = !!isatty(2);
+
        remote = remote_get(argv[1]);
 
        if (argc > 2) {
@@ -198,8 +250,28 @@ int main(int argc, const char **argv)
                        }
                        printf("\n");
                        fflush(stdout);
+               } else if (!prefixcmp(buf.buf, "option ")) {
+                       char *name = buf.buf + strlen("option ");
+                       char *value = strchr(name, ' ');
+                       int result;
+
+                       if (value)
+                               *value++ = '\0';
+                       else
+                               value = "true";
+
+                       result = set_option(name, value);
+                       if (!result)
+                               printf("ok\n");
+                       else if (result < 0)
+                               printf("error invalid value\n");
+                       else
+                               printf("unsupported\n");
+                       fflush(stdout);
+
                } else if (!strcmp(buf.buf, "capabilities")) {
                        printf("fetch\n");
+                       printf("option\n");
                        printf("\n");
                        fflush(stdout);
                } else {

diff --git a/transport-helper.c b/transport-helper.c
index 9de34089478665c498e59d15f16cf0856f0cdac6..577abc638eb47417277a45a6bd568e24d48e928b 100644 (file)
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -5,13 +5,15 @@
 #include "commit.h"
 #include "diff.h"
 #include "revision.h"
+#include "quote.h"
 
 struct helper_data
 {
        const char *name;
        struct child_process *helper;
        FILE *out;
-       unsigned fetch : 1;
+       unsigned fetch : 1,
+               option : 1;
 };
 
 static struct child_process *get_helper(struct transport *transport)
@@ -48,6 +50,8 @@ static struct child_process *get_helper(struct transport *transport)
                        break;
                if (!strcmp(buf.buf, "fetch"))
                        data->fetch = 1;
+               if (!strcmp(buf.buf, "option"))
+                       data->option = 1;
        }
        return data->helper;
 }
@@ -65,9 +69,88 @@ static int disconnect_helper(struct transport *transport)
                free(data->helper);
                data->helper = NULL;
        }
+       free(data);
        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 child_process *helper = get_helper(transport);
+       struct strbuf buf = STRBUF_INIT;
+       int i, ret, is_bool = 0;
+
+       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');
+
+       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 */
+
+       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;
+       int no_progress = v < 0 || (!t->progress && !isatty(1));
+
+       set_helper_option(t, "progress", !no_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 fetch_with_fetch(struct transport *transport,
                            int nr_heads, const struct ref **to_fetch)
 {
@@ -75,6 +158,8 @@ static int fetch_with_fetch(struct transport *transport,
        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)
@@ -178,6 +263,7 @@ int transport_helper_init(struct transport *transport, const char *name)
        data->name = name;
 
        transport->data = data;
+       transport->set_option = set_helper_option;
        transport->get_refs_list = get_refs_list;
        transport->fetch = fetch;
        transport->disconnect = disconnect_helper;