transport_get() can call transport_shim_init() to have list and
fetch-ref operations handled by running a separate program as:
git shim-<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@xxxxxxxxxxxx>
---
This is similar to, but different from, my git-vcs-* stuff; this one
expects the helper to be able to look up sha1s for refs efficiently, and
to be able to fetch objects directly into the local object database
without fast-import. On the otherhand, it should be sufficiently general
to allow arbitrary methods for moving the data around.
Documentation/git-shim.txt | 37 ++++++++++++
Makefile | 1 +
transport-shim.c | 140 ++++++++++++++++++++++++++++++++++++++++++++
transport.h | 3 +
4 files changed, 181 insertions(+), 0 deletions(-)
create mode 100644 Documentation/git-shim.txt
create mode 100644 transport-shim.c
diff --git a/Documentation/git-shim.txt b/Documentation/git-shim.txt
new file mode 100644
index 0000000..26a611f
--- /dev/null
+++ b/Documentation/git-shim.txt
@@ -0,0 +1,37 @@
+git-shim(1)
+============
+
+NAME
+----
+git-shim - Helper programs for interoperation with remote git
+
+SYNOPSIS
+--------
+'git shim-<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.
+
+COMMANDS
+--------
+
+Commands are given by the caller on the helper's standard input, one per line.
+
+'list'::
+ Outputs the names of refs followed by the hex of their values
+ or "@<name>" for symrefs, one per line. After the complete
+ list, outputs a blank line.
+
+'fetch' ref::
+ Fetches the given ref, writing the necessary objects to the
+ database. Outputs a blank line when the fetch is complete.
++
+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.
diff --git a/Makefile b/Makefile
index bde27ed..01efc73 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-shim.o
LIB_OBJS += tree-diff.o
LIB_OBJS += tree.o
LIB_OBJS += tree-walk.o
diff --git a/transport-shim.c b/transport-shim.c
new file mode 100644
index 0000000..3fc6abf
--- /dev/null
+++ b/transport-shim.c
@@ -0,0 +1,140 @@
+#include "cache.h"
+#include "transport.h"
+
+#include "run-command.h"
+#include "commit.h"
+#include "diff.h"
+#include "revision.h"
+
+struct shim_data
+{
+ const char *name;
+ struct child_process *shim;
+};
+
+static struct child_process *get_shim(struct transport *transport)
+{
+ struct shim_data *data = transport->data;
+ if (!data->shim) {
+ struct strbuf buf = STRBUF_INIT;
+ struct child_process *shim = xcalloc(1, sizeof(*shim));
+ shim->in = -1;
+ shim->out = -1;
+ shim->err = 0;
+ shim->argv = xcalloc(4, sizeof(*shim->argv));
+ strbuf_addf(&buf, "shim-%s", data->name);
+ shim->argv[0] = buf.buf;
+ shim->argv[1] = transport->remote->name;
+ shim->argv[2] = transport->url;
+ shim->git_cmd = 1;
+ start_command(shim);
+ data->shim = shim;
+ }
+ return data->shim;
+}
+
+static int disconnect_shim(struct transport *transport)
+{
+ struct shim_data *data = transport->data;
+ if (data->shim) {
+ write(data->shim->in, "\n", 1);
+ close(data->shim->in);
+ finish_command(data->shim);
+ free(data->shim);
+ transport->data = NULL;
+ }
+ return 0;
+}
+
+static int fetch_refs_via_shim(struct transport *transport,
+ int nr_heads, const struct ref **to_fetch)
+{
+ struct child_process *shim;
+ 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) {
+ shim = get_shim(transport);
+ for (i = 0; i < nr_heads; i++) {
+ posn = to_fetch[i];
+ if (posn->status & REF_STATUS_UPTODATE)
+ continue;
+ write(shim->in, "fetch ", 6);
+ write(shim->in, sha1_to_hex(posn->old_sha1), 40);
+ write(shim->in, " ", 1);
+ write(shim->in, posn->name, strlen(posn->name));
+ write(shim->in, "\n", 1);
+ }
+ file = fdopen(shim->out, "r");
+ while (count) {
+ if (strbuf_getline(&buf, file, '\n') == EOF)
+ exit(128); // child died, message supplied already
+
+ count--;
+ }
+ }
+ return 0;
+}
+
+static struct ref *get_refs_via_shim(struct transport *transport, int for_push)
+{
+ struct child_process *shim;
+ struct ref *ret = NULL;
+ struct ref **end = &ret;
+ struct ref *posn;
+ struct strbuf buf = STRBUF_INIT;
+ FILE *file;
+
+ shim = get_shim(transport);
+ write(shim->in, "list\n", 5);
+
+ file = fdopen(shim->out, "r");
+ while (1) {
+ char *eon;
+ if (strbuf_getline(&buf, file, '\n') == EOF)
+ exit(128); // child died, message supplied already
+
+ if (!*buf.buf)
+ break;
+
+ eon = strchr(buf.buf, ' ');
+ if (eon)
+ *eon = '\0';
+ *end = alloc_ref(buf.buf);
+ if (eon) {
+ if (eon[1] == '@')
+ (*end)->symref = xstrdup(eon + 2);
+ else
+ get_sha1_hex(eon + 1, (*end)->old_sha1);
+ }
+ end = &((*end)->next);
+ strbuf_reset(&buf);
+ }
+ strbuf_release(&buf);
+
+ for (posn = ret; posn; posn = posn->next)
+ resolve_remote_symref(posn, ret);
+
+ return ret;
+}
+
+void transport_shim_init(struct transport *transport, const char *name)
+{
+ struct shim_data *data = xmalloc(sizeof(*data));
+ data->shim = NULL;
+ data->name = name;
+ transport->data = data;
+ transport->get_refs_list = get_refs_via_shim;
+ transport->fetch = fetch_refs_via_shim;
+ transport->disconnect = disconnect_shim;
+}
diff --git a/transport.h b/transport.h
index 51b5397..01f650d 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 */
+void transport_shim_init(struct transport *transport, const char *name);
+
#endif
--
1.6.3.2.425.g3dedc
--
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