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[RFC 04/11] Add a transport implementation using git-vcs-* helpers

From
Johan Herland <johan@herland.net>
Date
Jul 27, 2009, 01:04 UTC
Message-ID
<1248656659-21415-5-git-send-email-johan@herland.net>
In-Reply-To
<1248656659-21415-1-git-send-email-johan@herland.net>
From: Daniel Barkalow <barkalow@iabervon.org>

This is somewhat careless about pushes (that is, it attempts to make pushes that the helper can't necessarily handle), but actually works for fetches and simple pushes.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Johan Herland <johan@herland.net>
---
 Makefile            |    1 +
 remote.c            |    2 +-
 transport-foreign.c |  200 +++++++++++++++++++++++++++++++++++++++++++++++++++
 transport.c         |    1 +
 transport.h         |    1 +
 5 files changed, 204 insertions(+), 1 deletions(-)
 create mode 100644 transport-foreign.c
diff --git a/Makefile b/Makefile
index f396e52..6b39d56 100644
--- a/Makefile
+++ b/Makefile
@@ -554,6 +554,7 @@ LIB_OBJS += symlinks.o
 LIB_OBJS += tag.o
 LIB_OBJS += trace.o
 LIB_OBJS += transport.o
+LIB_OBJS += transport-foreign.o
 LIB_OBJS += transport-shim.o
 LIB_OBJS += tree-diff.o
 LIB_OBJS += tree.o
diff --git a/remote.c b/remote.c
index c5ac881..8d1560e 100644
--- a/remote.c
+++ b/remote.c
@@ -50,7 +50,7 @@ static char buffer[BUF_SIZE];
 
 static int valid_remote(const struct remote *remote)
 {
-	return !!remote->url;
+	return remote->url || remote->foreign_vcs;
 }
 
 static const char *alias_url(const char *url)
diff --git a/transport-foreign.c b/transport-foreign.c
new file mode 100644
index 0000000..29aad77
--- /dev/null
+++ b/transport-foreign.c
@@ -0,0 +1,200 @@
+#include "cache.h"
+#include "transport.h"
+
+#include "run-command.h"
+#include "commit.h"
+#include "diff.h"
+#include "revision.h"
+
+struct foreign_data
+{
+	struct child_process *importer;
+};
+
+static struct child_process *get_importer(struct transport *transport)
+{
+	struct child_process *importer = transport->data;
+	if (!importer) {
+		struct strbuf buf;
+		importer = xcalloc(1, sizeof(*importer));
+		importer->in = -1;
+		importer->out = -1;
+		importer->err = 0;
+		importer->argv = xcalloc(3, sizeof(*importer->argv));
+		strbuf_init(&buf, 80);
+		strbuf_addf(&buf, "vcs-%s", transport->remote->foreign_vcs);
+		importer->argv[0] = buf.buf;
+		importer->argv[1] = transport->remote->name;
+		importer->git_cmd = 1;
+		start_command(importer);
+		transport->data = importer;
+	}
+	return importer;
+}
+
+static int disconnect_foreign(struct transport *transport)
+{
+	struct child_process *importer = transport->data;
+	if (importer) {
+		write(importer->in, "\n", 1);
+		close(importer->in);
+		finish_command(importer);
+		free(importer);
+		transport->data = NULL;
+	}
+	return 0;
+}
+
+static int fetch_refs_via_foreign(struct transport *transport,
+				  int nr_heads, struct ref **to_fetch)
+{
+	struct child_process *importer;
+	struct child_process fastimport;
+	struct ref *posn;
+	int i, count;
+
+	count = 0;
+	for (i = 0; i < nr_heads; i++) {
+		posn = to_fetch[i];
+		if (posn->status & REF_STATUS_UPTODATE)
+			continue;
+		count++;
+	}
+	if (count) {
+		importer = get_importer(transport);
+
+		memset(&fastimport, 0, sizeof(fastimport));
+		fastimport.in = importer->out;
+		fastimport.argv = xcalloc(3, sizeof(*fastimport.argv));
+		fastimport.argv[0] = "fast-import";
+		fastimport.argv[1] = "--quiet";
+		fastimport.git_cmd = 1;
+		start_command(&fastimport);
+
+		for (i = 0; i < nr_heads; i++) {
+			posn = to_fetch[i];
+			if (posn->status & REF_STATUS_UPTODATE)
+				continue;
+			write(importer->in, "import ", 7);
+			write(importer->in, posn->name, strlen(posn->name));
+			write(importer->in, "\n", 1);
+		}
+		disconnect_foreign(transport);
+		finish_command(&fastimport);
+	}
+	for (i = 0; i < nr_heads; i++) {
+		posn = to_fetch[i];
+		if (posn->status & REF_STATUS_UPTODATE)
+			continue;
+		read_ref(posn->name, posn->old_sha1);
+	}
+	return 0;
+}
+
+static struct ref *get_refs_via_foreign(struct transport *transport, int for_push)
+{
+	struct child_process *importer;
+	struct ref *ret = NULL;
+	struct ref **end = &ret;
+	struct strbuf buf;
+	FILE *file;
+
+	importer = get_importer(transport);
+	write(importer->in, "list\n", 5);
+
+	strbuf_init(&buf, 0);
+	file = fdopen(importer->out, "r");
+	while (1) {
+		char *eon;
+		if (strbuf_getline(&buf, file, '\n') == EOF)
+			break;
+
+		if (!*buf.buf)
+			break;
+
+		eon = strchr(buf.buf, ' ');
+		if (eon)
+			*eon = '\0';
+		*end = alloc_ref(buf.buf);
+		if (eon) {
+			if (strstr(eon + 1, "unchanged")) {
+				(*end)->status |= REF_STATUS_UPTODATE;
+				if (read_ref((*end)->name, (*end)->old_sha1))
+					die("Unchanged?");
+				fprintf(stderr, "Old: %p %s\n", *end, sha1_to_hex((*end)->old_sha1));
+			}
+		}
+		end = &((*end)->next);
+		strbuf_reset(&buf);
+	}
+
+	strbuf_release(&buf);
+	return ret;
+}
+
+static int foreign_push(struct transport *transport, struct ref *remote_refs, int flags) {
+	struct ref *ref, *has;
+	struct child_process *importer;
+	struct rev_info revs;
+	struct commit *commit;
+	struct child_process fastimport;
+
+	importer = get_importer(transport);
+
+	memset(&fastimport, 0, sizeof(fastimport));
+	fastimport.in = importer->out;
+	fastimport.argv = xcalloc(3, sizeof(*fastimport.argv));
+	fastimport.argv[0] = "fast-import";
+	fastimport.argv[1] = "--quiet";
+	fastimport.git_cmd = 1;
+	start_command(&fastimport);
+	for (ref = remote_refs; ref; ref = ref->next) {
+		if (!ref->peer_ref) {
+			ref->status = REF_STATUS_NONE;
+			continue;
+		}
+		init_revisions(&revs, NULL);
+		revs.reverse = 1;
+		for (has = remote_refs; has; has = has->next) {
+			commit = lookup_commit(has->old_sha1);
+			commit->object.flags |= UNINTERESTING;
+			add_pending_object(&revs, &commit->object, has->name);
+		}
+		commit = lookup_commit(ref->peer_ref->new_sha1);
+		add_pending_object(&revs, &commit->object, ref->name);
+
+		if (prepare_revision_walk(&revs))
+			die("Something wrong");
+
+		ref->status = REF_STATUS_UPTODATE;
+		while ((commit = get_revision(&revs))) {
+			ref->status = REF_STATUS_EXPECTING_REPORT;
+			fprintf(stderr, "export %s %s\n", sha1_to_hex(commit->object.sha1), ref->name);
+			write(importer->in, "export ", 7);
+			write(importer->in, sha1_to_hex(commit->object.sha1), 40);
+			write(importer->in, " ", 1);
+			write(importer->in, ref->name, strlen(ref->name));
+			write(importer->in, "\n", 1);
+		}
+	}
+
+	disconnect_foreign(transport);
+	finish_command(&fastimport);
+
+	for (ref = remote_refs; ref; ref = ref->next) {
+		read_ref(ref->name, ref->new_sha1);
+		if (ref->status == REF_STATUS_EXPECTING_REPORT)
+			ref->status = REF_STATUS_OK;
+	}
+
+	return 0;
+}
+
+void transport_foreign_init(struct transport *transport)
+{
+	transport->get_refs_list = get_refs_via_foreign;
+	transport->fetch = fetch_refs_via_foreign;
+	transport->push_refs = foreign_push;
+	transport->disconnect = disconnect_foreign;
+	transport->url = transport->remote->foreign_vcs;
+}
diff --git a/transport.c b/transport.c
index 2864f40..4e984ca 100644
--- a/transport.c
+++ b/transport.c
@@ -799,6 +799,7 @@ struct transport *transport_get(struct remote *remote, const char *url)
 	ret->url = url;
 
 	if (remote && remote->foreign_vcs) {
+		transport_foreign_init(ret);
 	} else if (!prefixcmp(url, "rsync:")) {
 		ret->get_refs_list = get_refs_via_rsync;
 		ret->fetch = fetch_objs_via_rsync;
diff --git a/transport.h b/transport.h
index 229a7b4..2e1bd6c 100644
--- a/transport.h
+++ b/transport.h
@@ -116,6 +116,7 @@ int transport_disconnect(struct transport *transport);
 char *transport_anonymize_url(const char *url);
 
 /* Transport methods defined outside transport.c */
+void transport_foreign_init(struct transport *transport);
 void transport_shim_init(struct transport *transport, const char *name);
 
 #endif

-- 
1.6.4.rc3.138.ga6b98.dirty
Previous: Johan HerlandNext: Johan Herland
Message 9 of 30 in “[RFC 00/11] Foreign VCS helper program for CVS repositories”
  1. Johan HerlandJul 27, 2009
  2. 01/11 Add specification of git-vcs-* helper programsJohan Herland, Jul 27, 2009
  3. 02/11 Use a function to determine whether a remote is validJohan Herland, Jul 27, 2009
  4. 03/11 Allow programs to not depend on remotes having urlsJohan Herland, Jul 27, 2009
  5. Junio C HamanoJul 27, 2009
  6. Daniel BarkalowJul 27, 2009
  7. Alex RiesenJul 29, 2009
  8. Johan HerlandJul 30, 2009
  9. 04/11 Add a transport implementation using git-vcs-* helpersJohan Herland, Jul 27, 2009
  10. 05/11 Refactor path name parsing into new function: get_path_str()Johan Herland, Jul 27, 2009
  11. 06/11 Add support for mark references as path namesJohan Herland, Jul 27, 2009
  12. Shawn O. PearceJul 27, 2009
  13. Johan HerlandJul 27, 2009
  14. Shawn O. PearceJul 27, 2009
  15. 06/11 fast-import: Add support for importing commit notesJohan Herland, Jul 28, 2009
  16. Junio C HamanoJul 29, 2009
  17. Johan HerlandJul 29, 2009
  18. Shawn O. PearceJul 29, 2009
  19. Junio C HamanoJul 29, 2009
  20. Johan HerlandJul 30, 2009
  21. Junio C HamanoJul 30, 2009
  22. Junio C HamanoJul 29, 2009
  23. Johan HerlandJul 29, 2009
  24. 07/11 Preliminary clarifications to git-vcs documentationJohan Herland, Jul 27, 2009
  25. 08/11 Teach foreign transport code to perform the "capabilities" commandJohan Herland, Jul 27, 2009
  26. 09/11 Introduce a 'marks <filename>' feature to the foreign transport codeJohan Herland, Jul 27, 2009
  27. 11/11 Add simple test cases of git-vcs-cvs functionalityJohan Herland, Jul 27, 2009
  28. Daniel BarkalowJul 27, 2009
  29. Johan HerlandJul 27, 2009
  30. Daniel BarkalowJul 27, 2009

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