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[PATCH 02/19] Allow fetch to modify refs

From
Sverre Rabbelier <srabbelier@gmail.com>
Date
Oct 29, 2009, 18:01 UTC
Message-ID
<1256839287-19016-3-git-send-email-srabbelier@gmail.com>
In-Reply-To
<1256839287-19016-1-git-send-email-srabbelier@gmail.com>
From: Daniel Barkalow <barkalow@iabervon.org>

This allows the transport to use the null sha1 for a ref reported to be present in the remote repository to indicate that a ref exists but its actual value is presently unknown and will be set if the objects are fetched.

Also adds documentation to the API to specify exactly what the methods should do and how they should interpret arguments.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---
	Signed off by me because I rebased it on master and fixed the
	conflicts with nico's patch.
 builtin-clone.c    |    5 +++--
 transport-helper.c |    4 ++--
 transport.c        |   13 +++++++------
 transport.h        |   41 +++++++++++++++++++++++++++++++++++++++--
 4 files changed, 51 insertions(+), 12 deletions(-)
diff --git a/builtin-clone.c b/builtin-clone.c
index 5762a6f..0042bee 100644
--- a/builtin-clone.c
+++ b/builtin-clone.c
@@ -526,8 +526,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 		refs = transport_get_remote_refs(transport);
 		if (refs) {
-			mapped_refs = wanted_peer_refs(refs, refspec);
-			transport_fetch_refs(transport, mapped_refs);
+			struct ref *ref_cpy = wanted_peer_refs(refs, refspec);
+			mapped_refs = ref_cpy;
+			transport_fetch_refs(transport, ref_cpy);
 		}
 	}
 
diff --git a/transport-helper.c b/transport-helper.c
index f57e84c..a0e4219 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -68,7 +68,7 @@ static int disconnect_helper(struct transport *transport)
 }
 
 static int fetch_with_fetch(struct transport *transport,
-			    int nr_heads, const struct ref **to_fetch)
+			    int nr_heads, struct ref **to_fetch)
 {
 	struct child_process *helper = get_helper(transport);
 	FILE *file = xfdopen(helper->out, "r");
@@ -92,7 +92,7 @@ static int fetch_with_fetch(struct transport *transport,
 }
 
 static int fetch(struct transport *transport,
-		 int nr_heads, const struct ref **to_fetch)
+		 int nr_heads, struct ref **to_fetch)
 {
 	struct helper_data *data = transport->data;
 	int i, count;
diff --git a/transport.c b/transport.c
index 644a30a..3822fc7 100644
--- a/transport.c
+++ b/transport.c
@@ -204,7 +204,7 @@ static struct ref *get_refs_via_rsync(struct transport *transport, int for_push)
 }
 
 static int fetch_objs_via_rsync(struct transport *transport,
-				int nr_objs, const struct ref **to_fetch)
+				int nr_objs, struct ref **to_fetch)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct child_process rsync;
@@ -408,7 +408,7 @@ static struct ref *get_refs_from_bundle(struct transport *transport, int for_pus
 }
 
 static int fetch_refs_from_bundle(struct transport *transport,
-			       int nr_heads, const struct ref **to_fetch)
+			       int nr_heads, struct ref **to_fetch)
 {
 	struct bundle_transport_data *data = transport->data;
 	return unbundle(&data->header, data->fd);
@@ -486,7 +486,7 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 }
 
 static int fetch_refs_via_pack(struct transport *transport,
-			       int nr_heads, const struct ref **to_fetch)
+			       int nr_heads, struct ref **to_fetch)
 {
 	struct git_transport_data *data = transport->data;
 	char **heads = xmalloc(nr_heads * sizeof(*heads));
@@ -923,16 +923,17 @@ const struct ref *transport_get_remote_refs(struct transport *transport)
 	return transport->remote_refs;
 }
 
-int transport_fetch_refs(struct transport *transport, const struct ref *refs)
+int transport_fetch_refs(struct transport *transport, struct ref *refs)
 {
 	int rc;
 	int nr_heads = 0, nr_alloc = 0, nr_refs = 0;
-	const struct ref **heads = NULL;
-	const struct ref *rm;
+	struct ref **heads = NULL;
+	struct ref *rm;
 
 	for (rm = refs; rm; rm = rm->next) {
 		nr_refs++;
 		if (rm->peer_ref &&
+		    !is_null_sha1(rm->old_sha1) &&
 		    !hashcmp(rm->peer_ref->old_sha1, rm->old_sha1))
 			continue;
 		ALLOC_GROW(heads, nr_heads + 1, nr_alloc);
diff --git a/transport.h b/transport.h
index c14da6f..503db11 100644
--- a/transport.h
+++ b/transport.h
@@ -18,11 +18,48 @@ struct transport {
 	int (*set_option)(struct transport *connection, const char *name,
 			  const char *value);
 
+	/**
+	 * Returns a list of the remote side's refs. In order to allow
+	 * the transport to try to share connections, for_push is a
+	 * hint as to whether the ultimate operation is a push or a fetch.
+	 *
+	 * If the transport is able to determine the remote hash for
+	 * the ref without a huge amount of effort, it should store it
+	 * in the ref's old_sha1 field; otherwise it should be all 0.
+	 **/
 	struct ref *(*get_refs_list)(struct transport *transport, int for_push);
-	int (*fetch)(struct transport *transport, int refs_nr, const struct ref **refs);
+
+	/**
+	 * Fetch the objects for the given refs. Note that this gets
+	 * an array, and should ignore the list structure.
+	 *
+	 * If the transport did not get hashes for refs in
+	 * get_refs_list(), it should set the old_sha1 fields in the
+	 * provided refs now.
+	 **/
+	int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);
+
+	/**
+	 * Push the objects and refs. Send the necessary objects, and
+	 * then, for any refs where peer_ref is set and
+	 * peer_ref->new_sha1 is different from old_sha1, tell the
+	 * remote side to update each ref in the list from old_sha1 to
+	 * peer_ref->new_sha1.
+	 *
+	 * Where possible, set the status for each ref appropriately.
+	 *
+	 * The transport must modify new_sha1 in the ref to the new
+	 * value if the remote accepted the change. Note that this
+	 * could be a different value from peer_ref->new_sha1 if the
+	 * process involved generating new commits.
+	 **/
 	int (*push_refs)(struct transport *transport, struct ref *refs, int flags);
 	int (*push)(struct transport *connection, int refspec_nr, const char **refspec, int flags);
 
+	/** get_refs_list(), fetch(), and push_refs() can keep
+	 * resources (such as a connection) reserved for futher
+	 * use. disconnect() releases these resources.
+	 **/
 	int (*disconnect)(struct transport *connection);
 	char *pack_lockfile;
 	signed verbose : 2;
@@ -74,7 +111,7 @@ int transport_push(struct transport *connection,
 
 const struct ref *transport_get_remote_refs(struct transport *transport);
 
-int transport_fetch_refs(struct transport *transport, const struct ref *refs);
+int transport_fetch_refs(struct transport *transport, struct ref *refs);
 void transport_unlock_pack(struct transport *transport);
 int transport_disconnect(struct transport *transport);
 char *transport_anonymize_url(const char *url);

-- 
1.6.5.2.291.gf76a3
Previous: Sverre RabbelierNext: Daniel Barkalow
Message 3 of 43 in “Reroll of the remote-vcs-helper series”
  1. 0/19 Reroll of the remote-vcs-helper seriesSverre Rabbelier, Oct 29, 2009
  2. 01/19 Use a function to determine whether a remote is validSverre Rabbelier, Oct 29, 2009
  3. 02/19 Allow fetch to modify refsSverre Rabbelier, Oct 29, 2009
  4. Daniel BarkalowOct 30, 2009
  5. Sverre RabbelierOct 30, 2009
  6. Daniel BarkalowOct 30, 2009
  7. Sverre RabbelierOct 30, 2009
  8. 03/19 Allow programs to not depend on remotes having urlsSverre Rabbelier, Oct 29, 2009
  9. Daniel BarkalowOct 30, 2009
  10. Sverre RabbelierOct 30, 2009
  11. 04/19 Add a config option for remotes to specify a foreign vcsSverre Rabbelier, Oct 29, 2009
  12. 05/19 Add support for "import" helper commandSverre Rabbelier, Oct 29, 2009
  13. 06/19 Factor ref updating out of fetch_with_importSverre Rabbelier, Oct 29, 2009
  14. Daniel BarkalowOct 30, 2009
  15. Sverre RabbelierOct 30, 2009
  16. Daniel BarkalowOct 30, 2009
  17. Sverre RabbelierNov 2, 2009
  18. Daniel BarkalowNov 2, 2009
  19. Sverre RabbelierNov 2, 2009
  20. Daniel BarkalowNov 2, 2009
  21. 07/19 Allow helpers to report in "list" command that the ref is unchangedSverre Rabbelier, Oct 29, 2009
  22. 08/19 Fix memory leak in helper method for disconnectSverre Rabbelier, Oct 29, 2009
  23. 09/19 Finally make remote helper support usefulSverre Rabbelier, Oct 29, 2009
  24. 10/19 Allow helpers to request marks for fast-importSverre Rabbelier, Oct 29, 2009
  25. Johan HerlandOct 30, 2009
  26. Sverre RabbelierOct 30, 2009
  27. Johan HerlandOct 31, 2009
  28. Sverre RabbelierOct 31, 2009
  29. 11/19 Basic build infrastructure for Python scriptsSverre Rabbelier, Oct 29, 2009
  30. 12/19 1/2: Add Python support library for CVS remote helperSverre Rabbelier, Oct 29, 2009
  31. Johan HerlandOct 30, 2009
  32. Sverre RabbelierOct 30, 2009
  33. 13/19 2/2: Add Python support library for CVS remote helperSverre Rabbelier, Oct 29, 2009
  34. 14/19 git-remote-cvs: Remote helper program for CVS repositoriesSverre Rabbelier, Oct 29, 2009
  35. 15/19 Add simple selftests of git-remote-cvs functionalitySverre Rabbelier, Oct 29, 2009
  36. 16/19 Fix the Makefile-generated path to the git_remote_cvs package in git-remote-cvsSverre Rabbelier, Oct 29, 2009
  37. 17/19 More fixes to the git-remote-cvs installation procedureSverre Rabbelier, Oct 29, 2009
  38. 18/19 Refactor git_remote_cvs to a more generic git_remote_helpersSverre Rabbelier, Oct 29, 2009
  39. Johan HerlandOct 30, 2009
  40. Sverre RabbelierOct 30, 2009
  41. 19/19 .gitignore: add git-remote-cvsSverre Rabbelier, Oct 29, 2009
  42. Shawn O. PearceOct 29, 2009
  43. Sverre RabbelierOct 29, 2009

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