Introduce the new files fetch-negotiator.{h,c}, which contains an API
behind which the details of negotiation are abstracted. Currently, only
one algorithm is available: the existing one.
This patch is written to be more easily reviewed: static functions are
moved verbatim from fetch-pack.c to negotiator/default.c, and it can be
seen that the lines replaced by negotiator->X() calls are present in the
X() functions respectively.
Signed-off-by: Jonathan Tan <jonathantanmy@xxxxxxxxxx>
---
Makefile | 2 +
fetch-negotiator.c | 7 ++
fetch-negotiator.h | 45 ++++++++++
fetch-pack.c | 207 ++++++++++---------------------------------
negotiator/default.c | 173 ++++++++++++++++++++++++++++++++++++
negotiator/default.h | 8 ++
object.h | 3 +-
7 files changed, 282 insertions(+), 163 deletions(-)
create mode 100644 fetch-negotiator.c
create mode 100644 fetch-negotiator.h
create mode 100644 negotiator/default.c
create mode 100644 negotiator/default.h
diff --git a/Makefile b/Makefile
index 4bca65383..8f1df08ac 100644
--- a/Makefile
+++ b/Makefile
@@ -859,6 +859,7 @@ LIB_OBJS += ewah/ewah_bitmap.o
LIB_OBJS += ewah/ewah_io.o
LIB_OBJS += ewah/ewah_rlw.o
LIB_OBJS += exec-cmd.o
+LIB_OBJS += fetch-negotiator.o
LIB_OBJS += fetch-object.o
LIB_OBJS += fetch-pack.o
LIB_OBJS += fsck.o
@@ -891,6 +892,7 @@ LIB_OBJS += merge-blobs.o
LIB_OBJS += merge-recursive.o
LIB_OBJS += mergesort.o
LIB_OBJS += name-hash.o
+LIB_OBJS += negotiator/default.o
LIB_OBJS += notes.o
LIB_OBJS += notes-cache.o
LIB_OBJS += notes-merge.o
diff --git a/fetch-negotiator.c b/fetch-negotiator.c
new file mode 100644
index 000000000..756c35d15
--- /dev/null
+++ b/fetch-negotiator.c
@@ -0,0 +1,7 @@
+#include "fetch-negotiator.h"
+#include "negotiator/default.h"
+
+void fetch_negotiator_init(struct fetch_negotiator *negotiator)
+{
+ default_negotiator_init(negotiator);
+}
diff --git a/fetch-negotiator.h b/fetch-negotiator.h
new file mode 100644
index 000000000..b717b80dd
--- /dev/null
+++ b/fetch-negotiator.h
@@ -0,0 +1,45 @@
+#ifndef FETCH_NEGOTIATOR
+#define FETCH_NEGOTIATOR
+
+#include "cache.h"
+#include "commit.h"
+
+struct fetch_negotiator {
+ /*
+ * Before negotiation starts, indicate that the server is known to have
+ * this commit.
+ */
+ void (*known_common)(struct fetch_negotiator *, struct commit *);
+
+ /*
+ * Once this function is invoked, known_common() cannot be invoked any
+ * more.
+ *
+ * Indicate that this commit and all its ancestors are to be checked
+ * for commonality with the server.
+ */
+ void (*add_tip)(struct fetch_negotiator *, struct commit *);
+
+ /*
+ * Once this function is invoked, known_common() and add_tip() cannot
+ * be invoked any more.
+ *
+ * Return the next commit that the client should send as a "have" line.
+ */
+ const struct object_id *(*next)(struct fetch_negotiator *);
+
+ /*
+ * Inform the negotiator that the server has the given commit. This
+ * method must only be called on commits returned by next().
+ */
+ int (*ack)(struct fetch_negotiator *, struct commit *);
+
+ void (*release)(struct fetch_negotiator *);
+
+ /* internal use */
+ void *data;
+};
+
+void fetch_negotiator_init(struct fetch_negotiator *negotiator);
+
+#endif
diff --git a/fetch-pack.c b/fetch-pack.c
index 54dd3feb8..a399a62e1 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -15,10 +15,10 @@
#include "connect.h"
#include "transport.h"
#include "version.h"
-#include "prio-queue.h"
#include "sha1-array.h"
#include "oidset.h"
#include "packfile.h"
+#include "fetch-negotiator.h"
static int transfer_unpack_limit = -1;
static int fetch_unpack_limit = -1;
@@ -36,13 +36,7 @@ static const char *alternate_shallow_file;
/* Remember to update object flag allocation in object.h */
#define COMPLETE (1U << 0)
-#define COMMON (1U << 1)
-#define COMMON_REF (1U << 2)
-#define SEEN (1U << 3)
-#define POPPED (1U << 4)
-#define ALTERNATE (1U << 5)
-
-static int marked;
+#define ALTERNATE (1U << 1)
/*
* After sending this many "have"s if we do not get any new ACK , we
@@ -50,11 +44,6 @@ static int marked;
*/
#define MAX_IN_VAIN 256
-struct data {
- struct prio_queue rev_list;
- int non_common_revs;
-};
-
static int multi_ack, use_sideband;
/* Allow specifying sha1 if it is a ref tip. */
#define ALLOW_TIP_SHA1 01
@@ -97,8 +86,8 @@ static void cache_one_alternate(const char *refname,
cache->items[cache->nr++] = obj;
}
-static void for_each_cached_alternate(struct data *data,
- void (*cb)(struct data *, struct object *))
+static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
+ void (*cb)(struct fetch_negotiator *, struct object *))
{
static int initialized;
static struct alternate_object_cache cache;
@@ -110,31 +99,17 @@ static void for_each_cached_alternate(struct data *data,
}
for (i = 0; i < cache.nr; i++)
- cb(data, cache.items[i]);
-}
-
-static void rev_list_push(struct data *data, struct commit *commit, int mark)
-{
- if (!(commit->object.flags & mark)) {
- commit->object.flags |= mark;
-
- if (parse_commit(commit))
- return;
-
- prio_queue_put(&data->rev_list, commit);
-
- if (!(commit->object.flags & COMMON))
- data->non_common_revs++;
- }
+ cb(negotiator, cache.items[i]);
}
-static int rev_list_insert_ref(struct data *data, const char *refname,
+static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
+ const char *refname,
const struct object_id *oid)
{
struct object *o = deref_tag(parse_object(oid), refname, 0);
if (o && o->type == OBJ_COMMIT)
- rev_list_push(data, (struct commit *)o, SEEN);
+ negotiator->add_tip(negotiator, (struct commit *)o);
return 0;
}
@@ -145,97 +120,6 @@ static int rev_list_insert_ref_oid(const char *refname, const struct object_id *
return rev_list_insert_ref(cb_data, refname, oid);
}
-static int clear_marks(const char *refname, const struct object_id *oid,
- int flag, void *cb_data)
-{
- struct object *o = deref_tag(parse_object(oid), refname, 0);
-
- if (o && o->type == OBJ_COMMIT)
- clear_commit_marks((struct commit *)o,
- COMMON | COMMON_REF | SEEN | POPPED);
- return 0;
-}
-
-/*
- This function marks a rev and its ancestors as common.
- In some cases, it is desirable to mark only the ancestors (for example
- when only the server does not yet know that they are common).
-*/
-
-static void mark_common(struct data *data, struct commit *commit,
- int ancestors_only, int dont_parse)
-{
- if (commit != NULL && !(commit->object.flags & COMMON)) {
- struct object *o = (struct object *)commit;
-
- if (!ancestors_only)
- o->flags |= COMMON;
-
- if (!(o->flags & SEEN))
- rev_list_push(data, commit, SEEN);
- else {
- struct commit_list *parents;
-
- if (!ancestors_only && !(o->flags & POPPED))
- data->non_common_revs--;
- if (!o->parsed && !dont_parse)
- if (parse_commit(commit))
- return;
-
- for (parents = commit->parents;
- parents;
- parents = parents->next)
- mark_common(data, parents->item, 0, dont_parse);
- }
- }
-}
-
-/*
- Get the next rev to send, ignoring the common.
-*/
-
-static const struct object_id *get_rev(struct data *data)
-{
- struct commit *commit = NULL;
-
- while (commit == NULL) {
- unsigned int mark;
- struct commit_list *parents;
-
- if (data->rev_list.nr == 0 || data->non_common_revs == 0)
- return NULL;
-
- commit = prio_queue_get(&data->rev_list);
- parse_commit(commit);
- parents = commit->parents;
-
- commit->object.flags |= POPPED;
- if (!(commit->object.flags & COMMON))
- data->non_common_revs--;
-
- if (commit->object.flags & COMMON) {
- /* do not send "have", and ignore ancestors */
- commit = NULL;
- mark = COMMON | SEEN;
- } else if (commit->object.flags & COMMON_REF)
- /* send "have", and ignore ancestors */
- mark = COMMON | SEEN;
- else
- /* send "have", also for its ancestors */
- mark = SEEN;
-
- while (parents) {
- if (!(parents->item->object.flags & SEEN))
- rev_list_push(data, parents->item, mark);
- if (mark & COMMON)
- mark_common(data, parents->item, 1, 0);
- parents = parents->next;
- }
- }
-
- return &commit->object.oid;
-}
-
enum ack_type {
NAK = 0,
ACK,
@@ -302,9 +186,10 @@ static void send_request(struct fetch_pack_args *args,
write_or_die(fd, buf->buf, buf->len);
}
-static void insert_one_alternate_object(struct data *data, struct object *obj)
+static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
+ struct object *obj)
{
- rev_list_insert_ref(data, NULL, &obj->oid);
+ rev_list_insert_ref(negotiator, NULL, &obj->oid);
}
#define INITIAL_FLUSH 16
@@ -327,7 +212,8 @@ static int next_flush(int stateless_rpc, int count)
return count;
}
-static int find_common(struct data *data, struct fetch_pack_args *args,
+static int find_common(struct fetch_negotiator *negotiator,
+ struct fetch_pack_args *args,
int fd[2], struct object_id *result_oid,
struct ref *refs)
{
@@ -343,8 +229,8 @@ static int find_common(struct data *data, struct fetch_pack_args *args,
if (args->stateless_rpc && multi_ack == 1)
die(_("--stateless-rpc requires multi_ack_detailed"));
- for_each_ref(rev_list_insert_ref_oid, data);
- for_each_cached_alternate(data, insert_one_alternate_object);
+ for_each_ref(rev_list_insert_ref_oid, negotiator);
+ for_each_cached_alternate(negotiator, insert_one_alternate_object);
fetching = 0;
for ( ; refs ; refs = refs->next) {
@@ -462,7 +348,7 @@ static int find_common(struct data *data, struct fetch_pack_args *args,
retval = -1;
if (args->no_dependents)
goto done;
- while ((oid = get_rev(data))) {
+ while ((oid = negotiator->next(negotiator))) {
packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
print_verbose(args, "have %s", oid_to_hex(oid));
in_vain++;
@@ -502,8 +388,7 @@ static int find_common(struct data *data, struct fetch_pack_args *args,
int was_common;
if (!commit)
die(_("invalid commit %s"), oid_to_hex(result_oid));
- was_common = commit->object.flags & COMMON;
- mark_common(data, commit, 0, 1);
+ was_common = negotiator->ack(negotiator, commit);
if (args->stateless_rpc
&& ack == ACK_common
&& !was_common) {
@@ -712,7 +597,8 @@ static void filter_refs(struct fetch_pack_args *args,
*refs = newlist;
}
-static void mark_alternate_complete(struct data *unused, struct object *obj)
+static void mark_alternate_complete(struct fetch_negotiator *unused,
+ struct object *obj)
{
mark_complete(&obj->oid);
}
@@ -739,7 +625,7 @@ static int add_loose_objects_to_set(const struct object_id *oid,
return 0;
}
-static int everything_local(struct data *data,
+static int everything_local(struct fetch_negotiator *negotiator,
struct fetch_pack_args *args,
struct ref **refs,
struct ref **sought, int nr_sought)
@@ -810,12 +696,8 @@ static int everything_local(struct data *data,
if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
continue;
- if (!(o->flags & SEEN)) {
- rev_list_push(data, (struct commit *)o,
- COMMON_REF | SEEN);
-
- mark_common(data, (struct commit *)o, 1, 1);
- }
+ negotiator->known_common(negotiator,
+ (struct commit *)o);
}
}
@@ -988,7 +870,8 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
struct object_id oid;
const char *agent_feature;
int agent_len;
- struct data data = { { compare_commits_by_commit_date } };
+ struct fetch_negotiator negotiator;
+ fetch_negotiator_init(&negotiator);
sort_ref_list(&ref, ref_compare_name);
QSORT(sought, nr_sought, cmp_ref_by_name);
@@ -1061,19 +944,17 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
if (!server_supports("deepen-relative") && args->deepen_relative)
die(_("Server does not support --deepen"));
- if (marked)
- for_each_ref(clear_marks, NULL);
- marked = 1;
- if (everything_local(&data, args, &ref, sought, nr_sought)) {
+ if (everything_local(&negotiator, args, &ref, sought, nr_sought)) {
packet_flush(fd[1]);
goto all_done;
}
- if (find_common(&data, args, fd, &oid, ref) < 0)
+ if (find_common(&negotiator, args, fd, &oid, ref) < 0)
if (!args->keep_pack)
/* When cloning, it is not unusual to have
* no common commit.
*/
warning(_("no common commits"));
+ negotiator.release(&negotiator);
if (args->stateless_rpc)
packet_flush(fd[1]);
@@ -1149,14 +1030,15 @@ static void add_common(struct strbuf *req_buf, struct oidset *common)
}
}
-static int add_haves(struct data *data, struct strbuf *req_buf,
+static int add_haves(struct fetch_negotiator *negotiator,
+ struct strbuf *req_buf,
int *haves_to_send, int *in_vain)
{
int ret = 0;
int haves_added = 0;
const struct object_id *oid;
- while ((oid = get_rev(data))) {
+ while ((oid = negotiator->next(negotiator))) {
packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
if (++haves_added >= *haves_to_send)
break;
@@ -1175,7 +1057,7 @@ static int add_haves(struct data *data, struct strbuf *req_buf,
return ret;
}
-static int send_fetch_request(struct data *data, int fd_out,
+static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
const struct fetch_pack_args *args,
const struct ref *wants, struct oidset *common,
int *haves_to_send, int *in_vain)
@@ -1232,7 +1114,7 @@ static int send_fetch_request(struct data *data, int fd_out,
add_common(&req_buf, common);
/* Add initial haves */
- ret = add_haves(data, &req_buf, haves_to_send, in_vain);
+ ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
}
/* Send request */
@@ -1269,7 +1151,8 @@ static int process_section_header(struct packet_reader *reader,
return ret;
}
-static int process_acks(struct data *data, struct packet_reader *reader,
+static int process_acks(struct fetch_negotiator *negotiator,
+ struct packet_reader *reader,
struct oidset *common)
{
/* received */
@@ -1289,7 +1172,7 @@ static int process_acks(struct data *data, struct packet_reader *reader,
struct commit *commit;
oidset_insert(common, &oid);
commit = lookup_commit(&oid);
- mark_common(data, commit, 0, 1);
+ negotiator->ack(negotiator, commit);
}
continue;
}
@@ -1367,7 +1250,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
struct packet_reader reader;
int in_vain = 0;
int haves_to_send = INITIAL_FLUSH;
- struct data data = { { compare_commits_by_commit_date } };
+ struct fetch_negotiator negotiator;
+ fetch_negotiator_init(&negotiator);
packet_reader_init(&reader, fd[0], NULL, 0,
PACKET_READ_CHOMP_NEWLINE);
@@ -1383,22 +1267,20 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
if (args->depth > 0 || args->deepen_since || args->deepen_not)
args->deepen = 1;
- if (marked)
- for_each_ref(clear_marks, NULL);
- marked = 1;
-
/* Filter 'ref' by 'sought' and those that aren't local */
- if (everything_local(&data, args, &ref, sought, nr_sought))
+ if (everything_local(&negotiator, args, &ref, sought,
+ nr_sought))
state = FETCH_DONE;
else
state = FETCH_SEND_REQUEST;
- for_each_ref(rev_list_insert_ref_oid, &data);
- for_each_cached_alternate(&data,
+ for_each_ref(rev_list_insert_ref_oid, &negotiator);
+ for_each_cached_alternate(&negotiator,
insert_one_alternate_object);
break;
case FETCH_SEND_REQUEST:
- if (send_fetch_request(&data, fd[1], args, ref, &common,
+ if (send_fetch_request(&negotiator, fd[1], args, ref,
+ &common,
&haves_to_send, &in_vain))
state = FETCH_GET_PACK;
else
@@ -1406,7 +1288,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
break;
case FETCH_PROCESS_ACKS:
/* Process ACKs/NAKs */
- switch (process_acks(&data, &reader, &common)) {
+ switch (process_acks(&negotiator, &reader, &common)) {
case 2:
state = FETCH_GET_PACK;
break;
@@ -1434,6 +1316,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
continue;
}
}
+ negotiator.release(&negotiator);
oidset_clear(&common);
return ref;
diff --git a/negotiator/default.c b/negotiator/default.c
new file mode 100644
index 000000000..48d290e06
--- /dev/null
+++ b/negotiator/default.c
@@ -0,0 +1,173 @@
+#include "default.h"
+#include "../prio-queue.h"
+#include "../refs.h"
+#include "../tag.h"
+
+/* Remember to update object flag allocation in object.h */
+#define COMMON (1U << 2)
+#define COMMON_REF (1U << 3)
+#define SEEN (1U << 4)
+#define POPPED (1U << 5)
+
+static int marked;
+
+struct data {
+ struct prio_queue rev_list;
+ int non_common_revs;
+};
+
+static void rev_list_push(struct data *data, struct commit *commit, int mark)
+{
+ if (!(commit->object.flags & mark)) {
+ commit->object.flags |= mark;
+
+ if (parse_commit(commit))
+ return;
+
+ prio_queue_put(&data->rev_list, commit);
+
+ if (!(commit->object.flags & COMMON))
+ data->non_common_revs++;
+ }
+}
+
+static int clear_marks(const char *refname, const struct object_id *oid,
+ int flag, void *cb_data)
+{
+ struct object *o = deref_tag(parse_object(oid), refname, 0);
+
+ if (o && o->type == OBJ_COMMIT)
+ clear_commit_marks((struct commit *)o,
+ COMMON | COMMON_REF | SEEN | POPPED);
+ return 0;
+}
+
+/*
+ This function marks a rev and its ancestors as common.
+ In some cases, it is desirable to mark only the ancestors (for example
+ when only the server does not yet know that they are common).
+*/
+
+static void mark_common(struct data *data, struct commit *commit,
+ int ancestors_only, int dont_parse)
+{
+ if (commit != NULL && !(commit->object.flags & COMMON)) {
+ struct object *o = (struct object *)commit;
+
+ if (!ancestors_only)
+ o->flags |= COMMON;
+
+ if (!(o->flags & SEEN))
+ rev_list_push(data, commit, SEEN);
+ else {
+ struct commit_list *parents;
+
+ if (!ancestors_only && !(o->flags & POPPED))
+ data->non_common_revs--;
+ if (!o->parsed && !dont_parse)
+ if (parse_commit(commit))
+ return;
+
+ for (parents = commit->parents;
+ parents;
+ parents = parents->next)
+ mark_common(data, parents->item, 0, dont_parse);
+ }
+ }
+}
+
+/*
+ Get the next rev to send, ignoring the common.
+*/
+
+static const struct object_id *get_rev(struct data *data)
+{
+ struct commit *commit = NULL;
+
+ while (commit == NULL) {
+ unsigned int mark;
+ struct commit_list *parents;
+
+ if (data->rev_list.nr == 0 || data->non_common_revs == 0)
+ return NULL;
+
+ commit = prio_queue_get(&data->rev_list);
+ parse_commit(commit);
+ parents = commit->parents;
+
+ commit->object.flags |= POPPED;
+ if (!(commit->object.flags & COMMON))
+ data->non_common_revs--;
+
+ if (commit->object.flags & COMMON) {
+ /* do not send "have", and ignore ancestors */
+ commit = NULL;
+ mark = COMMON | SEEN;
+ } else if (commit->object.flags & COMMON_REF)
+ /* send "have", and ignore ancestors */
+ mark = COMMON | SEEN;
+ else
+ /* send "have", also for its ancestors */
+ mark = SEEN;
+
+ while (parents) {
+ if (!(parents->item->object.flags & SEEN))
+ rev_list_push(data, parents->item, mark);
+ if (mark & COMMON)
+ mark_common(data, parents->item, 1, 0);
+ parents = parents->next;
+ }
+ }
+
+ return &commit->object.oid;
+}
+
+static void known_common(struct fetch_negotiator *n, struct commit *c)
+{
+ if (!(c->object.flags & SEEN)) {
+ rev_list_push(n->data, c, COMMON_REF | SEEN);
+ mark_common(n->data, c, 1, 1);
+ }
+}
+
+static void add_tip(struct fetch_negotiator *n, struct commit *c)
+{
+ n->known_common = NULL;
+ rev_list_push(n->data, c, SEEN);
+}
+
+static const struct object_id *next(struct fetch_negotiator *n)
+{
+ n->known_common = NULL;
+ n->add_tip = NULL;
+ return get_rev(n->data);
+}
+
+static int ack(struct fetch_negotiator *n, struct commit *c)
+{
+ int known_to_be_common = !!(c->object.flags & COMMON);
+ mark_common(n->data, c, 0, 1);
+ return known_to_be_common;
+}
+
+static void release(struct fetch_negotiator *n)
+{
+ clear_prio_queue(&((struct data *)n->data)->rev_list);
+ FREE_AND_NULL(n->data);
+}
+
+void default_negotiator_init(struct fetch_negotiator *negotiator)
+{
+ struct data *data;
+ negotiator->known_common = known_common;
+ negotiator->add_tip = add_tip;
+ negotiator->next = next;
+ negotiator->ack = ack;
+ negotiator->release = release;
+ negotiator->data = data = xcalloc(1, sizeof(*data));
+ data->rev_list.compare = compare_commits_by_commit_date;
+
+ if (marked)
+ for_each_ref(clear_marks, NULL);
+ marked = 1;
+}
diff --git a/negotiator/default.h b/negotiator/default.h
new file mode 100644
index 000000000..6c4b7e526
--- /dev/null
+++ b/negotiator/default.h
@@ -0,0 +1,8 @@
+#ifndef NEGOTIATOR_DEFAULT_H
+#define NEGOTIATOR_DEFAULT_H
+
+#include "fetch-negotiator.h"
+
+void default_negotiator_init(struct fetch_negotiator *negotiator);
+
+#endif
diff --git a/object.h b/object.h
index 5c1395500..7db4941d6 100644
--- a/object.h
+++ b/object.h
@@ -28,7 +28,8 @@ struct object_array {
/*
* object flag allocation:
* revision.h: 0---------10 26
- * fetch-pack.c: 0----5
+ * fetch-pack.c: 01
+ * negotiator/default.c: 2--5
* walker.c: 0-2
* upload-pack.c: 4 11----------------19
* builtin/blame.c: 12-13
--
2.17.0.768.g1526ddbba1.dirty
