From: Calvin Wan <calvinwan@xxxxxxxxxx>
Sometimes, it is beneficial to retrieve information about an object
without downloading it entirely. The server-side logic for this
functionality was implemented in commit "a2ba162cda (object-info:
support for retrieving object info, 2021-04-20)."
This commit introduces client functions to interact with the server.
Currently, the client supports requesting a list of object IDs with
the ‘size’ feature from a v2 server. If the server does not advertise
this feature (i.e., transfer.advertiseobjectinfo is set to false),
the client will return an error and exit.
Helped-by: Jonathan Tan <jonathantanmy@xxxxxxxxxx>
Helped-by: Christian Couder <chriscool@xxxxxxxxxxxxx>
Signed-off-by: Calvin Wan <calvinwan@xxxxxxxxxx>
Signed-off-by: Eric Ju <eric.peijian@xxxxxxxxx>
---
Makefile | 1 +
fetch-object-info.c | 92 +++++++++++++++++++++++++++++++++++++++++++++
fetch-object-info.h | 18 +++++++++
fetch-pack.c | 3 ++
fetch-pack.h | 2 +
transport-helper.c | 11 +++++-
transport.c | 28 +++++++++++++-
transport.h | 11 ++++++
8 files changed, 163 insertions(+), 3 deletions(-)
create mode 100644 fetch-object-info.c
create mode 100644 fetch-object-info.h
diff --git a/Makefile b/Makefile
index d06c9a8ffa..beca828963 100644
--- a/Makefile
+++ b/Makefile
@@ -1024,6 +1024,7 @@ LIB_OBJS += ewah/ewah_rlw.o
LIB_OBJS += exec-cmd.o
LIB_OBJS += fetch-negotiator.o
LIB_OBJS += fetch-pack.o
+LIB_OBJS += fetch-object-info.o
LIB_OBJS += fmt-merge-msg.o
LIB_OBJS += fsck.o
LIB_OBJS += fsmonitor.o
diff --git a/fetch-object-info.c b/fetch-object-info.c
new file mode 100644
index 0000000000..2aa9f2b70d
--- /dev/null
+++ b/fetch-object-info.c
@@ -0,0 +1,92 @@
+#include "git-compat-util.h"
+#include "gettext.h"
+#include "hex.h"
+#include "pkt-line.h"
+#include "connect.h"
+#include "oid-array.h"
+#include "object-store-ll.h"
+#include "fetch-object-info.h"
+#include "string-list.h"
+
+/**
+ * send_object_info_request sends git-cat-file object-info command and its
+ * arguments into the request buffer.
+ */
+static void send_object_info_request(const int fd_out, struct object_info_args *args)
+{
+ struct strbuf req_buf = STRBUF_INIT;
+
+ write_command_and_capabilities(&req_buf, "object-info", args->server_options);
+
+ if (unsorted_string_list_has_string(args->object_info_options, "size"))
+ packet_buf_write(&req_buf, "size");
+
+ if (args->oids) {
+ for (size_t i = 0; i < args->oids->nr; i++)
+ packet_buf_write(&req_buf, "oid %s", oid_to_hex(&args->oids->oid[i]));
+ }
+
+ packet_buf_flush(&req_buf);
+ if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
+ die_errno(_("unable to write request to remote"));
+
+ strbuf_release(&req_buf);
+}
+
+/**
+ * fetch_object_info sends git-cat-file object-info command into the request buf
+ * and read the results from packets.
+ */
+int fetch_object_info(const enum protocol_version version, struct object_info_args *args,
+ struct packet_reader *reader, struct object_info *object_info_data,
+ const int stateless_rpc, const int fd_out)
+{
+ int size_index = -1;
+
+ switch (version) {
+ case protocol_v2:
+ if (!server_supports_v2("object-info"))
+ die(_("object-info capability is not enabled on the server"));
+ send_object_info_request(fd_out, args);
+ break;
+ case protocol_v1:
+ case protocol_v0:
+ die(_("wrong protocol version. expected v2"));
+ case protocol_unknown_version:
+ BUG("unknown protocol version");
+ }
+
+ for (size_t i = 0; i < args->object_info_options->nr; i++) {
+ if (packet_reader_read(reader) != PACKET_READ_NORMAL) {
+ check_stateless_delimiter(stateless_rpc, reader, "stateless delimiter expected");
+ return -1;
+ }
+ if (unsorted_string_list_has_string(args->object_info_options, reader->line)) {
+ if (!strcmp(reader->line, "size")) {
+ size_index = i;
+ for (size_t j = 0; j < args->oids->nr; j++)
+ object_info_data[j].sizep = xcalloc(1, sizeof(long));
+ }
+ continue;
+ }
+ return -1;
+ }
+
+ for (size_t i = 0; packet_reader_read(reader) == PACKET_READ_NORMAL && i < args->oids->nr; i++){
+ struct string_list object_info_values = STRING_LIST_INIT_DUP;
+
+ string_list_split(&object_info_values, reader->line, ' ', -1);
+ if (0 <= size_index) {
+ if (!strcmp(object_info_values.items[1 + size_index].string, ""))
+ die("object-info: not our ref %s",
+ object_info_values.items[0].string);
+
+ *object_info_data[i].sizep = strtoul(object_info_values.items[1 + size_index].string, NULL, 10);
+ }
+
+ string_list_clear(&object_info_values, 0);
+ }
+ check_stateless_delimiter(stateless_rpc, reader, "stateless delimiter expected");
+
+ return 0;
+}
diff --git a/fetch-object-info.h b/fetch-object-info.h
new file mode 100644
index 0000000000..ce1a05dc96
--- /dev/null
+++ b/fetch-object-info.h
@@ -0,0 +1,18 @@
+#ifndef FETCH_OBJECT_INFO_H
+#define FETCH_OBJECT_INFO_H
+
+#include "pkt-line.h"
+#include "protocol.h"
+#include "object-store-ll.h"
+
+struct object_info_args {
+ struct string_list *object_info_options;
+ const struct string_list *server_options;
+ struct oid_array *oids;
+};
+
+int fetch_object_info(enum protocol_version version, struct object_info_args *args,
+ struct packet_reader *reader, struct object_info *object_info_data,
+ int stateless_rpc, int fd_out);
+
+#endif /* FETCH_OBJECT_INFO_H */
diff --git a/fetch-pack.c b/fetch-pack.c
index eb4aface36..6e5d7df2dc 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1653,6 +1653,9 @@ 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 (args->object_info)
+ state = FETCH_SEND_REQUEST;
+
while (state != FETCH_DONE) {
switch (state) {
case FETCH_CHECK_LOCAL:
diff --git a/fetch-pack.h b/fetch-pack.h
index b5c579cdae..cf7cedf161 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -16,6 +16,7 @@ struct fetch_pack_args {
const struct string_list *deepen_not;
struct list_objects_filter_options filter_options;
const struct string_list *server_options;
+ struct object_info *object_info_data;
/*
* If not NULL, during packfile negotiation, fetch-pack will send "have"
@@ -42,6 +43,7 @@ struct fetch_pack_args {
unsigned reject_shallow_remote:1;
unsigned deepen:1;
unsigned refetch:1;
+ unsigned object_info:1;
/*
* Indicate that the remote of this request is a promisor remote. The
diff --git a/transport-helper.c b/transport-helper.c
index bc27653cde..bf0a1877c7 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -711,8 +711,8 @@ static int fetch_refs(struct transport *transport,
/*
* If we reach here, then the server, the client, and/or the transport
- * helper does not support protocol v2. --negotiate-only requires
- * protocol v2.
+ * helper does not support protocol v2. --negotiate-only and cat-file
+ * remote-object-info require protocol v2.
*/
if (data->transport_options.acked_commits) {
warning(_("--negotiate-only requires protocol v2"));
@@ -728,6 +728,13 @@ static int fetch_refs(struct transport *transport,
free_refs(dummy);
}
+ /* fail the command explicitly to avoid further commands input. */
+ if (transport->smart_options->object_info)
+ die(_("remote-object-info requires protocol v2"));
+
+ if (!data->get_refs_list_called)
+ get_refs_list_using_list(transport, 0);
+
count = 0;
for (i = 0; i < nr_heads; i++)
if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
diff --git a/transport.c b/transport.c
index 47fda6a773..746ec19ddc 100644
--- a/transport.c
+++ b/transport.c
@@ -9,6 +9,7 @@
#include "hook.h"
#include "pkt-line.h"
#include "fetch-pack.h"
+#include "fetch-object-info.h"
#include "remote.h"
#include "connect.h"
#include "send-pack.h"
@@ -444,8 +445,33 @@ static int fetch_refs_via_pack(struct transport *transport,
args.server_options = transport->server_options;
args.negotiation_tips = data->options.negotiation_tips;
args.reject_shallow_remote = transport->smart_options->reject_shallow;
+ args.object_info = transport->smart_options->object_info;
+
+ if (transport->smart_options
+ && transport->smart_options->object_info
+ && transport->smart_options->object_info_oids->nr > 0) {
+ struct packet_reader reader;
+ struct object_info_args obj_info_args = { 0 };
+
+ obj_info_args.server_options = transport->server_options;
+ obj_info_args.object_info_options = transport->smart_options->object_info_options;
+ obj_info_args.oids = transport->smart_options->object_info_oids;
+
+ connect_setup(transport, 0);
+ packet_reader_init(&reader, data->fd[0], NULL, 0,
+ PACKET_READ_CHOMP_NEWLINE |
+ PACKET_READ_GENTLE_ON_EOF |
+ PACKET_READ_DIE_ON_ERR_PACKET);
+
+ data->version = discover_version(&reader);
+ transport->hash_algo = reader.hash_algo;
+
+ ret = fetch_object_info(data->version, &obj_info_args, &reader,
+ data->options.object_info_data, transport->stateless_rpc,
+ data->fd[1]);
+ goto cleanup;
- if (!data->finished_handshake) {
+ } else if (!data->finished_handshake) {
int i;
int must_list_refs = 0;
for (i = 0; i < nr_heads; i++) {
diff --git a/transport.h b/transport.h
index 44100fa9b7..e61e931863 100644
--- a/transport.h
+++ b/transport.h
@@ -5,6 +5,7 @@
#include "remote.h"
#include "list-objects-filter-options.h"
#include "string-list.h"
+#include "object-store.h"
struct git_transport_options {
unsigned thin : 1;
@@ -30,6 +31,12 @@ struct git_transport_options {
*/
unsigned connectivity_checked:1;
+ /*
+ * Transport will attempt to retrieve only object-info.
+ * If object-info is not supported, the operation will error and exit.
+ */
+ unsigned object_info : 1;
+
int depth;
const char *deepen_since;
const struct string_list *deepen_not;
@@ -53,6 +60,10 @@ struct git_transport_options {
* common commits to this oidset instead of fetching any packfiles.
*/
struct oidset *acked_commits;
+
+ struct oid_array *object_info_oids;
+ struct object_info *object_info_data;
+ struct string_list *object_info_options;
};
enum transport_family {
--
2.47.0
