git/protocol.c
Jonathan Nieder 684ceae32d fetch: default to protocol version 2
The Git users at $DAYJOB have been using protocol v2 as a default for
~1.5 years now and others have been also reporting good experiences
with it, so it seems like a good time to bump the default version.  It
produces a significant performance improvement when fetching from
repositories with many refs, such as
https://chromium.googlesource.com/chromium/src.

This only affects the client, not the server.  (The server already
defaults to supporting protocol v2.)  The protocol change is backward
compatible, so this should produce no significant effect when
contacting servers that only speak protocol v0.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 14:03:55 -08:00

93 lines
2.4 KiB
C

#include "cache.h"
#include "config.h"
#include "protocol.h"
static enum protocol_version parse_protocol_version(const char *value)
{
if (!strcmp(value, "0"))
return protocol_v0;
else if (!strcmp(value, "1"))
return protocol_v1;
else if (!strcmp(value, "2"))
return protocol_v2;
else
return protocol_unknown_version;
}
enum protocol_version get_protocol_version_config(void)
{
const char *value;
const char *git_test_k = "GIT_TEST_PROTOCOL_VERSION";
const char *git_test_v;
if (!git_config_get_string_const("protocol.version", &value)) {
enum protocol_version version = parse_protocol_version(value);
if (version == protocol_unknown_version)
die("unknown value for config 'protocol.version': %s",
value);
return version;
}
git_test_v = getenv(git_test_k);
if (git_test_v && *git_test_v) {
enum protocol_version env = parse_protocol_version(git_test_v);
if (env == protocol_unknown_version)
die("unknown value for %s: %s", git_test_k, git_test_v);
return env;
}
return protocol_v2;
}
enum protocol_version determine_protocol_version_server(void)
{
const char *git_protocol = getenv(GIT_PROTOCOL_ENVIRONMENT);
enum protocol_version version = protocol_v0;
/*
* Determine which protocol version the client has requested. Since
* multiple 'version' keys can be sent by the client, indicating that
* the client is okay to speak any of them, select the greatest version
* that the client has requested. This is due to the assumption that
* the most recent protocol version will be the most state-of-the-art.
*/
if (git_protocol) {
struct string_list list = STRING_LIST_INIT_DUP;
const struct string_list_item *item;
string_list_split(&list, git_protocol, ':', -1);
for_each_string_list_item(item, &list) {
const char *value;
enum protocol_version v;
if (skip_prefix(item->string, "version=", &value)) {
v = parse_protocol_version(value);
if (v > version)
version = v;
}
}
string_list_clear(&list, 0);
}
return version;
}
enum protocol_version determine_protocol_version_client(const char *server_response)
{
enum protocol_version version = protocol_v0;
if (skip_prefix(server_response, "version ", &server_response)) {
version = parse_protocol_version(server_response);
if (version == protocol_unknown_version)
die("server is speaking an unknown protocol");
if (version == protocol_v0)
die("protocol error: server explicitly said version 0");
}
return version;
}