Create protocol.{c,h} and provide functions which future servers and
clients can use to determine which protocol to use or is being used.
Also introduce the 'GIT_PROTOCOL' environment variable which will be
used to communicate a colon separated list of keys with optional values
to a server.  Unknown keys and values must be tolerated.  This mechanism
is used to communicate which version of the wire protocol a client would
like to use with a server.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
		
	
		
			
				
	
	
		
			80 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			80 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#include "cache.h"
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#include "config.h"
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#include "protocol.h"
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static enum protocol_version parse_protocol_version(const char *value)
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{
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	if (!strcmp(value, "0"))
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		return protocol_v0;
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	else if (!strcmp(value, "1"))
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		return protocol_v1;
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	else
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		return protocol_unknown_version;
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}
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enum protocol_version get_protocol_version_config(void)
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{
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	const char *value;
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	if (!git_config_get_string_const("protocol.version", &value)) {
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		enum protocol_version version = parse_protocol_version(value);
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		if (version == protocol_unknown_version)
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			die("unknown value for config 'protocol.version': %s",
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			    value);
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		return version;
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	}
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	return protocol_v0;
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}
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enum protocol_version determine_protocol_version_server(void)
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{
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	const char *git_protocol = getenv(GIT_PROTOCOL_ENVIRONMENT);
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	enum protocol_version version = protocol_v0;
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	/*
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	 * Determine which protocol version the client has requested.  Since
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	 * multiple 'version' keys can be sent by the client, indicating that
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	 * the client is okay to speak any of them, select the greatest version
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	 * that the client has requested.  This is due to the assumption that
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	 * the most recent protocol version will be the most state-of-the-art.
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	 */
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	if (git_protocol) {
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		struct string_list list = STRING_LIST_INIT_DUP;
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		const struct string_list_item *item;
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		string_list_split(&list, git_protocol, ':', -1);
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		for_each_string_list_item(item, &list) {
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			const char *value;
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			enum protocol_version v;
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			if (skip_prefix(item->string, "version=", &value)) {
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				v = parse_protocol_version(value);
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				if (v > version)
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					version = v;
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			}
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		}
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		string_list_clear(&list, 0);
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	}
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	return version;
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}
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enum protocol_version determine_protocol_version_client(const char *server_response)
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{
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	enum protocol_version version = protocol_v0;
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	if (skip_prefix(server_response, "version ", &server_response)) {
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		version = parse_protocol_version(server_response);
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		if (version == protocol_unknown_version)
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			die("server is speaking an unknown protocol");
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		if (version == protocol_v0)
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			die("protocol error: server explicitly said version 0");
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	}
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	return version;
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}
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