"""CDDB protocol implementation. Future Plans: - add server protocol - add not readonly client commands """ from twisted.internet import reactor, protocol from twisted.protocols import basic TERMINATING_MARKER = "." MAX_PROTO = "6" # response codes OK = 200 EXACT_MATCH = OK CURRENT_PROTO_LEVEL = OK OK_READ_ONLY = 201 OK_PROTO_LEVEL_CHANGED = 201 NO_MATCH_FOUND = 202 OK_FURTHER_DATA_FOLLOWS = 210 MULTIPLE_INEXACT_MATCHES = 211 OK_VERSION_INFO_FOLLOWS = 211 QUIT_OK_CLOSING = 230 NOT_AVAILABLE = 401 UNLINK_PERMISSION_DENIED = 401 FILE_ACCESS_FAILED = 402 SERVER_ERROR = 402 HANDSHAKE_ALREADY_DONE = 402 DB_ENTRY_CORRUPTED = 403 CGI_ENV_ERROR = 408 HANDSHAKE_NOT_DONE = 409 HANDSHAKE_FAILED = 431 CONNECT_PERMISSION_DENIED = 432 USER_LIMIT_EXCEED = 433 SYSTEM_LOAD_TOO_HIGH = 434 SYNTAX_ERROR = 500 UNKOWN_COMMAND = SYNTAX_ERROR UNIMPLEMENTED_COMMAND = SYNTAX_ERROR INVALID_DATA = 501 SAME_PROTO_LEVEL = 502 QUIT_ERROR_CLOSING = 530 SERVER_TIMEOUT = 530 # proper codes for each supported command login_codes = [OK, OK_READ_ONLY, CONNECT_PERMISSION_DENIED, USER_LIMIT_EXCEED, SYSTEM_LOAD_TOO_HIGH] hello_codes = [OK, HANDSHAKE_FAILED, HANDSHAKE_ALREADY_DONE] lscat_codes = [OK_FURTHER_DATA_FOLLOWS] query_codes = [EXACT_MATCH, MULTIPLE_INEXACT_MATCHES, NO_MATCH_FOUND, DB_ENTRY_CORRUPTED, HANDSHAKE_NOT_DONE] read_codes = [OK_FURTHER_DATA_FOLLOWS, NOT_AVAILABLE, SERVER_ERROR, DB_ENTRY_CORRUPTED, HANDSHAKE_NOT_DONE] discid_codes = [OK, SYNTAX_ERROR] help_codes = [OK_FURTHER_DATA_FOLLOWS, NOT_AVAILABLE] motd_codes = [OK_FURTHER_DATA_FOLLOWS, NOT_AVAILABLE] proto_codes = [CURRENT_PROTO_LEVEL, OK_PROTO_LEVEL_CHANGED, INVALID_DATA, SAME_PROTO_LEVEL] quit_codes = [QUIT_OK_CLOSING, QUIT_ERROR_CLOSING] sites_codes = [OK_FURTHER_DATA_FOLLOWS, NOT_AVAILABLE] stat_codes = [OK_FURTHER_DATA_FOLLOWS] ver_codes = [OK, OK_FURTHER_DATA_FOLLOWS] misc_codes = [SERVER_ERROR, CGI_ENV_ERROR, SYNTAX_ERROR, UNKOWN_COMMAND, UNIMPLEMENTED_COMMAND, SERVER_TIMEOUT] unlink_codes = [OK, UNLINK_PERMISSION_DENIED, FILE_ACCESS_FAILED, INVALID_DATA] # helper codes list successful_codes = [200, 201, 230] multi_line_codes = [210, 211] failure_error_codes = [431, 432, 433, 434] # dictionary to map codes RESPONSE_CODES = { "login": login_codes, "hello": hello_codes, "lscat": lscat_codes, "query": query_codes, "read": read_codes, "discid": discid_codes, "help": help_codes, "motd": motd_codes, "proto": proto_codes, "quit": quit_codes, "sites": sites_codes, "stat": stat_codes, "ver": ver_codes, "unlink": unlink_codes, "general_errors": misc_codes } class CDDBPClient(basic.LineReceiver): """ CDDB Protocol client implementation. @cvar buffer: Holds multi line reponse data. @cvar command: The current executing command. @cvar multi_line: Set it to true in L{self.handleStatus} when you expect further incoming data. """ buffer = [] command = "" multi_line = False def connectionMade(self): self.buffer = [] self.command = "login" self.multi_line = False def lineReceived(self, line): """ Called when a line is received from the server. This method checks if the current running command expects a multi line response or not and calls the right method to handle the incoming data. """ if not self.multi_line: code = int(line.split(" ", 1)[0]) self.handleStatus(code, line) else: if line == TERMINATING_MARKER: self.parseResponse(self.buffer[:]) self.buffer = [] self.multi_line = False else: self.buffer.append(line) def sendCommand(self, command, args=[]): """ Create string commands to send to the server. """ str = "%s %s" % (command, " ".join(args)) self.sendLine(str) def hello(self, username, hostname, app_name, app_version): """ Send 'hello' command to initiate the session (handshake). sample command: - C{cddb hello foo localhost app 1.0} """ self.command = "hello" self.sendCommand("cddb", [self.command, username, hostname, app_name, app_version]) def lscat(self): """ Send 'lscat' command to get the list of available categories. sample command: - C{cddb lscat} """ self.command = "lscat" self.sendCommand("cddb", [self.command]) def query(self, full_discid): """ Send 'query' command to query freedb for matching entries. full_discid has to be in the form explained in the U{CDDB-protocol documentation} sample command: - C{cddb query f2123610 16 150 29977 46577 68970 85297 104922 131622 150317 157300 181212 208612 231910 253045 273352 295987 326627 4664} @type full_discid: string @param full_discid: The discid (in hexadecimal lower case representation), followed by the number of tracks, the frame offset for each track and finally the length of the cd in seconds, for example: C{f2123610 16 150 29977 46577 68970 85297 104922 131622 150317 157300 181212 208612 231910 253045 273352 295987 326627 4664} """ self.command = "query" self.sendCommand("cddb", [self.command, full_discid]) def read(self, category, discid): """ Send 'read' command to read entries from a freedb server. L{query} must B{always} be called before this method. sample command: - C{cddb read misc f2123610} @type category: string @param category: Category has to be one of the available categories, call L{self.lscat} to know them. """ self.command = "read" self.sendCommand("cddb", [self.command, category, discid]) def discid(self, cd_data): """ Send 'discid' command to let the server compute discid from cd data. sample command: - C{discid 16 150 29977 46577 68970 85297 104922 131622 150317 157300 181212 208612 231910 253045 273352 295987 326627 4664} @type cd_data: string @param cd_data: The number of tracks followed by the frame offset of each cd track and the length of the cd in seconds, for example: C{16 150 29977 46577 68970 85297 104922 131622 150317 157300 181212 208612 231910 253045 273352 295987 326627 4664} """ self.command = "discid" self.sendCommand(self.command, [cd_data]) def proto(self, level=""): """ Send 'proto' command to get/set the server's current cddbp protocol level. The protocol level is a number between 1 and L{MAX_PROTO}. The protocol level number is optional (if you let it blank you get the current level). sample commands: - C{proto} or - C{proto 6} @type level: int @param level: The protocol level to set. """ self.command = "proto" self.sendCommand(self.command, [level]) def help(self, help_cmd="", help_subcmd=""): """ Send 'help' command to get help about supported commands. Sending only I{help} returns a brief explanation of available commands. You can gain more help adding a specific command to help_cmd argument and help_subcmd argument. sample commands: - C{help} or - C{help quit} or - C{help cddb hello} @type help_cmd: string @param help_cmd: Represents the command to get help for @type help_subcmd: string @param help_subcmd: Represents the sub command to get help for """ self.command = "help" self.sendCommand(self.command, [help_cmd, help_subcmd]) def motd(self): """ Send 'motd' command to get the message of the day. sample command: - C{motd} """ self.command = "motd" self.sendCommand(self.command) def quit(self): """ Send 'quit' command to close the connection. sample command: - C{quit} """ self.command = "quit" self.sendCommand(self.command) def sites(self): """ Send 'sites' command to get the whole list of known freedb mirrors. sample command: - C{sites} """ self.command = "sites" self.sendCommand(self.command) def stat(self): """ Send 'stat' command to get the server's status. sample command: - C{stat} """ self.command = "stat" self.sendCommand(self.command) def ver(self): """ Send 'ver' command to get the server's version. sample command: - C{ver} """ self.command = "ver" self.sendCommand(self.command) def unlink(self, category, discid): """ Send 'unlink' command to delete an entry from database. Only administrative users could succeed issuing this command. sample command: - C{cddb unlink misc f2123610} @type category: string @param category: Category has to be one of the available categories, call L{self.lscat} to know them. """ self.command = "unlink" self.sendCommand("cddb", [self.command, category, discid]) def handleStatus(self, code, line): """ Handle status response strings. Called from L{self.lineReceived} when it encounters the first line of a a response received from the server. Use I{code} parameter and L{self.command} variable to check if the current command response will have subsequents response lines setting L{self.multi_line} to True. Due to oddities in the protocol you have to remember to set it manually. @type code: int @param code: The response code @type line: string @param line: The first line of incoming data. """ raise NotImplementedError def parseResponse(self, response): """ Parse multi line response data. Called from L{self.lineReceived} when multi line response data has ended, so you could extract needed information from the data. @type response: list @param response: Holds the full response data, each item of the list corresponds to a new line in the response. """ raise NotImplementedError class CDDBPClientFactory(protocol.ClientFactory): protocol = CDDBPClient def clientLostConnection(self, connector, reason): print reason clientConnectionFailed = clientLostConnection