ais.ais_msg

1 #!/usr/bin/env python 2 3 __version__ = '$Revision: 4791 $'.split()[1] 4 __date__ = '$Date: 2007-03-31 $'.split()[1] 5 __author__ = 'xmlbinmsg' 6 7 __doc__=''' 8 9 Autogenerated python functions to serialize/deserialize binary messages. 10 11 Generated by: ./aisxmlbinmsg2py.py 12 13 Need to then wrap these functions with the outer AIS packet and then 14 convert the whole binary blob to a NMEA string. Those functions are 15 not currently provided in this file. 16 17 serialize: python to ais binary 18 deserialize: ais binary to python 19 20 The generated code uses translators.py, binary.py, and aisstring.py 21 which should be packaged with the resulting files. 22 23 24 @requires: U{epydoc<http://epydoc.sourceforge.net/>} > 3.0alpha3 25 @requires: U{BitVector<http://cheeseshop.python.org/pypi/BitVector>} 26 27 @author: '''+__author__+''' 28 @version: ''' + __version__ +''' 29 @var __date__: Date of last svn commit 30 @undocumented: __version__ __author__ __doc__ parser 31 @status: under development 32 @license: Generated code has no license 33 @todo: FIX: put in a description of the message here with fields and types. 34 ''' 35 36 import sys 37 from decimal import Decimal 38 from BitVector import BitVector 39 40 import binary, aisstring 41 42 # FIX: check to see if these will be needed 43 TrueBV = BitVector(bitstring="1") 44 "Why always rebuild the True bit? This should speed things up a bunch" 45 FalseBV = BitVector(bitstring="0") 46 "Why always rebuild the False bit? This should speed things up a bunch" 47 48 49 fieldList = ( 50 'MessageID', 51 'RepeatIndicator', 52 'UserID', 53 'SeqNum', 54 'DestinationID', 55 'RetransmitFlag', 56 'Spare', 57 ) 58 59 fieldListPostgres = ( 60 'MessageID', 61 'RepeatIndicator', 62 'UserID', 63 'SeqNum', 64 'DestinationID', 65 'RetransmitFlag', 66 'Spare', 67 ) 68 69 toPgFields = { 70 } 71 ''' 72 Go to the Postgis field names from the straight field name 73 ''' 74 75 fromPgFields = { 76 } 77 ''' 78 Go from the Postgis field names to the straight field name 79 ''' 80 81 pgTypes = { 82 } 83 ''' 84 Lookup table for each postgis field name to get its type. 85 ''' 86

87 -def encode(params, validate=False):

88 '''Create a asrm binary message payload to pack into an AIS Msg asrm. 89 90 Fields in params: 91 - MessageID(uint): AIS message number. Must be 6 (field automatically set to "6") 92 - RepeatIndicator(uint): Indicated how many times a message has been repeated 93 - UserID(uint): Unique ship identification number (MMSI). Also known as the Source ID 94 - SeqNum(uint): Sequence number as described in 5.3.1. Assigned to each station 95 - DestinationID(uint): Unique ship identification number (MMSI). 96 - RetransmitFlag(bool): Should the message be restransmitted? 97 - Spare(uint): Must be 0 (field automatically set to "0") 98 @param params: Dictionary of field names/values. Throws a ValueError exception if required is missing 99 @param validate: Set to true to cause checking to occur. Runs slower. FIX: not implemented. 100 @rtype: BitVector 101 @return: encoded binary message (for binary messages, this needs to be wrapped in a msg 8 102 @note: The returned bits may not be 6 bit aligned. It is up to you to pad out the bits. 103 ''' 104 105 bvList = [] 106 bvList.append(binary.setBitVectorSize(BitVector(intVal=6),6)) 107 if 'RepeatIndicator' in params: 108 bvList.append(binary.setBitVectorSize(BitVector(intVal=params['RepeatIndicator']),2)) 109 else: 110 bvList.append(binary.setBitVectorSize(BitVector(intVal=0),2)) 111 bvList.append(binary.setBitVectorSize(BitVector(intVal=params['UserID']),30)) 112 bvList.append(binary.setBitVectorSize(BitVector(intVal=params['SeqNum']),2)) 113 bvList.append(binary.setBitVectorSize(BitVector(intVal=params['DestinationID']),30)) 114 if params["RetransmitFlag"]: bvList.append(TrueBV) 115 else: bvList.append(FalseBV) 116 bvList.append(binary.setBitVectorSize(BitVector(intVal=0),1)) 117 118 return binary.joinBV(bvList)

119

120 -def decode(bv, validate=False):

121 '''Unpack a asrm message 122 123 Fields in params: 124 - MessageID(uint): AIS message number. Must be 6 (field automatically set to "6") 125 - RepeatIndicator(uint): Indicated how many times a message has been repeated 126 - UserID(uint): Unique ship identification number (MMSI). Also known as the Source ID 127 - SeqNum(uint): Sequence number as described in 5.3.1. Assigned to each station 128 - DestinationID(uint): Unique ship identification number (MMSI). 129 - RetransmitFlag(bool): Should the message be restransmitted? 130 - Spare(uint): Must be 0 (field automatically set to "0") 131 @type bv: BitVector 132 @param bv: Bits defining a message 133 @param validate: Set to true to cause checking to occur. Runs slower. FIX: not implemented. 134 @rtype: dict 135 @return: params 136 ''' 137 138 #Would be nice to check the bit count here.. 139 #if validate: 140 # assert (len(bv)==FIX: SOME NUMBER) 141 r = {} 142 r['MessageID']=6 143 r['RepeatIndicator']=int(bv[6:8]) 144 r['UserID']=int(bv[8:38]) 145 r['SeqNum']=int(bv[38:40]) 146 r['DestinationID']=int(bv[40:70]) 147 r['RetransmitFlag']=bool(int(bv[70:71])) 148 r['Spare']=0 149 return r

150

151 -def decodeMessageID(bv, validate=False):

152 return 6

153

154 -def decodeRepeatIndicator(bv, validate=False):

155 return int(bv[6:8])

156

157 -def decodeUserID(bv, validate=False):

158 return int(bv[8:38])

159

160 -def decodeSeqNum(bv, validate=False):

161 return int(bv[38:40])

162

163 -def decodeDestinationID(bv, validate=False):

164 return int(bv[40:70])

165

166 -def decodeRetransmitFlag(bv, validate=False):

167 return bool(int(bv[70:71]))

168

169 -def decodeSpare(bv, validate=False):

170 return 0

171 172

173 -def printHtml(params, out=sys.stdout):

174 out.write("<h3>asrm<h3>\n") 175 out.write("<table border=\"1\">\n") 176 out.write("<tr bgcolor=\"orange\">\n") 177 out.write("<th align=\"left\">Field Name</th>\n") 178 out.write("<th align=\"left\">Type</th>\n") 179 out.write("<th align=\"left\">Value</th>\n") 180 out.write("<th align=\"left\">Value in Lookup Table</th>\n") 181 out.write("<th align=\"left\">Units</th>\n") 182 out.write("\n") 183 out.write("<tr>\n") 184 out.write("<td>MessageID</td>\n") 185 out.write("<td>uint</td>\n") 186 if 'MessageID' in params: 187 out.write(" <td>"+str(params['MessageID'])+"</td>\n") 188 out.write(" <td>"+str(params['MessageID'])+"</td>\n") 189 out.write("</tr>\n") 190 out.write("\n") 191 out.write("<tr>\n") 192 out.write("<td>RepeatIndicator</td>\n") 193 out.write("<td>uint</td>\n") 194 if 'RepeatIndicator' in params: 195 out.write(" <td>"+str(params['RepeatIndicator'])+"</td>\n") 196 if str(params['RepeatIndicator']) in RepeatIndicatorDecodeLut: 197 out.write("<td>"+RepeatIndicatorDecodeLut[str(params['RepeatIndicator'])]+"</td>") 198 else: 199 out.write("<td><i>Missing LUT entry</i></td>") 200 out.write("</tr>\n") 201 out.write("\n") 202 out.write("<tr>\n") 203 out.write("<td>UserID</td>\n") 204 out.write("<td>uint</td>\n") 205 if 'UserID' in params: 206 out.write(" <td>"+str(params['UserID'])+"</td>\n") 207 out.write(" <td>"+str(params['UserID'])+"</td>\n") 208 out.write("</tr>\n") 209 out.write("\n") 210 out.write("<tr>\n") 211 out.write("<td>SeqNum</td>\n") 212 out.write("<td>uint</td>\n") 213 if 'SeqNum' in params: 214 out.write(" <td>"+str(params['SeqNum'])+"</td>\n") 215 out.write(" <td>"+str(params['SeqNum'])+"</td>\n") 216 out.write("</tr>\n") 217 out.write("\n") 218 out.write("<tr>\n") 219 out.write("<td>DestinationID</td>\n") 220 out.write("<td>uint</td>\n") 221 if 'DestinationID' in params: 222 out.write(" <td>"+str(params['DestinationID'])+"</td>\n") 223 out.write(" <td>"+str(params['DestinationID'])+"</td>\n") 224 out.write("</tr>\n") 225 out.write("\n") 226 out.write("<tr>\n") 227 out.write("<td>RetransmitFlag</td>\n") 228 out.write("<td>bool</td>\n") 229 if 'RetransmitFlag' in params: 230 out.write(" <td>"+str(params['RetransmitFlag'])+"</td>\n") 231 out.write(" <td>"+str(params['RetransmitFlag'])+"</td>\n") 232 out.write("</tr>\n") 233 out.write("\n") 234 out.write("<tr>\n") 235 out.write("<td>Spare</td>\n") 236 out.write("<td>uint</td>\n") 237 if 'Spare' in params: 238 out.write(" <td>"+str(params['Spare'])+"</td>\n") 239 out.write(" <td>"+str(params['Spare'])+"</td>\n") 240 out.write("</tr>\n") 241 out.write("</table>\n")

242

243 -def printFields(params, out=sys.stdout, format='std', fieldList=None, dbType='postgres'):

244 '''Print a asrm message to stdout. 245 246 Fields in params: 247 - MessageID(uint): AIS message number. Must be 6 (field automatically set to "6") 248 - RepeatIndicator(uint): Indicated how many times a message has been repeated 249 - UserID(uint): Unique ship identification number (MMSI). Also known as the Source ID 250 - SeqNum(uint): Sequence number as described in 5.3.1. Assigned to each station 251 - DestinationID(uint): Unique ship identification number (MMSI). 252 - RetransmitFlag(bool): Should the message be restransmitted? 253 - Spare(uint): Must be 0 (field automatically set to "0") 254 @param params: Dictionary of field names/values. 255 @param out: File like object to write to 256 @rtype: stdout 257 @return: text to out 258 ''' 259 260 if 'std'==format: 261 out.write("asrm:\n") 262 if 'MessageID' in params: out.write(" MessageID: "+str(params['MessageID'])+"\n") 263 if 'RepeatIndicator' in params: out.write(" RepeatIndicator: "+str(params['RepeatIndicator'])+"\n") 264 if 'UserID' in params: out.write(" UserID: "+str(params['UserID'])+"\n") 265 if 'SeqNum' in params: out.write(" SeqNum: "+str(params['SeqNum'])+"\n") 266 if 'DestinationID' in params: out.write(" DestinationID: "+str(params['DestinationID'])+"\n") 267 if 'RetransmitFlag' in params: out.write(" RetransmitFlag: "+str(params['RetransmitFlag'])+"\n") 268 if 'Spare' in params: out.write(" Spare: "+str(params['Spare'])+"\n") 269 elif 'csv'==format: 270 if None == options.fieldList: 271 options.fieldList = fieldList 272 needComma = False; 273 for field in fieldList: 274 if needComma: out.write(',') 275 needComma = True 276 if field in params: 277 out.write(str(params[field])) 278 # else: leave it empty 279 out.write("\n") 280 elif 'html'==format: 281 printHtml(params,out) 282 elif 'sql'==format: 283 sqlInsertStr(params,out,dbType=dbType) 284 else: 285 print "ERROR: unknown format:",format 286 assert False 287 288 return # Nothing to return

289 290 RepeatIndicatorEncodeLut = { 291 'default':'0', 292 'do not repeat any more':'3', 293 } #RepeatIndicatorEncodeLut 294 295 RepeatIndicatorDecodeLut = { 296 '0':'default', 297 '3':'do not repeat any more', 298 } # RepeatIndicatorEncodeLut 299 300 ###################################################################### 301 # SQL SUPPORT 302 ###################################################################### 303

304 -def sqlCreateStr(outfile=sys.stdout, fields=None, extraFields=None 305 ,addCoastGuardFields=True 306 ,dbType='postgres' 307 ):

308 ''' 309 Return the SQL CREATE command for this message type 310 @param outfile: file like object to print to. 311 @param fields: which fields to put in the create. Defaults to all. 312 @param extraFields: A sequence of tuples containing (name,sql type) for additional fields 313 @param addCoastGuardFields: Add the extra fields that come after the NMEA check some from the USCG N-AIS format 314 @param dbType: Which flavor of database we are using so that the create is tailored ('sqlite' or 'postgres') 315 @type addCoastGuardFields: bool 316 @return: sql create string 317 @rtype: str 318 319 @see: sqlCreate 320 ''' 321 # FIX: should this sqlCreate be the same as in LaTeX (createFuncName) rather than hard coded? 322 outfile.write(str(sqlCreate(fields,extraFields,addCoastGuardFields,dbType=dbType)))

323

324 -def sqlCreate(fields=None, extraFields=None, addCoastGuardFields=True, dbType='postgres'):

325 ''' 326 Return the sqlhelp object to create the table. 327 328 @param fields: which fields to put in the create. Defaults to all. 329 @param extraFields: A sequence of tuples containing (name,sql type) for additional fields 330 @param addCoastGuardFields: Add the extra fields that come after the NMEA check some from the USCG N-AIS format 331 @type addCoastGuardFields: bool 332 @param dbType: Which flavor of database we are using so that the create is tailored ('sqlite' or 'postgres') 333 @return: An object that can be used to generate a return 334 @rtype: sqlhelp.create 335 ''' 336 if None == fields: fields = fieldList 337 import sqlhelp 338 c = sqlhelp.create('asrm',dbType=dbType) 339 c.addPrimaryKey() 340 if 'MessageID' in fields: c.addInt ('MessageID') 341 if 'RepeatIndicator' in fields: c.addInt ('RepeatIndicator') 342 if 'UserID' in fields: c.addInt ('UserID') 343 if 'SeqNum' in fields: c.addInt ('SeqNum') 344 if 'DestinationID' in fields: c.addInt ('DestinationID') 345 if 'RetransmitFlag' in fields: c.addBool('RetransmitFlag') 346 if 'Spare' in fields: c.addInt ('Spare') 347 348 if addCoastGuardFields: 349 # c.addInt('cg_rssi') # Relative signal strength indicator 350 # c.addInt('cg_d') # dBm receive strength 351 # c.addInt('cg_T') # Receive timestamp from the AIS equipment 352 # c.addInt('cg_S') # Slot received in 353 # c.addVarChar('cg_x',10) # Idonno 354 c.addVarChar('cg_r',15) # Receiver station ID - should usually be an MMSI, but sometimes is a string 355 c.addInt('cg_sec') # UTC seconds since the epoch 356 357 c.addTimestamp('cg_timestamp') # UTC decoded cg_sec - not actually in the data stream 358 359 return c

360

361 -def sqlInsertStr(params, outfile=sys.stdout, extraParams=None, dbType='postgres'):

362 ''' 363 Return the SQL INSERT command for this message type 364 @param params: dictionary of values keyed by field name 365 @param outfile: file like object to print to. 366 @param extraParams: A sequence of tuples containing (name,sql type) for additional fields 367 @return: sql create string 368 @rtype: str 369 370 @see: sqlCreate 371 ''' 372 outfile.write(str(sqlInsert(params,extraParams,dbType=dbType)))

373 374

375 -def sqlInsert(params,extraParams=None,dbType='postgres'):

376 ''' 377 Give the SQL INSERT statement 378 @param params: dict keyed by field name of values 379 @param extraParams: any extra fields that you have created beyond the normal ais message fields 380 @rtype: sqlhelp.insert 381 @return: insert class instance 382 @todo: allow optional type checking of params? 383 @warning: this will take invalid keys happily and do what??? 384 ''' 385 import sqlhelp 386 i = sqlhelp.insert('asrm',dbType=dbType) 387 388 if dbType=='postgres': 389 finished = [] 390 for key in params: 391 if key in finished: 392 continue 393 394 if key not in toPgFields and key not in fromPgFields: 395 if type(params[key])==Decimal: i.add(key,float(params[key])) 396 else: i.add(key,params[key]) 397 else: 398 if key in fromPgFields: 399 val = params[key] 400 # Had better be a WKT type like POINT(-88.1 30.321) 401 i.addPostGIS(key,val) 402 finished.append(key) 403 else: 404 # Need to construct the type. 405 pgName = toPgFields[key] 406 #valStr='GeomFromText(\''+pgTypes[pgName]+'(' 407 valStr=pgTypes[pgName]+'(' 408 vals = [] 409 for nonPgKey in fromPgFields[pgName]: 410 vals.append(str(params[nonPgKey])) 411 finished.append(nonPgKey) 412 valStr+=' '.join(vals)+')' 413 i.addPostGIS(pgName,valStr) 414 else: 415 for key in params: 416 if type(params[key])==Decimal: i.add(key,float(params[key])) 417 else: i.add(key,params[key]) 418 419 if None != extraParams: 420 for key in extraParams: 421 i.add(key,extraParams[key]) 422 423 return i

424 425 ###################################################################### 426 # LATEX SUPPORT 427 ###################################################################### 428

429 -def latexDefinitionTable(outfile=sys.stdout 430 ):

431 ''' 432 Return the LaTeX definition table for this message type 433 @param outfile: file like object to print to. 434 @type outfile: file obj 435 @return: LaTeX table string via the outfile 436 @rtype: str 437 438 ''' 439 o = outfile 440 441 o.write(''' 442 \\begin{table}%[htb] 443 \\centering 444 \\begin{tabular}{|l|c|l|} 445 \\hline 446 Parameter & Number of bits & Description 447 \\\\ \\hline\\hline 448 MessageID & 6 & AIS message number. Must be 6 \\\\ \hline 449 RepeatIndicator & 2 & Indicated how many times a message has been repeated \\\\ \hline 450 UserID & 30 & Unique ship identification number (MMSI). Also known as the Source ID \\\\ \hline 451 SeqNum & 2 & Sequence number as described in 5.3.1. Assigned to each station \\\\ \hline 452 DestinationID & 30 & Unique ship identification number (MMSI). \\\\ \hline 453 RetransmitFlag & 1 & Should the message be restransmitted? \\\\ \hline 454 Spare & 1 & Must be 0\\\\ \\hline \\hline 455 Total bits & 72 & Appears to take 1 slot with 96 pad bits to fill the last slot \\\\ \\hline 456 \\end{tabular} 457 \\caption{AIS message number 8: Addressed safety related message. FIX: need to handle the -1 string length at the end} 458 \\label{tab:asrm} 459 \\end{table} 460 ''')

461 462 463 ###################################################################### 464 # UNIT TESTING 465 ###################################################################### 466 import unittest

467 -def testParams():

468 '''Return a params file base on the testvalue tags. 469 @rtype: dict 470 @return: params based on testvalue tags 471 ''' 472 params = {} 473 params['MessageID'] = 6 474 params['RepeatIndicator'] = 1 475 params['UserID'] = 1193046 476 params['SeqNum'] = 3 477 params['DestinationID'] = 1193047 478 params['RetransmitFlag'] = True 479 params['Spare'] = 0 480 481 return params

482

483 -class Testasrm(unittest.TestCase):

484 '''Use testvalue tag text from each type to build test case the asrm message'''

485 - def testEncodeDecode(self):

486 487 params = testParams() 488 bits = encode(params) 489 r = decode(bits) 490 491 # Check that each parameter came through ok. 492 self.failUnlessEqual(r['MessageID'],params['MessageID']) 493 self.failUnlessEqual(r['RepeatIndicator'],params['RepeatIndicator']) 494 self.failUnlessEqual(r['UserID'],params['UserID']) 495 self.failUnlessEqual(r['SeqNum'],params['SeqNum']) 496 self.failUnlessEqual(r['DestinationID'],params['DestinationID']) 497 self.failUnlessEqual(r['RetransmitFlag'],params['RetransmitFlag']) 498 self.failUnlessEqual(r['Spare'],params['Spare'])

499

500 -def addMsgOptions(parser):

501 parser.add_option('-d','--decode',dest='doDecode',default=False,action='store_true', 502 help='decode a "asrm" AIS message') 503 parser.add_option('-e','--encode',dest='doEncode',default=False,action='store_true', 504 help='encode a "asrm" AIS message') 505 parser.add_option('--RepeatIndicator-field', dest='RepeatIndicatorField',default=0,metavar='uint',type='int' 506 ,help='Field parameter value [default: %default]') 507 parser.add_option('--UserID-field', dest='UserIDField',metavar='uint',type='int' 508 ,help='Field parameter value [default: %default]') 509 parser.add_option('--SeqNum-field', dest='SeqNumField',metavar='uint',type='int' 510 ,help='Field parameter value [default: %default]') 511 parser.add_option('--DestinationID-field', dest='DestinationIDField',metavar='uint',type='int' 512 ,help='Field parameter value [default: %default]') 513 parser.add_option('--RetransmitFlag-field', dest='RetransmitFlagField',metavar='bool',type='int' 514 ,help='Field parameter value [default: %default]')

515 516 ############################################################ 517 if __name__=='__main__': 518 519 from optparse import OptionParser 520 parser = OptionParser(usage="%prog [options]", 521 version="%prog "+__version__) 522 523 parser.add_option('--doc-test',dest='doctest',default=False,action='store_true', 524 help='run the documentation tests') 525 parser.add_option('--unit-test',dest='unittest',default=False,action='store_true', 526 help='run the unit tests') 527 parser.add_option('-v','--verbose',dest='verbose',default=False,action='store_true', 528 help='Make the test output verbose') 529 530 # FIX: remove nmea from binary messages. No way to build the whole packet? 531 # FIX: or build the surrounding msg 8 for a broadcast? 532 typeChoices = ('binary','nmeapayload','nmea') # FIX: what about a USCG type message? 533 parser.add_option('-t','--type',choices=typeChoices,type='choice',dest='ioType' 534 ,default='nmeapayload' 535 ,help='What kind of string to write for encoding ('+', '.join(typeChoices)+') [default: %default]') 536 537 538 outputChoices = ('std','html','csv','sql' ) 539 parser.add_option('-T','--output-type',choices=outputChoices,type='choice',dest='outputType' 540 ,default='std' 541 ,help='What kind of string to output ('+', '.join(outputChoices)+') [default: %default]') 542 543 parser.add_option('-o','--output',dest='outputFileName',default=None, 544 help='Name of the python file to write [default: stdout]') 545 546 parser.add_option('-f','--fields',dest='fieldList',default=None, action='append', 547 choices=fieldList, 548 help='Which fields to include in the output. Currently only for csv output [default: all]') 549 550 parser.add_option('-p','--print-csv-field-list',dest='printCsvfieldList',default=False,action='store_true', 551 help='Print the field name for csv') 552 553 parser.add_option('-c','--sql-create',dest='sqlCreate',default=False,action='store_true', 554 help='Print out an sql create command for the table.') 555 556 parser.add_option('--latex-table',dest='latexDefinitionTable',default=False,action='store_true', 557 help='Print a LaTeX table of the type') 558 559 dbChoices = ('sqlite','postgres') 560 parser.add_option('-D','--db-type',dest='dbType',default='postgres' 561 ,choices=dbChoices,type='choice' 562 ,help='What kind of database ('+', '.join(dbChoices)+') [default: %default]') 563 564 addMsgOptions(parser) 565 566 (options,args) = parser.parse_args() 567 success=True 568 569 if options.doctest: 570 import os; print os.path.basename(sys.argv[0]), 'doctests ...', 571 sys.argv= [sys.argv[0]] 572 if options.verbose: sys.argv.append('-v') 573 import doctest 574 numfail,numtests=doctest.testmod() 575 if numfail==0: print 'ok' 576 else: 577 print 'FAILED' 578 success=False 579 580 if not success: sys.exit('Something Failed') 581 del success # Hide success from epydoc 582 583 if options.unittest: 584 sys.argv = [sys.argv[0]] 585 if options.verbose: sys.argv.append('-v') 586 unittest.main() 587 588 outfile = sys.stdout 589 if None!=options.outputFileName: 590 outfile = file(options.outputFileName,'w') 591 592 593 if options.doEncode: 594 # First make sure all non required options are specified 595 if None==options.RepeatIndicatorField: parser.error("missing value for RepeatIndicatorField") 596 if None==options.UserIDField: parser.error("missing value for UserIDField") 597 if None==options.SeqNumField: parser.error("missing value for SeqNumField") 598 if None==options.DestinationIDField: parser.error("missing value for DestinationIDField") 599 if None==options.RetransmitFlagField: parser.error("missing value for RetransmitFlagField") 600 msgDict={ 601 'MessageID': '6', 602 'RepeatIndicator': options.RepeatIndicatorField, 603 'UserID': options.UserIDField, 604 'SeqNum': options.SeqNumField, 605 'DestinationID': options.DestinationIDField, 606 'RetransmitFlag': options.RetransmitFlagField, 607 'Spare': '0', 608 } 609 610 bits = encode(msgDict) 611 if 'binary'==options.ioType: print str(bits) 612 elif 'nmeapayload'==options.ioType: 613 # FIX: figure out if this might be necessary at compile time 614 print "bitLen",len(bits) 615 bitLen=len(bits) 616 if bitLen%6!=0: 617 bits = bits + BitVector(size=(6 - (bitLen%6))) # Pad out to multiple of 6 618 print "result:",binary.bitvectoais6(bits)[0] 619 620 621 # FIX: Do not emit this option for the binary message payloads. Does not make sense. 622 elif 'nmea'==options.ioType: sys.exit("FIX: need to implement this capability") 623 else: sys.exit('ERROR: unknown ioType. Help!') 624 625 626 if options.sqlCreate: 627 sqlCreateStr(outfile,options.fieldList,dbType=options.dbType) 628 629 if options.latexDefinitionTable: 630 latexDefinitionTable(outfile) 631 632 if options.printCsvfieldList: 633 # Make a csv separated list of fields that will be displayed for csv 634 if None == options.fieldList: options.fieldList = fieldList 635 import StringIO 636 buf = StringIO.StringIO() 637 for field in options.fieldList: 638 buf.write(field+',') 639 result = buf.getvalue() 640 if result[-1] == ',': print result[:-1] 641 else: print result 642 643 if options.doDecode: 644 for msg in args: 645 bv = None 646 647 if msg[0] in ('$','!') and msg[3:6] in ('VDM','VDO'): 648 # Found nmea 649 # FIX: do checksum 650 bv = binary.ais6tobitvec(msg.split(',')[5]) 651 else: # either binary or nmeapayload... expect mostly nmeapayloads 652 # assumes that an all 0 and 1 string can not be a nmeapayload 653 binaryMsg=True 654 for c in msg: 655 if c not in ('0','1'): 656 binaryMsg=False 657 break 658 if binaryMsg: 659 bv = BitVector(bitstring=msg) 660 else: # nmeapayload 661 bv = binary.ais6tobitvec(msg) 662 663 printFields(decode(bv) 664 ,out=outfile 665 ,format=options.outputType 666 ,fieldList=options.fieldList 667 ,dbType=options.dbType 668 ) 669

Source Code for Module ais.ais_msg_12