codegen.py

# ***** BEGIN LICENSE BLOCK *****
#
# For copyright and licensing please refer to COPYING.
#
# ***** END LICENSE BLOCK *****

from __future__ import nested_scopes

import sys
sys.path.append("../rabbitmq-codegen")  # in case we're next to an experimental revision
sys.path.append("codegen")              # in case we're building from a distribution package

from amqp_codegen import *
import re

DRIVER_METHODS = {
    "Exchange.Bind": ["Exchange.BindOk"],
    "Exchange.Unbind": ["Exchange.UnbindOk"],
    "Exchange.Declare": ["Exchange.DeclareOk"],
    "Exchange.Delete": ["Exchange.DeleteOk"],
    "Queue.Declare": ["Queue.DeclareOk"],
    "Queue.Bind": ["Queue.BindOk"],
    "Queue.Purge": ["Queue.PurgeOk"],
    "Queue.Delete": ["Queue.DeleteOk"],
    "Queue.Unbind": ["Queue.UnbindOk"],
    "Basic.Qos": ["Basic.QosOk"],
    "Basic.Get": ["Basic.GetOk", "Basic.GetEmpty"],
    "Basic.Ack": [],
    "Basic.Reject": [],
    "Basic.Recover": ["Basic.RecoverOk"],
    "Basic.RecoverAsync": [],
    "Tx.Select": ["Tx.SelectOk"],
    "Tx.Commit": ["Tx.CommitOk"],
    "Tx.Rollback": ["Tx.RollbackOk"]
    }


def fieldvalue(v):
    if isinstance(v, unicode):
        return repr(v.encode('ascii'))
    else:
        return repr(v)


def normalize_separators(s):
    s = s.replace('-', '_')
    s = s.replace(' ', '_')
    return s


def pyize(s):
    s = normalize_separators(s)
    if s in ('global', 'class'):
        s += '_'
    return s


def camel(s):
    return normalize_separators(s).title().replace('_', '')


AmqpMethod.structName = lambda m: camel(m.klass.name) + '.' + camel(m.name)
AmqpClass.structName = lambda c: camel(c.name) + "Properties"


def constantName(s):
    return '_'.join(re.split('[- ]', s.upper()))


def flagName(c, f):
    if c:
        return c.structName() + '.' + constantName('flag_' + f.name)
    else:
        return constantName('flag_' + f.name)


def generate(specPath):
    spec = AmqpSpec(specPath)

    def genSingleDecode(prefix, cLvalue, unresolved_domain):
        type = spec.resolveDomain(unresolved_domain)
        if type == 'shortstr':
            print prefix + "length = struct.unpack_from('B', encoded, offset)[0]"
            print prefix + "offset += 1"
            print prefix + "%s = encoded[offset:offset + length]" % cLvalue
            print prefix + "offset += length"
        elif type == 'longstr':
            print prefix + "length = struct.unpack_from('>I', encoded, offset)[0]"
            print prefix + "offset += 4"
            print prefix + "%s = encoded[offset:offset + length]" % cLvalue
            print prefix + "offset += length"
        elif type == 'octet':
            print prefix + "%s = struct.unpack_from('B', encoded, offset)[0]" % cLvalue
            print prefix + "offset += 1"
        elif type == 'short':
            print prefix + "%s = struct.unpack_from('>H', encoded, offset)[0]" % cLvalue
            print prefix + "offset += 2"
        elif type == 'long':
            print prefix + "%s = struct.unpack_from('>I', encoded, offset)[0]" % cLvalue
            print prefix + "offset += 4"
            print prefix + "if PYTHON_VERSION == 2.4:"
            print prefix + "    %s = int(%s)" % (cLvalue, cLvalue)
        elif type == 'longlong':
            print prefix + "%s = struct.unpack_from('>Q', encoded, offset)[0]" % cLvalue
            print prefix + "offset += 8"
            print prefix + "if PYTHON_VERSION == 2.4:"
            print prefix + "    %s = int(%s)" % (cLvalue, cLvalue)
        elif type == 'timestamp':
            print prefix + "%s = struct.unpack_from('>Q', encoded, offset)[0]" % cLvalue
            print prefix + "offset += 8"
        elif type == 'bit':
            raise Exception("Can't decode bit in genSingleDecode")
        elif type == 'table':
            print Exception(prefix + "(%s, offset) = data.decode_table(encoded, offset)" % \
                  cLvalue)
        else:
            raise Exception("Illegal domain in genSingleDecode", type)

    def genSingleEncode(prefix, cValue, unresolved_domain):
        type = spec.resolveDomain(unresolved_domain)
        if type == 'shortstr':
            print prefix + "pieces.append(struct.pack('B', len(%s)))" % cValue
            print prefix + "pieces.append(%s)" % cValue
        elif type == 'longstr':
            print prefix + "pieces.append(struct.pack('>I', len(%s)))" % cValue
            print prefix + "pieces.append(%s)" % cValue
        elif type == 'octet':
            print prefix + "pieces.append(struct.pack('B', %s))" % cValue
        elif type == 'short':
            print prefix + "pieces.append(struct.pack('>H', %s))" % cValue
        elif type == 'long':
            print prefix + "pieces.append(struct.pack('>I', %s))" % cValue
        elif type == 'longlong':
            print prefix + "pieces.append(struct.pack('>Q', %s))" % cValue
        elif type == 'timestamp':
            print prefix + "pieces.append(struct.pack('>Q', %s))" % cValue
        elif type == 'bit':
            raise Exception("Can't encode bit in genSingleEncode")
        elif type == 'table':
            print Exception(prefix + "data.encode_table(pieces, %s)" % cValue)
        else:
            raise Exception("Illegal domain in genSingleEncode", type)

    def genDecodeMethodFields(m):
        print "        def decode(self, encoded, offset=0):"
        bitindex = None
        for f in m.arguments:
            if spec.resolveDomain(f.domain) == 'bit':
                if bitindex is None:
                    bitindex = 0
                if bitindex >= 8:
                    bitindex = 0
                if not bitindex:
                    print "            bit_buffer = struct.unpack_from('B', encoded, offset)[0]"
                    print "            offset += 1"
                print "            self.%s = (bit_buffer & (1 << %d)) != 0" % \
                      (pyize(f.name), bitindex)
                bitindex += 1
            else:
                bitindex = None
                genSingleDecode("            ", "self.%s" % (pyize(f.name),), f.domain)
        print "            return self"
        print

    def genDecodeProperties(c):
        print "    def decode(self, encoded, offset=0):"
        print "        flags = 0"
        print "        flagword_index = 0"
        print "        while True:"
        print "            partial_flags = struct.unpack_from('>H', encoded, offset)[0]"
        print "            offset += 2"
        print "            flags = flags | (partial_flags << (flagword_index * 16))"
        print "            if not (partial_flags & 1):"
        print "                break"
        print "            flagword_index += 1"
        for f in c.fields:
            if spec.resolveDomain(f.domain) == 'bit':
                print "        self.%s = (flags & %s) != 0" % (pyize(f.name), flagName(c, f))
            else:
                print "        if flags & %s:" % (flagName(c, f),)
                genSingleDecode("            ", "self.%s" % (pyize(f.name),), f.domain)
                print "        else:"
                print "            self.%s = None" % (pyize(f.name),)
        print "        return self"
        print

    def genEncodeMethodFields(m):
        print "        def encode(self):"
        print "            pieces = list()"
        bitindex = None

        def finishBits():
            if bitindex is not None:
                print "            pieces.append(struct.pack('B', bit_buffer))"
        for f in m.arguments:
            if spec.resolveDomain(f.domain) == 'bit':
                if bitindex is None:
                    bitindex = 0
                    print "            bit_buffer = 0"
                if bitindex >= 8:
                    finishBits()
                    print "            bit_buffer = 0"
                    bitindex = 0
                print "            if self.%s:" % pyize(f.name)
                print "                bit_buffer = bit_buffer | (1 << %d)" % \
                    bitindex
                bitindex += 1
            else:
                finishBits()
                bitindex = None
                genSingleEncode("            ", "self.%s" % (pyize(f.name),), f.domain)
        finishBits()
        print "            return pieces"
        print

    def genEncodeProperties(c):
        print "    def encode(self):"
        print "        pieces = list()"
        print "        flags = 0"
        for f in c.fields:
            if spec.resolveDomain(f.domain) == 'bit':
                print "        if self.%s: flags = flags | %s" % (pyize(f.name), flagName(c, f))
            else:
                print "        if self.%s is not None:" % (pyize(f.name),)
                print "            flags = flags | %s" % (flagName(c, f),)
                genSingleEncode("            ", "self.%s" % (pyize(f.name),), f.domain)
        print "        flag_pieces = list()"
        print "        while True:"
        print "            remainder = flags >> 16"
        print "            partial_flags = flags & 0xFFFE"
        print "            if remainder != 0:"
        print "                partial_flags |= 1"
        print "            flag_pieces.append(struct.pack('>H', partial_flags))"
        print "            flags = remainder"
        print "            if not flags:"
        print "                break"
        print "        return flag_pieces + pieces"
        print

    def fieldDeclList(fields):
        return ''.join([", %s=%s" % (pyize(f.name), fieldvalue(f.defaultvalue)) for f in fields])

    def fieldInitList(prefix, fields):
        if fields:
            return ''.join(["%sself.%s = %s\n" % (prefix, pyize(f.name), pyize(f.name)) \
                            for f in fields])
        else:
            return '%spass\n' % (prefix,)

    print """# ***** BEGIN LICENSE BLOCK *****
#
# For copyright and licensing please refer to COPYING.
#
# ***** END LICENSE BLOCK *****

# NOTE: Autogenerated code by codegen.py, do not edit

import struct
import pika.data as data
import pika.object

# Determine the version of PYTHON running so we can properly use the correct
# struct variable type for decoding >Q in Python 2.4
from platform import python_version_tuple
major, minor, revision = python_version_tuple()
PYTHON_VERSION = float("%s.%s" % (major, minor))
"""

    print "PROTOCOL_VERSION = (%d, %d, %d)" % (spec.major, spec.minor,
                                               spec.revision)
    print "PORT = %d" % spec.port
    print

    # Append some constants that arent in the spec json file
    spec.constants.append(('FRAME_MAX_SIZE', 131072, ''))
    spec.constants.append(('FRAME_HEADER_SIZE', 7, ''))
    spec.constants.append(('FRAME_END_SIZE', 1, ''))

    constants = {}
    for c, v, cls in spec.constants:
        constants[constantName(c)] = v

    for key in sorted(constants.iterkeys()):
        print "%s = %s" % (key, constants[key])
    print

    for c in spec.allClasses():
        print
        print 'class %s(pika.object.Class):' % (camel(c.name),)
        print
        print "    INDEX = 0x%.04X  # %d" % (c.index, c.index)
        print "    NAME = %s" % (fieldvalue(camel(c.name)),)
        print

        for m in c.allMethods():
            print '    class %s(pika.object.Method):' % (camel(m.name),)
            print
            methodid = m.klass.index << 16 | m.index
            print "        INDEX = 0x%.08X  # %d, %d; %d" % \
                  (methodid,
                   m.klass.index,
                   m.index,
                   methodid)
            print "        NAME = %s" % (fieldvalue(m.structName(),))
            print
            print "        def __init__(self%s):" % (fieldDeclList(m.arguments),)
            print fieldInitList('            ', m.arguments)
            print "        @property"
            print "        def synchronous(self):"
            print "            return %s" % m.isSynchronous
            print
            genDecodeMethodFields(m)
            genEncodeMethodFields(m)

    for c in spec.allClasses():
        if c.fields:
            print
            print 'class %s(pika.object.Properties):' % (c.structName(),)
            print
            print "    CLASS = %s" % (camel(c.name),)
            print "    INDEX = 0x%.04X  # %d" % (c.index, c.index)
            print "    NAME = %s" % (fieldvalue(c.structName(),))
            print

            index = 0
            if c.fields:
                for f in c.fields:
                    if index % 16 == 15:
                        index += 1
                    shortnum = index / 16
                    partialindex = 15 - (index % 16)
                    bitindex = shortnum * 16 + partialindex
                    print '    %s = (1 << %d)' % (flagName(None, f), bitindex)
                    index += 1
                print

            print "    def __init__(self%s):" % (fieldDeclList(c.fields),)
            print fieldInitList('        ', c.fields)
            genDecodeProperties(c)
            genEncodeProperties(c)

    print "methods = {"
    print ',\n'.join(["    0x%08X: %s" % (m.klass.index << 16 | m.index, m.structName()) \
                      for m in spec.allMethods()])
    print "}"
    print

    print "props = {"
    print ',\n'.join(["    0x%04X: %s" % (c.index, c.structName()) \
                      for c in spec.allClasses() \
                      if c.fields])
    print "}"
    print
    print

    print "def has_content(methodNumber):"
    print
    for m in spec.allMethods():
        if m.hasContent:
            print '    if methodNumber == %s.INDEX:' % m.structName()
            print '        return True'
    print "    return False"
    print
    print

    print "class DriverMixin(object):"

    for m in spec.allMethods():
        if m.structName() in DRIVER_METHODS:
            acceptable_replies = DRIVER_METHODS[m.structName()]
            print
            anchor = pyize("%s.%s" % (m.klass.name, m.name))
            if m.isSynchronous:

                #Synchronous events have a CPS callback parameter
                print "    def %s(self, callback=None%s):" % \
                      (pyize("%s_%s" % (m.klass.name, m.name)),
                      fieldDeclList(m.arguments))
                print '        """'
                print '        Implements the %s AMQP command. For context and usage:' % m.structName()
                print
                print '          http://www.rabbitmq.com/amqp-0-9-1-quickref.html#%s' % anchor
                print
                print '        This is a synchronous method that will not allow other commands to be'
                print '        send to the AMQP broker until it has completed. It is recommended to'
                print '        pass in a parameter to callback to be notified when this command has'
                print '        completed.'
                print '        """'

                for argument in m.arguments:
                    print "        data.validate_type('%s', %s, '%s')" % \
                          (pyize(argument.name), pyize(argument.name),
                           argument.domain)

                print
                print "        return self.transport.rpc(%s(%s), callback," % \
                       (m.structName(),
                       ', '.join(["%s=%s" % (pyize(f.name), pyize(f.name))
                       for f in m.arguments]))
                print "                                  [%s])" % \
                      ', '.join(acceptable_replies)

            else:
                print "    def %s(self%s):" % \
                      (pyize("%s_%s" % (m.klass.name, m.name)),
                      fieldDeclList(m.arguments))
                print '        """'
                print '        Implements the %s.%s AMQP command. For context and usage:' % (m.klass.name, m.name)
                print
                print '          http://www.rabbitmq.com/amqp-0-9-1-quickref.html#%s' % anchor
                print '        """'
                print

                for argument in m.arguments:
                    print "        data.validate_type('%s', %s, '%s')" % \
                          (pyize(argument.name), pyize(argument.name),
                           argument.domain)

                print "        return self.transport.rpc(%s(%s))" % \
                       (m.structName(),
                       ', '.join(["%s=%s" % (pyize(f.name), pyize(f.name))
                       for f in m.arguments]))

if __name__ == "__main__":
    do_main_dict({"spec": generate})