[8979f90] | 1 | #!/usr/bin/python |
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| 2 | |
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| 3 | import sys, struct, logging |
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[7a1c039] | 4 | from .constants import OutOfBandTags, IntegerTags, OctetStringTags, CharacterStringTags |
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[8979f90] | 5 | |
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| 6 | # initialize logger |
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[7a1c039] | 7 | logger = logging.getLogger(__name__) |
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[8979f90] | 8 | |
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[a6a1f43] | 9 | def setter(prop): |
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| 10 | def f(func): |
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| 11 | return property(prop.fget, func, prop.fdel, prop.__doc__) |
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| 12 | return f |
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| 13 | |
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[fa0d0ef] | 14 | class Value(object): |
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[8979f90] | 15 | """ |
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[5cfb358] | 16 | An IPP value consists of a tag and a value. |
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[8979f90] | 17 | |
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| 18 | From RFC 2565: |
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| 19 | ----------------------------------------------- |
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| 20 | | value-tag | 1 byte |
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| 21 | ----------------------------------------------- |
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[5cfb358] | 22 | | name-length (value is 0x0000) | 2 bytes |
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[8979f90] | 23 | ----------------------------------------------- |
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| 24 | | value-length (value is v) | 2 bytes |
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| 25 | ----------------------------------------------- |
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| 26 | | value | v bytes |
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| 27 | ----------------------------------------------- |
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| 28 | """ |
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| 29 | |
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[fa0d0ef] | 30 | def __init__(self, value_tag=None, value=None): |
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[8979f90] | 31 | """ |
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[5cfb358] | 32 | Initialize a Value. There are three different ways you can |
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| 33 | call this method: |
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| 34 | |
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| 35 | Value() -- creates an empty Value instance |
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| 36 | |
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| 37 | Value(value_tag, value) -- creates a Value instance from |
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[fa0d0ef] | 38 | a non-binary value |
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[5cfb358] | 39 | |
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| 40 | If you create an empty Value instance, once you have set |
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[fa0d0ef] | 41 | value_tag and value, you can retrieve the packed value from |
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| 42 | the packed_value property. |
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[8979f90] | 43 | |
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| 44 | Arguments: |
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| 45 | |
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| 46 | value_tag -- one byte, identifying the type of value |
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| 47 | |
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[fa0d0ef] | 48 | value -- variable size, containing the actual value. |
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| 49 | It should be a string or number. |
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[8979f90] | 50 | """ |
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| 51 | |
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[5cfb358] | 52 | # make sure the arguments are valid |
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[fa0d0ef] | 53 | if value is not None: |
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| 54 | assert value_tag is not None, \ |
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| 55 | "value_tag must not be null because " + \ |
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| 56 | "value is not null!" |
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[8979f90] | 57 | |
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[5cfb358] | 58 | # initialize member variables |
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[fa0d0ef] | 59 | self.value_tag = value_tag # one byte, the type of value |
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| 60 | self.value = value # non-binary value of self.value |
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| 61 | |
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| 62 | @classmethod |
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| 63 | def unpack(cls, value_tag, packed_value): |
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| 64 | """Unpack a binary IPP value |
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| 65 | |
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| 66 | Unpacks a binary string into a Value object. |
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| 67 | |
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[5cfb358] | 68 | """ |
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[fa0d0ef] | 69 | return cls(value_tag, cls._unpack(value_tag, packed_value)) |
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| 70 | |
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| 71 | @staticmethod |
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| 72 | def _unpack(value_tag, packed_value): |
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| 73 | """ |
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| 74 | Given self.value_tag and self.packed_value, unpack the binary |
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[5cfb358] | 75 | value into either a string or number. These values MUST NOT |
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[fa0d0ef] | 76 | be null. |
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| 77 | |
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| 78 | Returns: unpacked value |
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[5cfb358] | 79 | |
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| 80 | """ |
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[8979f90] | 81 | |
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[fa0d0ef] | 82 | assert value_tag is not None, \ |
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[5cfb358] | 83 | "Cannot unpack values with unspecified value tag!" |
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[fa0d0ef] | 84 | assert packed_value is not None, \ |
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[5cfb358] | 85 | "Cannot unpack null values!" |
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| 86 | |
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| 87 | value = None |
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[8979f90] | 88 | |
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| 89 | # out-of-band value tags |
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[fa0d0ef] | 90 | if value_tag == OutOfBandTags.UNSUPPORTED or \ |
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| 91 | value_tag == OutOfBandTags.DEFAULT or \ |
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| 92 | value_tag == OutOfBandTags.UNKNOWN or \ |
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| 93 | value_tag == OutOfBandTags.NO_VALUE: |
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[5cfb358] | 94 | value_size = 0 |
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| 95 | value = '' |
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[8979f90] | 96 | |
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| 97 | # integer value tags |
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[fa0d0ef] | 98 | elif value_tag == IntegerTags.INTEGER: |
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| 99 | value = struct.unpack('>i', packed_value)[0] |
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| 100 | elif value_tag == IntegerTags.BOOLEAN: |
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[569c377] | 101 | value = struct.unpack('>b', packed_value)[0] |
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[fa0d0ef] | 102 | elif value_tag == IntegerTags.ENUM: |
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| 103 | value = struct.unpack('>i', packed_value)[0] |
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[8979f90] | 104 | |
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| 105 | |
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[fa0d0ef] | 106 | elif value_tag == OctetStringTags.DATETIME: |
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[8979f90] | 107 | # field octets contents range |
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| 108 | # ----- ------ -------- ----- |
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| 109 | # 1 1-2 year 0..65536 |
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| 110 | # 2 3 month 1..12 |
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| 111 | # 3 4 day 1..31 |
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| 112 | # 4 5 hour 0..23 |
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| 113 | # 5 6 minutes 0..59 |
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| 114 | # 6 7 seconds 0..60 |
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| 115 | # (use 60 for leap-second) |
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| 116 | # 7 8 deci-seconds 0..9 |
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| 117 | # 8 9 direction from UTC '+' / '-' |
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| 118 | # 9 10 hours from UTC 0..11 |
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| 119 | # 10 11 minutes from UTC 0..59 |
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| 120 | |
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[fa0d0ef] | 121 | value = struct.unpack('>hbbbbbbcbb', packed_value) |
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[8979f90] | 122 | |
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[fa0d0ef] | 123 | elif value_tag == OctetStringTags.RESOLUTION: |
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[8979f90] | 124 | # OCTET-STRING consisting of nine octets of 2 |
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| 125 | # SIGNED-INTEGERs followed by a SIGNED-BYTE. The first |
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| 126 | # SIGNED-INTEGER contains the value of cross feed |
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| 127 | # direction resolution. The second SIGNED-INTEGER contains |
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| 128 | # the value of feed direction resolution. The SIGNED-BYTE |
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| 129 | # contains the units |
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| 130 | |
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[fa0d0ef] | 131 | value = struct.unpack('>iib', packed_value) |
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[8979f90] | 132 | |
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[fa0d0ef] | 133 | elif value_tag == OctetStringTags.RANGE_OF_INTEGER: |
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[8979f90] | 134 | # Eight octets consisting of 2 SIGNED-INTEGERs. The first |
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| 135 | # SIGNED-INTEGER contains the lower bound and the second |
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| 136 | # SIGNED-INTEGER contains the upper bound. |
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| 137 | |
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[fa0d0ef] | 138 | value = struct.unpack('>ii', packed_value) |
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[8979f90] | 139 | |
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[fa0d0ef] | 140 | elif value_tag == OctetStringTags.TEXT_WITH_LANGUAGE or \ |
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| 141 | value_tag == OctetStringTags.NAME_WITH_LANGUAGE: |
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| 142 | a = struct.unpack('>h', packed_value[:2])[0] |
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| 143 | b = struct.unpack('>%ss' % a, packed_value[2:a+2])[0] |
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| 144 | c = struct.unpack('>h', packed_value[a+2:a+4])[0] |
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| 145 | d = struct.unpack('>%ss' % c, packed_value[a+4:][0]) |
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[5cfb358] | 146 | value = (a, b, c, d) |
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[8979f90] | 147 | |
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| 148 | # character string value tags |
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[fa0d0ef] | 149 | elif value_tag == \ |
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[5cfb358] | 150 | CharacterStringTags.TEXT_WITHOUT_LANGUAGE or \ |
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[fa0d0ef] | 151 | value_tag == \ |
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[5cfb358] | 152 | CharacterStringTags.NAME_WITHOUT_LANGUAGE: |
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[fa0d0ef] | 153 | value = str(packed_value) |
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| 154 | elif value_tag == CharacterStringTags.GENERIC or \ |
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| 155 | value_tag == CharacterStringTags.KEYWORD or \ |
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| 156 | value_tag == CharacterStringTags.URI or \ |
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| 157 | value_tag == CharacterStringTags.URI_SCHEME or \ |
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| 158 | value_tag == CharacterStringTags.CHARSET or \ |
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| 159 | value_tag == CharacterStringTags.NATURAL_LANGUAGE or \ |
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| 160 | value_tag == CharacterStringTags.MIME_MEDIA_TYPE: |
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| 161 | value = str(packed_value) |
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[8979f90] | 162 | |
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[5cfb358] | 163 | # anything else that we didn't handle |
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| 164 | else: |
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[fa0d0ef] | 165 | if value is None: |
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| 166 | value = packed_value |
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[5cfb358] | 167 | |
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[fa0d0ef] | 168 | return value |
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[5cfb358] | 169 | |
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[fa0d0ef] | 170 | @property |
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| 171 | def packed_value(self): |
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[5cfb358] | 172 | """ |
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| 173 | Given self.value_tag and self.value, pack the value into |
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[fa0d0ef] | 174 | binary form. These values MUST NOT be null. |
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| 175 | |
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| 176 | Returns: packed_value |
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[5cfb358] | 177 | |
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| 178 | """ |
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| 179 | |
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| 180 | assert self.value_tag is not None, \ |
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| 181 | "cannot pack value with null value tag!" |
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| 182 | assert self.value is not None, \ |
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| 183 | "cannot pack null value!" |
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| 184 | |
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[fa0d0ef] | 185 | packed_value = None |
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[8979f90] | 186 | |
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| 187 | # out-of-band value tags |
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[2646571] | 188 | if self.value_tag == OutOfBandTags.UNSUPPORTED or \ |
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| 189 | self.value_tag == OutOfBandTags.DEFAULT or \ |
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| 190 | self.value_tag == OutOfBandTags.UNKNOWN or \ |
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| 191 | self.value_tag == OutOfBandTags.NO_VALUE: |
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[fa0d0ef] | 192 | packed_value = '' |
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[8979f90] | 193 | |
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| 194 | # integer value tags |
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[2646571] | 195 | elif self.value_tag == IntegerTags.INTEGER: |
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[fa0d0ef] | 196 | packed_value = struct.pack('>i', self.value) |
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[2646571] | 197 | elif self.value_tag == IntegerTags.BOOLEAN: |
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[569c377] | 198 | packed_value = struct.pack('>b', self.value) |
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[2646571] | 199 | elif self.value_tag == IntegerTags.ENUM: |
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[fa0d0ef] | 200 | packed_value = struct.pack('>i', self.value) |
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[8979f90] | 201 | |
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| 202 | # octet string value tags |
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[2646571] | 203 | elif self.value_tag == OctetStringTags.DATETIME: |
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[8979f90] | 204 | # field octets contents range |
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| 205 | # ----- ------ -------- ----- |
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| 206 | # 1 1-2 year 0..65536 |
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| 207 | # 2 3 month 1..12 |
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| 208 | # 3 4 day 1..31 |
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| 209 | # 4 5 hour 0..23 |
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| 210 | # 5 6 minutes 0..59 |
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| 211 | # 6 7 seconds 0..60 |
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| 212 | # (use 60 for leap-second) |
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| 213 | # 7 8 deci-seconds 0..9 |
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| 214 | # 8 9 direction from UTC '+' / '-' |
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| 215 | # 9 10 hours from UTC 0..11 |
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| 216 | # 10 11 minutes from UTC 0..59 |
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[5cfb358] | 217 | |
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[fa0d0ef] | 218 | packed_value = struct.pack('>hbbbbbbcbb', *self.value) |
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[8979f90] | 219 | |
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[2646571] | 220 | elif self.value_tag == OctetStringTags.RESOLUTION: |
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[8979f90] | 221 | # OCTET-STRING consisting of nine octets of 2 |
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| 222 | # SIGNED-INTEGERs followed by a SIGNED-BYTE. The first |
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| 223 | # SIGNED-INTEGER contains the value of cross feed |
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| 224 | # direction resolution. The second SIGNED-INTEGER contains |
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| 225 | # the value of feed direction resolution. The SIGNED-BYTE |
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| 226 | # contains the units |
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[5cfb358] | 227 | |
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[fa0d0ef] | 228 | packed_value = truct.pack('>iib', self.value) |
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[8979f90] | 229 | |
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[2646571] | 230 | elif self.value_tag == OctetStringTags.RANGE_OF_INTEGER: |
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[8979f90] | 231 | # Eight octets consisting of 2 SIGNED-INTEGERs. The first |
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| 232 | # SIGNED-INTEGER contains the lower bound and the second |
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| 233 | # SIGNED-INTEGER contains the upper bound. |
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[5cfb358] | 234 | |
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[fa0d0ef] | 235 | packed_value = struct.pack('>ii', self.value) |
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[8979f90] | 236 | |
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[2646571] | 237 | elif self.value_tag == OctetStringTags.TEXT_WITH_LANGUAGE or \ |
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| 238 | self.value_tag == OctetStringTags.NAME_WITH_LANGUAGE: |
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[5cfb358] | 239 | |
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[8979f90] | 240 | a_bin = struct.pack('>h', self.value[0]) |
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| 241 | b_bin = struct.pack('>%ss' % self.value[0], self.value[1]) |
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| 242 | c_bin = struct.pack('>h', self.value[2]) |
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| 243 | d_bin = struct.pack('>%ss' % self.value[2], self.value[3]) |
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[5cfb358] | 244 | |
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[fa0d0ef] | 245 | packed_value = a_bin + b_bin + c_bin + d_bin |
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[8979f90] | 246 | |
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| 247 | # character string value tags |
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[5cfb358] | 248 | elif self.value_tag == \ |
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| 249 | CharacterStringTags.TEXT_WITHOUT_LANGUAGE or \ |
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| 250 | self.value_tag == \ |
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| 251 | CharacterStringTags.NAME_WITHOUT_LANGUAGE: |
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| 252 | |
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[fa0d0ef] | 253 | packed_value = struct.pack('>%ss' % len(self.value), |
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[5cfb358] | 254 | self.value) |
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| 255 | |
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[2646571] | 256 | elif self.value_tag == CharacterStringTags.GENERIC or \ |
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| 257 | self.value_tag == CharacterStringTags.KEYWORD or \ |
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| 258 | self.value_tag == CharacterStringTags.URI or \ |
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| 259 | self.value_tag == CharacterStringTags.URI_SCHEME or \ |
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| 260 | self.value_tag == CharacterStringTags.CHARSET or \ |
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| 261 | self.value_tag == CharacterStringTags.NATURAL_LANGUAGE or \ |
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| 262 | self.value_tag == CharacterStringTags.MIME_MEDIA_TYPE: |
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[5cfb358] | 263 | |
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[fa0d0ef] | 264 | packed_value = struct.pack('>%ss' % len(self.value), |
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[5cfb358] | 265 | self.value) |
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| 266 | |
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| 267 | else: |
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[fa0d0ef] | 268 | packed_value = self.value |
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[5cfb358] | 269 | |
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[fa0d0ef] | 270 | return packed_value |
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[5cfb358] | 271 | |
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[a6a1f43] | 272 | @setter(packed_value) |
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| 273 | def packed_value(self, packed_value): |
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[fa0d0ef] | 274 | """Replace a value using a new packed value |
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[5cfb358] | 275 | |
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[fa0d0ef] | 276 | Unpacks a new packed_value (of the same value_tag). |
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[5cfb358] | 277 | |
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| 278 | """ |
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[fa0d0ef] | 279 | self.value = self._unpack(self.value_tag, packed_value) |
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[5cfb358] | 280 | |
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[fa0d0ef] | 281 | @property |
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| 282 | def packed_value_size(self): |
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[5cfb358] | 283 | """ |
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| 284 | Get the size of the value in bytes. |
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| 285 | """ |
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| 286 | |
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[fa0d0ef] | 287 | return len(self.packed_value) |
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[8979f90] | 288 | |
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[fa0d0ef] | 289 | @property |
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| 290 | def total_size(self): |
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[c269bc7] | 291 | """ |
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| 292 | Get the total size of the IPP value. |
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| 293 | """ |
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| 294 | |
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[fa0d0ef] | 295 | # 1 byte for the tag |
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| 296 | return self.packed_value_size + 1 |
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[c269bc7] | 297 | |
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[5cfb358] | 298 | def __str__(self): |
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[fa0d0ef] | 299 | return str(self.value) |
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| 300 | |
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| 301 | def __repr__(self): |
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[94211df] | 302 | return '<IPPValue (%x, %r)>' % (self.value_tag, self.value) |
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