[7a1c039] | 1 | from .constants import OutOfBandTags, IntegerTags, OctetStringTags, CharacterStringTags |
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[d04a689] | 2 | import sys |
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| 3 | import struct |
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| 4 | import logging |
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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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[fa0d0ef] | 9 | class Value(object): |
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[5c5fe6d] | 10 | """An IPP value consists of a tag and a value. |
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[8979f90] | 11 | |
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| 12 | From RFC 2565: |
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| 13 | ----------------------------------------------- |
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| 14 | | value-tag | 1 byte |
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| 15 | ----------------------------------------------- |
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[5cfb358] | 16 | | name-length (value is 0x0000) | 2 bytes |
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[8979f90] | 17 | ----------------------------------------------- |
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| 18 | | value-length (value is v) | 2 bytes |
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| 19 | ----------------------------------------------- |
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| 20 | | value | v bytes |
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| 21 | ----------------------------------------------- |
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[5c5fe6d] | 22 | |
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[8979f90] | 23 | """ |
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| 24 | |
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[0c4f3bf] | 25 | def __init__(self, tag=None, value=None): |
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[5c5fe6d] | 26 | """Initialize a Value. There are three different ways you can |
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[5cfb358] | 27 | call this method: |
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| 28 | |
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| 29 | Value() -- creates an empty Value instance |
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| 30 | |
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[0c4f3bf] | 31 | Value(tag, value) -- creates a Value instance from |
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[fa0d0ef] | 32 | a non-binary value |
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[5cfb358] | 33 | |
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| 34 | If you create an empty Value instance, once you have set |
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[0c4f3bf] | 35 | tag and value, you can retrieve the packed value from |
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[fa0d0ef] | 36 | the packed_value property. |
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[8979f90] | 37 | |
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| 38 | Arguments: |
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| 39 | |
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[0c4f3bf] | 40 | tag -- one byte, identifying the type of value |
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[8979f90] | 41 | |
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[fa0d0ef] | 42 | value -- variable size, containing the actual value. |
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| 43 | It should be a string or number. |
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[5c5fe6d] | 44 | |
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[8979f90] | 45 | """ |
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| 46 | |
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[5cfb358] | 47 | # make sure the arguments are valid |
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[fa0d0ef] | 48 | if value is not None: |
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[0c4f3bf] | 49 | assert tag is not None, \ |
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| 50 | "tag must not be null because " + \ |
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[fa0d0ef] | 51 | "value is not null!" |
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[8979f90] | 52 | |
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[5cfb358] | 53 | # initialize member variables |
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[0c4f3bf] | 54 | self.tag = tag # one byte, the type of value |
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[fa0d0ef] | 55 | self.value = value # non-binary value of self.value |
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| 56 | |
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| 57 | @classmethod |
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[0c4f3bf] | 58 | def unpack(cls, tag, packed_value): |
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[5c5fe6d] | 59 | """Unpack a binary IPP value into a Value object. |
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[fa0d0ef] | 60 | |
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[5cfb358] | 61 | """ |
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[0c4f3bf] | 62 | return cls(tag, cls._unpack(tag, packed_value)) |
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[fa0d0ef] | 63 | |
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| 64 | @staticmethod |
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[0c4f3bf] | 65 | def _unpack(tag, packed_value): |
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| 66 | """Given self.tag and self.packed_value, unpack the |
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[5c5fe6d] | 67 | binary value into either a string or number. These values |
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| 68 | MUST NOT be null. |
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[fa0d0ef] | 69 | |
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| 70 | Returns: unpacked value |
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[5cfb358] | 71 | |
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| 72 | """ |
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[8979f90] | 73 | |
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[0c4f3bf] | 74 | assert tag is not None, \ |
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[5cfb358] | 75 | "Cannot unpack values with unspecified value tag!" |
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[fa0d0ef] | 76 | assert packed_value is not None, \ |
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[5cfb358] | 77 | "Cannot unpack null values!" |
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| 78 | |
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| 79 | value = None |
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[8979f90] | 80 | |
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| 81 | # out-of-band value tags |
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[0c4f3bf] | 82 | if tag == OutOfBandTags.UNSUPPORTED or \ |
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| 83 | tag == OutOfBandTags.DEFAULT or \ |
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| 84 | tag == OutOfBandTags.UNKNOWN or \ |
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| 85 | tag == OutOfBandTags.NO_VALUE: |
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[5cfb358] | 86 | value_size = 0 |
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| 87 | value = '' |
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[8979f90] | 88 | |
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| 89 | # integer value tags |
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[0c4f3bf] | 90 | elif tag == IntegerTags.INTEGER: |
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[fa0d0ef] | 91 | value = struct.unpack('>i', packed_value)[0] |
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[0c4f3bf] | 92 | elif tag == IntegerTags.BOOLEAN: |
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[569c377] | 93 | value = struct.unpack('>b', packed_value)[0] |
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[0c4f3bf] | 94 | elif tag == IntegerTags.ENUM: |
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[fa0d0ef] | 95 | value = struct.unpack('>i', packed_value)[0] |
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[8979f90] | 96 | |
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| 97 | |
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[0c4f3bf] | 98 | elif tag == OctetStringTags.DATETIME: |
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[8979f90] | 99 | # field octets contents range |
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| 100 | # ----- ------ -------- ----- |
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| 101 | # 1 1-2 year 0..65536 |
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| 102 | # 2 3 month 1..12 |
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| 103 | # 3 4 day 1..31 |
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| 104 | # 4 5 hour 0..23 |
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| 105 | # 5 6 minutes 0..59 |
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| 106 | # 6 7 seconds 0..60 |
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| 107 | # (use 60 for leap-second) |
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| 108 | # 7 8 deci-seconds 0..9 |
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| 109 | # 8 9 direction from UTC '+' / '-' |
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| 110 | # 9 10 hours from UTC 0..11 |
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| 111 | # 10 11 minutes from UTC 0..59 |
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| 112 | |
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[fa0d0ef] | 113 | value = struct.unpack('>hbbbbbbcbb', packed_value) |
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[8979f90] | 114 | |
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[0c4f3bf] | 115 | elif tag == OctetStringTags.RESOLUTION: |
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[8979f90] | 116 | # OCTET-STRING consisting of nine octets of 2 |
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| 117 | # SIGNED-INTEGERs followed by a SIGNED-BYTE. The first |
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| 118 | # SIGNED-INTEGER contains the value of cross feed |
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| 119 | # direction resolution. The second SIGNED-INTEGER contains |
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| 120 | # the value of feed direction resolution. The SIGNED-BYTE |
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| 121 | # contains the units |
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| 122 | |
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[fa0d0ef] | 123 | value = struct.unpack('>iib', packed_value) |
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[8979f90] | 124 | |
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[0c4f3bf] | 125 | elif tag == OctetStringTags.RANGE_OF_INTEGER: |
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[8979f90] | 126 | # Eight octets consisting of 2 SIGNED-INTEGERs. The first |
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| 127 | # SIGNED-INTEGER contains the lower bound and the second |
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| 128 | # SIGNED-INTEGER contains the upper bound. |
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| 129 | |
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[fa0d0ef] | 130 | value = struct.unpack('>ii', packed_value) |
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[8979f90] | 131 | |
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[0c4f3bf] | 132 | elif tag == OctetStringTags.TEXT_WITH_LANGUAGE or \ |
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| 133 | tag == OctetStringTags.NAME_WITH_LANGUAGE: |
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[fa0d0ef] | 134 | a = struct.unpack('>h', packed_value[:2])[0] |
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| 135 | b = struct.unpack('>%ss' % a, packed_value[2:a+2])[0] |
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| 136 | c = struct.unpack('>h', packed_value[a+2:a+4])[0] |
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| 137 | d = struct.unpack('>%ss' % c, packed_value[a+4:][0]) |
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[5cfb358] | 138 | value = (a, b, c, d) |
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[8979f90] | 139 | |
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| 140 | # character string value tags |
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[0c4f3bf] | 141 | elif tag == \ |
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[5cfb358] | 142 | CharacterStringTags.TEXT_WITHOUT_LANGUAGE or \ |
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[0c4f3bf] | 143 | tag == \ |
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[5cfb358] | 144 | CharacterStringTags.NAME_WITHOUT_LANGUAGE: |
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[fa0d0ef] | 145 | value = str(packed_value) |
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[0c4f3bf] | 146 | elif tag == CharacterStringTags.GENERIC or \ |
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| 147 | tag == CharacterStringTags.KEYWORD or \ |
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| 148 | tag == CharacterStringTags.URI or \ |
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| 149 | tag == CharacterStringTags.URI_SCHEME or \ |
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| 150 | tag == CharacterStringTags.CHARSET or \ |
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| 151 | tag == CharacterStringTags.NATURAL_LANGUAGE or \ |
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| 152 | tag == CharacterStringTags.MIME_MEDIA_TYPE: |
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[fa0d0ef] | 153 | value = str(packed_value) |
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[8979f90] | 154 | |
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[5cfb358] | 155 | # anything else that we didn't handle |
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| 156 | else: |
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[fa0d0ef] | 157 | if value is None: |
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| 158 | value = packed_value |
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[5cfb358] | 159 | |
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[fa0d0ef] | 160 | return value |
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[5cfb358] | 161 | |
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[fa0d0ef] | 162 | @property |
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| 163 | def packed_value(self): |
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[0c4f3bf] | 164 | """Given self.tag and self.value, pack the value into |
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[fa0d0ef] | 165 | binary form. These values MUST NOT be null. |
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| 166 | |
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| 167 | Returns: packed_value |
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[5cfb358] | 168 | |
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| 169 | """ |
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| 170 | |
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[0c4f3bf] | 171 | assert self.tag is not None, \ |
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[5cfb358] | 172 | "cannot pack value with null value tag!" |
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| 173 | assert self.value is not None, \ |
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| 174 | "cannot pack null value!" |
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| 175 | |
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[fa0d0ef] | 176 | packed_value = None |
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[8979f90] | 177 | |
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| 178 | # out-of-band value tags |
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[0c4f3bf] | 179 | if self.tag == OutOfBandTags.UNSUPPORTED or \ |
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| 180 | self.tag == OutOfBandTags.DEFAULT or \ |
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| 181 | self.tag == OutOfBandTags.UNKNOWN or \ |
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| 182 | self.tag == OutOfBandTags.NO_VALUE: |
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[fa0d0ef] | 183 | packed_value = '' |
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[8979f90] | 184 | |
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| 185 | # integer value tags |
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[0c4f3bf] | 186 | elif self.tag == IntegerTags.INTEGER: |
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[fa0d0ef] | 187 | packed_value = struct.pack('>i', self.value) |
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[0c4f3bf] | 188 | elif self.tag == IntegerTags.BOOLEAN: |
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[569c377] | 189 | packed_value = struct.pack('>b', self.value) |
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[0c4f3bf] | 190 | elif self.tag == IntegerTags.ENUM: |
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[fa0d0ef] | 191 | packed_value = struct.pack('>i', self.value) |
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[8979f90] | 192 | |
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| 193 | # octet string value tags |
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[0c4f3bf] | 194 | elif self.tag == OctetStringTags.DATETIME: |
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[8979f90] | 195 | # field octets contents range |
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| 196 | # ----- ------ -------- ----- |
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| 197 | # 1 1-2 year 0..65536 |
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| 198 | # 2 3 month 1..12 |
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| 199 | # 3 4 day 1..31 |
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| 200 | # 4 5 hour 0..23 |
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| 201 | # 5 6 minutes 0..59 |
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| 202 | # 6 7 seconds 0..60 |
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| 203 | # (use 60 for leap-second) |
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| 204 | # 7 8 deci-seconds 0..9 |
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| 205 | # 8 9 direction from UTC '+' / '-' |
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| 206 | # 9 10 hours from UTC 0..11 |
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| 207 | # 10 11 minutes from UTC 0..59 |
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[5cfb358] | 208 | |
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[fa0d0ef] | 209 | packed_value = struct.pack('>hbbbbbbcbb', *self.value) |
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[8979f90] | 210 | |
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[0c4f3bf] | 211 | elif self.tag == OctetStringTags.RESOLUTION: |
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[8979f90] | 212 | # OCTET-STRING consisting of nine octets of 2 |
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| 213 | # SIGNED-INTEGERs followed by a SIGNED-BYTE. The first |
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| 214 | # SIGNED-INTEGER contains the value of cross feed |
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| 215 | # direction resolution. The second SIGNED-INTEGER contains |
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| 216 | # the value of feed direction resolution. The SIGNED-BYTE |
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| 217 | # contains the units |
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[5cfb358] | 218 | |
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[556a285] | 219 | packed_value = truct.pack('>iib', *self.value) |
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[8979f90] | 220 | |
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[0c4f3bf] | 221 | elif self.tag == OctetStringTags.RANGE_OF_INTEGER: |
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[8979f90] | 222 | # Eight octets consisting of 2 SIGNED-INTEGERs. The first |
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| 223 | # SIGNED-INTEGER contains the lower bound and the second |
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| 224 | # SIGNED-INTEGER contains the upper bound. |
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[5cfb358] | 225 | |
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[556a285] | 226 | packed_value = struct.pack('>ii', *self.value) |
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[8979f90] | 227 | |
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[0c4f3bf] | 228 | elif self.tag == OctetStringTags.TEXT_WITH_LANGUAGE or \ |
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| 229 | self.tag == OctetStringTags.NAME_WITH_LANGUAGE: |
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[5cfb358] | 230 | |
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[8979f90] | 231 | a_bin = struct.pack('>h', self.value[0]) |
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| 232 | b_bin = struct.pack('>%ss' % self.value[0], self.value[1]) |
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| 233 | c_bin = struct.pack('>h', self.value[2]) |
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| 234 | d_bin = struct.pack('>%ss' % self.value[2], self.value[3]) |
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[5cfb358] | 235 | |
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[fa0d0ef] | 236 | packed_value = a_bin + b_bin + c_bin + d_bin |
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[8979f90] | 237 | |
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| 238 | # character string value tags |
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[0c4f3bf] | 239 | elif self.tag == \ |
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[5cfb358] | 240 | CharacterStringTags.TEXT_WITHOUT_LANGUAGE or \ |
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[0c4f3bf] | 241 | self.tag == \ |
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[5cfb358] | 242 | CharacterStringTags.NAME_WITHOUT_LANGUAGE: |
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| 243 | |
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[fa0d0ef] | 244 | packed_value = struct.pack('>%ss' % len(self.value), |
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[5cfb358] | 245 | self.value) |
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| 246 | |
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[0c4f3bf] | 247 | elif self.tag == CharacterStringTags.GENERIC or \ |
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| 248 | self.tag == CharacterStringTags.KEYWORD or \ |
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| 249 | self.tag == CharacterStringTags.URI or \ |
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| 250 | self.tag == CharacterStringTags.URI_SCHEME or \ |
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| 251 | self.tag == CharacterStringTags.CHARSET or \ |
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| 252 | self.tag == CharacterStringTags.NATURAL_LANGUAGE or \ |
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| 253 | self.tag == CharacterStringTags.MIME_MEDIA_TYPE: |
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[5cfb358] | 254 | |
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[fa0d0ef] | 255 | packed_value = struct.pack('>%ss' % len(self.value), |
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[5cfb358] | 256 | self.value) |
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| 257 | |
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| 258 | else: |
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[fa0d0ef] | 259 | packed_value = self.value |
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[5cfb358] | 260 | |
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[fa0d0ef] | 261 | return packed_value |
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[5cfb358] | 262 | |
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[5c5fe6d] | 263 | @packed_value.setter |
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[a6a1f43] | 264 | def packed_value(self, packed_value): |
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[fa0d0ef] | 265 | """Replace a value using a new packed value |
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[5cfb358] | 266 | |
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[0c4f3bf] | 267 | Unpacks a new packed_value (of the same tag). |
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[5cfb358] | 268 | |
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| 269 | """ |
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[0c4f3bf] | 270 | self.value = self._unpack(self.tag, packed_value) |
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[5cfb358] | 271 | |
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[fa0d0ef] | 272 | @property |
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| 273 | def packed_value_size(self): |
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[5c5fe6d] | 274 | """Get the size of the value in bytes. |
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| 275 | |
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[5cfb358] | 276 | """ |
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| 277 | |
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[fa0d0ef] | 278 | return len(self.packed_value) |
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[8979f90] | 279 | |
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[fa0d0ef] | 280 | @property |
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| 281 | def total_size(self): |
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[5c5fe6d] | 282 | """Get the total size of the IPP value. |
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| 283 | |
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[c269bc7] | 284 | """ |
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| 285 | |
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[fa0d0ef] | 286 | # 1 byte for the tag |
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| 287 | return self.packed_value_size + 1 |
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[c269bc7] | 288 | |
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[0c4f3bf] | 289 | @property |
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| 290 | def pyobj(self): |
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| 291 | return (self.tag, self.value) |
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| 292 | |
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[5cfb358] | 293 | def __str__(self): |
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[fa0d0ef] | 294 | return str(self.value) |
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| 295 | |
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| 296 | def __repr__(self): |
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[0c4f3bf] | 297 | return '<IPPValue (%x, %r)>' % (self.tag, self.value) |
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