Add support for loading WOFF file format
This commit is contained in:
Behdad Esfahbod
parent
f09f1d4064
commit
58d7416124
@ -69,7 +69,7 @@ class TTFont:
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"""
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def __init__(self, file=None, res_name_or_index=None,
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sfntVersion="\000\001\000\000", checkChecksums=0,
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sfntVersion="\000\001\000\000", flavor=None, checkChecksums=0,
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verbose=0, recalcBBoxes=1, allowVID=0, ignoreDecompileErrors=False,
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fontNumber=-1):
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@ -91,7 +91,8 @@ class TTFont:
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The TTFont constructor can also be called without a 'file'
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argument: this is the way to create a new empty font.
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In this case you can optionally supply the 'sfntVersion' argument.
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In this case you can optionally supply the 'sfntVersion' argument,
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and a 'flavor' which can be None, or 'woff'.
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If the recalcBBoxes argument is false, a number of things will *not*
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be recalculated upon save/compile:
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@ -135,6 +136,8 @@ class TTFont:
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if not file:
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self.sfntVersion = sfntVersion
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self.flavor = flavor
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self.flavorData = None
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return
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if not hasattr(file, "read"):
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# assume file is a string
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@ -155,6 +158,8 @@ class TTFont:
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pass # assume "file" is a readable file object
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self.reader = sfnt.SFNTReader(file, checkChecksums, fontNumber=fontNumber)
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self.sfntVersion = self.reader.sfntVersion
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self.flavor = self.reader.flavor
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self.flavorData = self.reader.flavorData
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def close(self):
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"""If we still have a reader object, close it."""
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@ -22,14 +22,14 @@ class SFNTReader:
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def __init__(self, file, checkChecksums=1, fontNumber=-1):
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self.file = file
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self.checkChecksums = checkChecksums
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data = self.file.read(sfntDirectorySize)
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if len(data) <> sfntDirectorySize:
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from fontTools import ttLib
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raise ttLib.TTLibError, "Not a TrueType or OpenType font (not enough data)"
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sstruct.unpack(sfntDirectoryFormat, data, self)
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self.flavor = None
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self.flavorData = None
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self.DirectoryEntry = SFNTDirectoryEntry
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self.sfntVersion = self.file.read(4)
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self.file.seek(0)
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if self.sfntVersion == "ttcf":
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assert ttcHeaderSize == sfntDirectorySize
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sstruct.unpack(ttcHeaderFormat, data, self)
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sstruct.unpack(ttcHeaderFormat, self.file.read(ttcHeaderSize), self)
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assert self.Version == 0x00010000 or self.Version == 0x00020000, "unrecognized TTC version 0x%08x" % self.Version
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if not 0 <= fontNumber < self.numFonts:
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from fontTools import ttLib
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@ -38,14 +38,20 @@ class SFNTReader:
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if self.Version == 0x00020000:
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pass # ignoring version 2.0 signatures
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self.file.seek(offsetTable[fontNumber])
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data = self.file.read(sfntDirectorySize)
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sstruct.unpack(sfntDirectoryFormat, data, self)
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sstruct.unpack(sfntDirectoryFormat, self.file.read(sfntDirectorySize), self)
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elif self.sfntVersion == "wOFF":
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self.flavor = "woff"
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self.DirectoryEntry = WOFFDirectoryEntry
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sstruct.unpack(woffDirectoryFormat, self.file.read(woffDirectorySize), self)
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else:
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sstruct.unpack(sfntDirectoryFormat, self.file.read(sfntDirectorySize), self)
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if self.sfntVersion not in ("\000\001\000\000", "OTTO", "true"):
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from fontTools import ttLib
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raise ttLib.TTLibError, "Not a TrueType or OpenType font (bad sfntVersion)"
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self.tables = {}
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for i in range(self.numTables):
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entry = SFNTDirectoryEntry()
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entry = self.DirectoryEntry()
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entry.fromFile(self.file)
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if entry.length > 0:
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self.tables[entry.tag] = entry
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@ -56,6 +62,10 @@ class SFNTReader:
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# *has* a zero-length table.
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pass
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# Load flavor data if any
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if self.flavor == "woff":
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self.flavorData = WOFFFlavorData(self)
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def has_key(self, tag):
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return self.tables.has_key(tag)
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@ -65,8 +75,7 @@ class SFNTReader:
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def __getitem__(self, tag):
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"""Fetch the raw table data."""
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entry = self.tables[tag]
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self.file.seek(entry.offset)
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data = self.file.read(entry.length)
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data = entry.loadData (self.file)
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if self.checkChecksums:
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if tag == 'head':
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# Beh: we have to special-case the 'head' table.
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@ -214,23 +223,105 @@ sfntDirectoryEntryFormat = """
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sfntDirectoryEntrySize = sstruct.calcsize(sfntDirectoryEntryFormat)
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class SFNTDirectoryEntry:
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woffDirectoryFormat = """
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> # big endian
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signature: 4s # "wOFF"
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sfntVersion: 4s
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length: L # total woff file size
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numTables: H # number of tables
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reserved: H # set to 0
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totalSfntSize: L # uncompressed size
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majorVersion: H # major version of WOFF file
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minorVersion: H # minor version of WOFF file
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metaOffset: L # offset to metadata block
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metaLength: L # length of compressed metadata
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metaOrigLength: L # length of uncompressed metadata
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privOffset: L # offset to private data block
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privLength: L # length of private data block
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"""
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woffDirectorySize = sstruct.calcsize(woffDirectoryFormat)
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woffDirectoryEntryFormat = """
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> # big endian
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tag: 4s
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offset: L
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length: L # compressed length
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origLength: L # original length
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checksum: L # original checksum
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"""
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woffDirectoryEntrySize = sstruct.calcsize(woffDirectoryEntryFormat)
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class DirectoryEntry:
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def fromFile(self, file):
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sstruct.unpack(sfntDirectoryEntryFormat,
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file.read(sfntDirectoryEntrySize), self)
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sstruct.unpack(self.format, file.read(self.formatSize), self)
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def fromString(self, str):
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sstruct.unpack(sfntDirectoryEntryFormat, str, self)
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sstruct.unpack(self.format, str, self)
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def toString(self):
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return sstruct.pack(sfntDirectoryEntryFormat, self)
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return sstruct.pack(self.format, self)
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def __repr__(self):
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if hasattr(self, "tag"):
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return "<SFNTDirectoryEntry '%s' at %x>" % (self.tag, id(self))
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return "<%s '%s' at %x>" % (self.__class__.__name__, self.tag, id(self))
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else:
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return "<SFNTDirectoryEntry at %x>" % id(self)
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return "<%s at %x>" % (self.__class__.__name__, id(self))
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def loadData(self, file):
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file.seek(self.offset)
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data = file.read(self.length)
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assert len(data) == self.length
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return self.decodeData (data)
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def decodeData(self, rawData):
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return rawData
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class SFNTDirectoryEntry(DirectoryEntry):
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format = sfntDirectoryEntryFormat
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formatSize = sfntDirectoryEntrySize
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class WOFFDirectoryEntry(DirectoryEntry):
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format = woffDirectoryEntryFormat
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formatSize = woffDirectoryEntrySize
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def decodeData(self, rawData):
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import zlib
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if self.length == self.origLength:
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data = rawData
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else:
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assert self.length < self.origLength
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data = zlib.decompress(rawData)
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assert len (data) == self.origLength
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return data
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class WOFFFlavorData():
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def __init__(self, reader=None):
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self.majorVersion = None
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self.minorVersion = None
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self.metaData = None
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self.privData = None
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if reader:
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self.majorVersion = reader.majorVersion
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self.minorVersion = reader.minorVersion
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if reader.metaLength:
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reader.file.seek(reader.metaOffset)
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rawData = read.file.read(reader.metaLength)
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assert len(rawData) == reader.metaLength
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data = zlib.decompress(rawData)
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assert len(data) == reader.metaOrigLength
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self.metaData = data
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if reader.privLength:
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reader.file.seek(reader.privOffset)
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data = read.file.read(reader.privLength)
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assert len(data) == reader.privLength
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self.privData = data
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def calcChecksum(data):
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