# Source code for fontTools.ttLib.tables.S_I_N_G_

    from fontTools.misc import sstruct
    from fontTools.misc.textTools import bytechr, byteord, tobytes, tostr, safeEval
    from . import DefaultTable

    SINGFormat = """
    		>	# big endian
    		tableVersionMajor:	H
    		tableVersionMinor: 	H
    		glyphletVersion:	H
    		permissions:		h
    		mainGID:			H
    		unitsPerEm:			H
    		vertAdvance:		h
    		vertOrigin:			h
    		uniqueName:			28s
    		METAMD5:			16s
    		nameLength:			1s
    """
    # baseGlyphName is a byte string which follows the record above.

    class table_S_I_N_G_(DefaultTable.DefaultTable):

    	dependencies = []

    	def decompile(self, data, ttFont):
    		dummy, rest = sstruct.unpack2(SINGFormat, data, self)
    		self.uniqueName = self.decompileUniqueName(self.uniqueName)
    		self.nameLength = byteord(self.nameLength)
    		assert len(rest) == self.nameLength
    		self.baseGlyphName = tostr(rest)

    		rawMETAMD5 = self.METAMD5
    		self.METAMD5 = "[" + hex(byteord(self.METAMD5[0]))
    		for char in rawMETAMD5[1:]:
    			self.METAMD5 = self.METAMD5 + ", " + hex(byteord(char))
    		self.METAMD5 = self.METAMD5 + "]"

    	def decompileUniqueName(self, data):
    		name = ""
    		for char in data:
    			val = byteord(char)
    			if val == 0:
    				break
    			if (val > 31) or (val < 128):
    				name += chr(val)
    			else:
    				octString = oct(val)
    				if len(octString) > 3:
    					octString = octString[1:] # chop off that leading zero.
    				elif len(octString) < 3:
    					octString.zfill(3)
    				name += "\\" + octString
    		return name

    	def compile(self, ttFont):
    		d = self.__dict__.copy()
    		d["nameLength"] = bytechr(len(self.baseGlyphName))
    		d["uniqueName"] = self.compilecompileUniqueName(self.uniqueName, 28)
    		METAMD5List = eval(self.METAMD5)
    		d["METAMD5"] = b""
    		for val in METAMD5List:
    			d["METAMD5"] += bytechr(val)
    		assert (len(d["METAMD5"]) == 16), "Failed to pack 16 byte MD5 hash in SING table"
    		data = sstruct.pack(SINGFormat, d)
    		data = data + tobytes(self.baseGlyphName)
    		return data

    	def compilecompileUniqueName(self, name, length):
    		nameLen = len(name)
    		if length <= nameLen:
    			name = name[:length-1] + "\000"
    		else:
    			name += (nameLen - length) * "\000"
    		return name

    	def toXML(self, writer, ttFont):
    		writer.comment("Most of this table will be recalculated by the compiler")
    		writer.newline()
    		formatstring, names, fixes = sstruct.getformat(SINGFormat)
    		for name in names:
    			value = getattr(self, name)
    			writer.simpletag(name, value=value)
    			writer.newline()
    		writer.simpletag("baseGlyphName", value=self.baseGlyphName)
    		writer.newline()

    	def fromXML(self, name, attrs, content, ttFont):
    		value = attrs["value"]
    		if name in ["uniqueName", "METAMD5", "baseGlyphName"]:
    			setattr(self, name, value)
    		else:
    			setattr(self, name, safeEval(value))