# Source code for fontTools.ttLib.woff2

    from io import BytesIO
    import sys
    import array
    import struct
    from collections import OrderedDict
    from fontTools.misc import sstruct
    from fontTools.misc.arrayTools import calcIntBounds
    from fontTools.misc.textTools import Tag, bytechr, byteord, bytesjoin, pad
    from fontTools.ttLib import (
        TTFont,
        TTLibError,
        getTableModule,
        getTableClass,
        getSearchRange,
    )
    from fontTools.ttLib.sfnt import (
        SFNTReader,
        SFNTWriter,
        DirectoryEntry,
        WOFFFlavorData,
        sfntDirectoryFormat,
        sfntDirectorySize,
        SFNTDirectoryEntry,
        sfntDirectoryEntrySize,
        calcChecksum,
    )
    from fontTools.ttLib.tables import ttProgram, _g_l_y_f
    import logging

    log = logging.getLogger("fontTools.ttLib.woff2")

    haveBrotli = False
    try:
        try:
            import brotlicffi as brotli
        except ImportError:
            import brotli
        haveBrotli = True
    except ImportError:
        pass

    class WOFF2Reader(SFNTReader):
        flavor = "woff2"

        def __init__(self, file, checkChecksums=0, fontNumber=-1):
            if not haveBrotli:
                log.error(
                    "The WOFF2 decoder requires the Brotli Python extension, available at: "
                    "https://github.com/google/brotli"
                )
                raise ImportError("No module named brotli")

            self.file = file

            signature = Tag(self.file.read(4))
            if signature != b"wOF2":
                raise TTLibError("Not a WOFF2 font (bad signature)")

            self.file.seek(0)
            self.DirectoryEntry = WOFF2DirectoryEntry
            data = self.file.read(woff2DirectorySize)
            if len(data) != woff2DirectorySize:
                raise TTLibError("Not a WOFF2 font (not enough data)")
            sstruct.unpack(woff2DirectoryFormat, data, self)

            self.tables = OrderedDict()
            offset = 0
            for i in range(self.numTables):
                entry = self.DirectoryEntry()
                entry.fromFile(self.file)
                tag = Tag(entry.tag)
                self.tables[tag] = entry
                entry.offset = offset
                offset += entry.length

            totalUncompressedSize = offset
            compressedData = self.file.read(self.totalCompressedSize)
            decompressedData = brotli.decompress(compressedData)
            if len(decompressedData) != totalUncompressedSize:
                raise TTLibError(
                    "unexpected size for decompressed font data: expected %d, found %d"
                    % (totalUncompressedSize, len(decompressedData))
                )
            self.transformBuffer = BytesIO(decompressedData)

            self.file.seek(0, 2)
            if self.length != self.file.tell():
                raise TTLibError("reported 'length' doesn't match the actual file size")

            self.flavorData = WOFF2FlavorData(self)

            # make empty TTFont to store data while reconstructing tables
            self.ttFont = TTFont(recalcBBoxes=False, recalcTimestamp=False)

        def __getitem__(self, tag):
            """Fetch the raw table data. Reconstruct transformed tables."""
            entry = self.tables[Tag(tag)]
            if not hasattr(entry, "data"):
                if entry.transformed:
                    entry.data = self.reconstructTable(tag)
                else:
                    entry.data = entry.loadData(self.transformBuffer)
            return entry.data

        def reconstructTable(self, tag):
            """Reconstruct table named 'tag' from transformed data."""
            entry = self.tables[Tag(tag)]
            rawData = entry.loadData(self.transformBuffer)
            if tag == "glyf":
                # no need to pad glyph data when reconstructing
                padding = self.padding if hasattr(self, "padding") else None
                data = self._reconstructGlyf(rawData, padding)
            elif tag == "loca":
                data = self._reconstructLoca()
            elif tag == "hmtx":
                data = self._reconstructHmtx(rawData)
            else:
                raise TTLibError("transform for table '%s' is unknown" % tag)
            return data

        def _reconstructGlyf(self, data, padding=None):
            """Return recostructed glyf table data, and set the corresponding loca's
            locations. Optionally pad glyph offsets to the specified number of bytes.
            """
            self.ttFont["loca"] = WOFF2LocaTable()
            glyfTable = self.ttFont["glyf"] = WOFF2GlyfTable()
            glyfTable.reconstruct(data, self.ttFont)
            if padding:
                glyfTable.padding = padding
            data = glyfTable.compile(self.ttFont)
            return data

        def _reconstructLoca(self):
            """Return reconstructed loca table data."""
            if "loca" not in self.ttFont:
                # make sure glyf is reconstructed first
                self.tables["glyf"].data = self.reconstructTable("glyf")
            locaTable = self.ttFont["loca"]
            data = locaTable.compile(self.ttFont)
            if len(data) != self.tables["loca"].origLength:
                raise TTLibError(
                    "reconstructed 'loca' table doesn't match original size: "
                    "expected %d, found %d" % (self.tables["loca"].origLength, len(data))
                )
            return data

        def _reconstructHmtx(self, data):
            """Return reconstructed hmtx table data."""
            # Before reconstructing 'hmtx' table we need to parse other tables:
            # 'glyf' is required for reconstructing the sidebearings from the glyphs'
            # bounding box; 'hhea' is needed for the numberOfHMetrics field.
            if "glyf" in self.flavorData.transformedTables:
                # transformed 'glyf' table is self-contained, thus 'loca' not needed
                tableDependencies = ("maxp", "hhea", "glyf")
            else:
                # decompiling untransformed 'glyf' requires 'loca', which requires 'head'
                tableDependencies = ("maxp", "head", "hhea", "loca", "glyf")
            for tag in tableDependencies:
                self._decompileTable(tag)
            hmtxTable = self.ttFont["hmtx"] = WOFF2HmtxTable()
            hmtxTable.reconstruct(data, self.ttFont)
            data = hmtxTable.compile(self.ttFont)
            return data

        def _decompileTable(self, tag):
            """Decompile table data and store it inside self.ttFont."""
            data = self[tag]
            if self.ttFont.isLoaded(tag):
                return self.ttFont[tag]
            tableClass = getTableClass(tag)
            table = tableClass(tag)
            self.ttFont.tables[tag] = table
            table.decompile(data, self.ttFont)

    class WOFF2Writer(SFNTWriter):
        flavor = "woff2"

        def __init__(
            self,
            file,
            numTables,
            sfntVersion="\000\001\000\000",
            flavor=None,
            flavorData=None,
        ):
            if not haveBrotli:
                log.error(
                    "The WOFF2 encoder requires the Brotli Python extension, available at: "
                    "https://github.com/google/brotli"
                )
                raise ImportError("No module named brotli")

            self.file = file
            self.numTables = numTables
            self.sfntVersion = Tag(sfntVersion)
            self.flavorData = WOFF2FlavorData(data=flavorData)

            self.directoryFormat = woff2DirectoryFormat
            self.directorySize = woff2DirectorySize
            self.DirectoryEntry = WOFF2DirectoryEntry

            self.signature = Tag("wOF2")

            self.nextTableOffset = 0
            self.transformBuffer = BytesIO()

            self.tables = OrderedDict()

            # make empty TTFont to store data while normalising and transforming tables
            self.ttFont = TTFont(recalcBBoxes=False, recalcTimestamp=False)

        def __setitem__(self, tag, data):
            """Associate new entry named 'tag' with raw table data."""
            if tag in self.tables:
                raise TTLibError("cannot rewrite '%s' table" % tag)
            if tag == "DSIG":
                # always drop DSIG table, since the encoding process can invalidate it
                self.numTables -= 1
                return

            entry = self.DirectoryEntry()
            entry.tag = Tag(tag)
            entry.flags = getKnownTagIndex(entry.tag)
            # WOFF2 table data are written to disk only on close(), after all tags
            # have been specified
            entry.data = data

            self.tables[tag] = entry

        def close(self):
            """All tags must have been specified. Now write the table data and directory."""
            if len(self.tables) != self.numTables:
                raise TTLibError(
                    "wrong number of tables; expected %d, found %d"
                    % (self.numTables, len(self.tables))
                )

            if self.sfntVersion in ("\x00\x01\x00\x00", "true"):
                isTrueType = True
            elif self.sfntVersion == "OTTO":
                isTrueType = False
            else:
                raise TTLibError("Not a TrueType or OpenType font (bad sfntVersion)")

            # The WOFF2 spec no longer requires the glyph offsets to be 4-byte aligned.
            # However, the reference WOFF2 implementation still fails to reconstruct
            # 'unpadded' glyf tables, therefore we need to 'normalise' them.
            # See:
            # https://github.com/khaledhosny/ots/issues/60
            # https://github.com/google/woff2/issues/15
            if (
                isTrueType
                and "glyf" in self.flavorData.transformedTables
                and "glyf" in self.tables
            ):
                self._normaliseGlyfAndLoca(padding=4)
            self._setHeadTransformFlag()

            # To pass the legacy OpenType Sanitiser currently included in browsers,
            # we must sort the table directory and data alphabetically by tag.
            # See:
            # https://github.com/google/woff2/pull/3
            # https://lists.w3.org/Archives/Public/public-webfonts-wg/2015Mar/0000.html
            #
            # 2023: We rely on this in _transformTables where we expect that
            # "loca" comes after "glyf" table.
            self.tables = OrderedDict(sorted(self.tables.items()))

            self.totalSfntSize = self._calcSFNTChecksumsLengthsAndOffsets()

            fontData = self._transformTables()
            compressedFont = brotli.compress(fontData, mode=brotli.MODE_FONT)

            self.totalCompressedSize = len(compressedFont)
            self.length = self._calcTotalSize()
            self.majorVersion, self.minorVersion = self._getVersion()
            self.reserved = 0

            directory = self._packTableDirectory()
            self.file.seek(0)
            self.file.write(pad(directory + compressedFont, size=4))
            self._writeFlavorData()

        def _normaliseGlyfAndLoca(self, padding=4):
            """Recompile glyf and loca tables, aligning glyph offsets to multiples of
            'padding' size. Update the head table's 'indexToLocFormat' accordingly while
            compiling loca.
            """
            if self.sfntVersion == "OTTO":
                return

            for tag in ("maxp", "head", "loca", "glyf", "fvar"):
                if tag in self.tables:
                    self._decompileTable(tag)
            self.ttFont["glyf"].padding = padding
            for tag in ("glyf", "loca"):
                self._compileTable(tag)

        def _setHeadTransformFlag(self):
            """Set bit 11 of 'head' table flags to indicate that the font has undergone
            a lossless modifying transform. Re-compile head table data."""
            self._decompileTable("head")
            self.ttFont["head"].flags |= 1 << 11
            self._compileTable("head")

        def _decompileTable(self, tag):
            """Fetch table data, decompile it, and store it inside self.ttFont."""
            tag = Tag(tag)
            if tag not in self.tables:
                raise TTLibError("missing required table: %s" % tag)
            if self.ttFont.isLoaded(tag):
                return
            data = self.tables[tag].data
            if tag == "loca":
                tableClass = WOFF2LocaTable
            elif tag == "glyf":
                tableClass = WOFF2GlyfTable
            elif tag == "hmtx":
                tableClass = WOFF2HmtxTable
            else:
                tableClass = getTableClass(tag)
            table = tableClass(tag)
            self.ttFont.tables[tag] = table
            table.decompile(data, self.ttFont)

        def _compileTable(self, tag):
            """Compile table and store it in its 'data' attribute."""
            self.tables[tag].data = self.ttFont[tag].compile(self.ttFont)

        def _calcSFNTChecksumsLengthsAndOffsets(self):
            """Compute the 'original' SFNT checksums, lengths and offsets for checksum
            adjustment calculation. Return the total size of the uncompressed font.
            """
            offset = sfntDirectorySize + sfntDirectoryEntrySize * len(self.tables)
            for tag, entry in self.tables.items():
                data = entry.data
                entry.origOffset = offset
                entry.origLength = len(data)
                if tag == "head":
                    entry.checkSum = calcChecksum(data[:8] + b"\0\0\0\0" + data[12:])
                else:
                    entry.checkSum = calcChecksum(data)
                offset += (entry.origLength + 3) & ~3
            return offset

        def _transformTables(self):
            """Return transformed font data."""
            transformedTables = self.flavorData.transformedTables
            for tag, entry in self.tables.items():
                data = None
                if tag in transformedTables:
                    data = self.transformTable(tag)
                    if data is not None:
                        entry.transformed = True
                if data is None:
                    if tag == "glyf":
                        # Currently we always sort table tags so
                        # 'loca' comes after 'glyf'.
                        transformedTables.discard("loca")
                    # pass-through the table data without transformation
                    data = entry.data
                    entry.transformed = False
                entry.offset = self.nextTableOffset
                entry.saveData(self.transformBuffer, data)
                self.nextTableOffset += entry.length
            self.writeMasterChecksum()
            fontData = self.transformBuffer.getvalue()
            return fontData

        def transformTable(self, tag):
            """Return transformed table data, or None if some pre-conditions aren't
            met -- in which case, the non-transformed table data will be used.
            """
            if tag == "loca":
                data = b""
            elif tag == "glyf":
                for tag in ("maxp", "head", "loca", "glyf"):
                    self._decompileTable(tag)
                glyfTable = self.ttFont["glyf"]
                data = glyfTable.transform(self.ttFont)
            elif tag == "hmtx":
                if "glyf" not in self.tables:
                    return
                for tag in ("maxp", "head", "hhea", "loca", "glyf", "hmtx"):
                    self._decompileTable(tag)
                hmtxTable = self.ttFont["hmtx"]
                data = hmtxTable.transform(self.ttFont)  # can be None
            else:
                raise TTLibError("Transform for table '%s' is unknown" % tag)
            return data

        def _calcMasterChecksum(self):
            """Calculate checkSumAdjustment."""
            tags = list(self.tables.keys())
            checksums = []
            for i in range(len(tags)):
                checksums.append(self.tables[tags[i]].checkSum)

            # Create a SFNT directory for checksum calculation purposes
            self.searchRange, self.entrySelector, self.rangeShift = getSearchRange(
                self.numTables, 16
            )
            directory = sstruct.pack(sfntDirectoryFormat, self)
            tables = sorted(self.tables.items())
            for tag, entry in tables:
                sfntEntry = SFNTDirectoryEntry()
                sfntEntry.tag = entry.tag
                sfntEntry.checkSum = entry.checkSum
                sfntEntry.offset = entry.origOffset
                sfntEntry.length = entry.origLength
                directory = directory + sfntEntry.toString()

            directory_end = sfntDirectorySize + len(self.tables) * sfntDirectoryEntrySize
            assert directory_end == len(directory)

            checksums.append(calcChecksum(directory))
            checksum = sum(checksums) & 0xFFFFFFFF
            # BiboAfba!
            checksumadjustment = (0xB1B0AFBA - checksum) & 0xFFFFFFFF
            return checksumadjustment

        def writeMasterChecksum(self):
            """Write checkSumAdjustment to the transformBuffer."""
            checksumadjustment = self._calcMasterChecksum()
            self.transformBuffer.seek(self.tables["head"].offset + 8)
            self.transformBuffer.write(struct.pack(">L", checksumadjustment))

        def _calcTotalSize(self):
            """Calculate total size of WOFF2 font, including any meta- and/or private data."""
            offset = self.directorySize
            for entry in self.tables.values():
                offset += len(entry.toString())
            offset += self.totalCompressedSize
            offset = (offset + 3) & ~3
            offset = self._calcFlavorDataOffsetsAndSize(offset)
            return offset

        def _calcFlavorDataOffsetsAndSize(self, start):
            """Calculate offsets and lengths for any meta- and/or private data."""
            offset = start
            data = self.flavorData
            if data.metaData:
                self.metaOrigLength = len(data.metaData)
                self.metaOffset = offset
                self.compressedMetaData = brotli.compress(
                    data.metaData, mode=brotli.MODE_TEXT
                )
                self.metaLength = len(self.compressedMetaData)
                offset += self.metaLength
            else:
                self.metaOffset = self.metaLength = self.metaOrigLength = 0
                self.compressedMetaData = b""
            if data.privData:
                # make sure private data is padded to 4-byte boundary
                offset = (offset + 3) & ~3
                self.privOffset = offset
                self.privLength = len(data.privData)
                offset += self.privLength
            else:
                self.privOffset = self.privLength = 0
            return offset

        def _getVersion(self):
            """Return the WOFF2 font's (majorVersion, minorVersion) tuple."""
            data = self.flavorData
            if data.majorVersion is not None and data.minorVersion is not None:
                return data.majorVersion, data.minorVersion
            else:
                # if None, return 'fontRevision' from 'head' table
                if "head" in self.tables:
                    return struct.unpack(">HH", self.tables["head"].data[4:8])
                else:
                    return 0, 0

        def _packTableDirectory(self):
            """Return WOFF2 table directory data."""
            directory = sstruct.pack(self.directoryFormat, self)
            for entry in self.tables.values():
                directory = directory + entry.toString()
            return directory

        def _writeFlavorData(self):
            """Write metadata and/or private data using appropiate padding."""
            compressedMetaData = self.compressedMetaData
            privData = self.flavorData.privData
            if compressedMetaData and privData:
                compressedMetaData = pad(compressedMetaData, size=4)
            if compressedMetaData:
                self.file.seek(self.metaOffset)
                assert self.file.tell() == self.metaOffset
                self.file.write(compressedMetaData)
            if privData:
                self.file.seek(self.privOffset)
                assert self.file.tell() == self.privOffset
                self.file.write(privData)

        def reordersTables(self):
            return True

    # -- woff2 directory helpers and cruft

    woff2DirectoryFormat = """
    		> # big endian
    		signature:           4s   # "wOF2"
    		sfntVersion:         4s
    		length:              L    # total woff2 file size
    		numTables:           H    # number of tables
    		reserved:            H    # set to 0
    		totalSfntSize:       L    # uncompressed size
    		totalCompressedSize: L    # compressed size
    		majorVersion:        H    # major version of WOFF file
    		minorVersion:        H    # minor version of WOFF file
    		metaOffset:          L    # offset to metadata block
    		metaLength:          L    # length of compressed metadata
    		metaOrigLength:      L    # length of uncompressed metadata
    		privOffset:          L    # offset to private data block
    		privLength:          L    # length of private data block
    """

    woff2DirectorySize = sstruct.calcsize(woff2DirectoryFormat)

    woff2KnownTags = (
        "cmap",
        "head",
        "hhea",
        "hmtx",
        "maxp",
        "name",
        "OS/2",
        "post",
        "cvt ",
        "fpgm",
        "glyf",
        "loca",
        "prep",
        "CFF ",
        "VORG",
        "EBDT",
        "EBLC",
        "gasp",
        "hdmx",
        "kern",
        "LTSH",
        "PCLT",
        "VDMX",
        "vhea",
        "vmtx",
        "BASE",
        "GDEF",
        "GPOS",
        "GSUB",
        "EBSC",
        "JSTF",
        "MATH",
        "CBDT",
        "CBLC",
        "COLR",
        "CPAL",
        "SVG ",
        "sbix",
        "acnt",
        "avar",
        "bdat",
        "bloc",
        "bsln",
        "cvar",
        "fdsc",
        "feat",
        "fmtx",
        "fvar",
        "gvar",
        "hsty",
        "just",
        "lcar",
        "mort",
        "morx",
        "opbd",
        "prop",
        "trak",
        "Zapf",
        "Silf",
        "Glat",
        "Gloc",
        "Feat",
        "Sill",
    )

    woff2FlagsFormat = """
    		> # big endian
    		flags: B  # table type and flags
    """

    woff2FlagsSize = sstruct.calcsize(woff2FlagsFormat)

    woff2UnknownTagFormat = """
    		> # big endian
    		tag: 4s  # 4-byte tag (optional)
    """

    woff2UnknownTagSize = sstruct.calcsize(woff2UnknownTagFormat)

    woff2UnknownTagIndex = 0x3F

    woff2Base128MaxSize = 5
    woff2DirectoryEntryMaxSize = (
        woff2FlagsSize + woff2UnknownTagSize + 2 * woff2Base128MaxSize
    )

    woff2TransformedTableTags = ("glyf", "loca")

    woff2GlyfTableFormat = """
    		> # big endian
    		version:                  H  # = 0x0000
    		optionFlags:              H  # Bit 0: we have overlapSimpleBitmap[], Bits 1-15: reserved
    		numGlyphs:                H  # Number of glyphs
    		indexFormat:              H  # Offset format for loca table
    		nContourStreamSize:       L  # Size of nContour stream
    		nPointsStreamSize:        L  # Size of nPoints stream
    		flagStreamSize:           L  # Size of flag stream
    		glyphStreamSize:          L  # Size of glyph stream
    		compositeStreamSize:      L  # Size of composite stream
    		bboxStreamSize:           L  # Comnined size of bboxBitmap and bboxStream
    		instructionStreamSize:    L  # Size of instruction stream
    """

    woff2GlyfTableFormatSize = sstruct.calcsize(woff2GlyfTableFormat)

    bboxFormat = """
    		>	# big endian
    		xMin:				h
    		yMin:				h
    		xMax:				h
    		yMax:				h
    """

    woff2OverlapSimpleBitmapFlag = 0x0001

    def getKnownTagIndex(tag):
        """Return index of 'tag' in woff2KnownTags list. Return 63 if not found."""
        for i in range(len(woff2KnownTags)):
            if tag == woff2KnownTags[i]:
                return i
        return woff2UnknownTagIndex

    class WOFF2DirectoryEntry(DirectoryEntry):

        def fromFile(self, file):
            pos = file.tell()
            data = file.read(woff2DirectoryEntryMaxSize)
            left = self.fromString(data)
            consumed = len(data) - len(left)
            file.seek(pos + consumed)

        def fromString(self, data):
            if len(data) < 1:
                raise TTLibError("can't read table 'flags': not enough data")
            dummy, data = sstruct.unpack2(woff2FlagsFormat, data, self)
            if self.flags & 0x3F == 0x3F:
                # if bits [0..5] of the flags byte == 63, read a 4-byte arbitrary tag value
                if len(data) < woff2UnknownTagSize:
                    raise TTLibError("can't read table 'tag': not enough data")
                dummy, data = sstruct.unpack2(woff2UnknownTagFormat, data, self)
            else:
                # otherwise, tag is derived from a fixed 'Known Tags' table
                self.tag = woff2KnownTags[self.flags & 0x3F]
            self.tag = Tag(self.tag)
            self.origLength, data = unpackBase128(data)
            self.length = self.origLength
            if self.transformed:
                self.length, data = unpackBase128(data)
                if self.tag == "loca" and self.length != 0:
                    raise TTLibError("the transformLength of the 'loca' table must be 0")
            # return left over data
            return data

        def toString(self):
            data = bytechr(self.flags)
            if (self.flags & 0x3F) == 0x3F:
                data += struct.pack(">4s", self.tag.tobytes())
            data += packBase128(self.origLength)
            if self.transformed:
                data += packBase128(self.length)
            return data

        @property
        def transformVersion(self):
            """Return bits 6-7 of table entry's flags, which indicate the preprocessing
            transformation version number (between 0 and 3).
            """
            return self.flags >> 6

        @transformVersion.setter
        def transformVersion(self, value):
            assert 0 <= value <= 3
            self.flags |= value << 6

        @property
        def transformed(self):
            """Return True if the table has any transformation, else return False."""
            # For all tables in a font, except for 'glyf' and 'loca', the transformation
            # version 0 indicates the null transform (where the original table data is
            # passed directly to the Brotli compressor). For 'glyf' and 'loca' tables,
            # transformation version 3 indicates the null transform
            if self.tag in {"glyf", "loca"}:
                return self.transformVersion != 3
            else:
                return self.transformVersion != 0

        @transformed.setter
        def transformed(self, booleanValue):
            # here we assume that a non-null transform means version 0 for 'glyf' and
            # 'loca' and 1 for every other table (e.g. hmtx); but that may change as
            # new transformation formats are introduced in the future (if ever).
            if self.tag in {"glyf", "loca"}:
                self.transformVersion = 3 if not booleanValue else 0
            else:
                self.transformVersion = int(booleanValue)

    class WOFF2LocaTable(getTableClass("loca")):
        """Same as parent class. The only difference is that it attempts to preserve
        the 'indexFormat' as encoded in the WOFF2 glyf table.
        """

        def __init__(self, tag=None):
            self.tableTag = Tag(tag or "loca")

        def compile(self, ttFont):
            try:
                max_location = max(self.locations)
            except AttributeError:
                self.set([])
                max_location = 0
            if "glyf" in ttFont and hasattr(ttFont["glyf"], "indexFormat"):
                # copile loca using the indexFormat specified in the WOFF2 glyf table
                indexFormat = ttFont["glyf"].indexFormat
                if indexFormat == 0:
                    if max_location >= 0x20000:
                        raise TTLibError("indexFormat is 0 but local offsets > 0x20000")
                    if not all(l % 2 == 0 for l in self.locations):
                        raise TTLibError(
                            "indexFormat is 0 but local offsets not multiples of 2"
                        )
                    locations = array.array("H")
                    for i in range(len(self.locations)):
                        locations.append(self.locations[i] // 2)
                else:
                    locations = array.array("I", self.locations)
                if sys.byteorder != "big":
                    locations.byteswap()
                data = locations.tobytes()
            else:
                # use the most compact indexFormat given the current glyph offsets
                data = super(WOFF2LocaTable, self).compile(ttFont)
            return data

    class WOFF2GlyfTable(getTableClass("glyf")):
        """Decoder/Encoder for WOFF2 'glyf' table transform."""

        subStreams = (
            "nContourStream",
            "nPointsStream",
            "flagStream",
            "glyphStream",
            "compositeStream",
            "bboxStream",
            "instructionStream",
        )

        def __init__(self, tag=None):
            self.tableTag = Tag(tag or "glyf")

        def reconstruct(self, data, ttFont):
            """Decompile transformed 'glyf' data."""
            inputDataSize = len(data)

            if inputDataSize < woff2GlyfTableFormatSize:
                raise TTLibError("not enough 'glyf' data")
            dummy, data = sstruct.unpack2(woff2GlyfTableFormat, data, self)
            offset = woff2GlyfTableFormatSize

            for stream in self.subStreams:
                size = getattr(self, stream + "Size")
                setattr(self, stream, data[:size])
                data = data[size:]
                offset += size

            hasOverlapSimpleBitmap = self.optionFlags & woff2OverlapSimpleBitmapFlag
            self.overlapSimpleBitmap = None
            if hasOverlapSimpleBitmap:
                overlapSimpleBitmapSize = (self.numGlyphs + 7) >> 3
                self.overlapSimpleBitmap = array.array("B", data[:overlapSimpleBitmapSize])
                offset += overlapSimpleBitmapSize

            if offset != inputDataSize:
                raise TTLibError(
                    "incorrect size of transformed 'glyf' table: expected %d, received %d bytes"
                    % (offset, inputDataSize)
                )

            bboxBitmapSize = ((self.numGlyphs + 31) >> 5) << 2
            bboxBitmap = self.bboxStream[:bboxBitmapSize]
            self.bboxBitmap = array.array("B", bboxBitmap)
            self.bboxStream = self.bboxStream[bboxBitmapSize:]

            self.nContourStream = array.array("h", self.nContourStream)
            if sys.byteorder != "big":
                self.nContourStream.byteswap()
            assert len(self.nContourStream) == self.numGlyphs

            if "head" in ttFont:
                ttFont["head"].indexToLocFormat = self.indexFormat
            try:
                self.glyphOrder = ttFont.getGlyphOrder()
            except:
                self.glyphOrder = None
            if self.glyphOrder is None:
                self.glyphOrder = [".notdef"]
                self.glyphOrder.extend(["glyph%.5d" % i for i in range(1, self.numGlyphs)])
            else:
                if len(self.glyphOrder) != self.numGlyphs:
                    raise TTLibError(
                        "incorrect glyphOrder: expected %d glyphs, found %d"
                        % (len(self.glyphOrder), self.numGlyphs)
                    )

            glyphs = self.glyphs = {}
            for glyphID, glyphName in enumerate(self.glyphOrder):
                glyph = self._decodeGlyph(glyphID)
                glyphs[glyphName] = glyph

        def transform(self, ttFont):
            """Return transformed 'glyf' data"""
            self.numGlyphs = len(self.glyphs)
            assert len(self.glyphOrder) == self.numGlyphs
            if "maxp" in ttFont:
                ttFont["maxp"].numGlyphs = self.numGlyphs
            self.indexFormat = ttFont["head"].indexToLocFormat

            for stream in self.subStreams:
                setattr(self, stream, b"")
            bboxBitmapSize = ((self.numGlyphs + 31) >> 5) << 2
            self.bboxBitmap = array.array("B", [0] * bboxBitmapSize)

            self.overlapSimpleBitmap = array.array("B", [0] * ((self.numGlyphs + 7) >> 3))
            for glyphID in range(self.numGlyphs):
                try:
                    self._encodeGlyph(glyphID)
                except NotImplementedError:
                    return None
            hasOverlapSimpleBitmap = any(self.overlapSimpleBitmap)

            self.bboxStream = self.bboxBitmap.tobytes() + self.bboxStream
            for stream in self.subStreams:
                setattr(self, stream + "Size", len(getattr(self, stream)))
            self.version = 0
            self.optionFlags = 0
            if hasOverlapSimpleBitmap:
                self.optionFlags |= woff2OverlapSimpleBitmapFlag
            data = sstruct.pack(woff2GlyfTableFormat, self)
            data += bytesjoin([getattr(self, s) for s in self.subStreams])
            if hasOverlapSimpleBitmap:
                data += self.overlapSimpleBitmap.tobytes()
            return data

        def _decodeGlyph(self, glyphID):
            glyph = getTableModule("glyf").Glyph()
            glyph.numberOfContours = self.nContourStream[glyphID]
            if glyph.numberOfContours == 0:
                return glyph
            elif glyph.isComposite():
                self._decodeComponents(glyph)
            else:
                self._decodeCoordinates(glyph)
                self._decodeOverlapSimpleFlag(glyph, glyphID)
            self._decodeBBox(glyphID, glyph)
            return glyph

        def _decodeComponents(self, glyph):
            data = self.compositeStream
            glyph.components = []
            more = 1
            haveInstructions = 0
            while more:
                component = getTableModule("glyf").GlyphComponent()
                more, haveInstr, data = component.decompile(data, self)
                haveInstructions = haveInstructions | haveInstr
                glyph.components.append(component)
            self.compositeStream = data
            if haveInstructions:
                self._decodeInstructions(glyph)

        def _decodeCoordinates(self, glyph):
            data = self.nPointsStream
            endPtsOfContours = []
            endPoint = -1
            for i in range(glyph.numberOfContours):
                ptsOfContour, data = unpack255UShort(data)
                endPoint += ptsOfContour
                endPtsOfContours.append(endPoint)
            glyph.endPtsOfContours = endPtsOfContours
            self.nPointsStream = data
            self._decodeTriplets(glyph)
            self._decodeInstructions(glyph)

        def _decodeOverlapSimpleFlag(self, glyph, glyphID):
            if self.overlapSimpleBitmap is None or glyph.numberOfContours <= 0:
                return
            byte = glyphID >> 3
            bit = glyphID & 7
            if self.overlapSimpleBitmap[byte] & (0x80 >> bit):
                glyph.flags[0] |= _g_l_y_f.flagOverlapSimple

        def _decodeInstructions(self, glyph):
            glyphStream = self.glyphStream
            instructionStream = self.instructionStream
            instructionLength, glyphStream = unpack255UShort(glyphStream)
            glyph.program = ttProgram.Program()
            glyph.program.fromBytecode(instructionStream[:instructionLength])
            self.glyphStream = glyphStream
            self.instructionStream = instructionStream[instructionLength:]

        def _decodeBBox(self, glyphID, glyph):
            haveBBox = bool(self.bboxBitmap[glyphID >> 3] & (0x80 >> (glyphID & 7)))
            if glyph.isComposite() and not haveBBox:
                raise TTLibError("no bbox values for composite glyph %d" % glyphID)
            if haveBBox:
                dummy, self.bboxStream = sstruct.unpack2(bboxFormat, self.bboxStream, glyph)
            else:
                glyph.recalcBounds(self)

        def _decodeTriplets(self, glyph):
            def withSign(flag, baseval):
                assert 0 <= baseval and baseval < 65536, "integer overflow"
                return baseval if flag & 1 else -baseval

            nPoints = glyph.endPtsOfContours[-1] + 1
            flagSize = nPoints
            if flagSize > len(self.flagStream):
                raise TTLibError("not enough 'flagStream' data")
            flagsData = self.flagStream[:flagSize]
            self.flagStream = self.flagStream[flagSize:]
            flags = array.array("B", flagsData)

            triplets = array.array("B", self.glyphStream)
            nTriplets = len(triplets)
            assert nPoints <= nTriplets

            x = 0
            y = 0
            glyph.coordinates = getTableModule("glyf").GlyphCoordinates.zeros(nPoints)
            glyph.flags = array.array("B")
            tripletIndex = 0
            for i in range(nPoints):
                flag = flags[i]
                onCurve = not bool(flag >> 7)
                flag &= 0x7F
                if flag < 84:
                    nBytes = 1
                elif flag < 120:
                    nBytes = 2
                elif flag < 124:
                    nBytes = 3
                else:
                    nBytes = 4
                assert (tripletIndex + nBytes) <= nTriplets
                if flag < 10:
                    dx = 0
                    dy = withSign(flag, ((flag & 14) << 7) + triplets[tripletIndex])
                elif flag < 20:
                    dx = withSign(flag, (((flag - 10) & 14) << 7) + triplets[tripletIndex])
                    dy = 0
                elif flag < 84:
                    b0 = flag - 20
                    b1 = triplets[tripletIndex]
                    dx = withSign(flag, 1 + (b0 & 0x30) + (b1 >> 4))
                    dy = withSign(flag >> 1, 1 + ((b0 & 0x0C) << 2) + (b1 & 0x0F))
                elif flag < 120:
                    b0 = flag - 84
                    dx = withSign(flag, 1 + ((b0 // 12) << 8) + triplets[tripletIndex])
                    dy = withSign(
                        flag >> 1, 1 + (((b0 % 12) >> 2) << 8) + triplets[tripletIndex + 1]
                    )
                elif flag < 124:
                    b2 = triplets[tripletIndex + 1]
                    dx = withSign(flag, (triplets[tripletIndex] << 4) + (b2 >> 4))
                    dy = withSign(
                        flag >> 1, ((b2 & 0x0F) << 8) + triplets[tripletIndex + 2]
                    )
                else:
                    dx = withSign(
                        flag, (triplets[tripletIndex] << 8) + triplets[tripletIndex + 1]
                    )
                    dy = withSign(
                        flag >> 1,
                        (triplets[tripletIndex + 2] << 8) + triplets[tripletIndex + 3],
                    )
                tripletIndex += nBytes
                x += dx
                y += dy
                glyph.coordinates[i] = (x, y)
                glyph.flags.append(int(onCurve))
            bytesConsumed = tripletIndex
            self.glyphStream = self.glyphStream[bytesConsumed:]

        def _encodeGlyph(self, glyphID):
            glyphName = self.getGlyphName(glyphID)
            glyph = self[glyphName]
            self.nContourStream += struct.pack(">h", glyph.numberOfContours)
            if glyph.numberOfContours == 0:
                return
            elif glyph.isComposite():
                self._encodeComponents(glyph)
            else:
                self._encodeCoordinates(glyph)
                self._encodeOverlapSimpleFlag(glyph, glyphID)
            self._encodeBBox(glyphID, glyph)

        def _encodeComponents(self, glyph):
            lastcomponent = len(glyph.components) - 1
            more = 1
            haveInstructions = 0
            for i in range(len(glyph.components)):
                if i == lastcomponent:
                    haveInstructions = hasattr(glyph, "program")
                    more = 0
                component = glyph.components[i]
                self.compositeStream += component.compile(more, haveInstructions, self)
            if haveInstructions:
                self._encodeInstructions(glyph)

        def _encodeCoordinates(self, glyph):
            lastEndPoint = -1
            if _g_l_y_f.flagCubic in glyph.flags:
                raise NotImplementedError
            for endPoint in glyph.endPtsOfContours:
                ptsOfContour = endPoint - lastEndPoint
                self.nPointsStream += pack255UShort(ptsOfContour)
                lastEndPoint = endPoint
            self._encodeTriplets(glyph)
            self._encodeInstructions(glyph)

        def _encodeOverlapSimpleFlag(self, glyph, glyphID):
            if glyph.numberOfContours <= 0:
                return
            if glyph.flags[0] & _g_l_y_f.flagOverlapSimple:
                byte = glyphID >> 3
                bit = glyphID & 7
                self.overlapSimpleBitmap[byte] |= 0x80 >> bit

        def _encodeInstructions(self, glyph):
            instructions = glyph.program.getBytecode()
            self.glyphStream += pack255UShort(len(instructions))
            self.instructionStream += instructions

        def _encodeBBox(self, glyphID, glyph):
            assert glyph.numberOfContours != 0, "empty glyph has no bbox"
            if not glyph.isComposite():
                # for simple glyphs, compare the encoded bounding box info with the calculated
                # values, and if they match omit the bounding box info
                currentBBox = glyph.xMin, glyph.yMin, glyph.xMax, glyph.yMax
                calculatedBBox = calcIntBounds(glyph.coordinates)
                if currentBBox == calculatedBBox:
                    return
            self.bboxBitmap[glyphID >> 3] |= 0x80 >> (glyphID & 7)
            self.bboxStream += sstruct.pack(bboxFormat, glyph)

        def _encodeTriplets(self, glyph):
            assert len(glyph.coordinates) == len(glyph.flags)
            coordinates = glyph.coordinates.copy()
            coordinates.absoluteToRelative()

            flags = array.array("B")
            triplets = array.array("B")
            for i in range(len(coordinates)):
                onCurve = glyph.flags[i] & _g_l_y_f.flagOnCurve
                x, y = coordinates[i]
                absX = abs(x)
                absY = abs(y)
                onCurveBit = 0 if onCurve else 128
                xSignBit = 0 if (x < 0) else 1
                ySignBit = 0 if (y < 0) else 1
                xySignBits = xSignBit + 2 * ySignBit

                if x == 0 and absY < 1280:
                    flags.append(onCurveBit + ((absY & 0xF00) >> 7) + ySignBit)
                    triplets.append(absY & 0xFF)
                elif y == 0 and absX < 1280:
                    flags.append(onCurveBit + 10 + ((absX & 0xF00) >> 7) + xSignBit)
                    triplets.append(absX & 0xFF)
                elif absX < 65 and absY < 65:
                    flags.append(
                        onCurveBit
                        + 20
                        + ((absX - 1) & 0x30)
                        + (((absY - 1) & 0x30) >> 2)
                        + xySignBits
                    )
                    triplets.append((((absX - 1) & 0xF) << 4) | ((absY - 1) & 0xF))
                elif absX < 769 and absY < 769:
                    flags.append(
                        onCurveBit
                        + 84
                        + 12 * (((absX - 1) & 0x300) >> 8)
                        + (((absY - 1) & 0x300) >> 6)
                        + xySignBits
                    )
                    triplets.append((absX - 1) & 0xFF)
                    triplets.append((absY - 1) & 0xFF)
                elif absX < 4096 and absY < 4096:
                    flags.append(onCurveBit + 120 + xySignBits)
                    triplets.append(absX >> 4)
                    triplets.append(((absX & 0xF) << 4) | (absY >> 8))
                    triplets.append(absY & 0xFF)
                else:
                    flags.append(onCurveBit + 124 + xySignBits)
                    triplets.append(absX >> 8)
                    triplets.append(absX & 0xFF)
                    triplets.append(absY >> 8)
                    triplets.append(absY & 0xFF)

            self.flagStream += flags.tobytes()
            self.glyphStream += triplets.tobytes()

    class WOFF2HmtxTable(getTableClass("hmtx")):
        def __init__(self, tag=None):
            self.tableTag = Tag(tag or "hmtx")

        def reconstruct(self, data, ttFont):
            (flags,) = struct.unpack(">B", data[:1])
            data = data[1:]
            if flags & 0b11111100 != 0:
                raise TTLibError("Bits 2-7 of '%s' flags are reserved" % self.tableTag)

            # When bit 0 is _not_ set, the lsb[] array is present
            hasLsbArray = flags & 1 == 0
            # When bit 1 is _not_ set, the leftSideBearing[] array is present
            hasLeftSideBearingArray = flags & 2 == 0
            if hasLsbArray and hasLeftSideBearingArray:
                raise TTLibError(
                    "either bits 0 or 1 (or both) must set in transformed '%s' flags"
                    % self.tableTag
                )

            glyfTable = ttFont["glyf"]
            headerTable = ttFont["hhea"]
            glyphOrder = glyfTable.glyphOrder
            numGlyphs = len(glyphOrder)
            numberOfHMetrics = min(int(headerTable.numberOfHMetrics), numGlyphs)

            assert len(data) >= 2 * numberOfHMetrics
            advanceWidthArray = array.array("H", data[: 2 * numberOfHMetrics])
            if sys.byteorder != "big":
                advanceWidthArray.byteswap()
            data = data[2 * numberOfHMetrics :]

            if hasLsbArray:
                assert len(data) >= 2 * numberOfHMetrics
                lsbArray = array.array("h", data[: 2 * numberOfHMetrics])
                if sys.byteorder != "big":
                    lsbArray.byteswap()
                data = data[2 * numberOfHMetrics :]
            else:
                # compute (proportional) glyphs' lsb from their xMin
                lsbArray = array.array("h")
                for i, glyphName in enumerate(glyphOrder):
                    if i >= numberOfHMetrics:
                        break
                    glyph = glyfTable[glyphName]
                    xMin = getattr(glyph, "xMin", 0)
                    lsbArray.append(xMin)

            numberOfSideBearings = numGlyphs - numberOfHMetrics
            if hasLeftSideBearingArray:
                assert len(data) >= 2 * numberOfSideBearings
                leftSideBearingArray = array.array("h", data[: 2 * numberOfSideBearings])
                if sys.byteorder != "big":
                    leftSideBearingArray.byteswap()
                data = data[2 * numberOfSideBearings :]
            else:
                # compute (monospaced) glyphs' leftSideBearing from their xMin
                leftSideBearingArray = array.array("h")
                for i, glyphName in enumerate(glyphOrder):
                    if i < numberOfHMetrics:
                        continue
                    glyph = glyfTable[glyphName]
                    xMin = getattr(glyph, "xMin", 0)
                    leftSideBearingArray.append(xMin)

            if data:
                raise TTLibError("too much '%s' table data" % self.tableTag)

            self.metrics = {}
            for i in range(numberOfHMetrics):
                glyphName = glyphOrder[i]
                advanceWidth, lsb = advanceWidthArray[i], lsbArray[i]
                self.metrics[glyphName] = (advanceWidth, lsb)
            lastAdvance = advanceWidthArray[-1]
            for i in range(numberOfSideBearings):
                glyphName = glyphOrder[i + numberOfHMetrics]
                self.metrics[glyphName] = (lastAdvance, leftSideBearingArray[i])

        def transform(self, ttFont):
            glyphOrder = ttFont.getGlyphOrder()
            glyf = ttFont["glyf"]
            hhea = ttFont["hhea"]
            numberOfHMetrics = hhea.numberOfHMetrics

            # check if any of the proportional glyphs has left sidebearings that
            # differ from their xMin bounding box values.
            hasLsbArray = False
            for i in range(numberOfHMetrics):
                glyphName = glyphOrder[i]
                lsb = self.metrics[glyphName][1]
                if lsb != getattr(glyf[glyphName], "xMin", 0):
                    hasLsbArray = True
                    break

            # do the same for the monospaced glyphs (if any) at the end of hmtx table
            hasLeftSideBearingArray = False
            for i in range(numberOfHMetrics, len(glyphOrder)):
                glyphName = glyphOrder[i]
                lsb = self.metrics[glyphName][1]
                if lsb != getattr(glyf[glyphName], "xMin", 0):
                    hasLeftSideBearingArray = True
                    break

            # if we need to encode both sidebearings arrays, then no transformation is
            # applicable, and we must use the untransformed hmtx data
            if hasLsbArray and hasLeftSideBearingArray:
                return

            # set bit 0 and 1 when the respective arrays are _not_ present
            flags = 0
            if not hasLsbArray:
                flags |= 1 << 0
            if not hasLeftSideBearingArray:
                flags |= 1 << 1

            data = struct.pack(">B", flags)

            advanceWidthArray = array.array(
                "H",
                [
                    self.metrics[glyphName][0]
                    for i, glyphName in enumerate(glyphOrder)
                    if i < numberOfHMetrics
                ],
            )
            if sys.byteorder != "big":
                advanceWidthArray.byteswap()
            data += advanceWidthArray.tobytes()

            if hasLsbArray:
                lsbArray = array.array(
                    "h",
                    [
                        self.metrics[glyphName][1]
                        for i, glyphName in enumerate(glyphOrder)
                        if i < numberOfHMetrics
                    ],
                )
                if sys.byteorder != "big":
                    lsbArray.byteswap()
                data += lsbArray.tobytes()

            if hasLeftSideBearingArray:
                leftSideBearingArray = array.array(
                    "h",
                    [
                        self.metrics[glyphOrder[i]][1]
                        for i in range(numberOfHMetrics, len(glyphOrder))
                    ],
                )
                if sys.byteorder != "big":
                    leftSideBearingArray.byteswap()
                data += leftSideBearingArray.tobytes()

            return data

    class WOFF2FlavorData(WOFFFlavorData):
        Flavor = "woff2"

        def __init__(self, reader=None, data=None, transformedTables=None):
            """Data class that holds the WOFF2 header major/minor version, any
            metadata or private data (as bytes strings), and the set of
            table tags that have transformations applied (if reader is not None),
            or will have once the WOFF2 font is compiled.

            Args:
                    reader: an SFNTReader (or subclass) object to read flavor data from.
                    data: another WOFFFlavorData object to initialise data from.
                    transformedTables: set of strings containing table tags to be transformed.

            Raises:
                    ImportError if the brotli module is not installed.

            NOTE: The 'reader' argument, on the one hand, and the 'data' and
            'transformedTables' arguments, on the other hand, are mutually exclusive.
            """
            if not haveBrotli:
                raise ImportError("No module named brotli")

            if reader is not None:
                if data is not None:
                    raise TypeError("'reader' and 'data' arguments are mutually exclusive")
                if transformedTables is not None:
                    raise TypeError(
                        "'reader' and 'transformedTables' arguments are mutually exclusive"
                    )

            if transformedTables is not None and (
                "glyf" in transformedTables
                and "loca" not in transformedTables
                or "loca" in transformedTables
                and "glyf" not in transformedTables
            ):
                raise ValueError("'glyf' and 'loca' must be transformed (or not) together")
            super(WOFF2FlavorData, self).__init__(reader=reader)
            if reader:
                transformedTables = [
                    tag for tag, entry in reader.tables.items() if entry.transformed
                ]
            elif data:
                self.majorVersion = data.majorVersion
                self.majorVersion = data.minorVersion
                self.metaData = data.metaData
                self.privData = data.privData
                if transformedTables is None and hasattr(data, "transformedTables"):
                    transformedTables = data.transformedTables

            if transformedTables is None:
                transformedTables = woff2TransformedTableTags

            self.transformedTables = set(transformedTables)

        def _decompress(self, rawData):
            return brotli.decompress(rawData)

    def unpackBase128(data):
        r"""Read one to five bytes from UIntBase128-encoded input string, and return
        a tuple containing the decoded integer plus any leftover data.

        >>> unpackBase128(b'\x3f\x00\x00') == (63, b"\x00\x00")
        True
        >>> unpackBase128(b'\x8f\xff\xff\xff\x7f')[0] == 4294967295
        True
        >>> unpackBase128(b'\x80\x80\x3f')  # doctest: +IGNORE_EXCEPTION_DETAIL
        Traceback (most recent call last):
          File "<stdin>", line 1, in ?
        TTLibError: UIntBase128 value must not start with leading zeros
        >>> unpackBase128(b'\x8f\xff\xff\xff\xff\x7f')[0]  # doctest: +IGNORE_EXCEPTION_DETAIL
        Traceback (most recent call last):
          File "<stdin>", line 1, in ?
        TTLibError: UIntBase128-encoded sequence is longer than 5 bytes
        >>> unpackBase128(b'\x90\x80\x80\x80\x00')[0]  # doctest: +IGNORE_EXCEPTION_DETAIL
        Traceback (most recent call last):
          File "<stdin>", line 1, in ?
        TTLibError: UIntBase128 value exceeds 2**32-1
        """
        if len(data) == 0:
            raise TTLibError("not enough data to unpack UIntBase128")
        result = 0
        if byteord(data[0]) == 0x80:
            # font must be rejected if UIntBase128 value starts with 0x80
            raise TTLibError("UIntBase128 value must not start with leading zeros")
        for i in range(woff2Base128MaxSize):
            if len(data) == 0:
                raise TTLibError("not enough data to unpack UIntBase128")
            code = byteord(data[0])
            data = data[1:]
            # if any of the top seven bits are set then we're about to overflow
            if result & 0xFE000000:
                raise TTLibError("UIntBase128 value exceeds 2**32-1")
            # set current value = old value times 128 bitwise-or (byte bitwise-and 127)
            result = (result << 7) | (code & 0x7F)
            # repeat until the most significant bit of byte is false
            if (code & 0x80) == 0:
                # return result plus left over data
                return result, data
        # make sure not to exceed the size bound
        raise TTLibError("UIntBase128-encoded sequence is longer than 5 bytes")

    def base128Size(n):
        """Return the length in bytes of a UIntBase128-encoded sequence with value n.

        >>> base128Size(0)
        1
        >>> base128Size(24567)
        3
        >>> base128Size(2**32-1)
        5
        """
        assert n >= 0
        size = 1
        while n >= 128:
            size += 1
            n >>= 7
        return size

    def packBase128(n):
        r"""Encode unsigned integer in range 0 to 2**32-1 (inclusive) to a string of
        bytes using UIntBase128 variable-length encoding. Produce the shortest possible
        encoding.

        >>> packBase128(63) == b"\x3f"
        True
        >>> packBase128(2**32-1) == b'\x8f\xff\xff\xff\x7f'
        True
        """
        if n < 0 or n >= 2**32:
            raise TTLibError("UIntBase128 format requires 0 <= integer <= 2**32-1")
        data = b""
        size = base128Size(n)
        for i in range(size):
            b = (n >> (7 * (size - i - 1))) & 0x7F
            if i < size - 1:
                b |= 0x80
            data += struct.pack("B", b)
        return data

    def unpack255UShort(data):
        """Read one to three bytes from 255UInt16-encoded input string, and return a
        tuple containing the decoded integer plus any leftover data.

        >>> unpack255UShort(bytechr(252))[0]
        252

        Note that some numbers (e.g. 506) can have multiple encodings:
        >>> unpack255UShort(struct.pack("BB", 254, 0))[0]
        506
        >>> unpack255UShort(struct.pack("BB", 255, 253))[0]
        506
        >>> unpack255UShort(struct.pack("BBB", 253, 1, 250))[0]
        506
        """
        code = byteord(data[:1])
        data = data[1:]
        if code == 253:
            # read two more bytes as an unsigned short
            if len(data) < 2:
                raise TTLibError("not enough data to unpack 255UInt16")
            (result,) = struct.unpack(">H", data[:2])
            data = data[2:]
        elif code == 254:
            # read another byte, plus 253 * 2
            if len(data) == 0:
                raise TTLibError("not enough data to unpack 255UInt16")
            result = byteord(data[:1])
            result += 506
            data = data[1:]
        elif code == 255:
            # read another byte, plus 253
            if len(data) == 0:
                raise TTLibError("not enough data to unpack 255UInt16")
            result = byteord(data[:1])
            result += 253
            data = data[1:]
        else:
            # leave as is if lower than 253
            result = code
        # return result plus left over data
        return result, data

    def pack255UShort(value):
        r"""Encode unsigned integer in range 0 to 65535 (inclusive) to a bytestring
        using 255UInt16 variable-length encoding.

        >>> pack255UShort(252) == b'\xfc'
        True
        >>> pack255UShort(506) == b'\xfe\x00'
        True
        >>> pack255UShort(762) == b'\xfd\x02\xfa'
        True
        """
        if value < 0 or value > 0xFFFF:
            raise TTLibError("255UInt16 format requires 0 <= integer <= 65535")
        if value < 253:
            return struct.pack(">B", value)
        elif value < 506:
            return struct.pack(">BB", 255, value - 253)
        elif value < 762:
            return struct.pack(">BB", 254, value - 506)
        else:
            return struct.pack(">BH", 253, value)

    def compress(input_file, output_file, transform_tables=None):
        """Compress OpenType font to WOFF2.

        Args:
                input_file: a file path, file or file-like object (open in binary mode)
                        containing an OpenType font (either CFF- or TrueType-flavored).
                output_file: a file path, file or file-like object where to save the
                        compressed WOFF2 font.
                transform_tables: Optional[Iterable[str]]: a set of table tags for which
                        to enable preprocessing transformations. By default, only 'glyf'
                        and 'loca' tables are transformed. An empty set means disable all
                        transformations.
        """
        log.info("Processing %s => %s" % (input_file, output_file))

        font = TTFont(input_file, recalcBBoxes=False, recalcTimestamp=False)
        font.flavor = "woff2"

        if transform_tables is not None:
            font.flavorData = WOFF2FlavorData(
                data=font.flavorData, transformedTables=transform_tables
            )

        font.save(output_file, reorderTables=False)

    def decompress(input_file, output_file):
        """Decompress WOFF2 font to OpenType font.

        Args:
                input_file: a file path, file or file-like object (open in binary mode)
                        containing a compressed WOFF2 font.
                output_file: a file path, file or file-like object where to save the
                        decompressed OpenType font.
        """
        log.info("Processing %s => %s" % (input_file, output_file))

        font = TTFont(input_file, recalcBBoxes=False, recalcTimestamp=False)
        font.flavor = None
        font.flavorData = None
        font.save(output_file, reorderTables=True)

    def main(args=None):
        """Compress and decompress WOFF2 fonts"""
        import argparse
        from fontTools import configLogger
        from fontTools.ttx import makeOutputFileName

        class _HelpAction(argparse._HelpAction):
            def __call__(self, parser, namespace, values, option_string=None):
                subparsers_actions = [
                    action
                    for action in parser._actions
                    if isinstance(action, argparse._SubParsersAction)
                ]
                for subparsers_action in subparsers_actions:
                    for choice, subparser in subparsers_action.choices.items():
                        print(subparser.format_help())
                parser.exit()

        class _NoGlyfTransformAction(argparse.Action):
            def __call__(self, parser, namespace, values, option_string=None):
                namespace.transform_tables.difference_update({"glyf", "loca"})

        class _HmtxTransformAction(argparse.Action):
            def __call__(self, parser, namespace, values, option_string=None):
                namespace.transform_tables.add("hmtx")

        parser = argparse.ArgumentParser(
            prog="fonttools ttLib.woff2", description=main.__doc__, add_help=False
        )

        parser.add_argument(
            "-h", "--help", action=_HelpAction, help="show this help message and exit"
        )

        parser_group = parser.add_subparsers(title="sub-commands")
        parser_compress = parser_group.add_parser(
            "compress", description="Compress a TTF or OTF font to WOFF2"
        )
        parser_decompress = parser_group.add_parser(
            "decompress", description="Decompress a WOFF2 font to OTF"
        )

        for subparser in (parser_compress, parser_decompress):
            group = subparser.add_mutually_exclusive_group(required=False)
            group.add_argument(
                "-v",
                "--verbose",
                action="store_true",
                help="print more messages to console",
            )
            group.add_argument(
                "-q",
                "--quiet",
                action="store_true",
                help="do not print messages to console",
            )

        parser_compress.add_argument(
            "input_file",
            metavar="INPUT",
            help="the input OpenType font (.ttf or .otf)",
        )
        parser_decompress.add_argument(
            "input_file",
            metavar="INPUT",
            help="the input WOFF2 font",
        )

        parser_compress.add_argument(
            "-o",
            "--output-file",
            metavar="OUTPUT",
            help="the output WOFF2 font",
        )
        parser_decompress.add_argument(
            "-o",
            "--output-file",
            metavar="OUTPUT",
            help="the output OpenType font",
        )

        transform_group = parser_compress.add_argument_group()
        transform_group.add_argument(
            "--no-glyf-transform",
            dest="transform_tables",
            nargs=0,
            action=_NoGlyfTransformAction,
            help="Do not transform glyf (and loca) tables",
        )
        transform_group.add_argument(
            "--hmtx-transform",
            dest="transform_tables",
            nargs=0,
            action=_HmtxTransformAction,
            help="Enable optional transformation for 'hmtx' table",
        )

        parser_compress.set_defaults(
            subcommand=compress,
            transform_tables={"glyf", "loca"},
        )
        parser_decompress.set_defaults(subcommand=decompress)

        options = vars(parser.parse_args(args))

        subcommand = options.pop("subcommand", None)
        if not subcommand:
            parser.print_help()
            return

        quiet = options.pop("quiet")
        verbose = options.pop("verbose")
        configLogger(
            level=("ERROR" if quiet else "DEBUG" if verbose else "INFO"),
        )

        if not options["output_file"]:
            if subcommand is compress:
                extension = ".woff2"
            elif subcommand is decompress:
                # choose .ttf/.otf file extension depending on sfntVersion
                with open(options["input_file"], "rb") as f:
                    f.seek(4)  # skip 'wOF2' signature
                    sfntVersion = f.read(4)
                assert len(sfntVersion) == 4, "not enough data"
                extension = ".otf" if sfntVersion == b"OTTO" else ".ttf"
            else:
                raise AssertionError(subcommand)
            options["output_file"] = makeOutputFileName(
                options["input_file"], outputDir=None, extension=extension
            )

        try:
            subcommand(**options)
        except TTLibError as e:
            parser.error(e)

    if __name__ == "__main__":
        sys.exit(main())