from fontTools.config import OPTIONS from fontTools.misc.textTools import Tag, bytesjoin from .DefaultTable import DefaultTable from enum import IntEnum import sys import array import struct import logging from functools import lru_cache from typing import Iterator, NamedTuple, Optional, Tuple log = logging.getLogger(__name__) have_uharfbuzz = False try: import uharfbuzz as hb # repack method added in uharfbuzz >= 0.23; if uharfbuzz *can* be # imported but repack method is missing, behave as if uharfbuzz # is not available (fallback to the slower Python implementation) have_uharfbuzz = callable(getattr(hb, "repack", None)) except ImportError: pass USE_HARFBUZZ_REPACKER = OPTIONS[f"{__name__}:USE_HARFBUZZ_REPACKER"] class OverflowErrorRecord(object): def __init__(self, overflowTuple): self.tableType = overflowTuple[0] self.LookupListIndex = overflowTuple[1] self.SubTableIndex = overflowTuple[2] self.itemName = overflowTuple[3] self.itemIndex = overflowTuple[4] def __repr__(self): return str( ( self.tableType, "LookupIndex:", self.LookupListIndex, "SubTableIndex:", self.SubTableIndex, "ItemName:", self.itemName, "ItemIndex:", self.itemIndex, ) ) class OTLOffsetOverflowError(Exception): def __init__(self, overflowErrorRecord): self.value = overflowErrorRecord def __str__(self): return repr(self.value) class RepackerState(IntEnum): # Repacking control flow is implemnted using a state machine. The state machine table: # # State | Packing Success | Packing Failed | Exception Raised | # ------------+-----------------+----------------+------------------+ # PURE_FT | Return result | PURE_FT | Return failure | # HB_FT | Return result | HB_FT | FT_FALLBACK | # FT_FALLBACK | HB_FT | FT_FALLBACK | Return failure | # Pack only with fontTools, don't allow sharing between extensions. PURE_FT = 1 # Attempt to pack with harfbuzz (allowing sharing between extensions) # use fontTools to attempt overflow resolution. HB_FT = 2 # Fallback if HB/FT packing gets stuck. Pack only with fontTools, don't allow sharing between # extensions. FT_FALLBACK = 3 class BaseTTXConverter(DefaultTable): """Generic base class for TTX table converters. It functions as an adapter between the TTX (ttLib actually) table model and the model we use for OpenType tables, which is necessarily subtly different. """ def decompile(self, data, font): """Create an object from the binary data. Called automatically on access.""" from . import otTables reader = OTTableReader(data, tableTag=self.tableTag) tableClass = getattr(otTables, self.tableTag) self.table = tableClass() self.table.decompile(reader, font) def compile(self, font): """Compiles the table into binary. Called automatically on save.""" # General outline: # Create a top-level OTTableWriter for the GPOS/GSUB table. # Call the compile method for the the table # for each 'converter' record in the table converter list # call converter's write method for each item in the value. # - For simple items, the write method adds a string to the # writer's self.items list. # - For Struct/Table/Subtable items, it add first adds new writer to the # to the writer's self.items, then calls the item's compile method. # This creates a tree of writers, rooted at the GUSB/GPOS writer, with # each writer representing a table, and the writer.items list containing # the child data strings and writers. # call the getAllData method # call _doneWriting, which removes duplicates # call _gatherTables. This traverses the tables, adding unique occurences to a flat list of tables # Traverse the flat list of tables, calling getDataLength on each to update their position # Traverse the flat list of tables again, calling getData each get the data in the table, now that # pos's and offset are known. # If a lookup subtable overflows an offset, we have to start all over. overflowRecord = None # this is 3-state option: default (None) means automatically use hb.repack or # silently fall back if it fails; True, use it and raise error if not possible # or it errors out; False, don't use it, even if you can. use_hb_repack = font.cfg[USE_HARFBUZZ_REPACKER] if self.tableTag in ("GSUB", "GPOS"): if use_hb_repack is False: log.debug( "hb.repack disabled, compiling '%s' with pure-python serializer", self.tableTag, ) elif not have_uharfbuzz: if use_hb_repack is True: raise ImportError("No module named 'uharfbuzz'") else: assert use_hb_repack is None log.debug( "uharfbuzz not found, compiling '%s' with pure-python serializer", self.tableTag, ) if ( use_hb_repack in (None, True) and have_uharfbuzz and self.tableTag in ("GSUB", "GPOS") ): state = RepackerState.HB_FT else: state = RepackerState.PURE_FT hb_first_error_logged = False lastOverflowRecord = None while True: try: writer = OTTableWriter(tableTag=self.tableTag) self.table.compile(writer, font) if state == RepackerState.HB_FT: return self.tryPackingHarfbuzz(writer, hb_first_error_logged) elif state == RepackerState.PURE_FT: return self.tryPackingFontTools(writer) elif state == RepackerState.FT_FALLBACK: # Run packing with FontTools only, but don't return the result as it will # not be optimally packed. Once a successful packing has been found, state is # changed back to harfbuzz packing to produce the final, optimal, packing. self.tryPackingFontTools(writer) log.debug( "Re-enabling sharing between extensions and switching back to " "harfbuzz+fontTools packing." ) state = RepackerState.HB_FT except OTLOffsetOverflowError as e: hb_first_error_logged = True ok = self.tryResolveOverflow(font, e, lastOverflowRecord) lastOverflowRecord = e.value if ok: continue if state is RepackerState.HB_FT: log.debug( "Harfbuzz packing out of resolutions, disabling sharing between extensions and " "switching to fontTools only packing." ) state = RepackerState.FT_FALLBACK else: raise def tryPackingHarfbuzz(self, writer, hb_first_error_logged): try: log.debug("serializing '%s' with hb.repack", self.tableTag) return writer.getAllDataUsingHarfbuzz(self.tableTag) except (ValueError, MemoryError, hb.RepackerError) as e: # Only log hb repacker errors the first time they occur in # the offset-overflow resolution loop, they are just noisy. # Maybe we can revisit this if/when uharfbuzz actually gives # us more info as to why hb.repack failed... if not hb_first_error_logged: error_msg = f"{type(e).__name__}" if str(e) != "": error_msg += f": {e}" log.warning( "hb.repack failed to serialize '%s', attempting fonttools resolutions " "; the error message was: %s", self.tableTag, error_msg, ) hb_first_error_logged = True return writer.getAllData(remove_duplicate=False) def tryPackingFontTools(self, writer): return writer.getAllData() def tryResolveOverflow(self, font, e, lastOverflowRecord): ok = 0 if lastOverflowRecord == e.value: # Oh well... return ok overflowRecord = e.value log.info("Attempting to fix OTLOffsetOverflowError %s", e) if overflowRecord.itemName is None: from .otTables import fixLookupOverFlows ok = fixLookupOverFlows(font, overflowRecord) else: from .otTables import fixSubTableOverFlows ok = fixSubTableOverFlows(font, overflowRecord) if ok: return ok # Try upgrading lookup to Extension and hope # that cross-lookup sharing not happening would # fix overflow... from .otTables import fixLookupOverFlows return fixLookupOverFlows(font, overflowRecord) def toXML(self, writer, font): self.table.toXML2(writer, font) def fromXML(self, name, attrs, content, font): from . import otTables if not hasattr(self, "table"): tableClass = getattr(otTables, self.tableTag) self.table = tableClass() self.table.fromXML(name, attrs, content, font) self.table.populateDefaults() def ensureDecompiled(self, recurse=True): self.table.ensureDecompiled(recurse=recurse) # https://github.com/fonttools/fonttools/pull/2285#issuecomment-834652928 assert len(struct.pack("i", 0)) == 4 assert array.array("i").itemsize == 4, "Oops, file a bug against fonttools." class OTTableReader(object): """Helper class to retrieve data from an OpenType table.""" __slots__ = ("data", "offset", "pos", "localState", "tableTag") def __init__(self, data, localState=None, offset=0, tableTag=None): self.data = data self.offset = offset self.pos = offset self.localState = localState self.tableTag = tableTag def advance(self, count): self.pos += count def seek(self, pos): self.pos = pos def copy(self): other = self.__class__(self.data, self.localState, self.offset, self.tableTag) other.pos = self.pos return other def getSubReader(self, offset): offset = self.offset + offset return self.__class__(self.data, self.localState, offset, self.tableTag) def readValue(self, typecode, staticSize): pos = self.pos newpos = pos + staticSize (value,) = struct.unpack(f">{typecode}", self.data[pos:newpos]) self.pos = newpos return value def readArray(self, typecode, staticSize, count): pos = self.pos newpos = pos + count * staticSize value = array.array(typecode, self.data[pos:newpos]) if sys.byteorder != "big": value.byteswap() self.pos = newpos return value.tolist() def readInt8(self): return self.readValue("b", staticSize=1) def readInt8Array(self, count): return self.readArray("b", staticSize=1, count=count) def readShort(self): return self.readValue("h", staticSize=2) def readShortArray(self, count): return self.readArray("h", staticSize=2, count=count) def readLong(self): return self.readValue("i", staticSize=4) def readLongArray(self, count): return self.readArray("i", staticSize=4, count=count) def readUInt8(self): return self.readValue("B", staticSize=1) def readUInt8Array(self, count): return self.readArray("B", staticSize=1, count=count) def readUShort(self): return self.readValue("H", staticSize=2) def readUShortArray(self, count): return self.readArray("H", staticSize=2, count=count) def readULong(self): return self.readValue("I", staticSize=4) def readULongArray(self, count): return self.readArray("I", staticSize=4, count=count) def readUInt24(self): pos = self.pos newpos = pos + 3 (value,) = struct.unpack(">l", b"\0" + self.data[pos:newpos]) self.pos = newpos return value def readUInt24Array(self, count): return [self.readUInt24() for _ in range(count)] def readTag(self): pos = self.pos newpos = pos + 4 value = Tag(self.data[pos:newpos]) assert len(value) == 4, value self.pos = newpos return value def readData(self, count): pos = self.pos newpos = pos + count value = self.data[pos:newpos] self.pos = newpos return value def __setitem__(self, name, value): state = self.localState.copy() if self.localState else dict() state[name] = value self.localState = state def __getitem__(self, name): return self.localState and self.localState[name] def __contains__(self, name): return self.localState and name in self.localState class OffsetToWriter(object): def __init__(self, subWriter, offsetSize): self.subWriter = subWriter self.offsetSize = offsetSize def __eq__(self, other): if type(self) != type(other): return NotImplemented return self.subWriter == other.subWriter and self.offsetSize == other.offsetSize def __hash__(self): # only works after self._doneWriting() has been called return hash((self.subWriter, self.offsetSize)) class OTTableWriter(object): """Helper class to gather and assemble data for OpenType tables.""" def __init__(self, localState=None, tableTag=None): self.items = [] self.pos = None self.localState = localState self.tableTag = tableTag self.parent = None def __setitem__(self, name, value): state = self.localState.copy() if self.localState else dict() state[name] = value self.localState = state def __getitem__(self, name): return self.localState[name] def __delitem__(self, name): del self.localState[name] # assembler interface def getDataLength(self): """Return the length of this table in bytes, without subtables.""" l = 0 for item in self.items: if hasattr(item, "getCountData"): l += item.size elif hasattr(item, "subWriter"): l += item.offsetSize else: l = l + len(item) return l def getData(self): """Assemble the data for this writer/table, without subtables.""" items = list(self.items) # make a shallow copy pos = self.pos numItems = len(items) for i in range(numItems): item = items[i] if hasattr(item, "subWriter"): if item.offsetSize == 4: items[i] = packULong(item.subWriter.pos - pos) elif item.offsetSize == 2: try: items[i] = packUShort(item.subWriter.pos - pos) except struct.error: # provide data to fix overflow problem. overflowErrorRecord = self.getOverflowErrorRecord( item.subWriter ) raise OTLOffsetOverflowError(overflowErrorRecord) elif item.offsetSize == 3: items[i] = packUInt24(item.subWriter.pos - pos) else: raise ValueError(item.offsetSize) return bytesjoin(items) def getDataForHarfbuzz(self): """Assemble the data for this writer/table with all offset field set to 0""" items = list(self.items) packFuncs = {2: packUShort, 3: packUInt24, 4: packULong} for i, item in enumerate(items): if hasattr(item, "subWriter"): # Offset value is not needed in harfbuzz repacker, so setting offset to 0 to avoid overflow here if item.offsetSize in packFuncs: items[i] = packFuncs[item.offsetSize](0) else: raise ValueError(item.offsetSize) return bytesjoin(items) def __hash__(self): # only works after self._doneWriting() has been called return hash(self.items) def __ne__(self, other): result = self.__eq__(other) return result if result is NotImplemented else not result def __eq__(self, other): if type(self) != type(other): return NotImplemented return self.items == other.items def _doneWriting(self, internedTables, shareExtension=False): # Convert CountData references to data string items # collapse duplicate table references to a unique entry # "tables" are OTTableWriter objects. # For Extension Lookup types, we can # eliminate duplicates only within the tree under the Extension Lookup, # as offsets may exceed 64K even between Extension LookupTable subtables. isExtension = hasattr(self, "Extension") # Certain versions of Uniscribe reject the font if the GSUB/GPOS top-level # arrays (ScriptList, FeatureList, LookupList) point to the same, possibly # empty, array. So, we don't share those. # See: https://github.com/fonttools/fonttools/issues/518 dontShare = hasattr(self, "DontShare") if isExtension and not shareExtension: internedTables = {} items = self.items for i in range(len(items)): item = items[i] if hasattr(item, "getCountData"): items[i] = item.getCountData() elif hasattr(item, "subWriter"): item.subWriter._doneWriting( internedTables, shareExtension=shareExtension ) # At this point, all subwriters are hashable based on their items. # (See hash and comparison magic methods above.) So the ``setdefault`` # call here will return the first writer object we've seen with # equal content, or store it in the dictionary if it's not been # seen yet. We therefore replace the subwriter object with an equivalent # object, which deduplicates the tree. if not dontShare: items[i].subWriter = internedTables.setdefault( item.subWriter, item.subWriter ) self.items = tuple(items) def _gatherTables(self, tables, extTables, done): # Convert table references in self.items tree to a flat # list of tables in depth-first traversal order. # "tables" are OTTableWriter objects. # We do the traversal in reverse order at each level, in order to # resolve duplicate references to be the last reference in the list of tables. # For extension lookups, duplicate references can be merged only within the # writer tree under the extension lookup. done[id(self)] = True numItems = len(self.items) iRange = list(range(numItems)) iRange.reverse() isExtension = hasattr(self, "Extension") selfTables = tables if isExtension: assert ( extTables is not None ), "Program or XML editing error. Extension subtables cannot contain extensions subtables" tables, extTables, done = extTables, None, {} # add Coverage table if it is sorted last. sortCoverageLast = False if hasattr(self, "sortCoverageLast"): # Find coverage table for i in range(numItems): item = self.items[i] if ( hasattr(item, "subWriter") and getattr(item.subWriter, "name", None) == "Coverage" ): sortCoverageLast = True break if id(item.subWriter) not in done: item.subWriter._gatherTables(tables, extTables, done) else: # We're a new parent of item pass for i in iRange: item = self.items[i] if not hasattr(item, "subWriter"): continue if ( sortCoverageLast and (i == 1) and getattr(item.subWriter, "name", None) == "Coverage" ): # we've already 'gathered' it above continue if id(item.subWriter) not in done: item.subWriter._gatherTables(tables, extTables, done) else: # Item is already written out by other parent pass selfTables.append(self) def _gatherGraphForHarfbuzz(self, tables, obj_list, done, objidx, virtual_edges): real_links = [] virtual_links = [] item_idx = objidx # Merge virtual_links from parent for idx in virtual_edges: virtual_links.append((0, 0, idx)) sortCoverageLast = False coverage_idx = 0 if hasattr(self, "sortCoverageLast"): # Find coverage table for i, item in enumerate(self.items): if getattr(item, "name", None) == "Coverage": sortCoverageLast = True if id(item) not in done: coverage_idx = item_idx = item._gatherGraphForHarfbuzz( tables, obj_list, done, item_idx, virtual_edges ) else: coverage_idx = done[id(item)] virtual_edges.append(coverage_idx) break child_idx = 0 offset_pos = 0 for i, item in enumerate(self.items): if hasattr(item, "subWriter"): pos = offset_pos elif hasattr(item, "getCountData"): offset_pos += item.size continue else: offset_pos = offset_pos + len(item) continue if id(item.subWriter) not in done: child_idx = item_idx = item.subWriter._gatherGraphForHarfbuzz( tables, obj_list, done, item_idx, virtual_edges ) else: child_idx = done[id(item.subWriter)] real_edge = (pos, item.offsetSize, child_idx) real_links.append(real_edge) offset_pos += item.offsetSize tables.append(self) obj_list.append((real_links, virtual_links)) item_idx += 1 done[id(self)] = item_idx if sortCoverageLast: virtual_edges.pop() return item_idx def getAllDataUsingHarfbuzz(self, tableTag): """The Whole table is represented as a Graph. Assemble graph data and call Harfbuzz repacker to pack the table. Harfbuzz repacker is faster and retain as much sub-table sharing as possible, see also: https://github.com/harfbuzz/harfbuzz/blob/main/docs/repacker.md The input format for hb.repack() method is explained here: https://github.com/harfbuzz/uharfbuzz/blob/main/src/uharfbuzz/_harfbuzz.pyx#L1149 """ internedTables = {} self._doneWriting(internedTables, shareExtension=True) tables = [] obj_list = [] done = {} objidx = 0 virtual_edges = [] self._gatherGraphForHarfbuzz(tables, obj_list, done, objidx, virtual_edges) # Gather all data in two passes: the absolute positions of all # subtable are needed before the actual data can be assembled. pos = 0 for table in tables: table.pos = pos pos = pos + table.getDataLength() data = [] for table in tables: tableData = table.getDataForHarfbuzz() data.append(tableData) if hasattr(hb, "repack_with_tag"): return hb.repack_with_tag(str(tableTag), data, obj_list) else: return hb.repack(data, obj_list) def getAllData(self, remove_duplicate=True): """Assemble all data, including all subtables.""" if remove_duplicate: internedTables = {} self._doneWriting(internedTables) tables = [] extTables = [] done = {} self._gatherTables(tables, extTables, done) tables.reverse() extTables.reverse() # Gather all data in two passes: the absolute positions of all # subtable are needed before the actual data can be assembled. pos = 0 for table in tables: table.pos = pos pos = pos + table.getDataLength() for table in extTables: table.pos = pos pos = pos + table.getDataLength() data = [] for table in tables: tableData = table.getData() data.append(tableData) for table in extTables: tableData = table.getData() data.append(tableData) return bytesjoin(data) # interface for gathering data, as used by table.compile() def getSubWriter(self): subwriter = self.__class__(self.localState, self.tableTag) subwriter.parent = ( self # because some subtables have idential values, we discard ) # the duplicates under the getAllData method. Hence some # subtable writers can have more than one parent writer. # But we just care about first one right now. return subwriter def writeValue(self, typecode, value): self.items.append(struct.pack(f">{typecode}", value)) def writeArray(self, typecode, values): a = array.array(typecode, values) if sys.byteorder != "big": a.byteswap() self.items.append(a.tobytes()) def writeInt8(self, value): assert -128 <= value < 128, value self.items.append(struct.pack(">b", value)) def writeInt8Array(self, values): self.writeArray("b", values) def writeShort(self, value): assert -32768 <= value < 32768, value self.items.append(struct.pack(">h", value)) def writeShortArray(self, values): self.writeArray("h", values) def writeLong(self, value): self.items.append(struct.pack(">i", value)) def writeLongArray(self, values): self.writeArray("i", values) def writeUInt8(self, value): assert 0 <= value < 256, value self.items.append(struct.pack(">B", value)) def writeUInt8Array(self, values): self.writeArray("B", values) def writeUShort(self, value): assert 0 <= value < 0x10000, value self.items.append(struct.pack(">H", value)) def writeUShortArray(self, values): self.writeArray("H", values) def writeULong(self, value): self.items.append(struct.pack(">I", value)) def writeULongArray(self, values): self.writeArray("I", values) def writeUInt24(self, value): assert 0 <= value < 0x1000000, value b = struct.pack(">L", value) self.items.append(b[1:]) def writeUInt24Array(self, values): for value in values: self.writeUInt24(value) def writeTag(self, tag): tag = Tag(tag).tobytes() assert len(tag) == 4, tag self.items.append(tag) def writeSubTable(self, subWriter, offsetSize): self.items.append(OffsetToWriter(subWriter, offsetSize)) def writeCountReference(self, table, name, size=2, value=None): ref = CountReference(table, name, size=size, value=value) self.items.append(ref) return ref def writeStruct(self, format, values): data = struct.pack(*(format,) + values) self.items.append(data) def writeData(self, data): self.items.append(data) def getOverflowErrorRecord(self, item): LookupListIndex = SubTableIndex = itemName = itemIndex = None if self.name == "LookupList": LookupListIndex = item.repeatIndex elif self.name == "Lookup": LookupListIndex = self.repeatIndex SubTableIndex = item.repeatIndex else: itemName = getattr(item, "name", "") if hasattr(item, "repeatIndex"): itemIndex = item.repeatIndex if self.name == "SubTable": LookupListIndex = self.parent.repeatIndex SubTableIndex = self.repeatIndex elif self.name == "ExtSubTable": LookupListIndex = self.parent.parent.repeatIndex SubTableIndex = self.parent.repeatIndex else: # who knows how far below the SubTable level we are! Climb back up to the nearest subtable. itemName = ".".join([self.name, itemName]) p1 = self.parent while p1 and p1.name not in ["ExtSubTable", "SubTable"]: itemName = ".".join([p1.name, itemName]) p1 = p1.parent if p1: if p1.name == "ExtSubTable": LookupListIndex = p1.parent.parent.repeatIndex SubTableIndex = p1.parent.repeatIndex else: LookupListIndex = p1.parent.repeatIndex SubTableIndex = p1.repeatIndex return OverflowErrorRecord( (self.tableTag, LookupListIndex, SubTableIndex, itemName, itemIndex) ) class CountReference(object): """A reference to a Count value, not a count of references.""" def __init__(self, table, name, size=None, value=None): self.table = table self.name = name self.size = size if value is not None: self.setValue(value) def setValue(self, value): table = self.table name = self.name if table[name] is None: table[name] = value else: assert table[name] == value, (name, table[name], value) def getValue(self): return self.table[self.name] def getCountData(self): v = self.table[self.name] if v is None: v = 0 return {1: packUInt8, 2: packUShort, 4: packULong}[self.size](v) def packUInt8(value): return struct.pack(">B", value) def packUShort(value): return struct.pack(">H", value) def packULong(value): assert 0 <= value < 0x100000000, value return struct.pack(">I", value) def packUInt24(value): assert 0 <= value < 0x1000000, value return struct.pack(">I", value)[1:] class BaseTable(object): """Generic base class for all OpenType (sub)tables.""" def __getattr__(self, attr): reader = self.__dict__.get("reader") if reader: del self.reader font = self.font del self.font self.decompile(reader, font) return getattr(self, attr) raise AttributeError(attr) def ensureDecompiled(self, recurse=False): reader = self.__dict__.get("reader") if reader: del self.reader font = self.font del self.font self.decompile(reader, font) if recurse: for subtable in self.iterSubTables(): subtable.value.ensureDecompiled(recurse) def __getstate__(self): # before copying/pickling 'lazy' objects, make a shallow copy of OTTableReader # https://github.com/fonttools/fonttools/issues/2965 if "reader" in self.__dict__: state = self.__dict__.copy() state["reader"] = self.__dict__["reader"].copy() return state return self.__dict__ @classmethod def getRecordSize(cls, reader): totalSize = 0 for conv in cls.converters: size = conv.getRecordSize(reader) if size is NotImplemented: return NotImplemented countValue = 1 if conv.repeat: if conv.repeat in reader: countValue = reader[conv.repeat] + conv.aux else: return NotImplemented totalSize += size * countValue return totalSize def getConverters(self): return self.converters def getConverterByName(self, name): return self.convertersByName[name] def populateDefaults(self, propagator=None): for conv in self.getConverters(): if conv.repeat: if not hasattr(self, conv.name): setattr(self, conv.name, []) countValue = len(getattr(self, conv.name)) - conv.aux try: count_conv = self.getConverterByName(conv.repeat) setattr(self, conv.repeat, countValue) except KeyError: # conv.repeat is a propagated count if propagator and conv.repeat in propagator: propagator[conv.repeat].setValue(countValue) else: if conv.aux and not eval(conv.aux, None, self.__dict__): continue if hasattr(self, conv.name): continue # Warn if it should NOT be present?! if hasattr(conv, "writeNullOffset"): setattr(self, conv.name, None) # Warn? # elif not conv.isCount: # # Warn? # pass if hasattr(conv, "DEFAULT"): # OptionalValue converters (e.g. VarIndex) setattr(self, conv.name, conv.DEFAULT) def decompile(self, reader, font): self.readFormat(reader) table = {} self.__rawTable = table # for debugging for conv in self.getConverters(): if conv.name == "SubTable": conv = conv.getConverter(reader.tableTag, table["LookupType"]) if conv.name == "ExtSubTable": conv = conv.getConverter(reader.tableTag, table["ExtensionLookupType"]) if conv.name == "FeatureParams": conv = conv.getConverter(reader["FeatureTag"]) if conv.name == "SubStruct": conv = conv.getConverter(reader.tableTag, table["MorphType"]) try: if conv.repeat: if isinstance(conv.repeat, int): countValue = conv.repeat elif conv.repeat in table: countValue = table[conv.repeat] else: # conv.repeat is a propagated count countValue = reader[conv.repeat] countValue += conv.aux table[conv.name] = conv.readArray(reader, font, table, countValue) else: if conv.aux and not eval(conv.aux, None, table): continue table[conv.name] = conv.read(reader, font, table) if conv.isPropagated: reader[conv.name] = table[conv.name] except Exception as e: name = conv.name e.args = e.args + (name,) raise if hasattr(self, "postRead"): self.postRead(table, font) else: self.__dict__.update(table) del self.__rawTable # succeeded, get rid of debugging info def compile(self, writer, font): self.ensureDecompiled() # TODO Following hack to be removed by rewriting how FormatSwitching tables # are handled. # https://github.com/fonttools/fonttools/pull/2238#issuecomment-805192631 if hasattr(self, "preWrite"): deleteFormat = not hasattr(self, "Format") table = self.preWrite(font) deleteFormat = deleteFormat and hasattr(self, "Format") else: deleteFormat = False table = self.__dict__.copy() # some count references may have been initialized in a custom preWrite; we set # these in the writer's state beforehand (instead of sequentially) so they will # be propagated to all nested subtables even if the count appears in the current # table only *after* the offset to the subtable that it is counting. for conv in self.getConverters(): if conv.isCount and conv.isPropagated: value = table.get(conv.name) if isinstance(value, CountReference): writer[conv.name] = value if hasattr(self, "sortCoverageLast"): writer.sortCoverageLast = 1 if hasattr(self, "DontShare"): writer.DontShare = True if hasattr(self.__class__, "LookupType"): writer["LookupType"].setValue(self.__class__.LookupType) self.writeFormat(writer) for conv in self.getConverters(): value = table.get( conv.name ) # TODO Handle defaults instead of defaulting to None! if conv.repeat: if value is None: value = [] countValue = len(value) - conv.aux if isinstance(conv.repeat, int): assert len(value) == conv.repeat, "expected %d values, got %d" % ( conv.repeat, len(value), ) elif conv.repeat in table: CountReference(table, conv.repeat, value=countValue) else: # conv.repeat is a propagated count writer[conv.repeat].setValue(countValue) try: conv.writeArray(writer, font, table, value) except Exception as e: e.args = e.args + (conv.name + "[]",) raise elif conv.isCount: # Special-case Count values. # Assumption: a Count field will *always* precede # the actual array(s). # We need a default value, as it may be set later by a nested # table. We will later store it here. # We add a reference: by the time the data is assembled # the Count value will be filled in. # We ignore the current count value since it will be recomputed, # unless it's a CountReference that was already initialized in a custom preWrite. if isinstance(value, CountReference): ref = value ref.size = conv.staticSize writer.writeData(ref) table[conv.name] = ref.getValue() else: ref = writer.writeCountReference(table, conv.name, conv.staticSize) table[conv.name] = None if conv.isPropagated: writer[conv.name] = ref elif conv.isLookupType: # We make sure that subtables have the same lookup type, # and that the type is the same as the one set on the # Lookup object, if any is set. if conv.name not in table: table[conv.name] = None ref = writer.writeCountReference( table, conv.name, conv.staticSize, table[conv.name] ) writer["LookupType"] = ref else: if conv.aux and not eval(conv.aux, None, table): continue try: conv.write(writer, font, table, value) except Exception as e: name = value.__class__.__name__ if value is not None else conv.name e.args = e.args + (name,) raise if conv.isPropagated: writer[conv.name] = value if deleteFormat: del self.Format def readFormat(self, reader): pass def writeFormat(self, writer): pass def toXML(self, xmlWriter, font, attrs=None, name=None): tableName = name if name else self.__class__.__name__ if attrs is None: attrs = [] if hasattr(self, "Format"): attrs = attrs + [("Format", self.Format)] xmlWriter.begintag(tableName, attrs) xmlWriter.newline() self.toXML2(xmlWriter, font) xmlWriter.endtag(tableName) xmlWriter.newline() def toXML2(self, xmlWriter, font): # Simpler variant of toXML, *only* for the top level tables (like GPOS, GSUB). # This is because in TTX our parent writes our main tag, and in otBase.py we # do it ourselves. I think I'm getting schizophrenic... for conv in self.getConverters(): if conv.repeat: value = getattr(self, conv.name, []) for i in range(len(value)): item = value[i] conv.xmlWrite(xmlWriter, font, item, conv.name, [("index", i)]) else: if conv.aux and not eval(conv.aux, None, vars(self)): continue value = getattr( self, conv.name, None ) # TODO Handle defaults instead of defaulting to None! conv.xmlWrite(xmlWriter, font, value, conv.name, []) def fromXML(self, name, attrs, content, font): try: conv = self.getConverterByName(name) except KeyError: raise # XXX on KeyError, raise nice error value = conv.xmlRead(attrs, content, font) if conv.repeat: seq = getattr(self, conv.name, None) if seq is None: seq = [] setattr(self, conv.name, seq) seq.append(value) else: setattr(self, conv.name, value) def __ne__(self, other): result = self.__eq__(other) return result if result is NotImplemented else not result def __eq__(self, other): if type(self) != type(other): return NotImplemented self.ensureDecompiled() other.ensureDecompiled() return self.__dict__ == other.__dict__ class SubTableEntry(NamedTuple): """See BaseTable.iterSubTables()""" name: str value: "BaseTable" index: Optional[int] = None # index into given array, None for single values def iterSubTables(self) -> Iterator[SubTableEntry]: """Yield (name, value, index) namedtuples for all subtables of current table. A sub-table is an instance of BaseTable (or subclass thereof) that is a child of self, the current parent table. The tuples also contain the attribute name (str) of the of parent table to get a subtable, and optionally, for lists of subtables (i.e. attributes associated with a converter that has a 'repeat'), an index into the list containing the given subtable value. This method can be useful to traverse trees of otTables. """ for conv in self.getConverters(): name = conv.name value = getattr(self, name, None) if value is None: continue if isinstance(value, BaseTable): yield self.SubTableEntry(name, value) elif isinstance(value, list): yield from ( self.SubTableEntry(name, v, index=i) for i, v in enumerate(value) if isinstance(v, BaseTable) ) # instance (not @class)method for consistency with FormatSwitchingBaseTable def getVariableAttrs(self): return getVariableAttrs(self.__class__) class FormatSwitchingBaseTable(BaseTable): """Minor specialization of BaseTable, for tables that have multiple formats, eg. CoverageFormat1 vs. CoverageFormat2.""" @classmethod def getRecordSize(cls, reader): return NotImplemented def getConverters(self): try: fmt = self.Format except AttributeError: # some FormatSwitchingBaseTables (e.g. Coverage) no longer have 'Format' # attribute after fully decompiled, only gain one in preWrite before being # recompiled. In the decompiled state, these hand-coded classes defined in # otTables.py lose their format-specific nature and gain more high-level # attributes that are not tied to converters. return [] return self.converters.get(self.Format, []) def getConverterByName(self, name): return self.convertersByName[self.Format][name] def readFormat(self, reader): self.Format = reader.readUShort() def writeFormat(self, writer): writer.writeUShort(self.Format) def toXML(self, xmlWriter, font, attrs=None, name=None): BaseTable.toXML(self, xmlWriter, font, attrs, name) def getVariableAttrs(self): return getVariableAttrs(self.__class__, self.Format) class UInt8FormatSwitchingBaseTable(FormatSwitchingBaseTable): def readFormat(self, reader): self.Format = reader.readUInt8() def writeFormat(self, writer): writer.writeUInt8(self.Format) formatSwitchingBaseTables = { "uint16": FormatSwitchingBaseTable, "uint8": UInt8FormatSwitchingBaseTable, } def getFormatSwitchingBaseTableClass(formatType): try: return formatSwitchingBaseTables[formatType] except KeyError: raise TypeError(f"Unsupported format type: {formatType!r}") # memoize since these are parsed from otData.py, thus stay constant @lru_cache() def getVariableAttrs(cls: BaseTable, fmt: Optional[int] = None) -> Tuple[str]: """Return sequence of variable table field names (can be empty). Attributes are deemed "variable" when their otData.py's description contain 'VarIndexBase + {offset}', e.g. COLRv1 PaintVar* tables. """ if not issubclass(cls, BaseTable): raise TypeError(cls) if issubclass(cls, FormatSwitchingBaseTable): if fmt is None: raise TypeError(f"'fmt' is required for format-switching {cls.__name__}") converters = cls.convertersByName[fmt] else: converters = cls.convertersByName # assume if no 'VarIndexBase' field is present, table has no variable fields if "VarIndexBase" not in converters: return () varAttrs = {} for name, conv in converters.items(): offset = conv.getVarIndexOffset() if offset is not None: varAttrs[name] = offset return tuple(sorted(varAttrs, key=varAttrs.__getitem__)) # # Support for ValueRecords # # This data type is so different from all other OpenType data types that # it requires quite a bit of code for itself. It even has special support # in OTTableReader and OTTableWriter... # valueRecordFormat = [ # Mask Name isDevice signed (0x0001, "XPlacement", 0, 1), (0x0002, "YPlacement", 0, 1), (0x0004, "XAdvance", 0, 1), (0x0008, "YAdvance", 0, 1), (0x0010, "XPlaDevice", 1, 0), (0x0020, "YPlaDevice", 1, 0), (0x0040, "XAdvDevice", 1, 0), (0x0080, "YAdvDevice", 1, 0), # reserved: (0x0100, "Reserved1", 0, 0), (0x0200, "Reserved2", 0, 0), (0x0400, "Reserved3", 0, 0), (0x0800, "Reserved4", 0, 0), (0x1000, "Reserved5", 0, 0), (0x2000, "Reserved6", 0, 0), (0x4000, "Reserved7", 0, 0), (0x8000, "Reserved8", 0, 0), ] def _buildDict(): d = {} for mask, name, isDevice, signed in valueRecordFormat: d[name] = mask, isDevice, signed return d valueRecordFormatDict = _buildDict() class ValueRecordFactory(object): """Given a format code, this object convert ValueRecords.""" def __init__(self, valueFormat): format = [] for mask, name, isDevice, signed in valueRecordFormat: if valueFormat & mask: format.append((name, isDevice, signed)) self.format = format def __len__(self): return len(self.format) def readValueRecord(self, reader, font): format = self.format if not format: return None valueRecord = ValueRecord() for name, isDevice, signed in format: if signed: value = reader.readShort() else: value = reader.readUShort() if isDevice: if value: from . import otTables subReader = reader.getSubReader(value) value = getattr(otTables, name)() value.decompile(subReader, font) else: value = None setattr(valueRecord, name, value) return valueRecord def writeValueRecord(self, writer, font, valueRecord): for name, isDevice, signed in self.format: value = getattr(valueRecord, name, 0) if isDevice: if value: subWriter = writer.getSubWriter() writer.writeSubTable(subWriter, offsetSize=2) value.compile(subWriter, font) else: writer.writeUShort(0) elif signed: writer.writeShort(value) else: writer.writeUShort(value) class ValueRecord(object): # see ValueRecordFactory def __init__(self, valueFormat=None, src=None): if valueFormat is not None: for mask, name, isDevice, signed in valueRecordFormat: if valueFormat & mask: setattr(self, name, None if isDevice else 0) if src is not None: for key, val in src.__dict__.items(): if not hasattr(self, key): continue setattr(self, key, val) elif src is not None: self.__dict__ = src.__dict__.copy() def getFormat(self): format = 0 for name in self.__dict__.keys(): format = format | valueRecordFormatDict[name][0] return format def getEffectiveFormat(self): format = 0 for name, value in self.__dict__.items(): if value: format = format | valueRecordFormatDict[name][0] return format def toXML(self, xmlWriter, font, valueName, attrs=None): if attrs is None: simpleItems = [] else: simpleItems = list(attrs) for mask, name, isDevice, format in valueRecordFormat[:4]: # "simple" values if hasattr(self, name): simpleItems.append((name, getattr(self, name))) deviceItems = [] for mask, name, isDevice, format in valueRecordFormat[4:8]: # device records if hasattr(self, name): device = getattr(self, name) if device is not None: deviceItems.append((name, device)) if deviceItems: xmlWriter.begintag(valueName, simpleItems) xmlWriter.newline() for name, deviceRecord in deviceItems: if deviceRecord is not None: deviceRecord.toXML(xmlWriter, font, name=name) xmlWriter.endtag(valueName) xmlWriter.newline() else: xmlWriter.simpletag(valueName, simpleItems) xmlWriter.newline() def fromXML(self, name, attrs, content, font): from . import otTables for k, v in attrs.items(): setattr(self, k, int(v)) for element in content: if not isinstance(element, tuple): continue name, attrs, content = element value = getattr(otTables, name)() for elem2 in content: if not isinstance(elem2, tuple): continue name2, attrs2, content2 = elem2 value.fromXML(name2, attrs2, content2, font) setattr(self, name, value) def __ne__(self, other): result = self.__eq__(other) return result if result is NotImplemented else not result def __eq__(self, other): if type(self) != type(other): return NotImplemented return self.__dict__ == other.__dict__