in infrastructure/pillow-layer/python/PIL/TiffImagePlugin.py [0:0]
def tobytes(self, offset=0):
# FIXME What about tagdata?
result = self._pack("H", len(self._tags_v2))
entries = []
offset = offset + len(result) + len(self._tags_v2) * 12 + 4
stripoffsets = None
# pass 1: convert tags to binary format
# always write tags in ascending order
for tag, value in sorted(self._tags_v2.items()):
if tag == STRIPOFFSETS:
stripoffsets = len(entries)
typ = self.tagtype.get(tag)
logger.debug(f"Tag {tag}, Type: {typ}, Value: {repr(value)}")
is_ifd = typ == TiffTags.LONG and isinstance(value, dict)
if is_ifd:
if self._endian == "<":
ifh = b"II\x2A\x00\x08\x00\x00\x00"
else:
ifh = b"MM\x00\x2A\x00\x00\x00\x08"
ifd = ImageFileDirectory_v2(ifh)
for ifd_tag, ifd_value in self._tags_v2[tag].items():
ifd[ifd_tag] = ifd_value
data = ifd.tobytes(offset)
else:
values = value if isinstance(value, tuple) else (value,)
data = self._write_dispatch[typ](self, *values)
tagname = TiffTags.lookup(tag).name
typname = "ifd" if is_ifd else TYPES.get(typ, "unknown")
msg = f"save: {tagname} ({tag}) - type: {typname} ({typ})"
msg += " - value: " + (
"<table: %d bytes>" % len(data) if len(data) >= 16 else str(values)
)
logger.debug(msg)
# count is sum of lengths for string and arbitrary data
if is_ifd:
count = 1
elif typ in [TiffTags.BYTE, TiffTags.ASCII, TiffTags.UNDEFINED]:
count = len(data)
else:
count = len(values)
# figure out if data fits into the entry
if len(data) <= 4:
entries.append((tag, typ, count, data.ljust(4, b"\0"), b""))
else:
entries.append((tag, typ, count, self._pack("L", offset), data))
offset += (len(data) + 1) // 2 * 2 # pad to word
# update strip offset data to point beyond auxiliary data
if stripoffsets is not None:
tag, typ, count, value, data = entries[stripoffsets]
if data:
raise NotImplementedError("multistrip support not yet implemented")
value = self._pack("L", self._unpack("L", value)[0] + offset)
entries[stripoffsets] = tag, typ, count, value, data
# pass 2: write entries to file
for tag, typ, count, value, data in entries:
logger.debug(f"{tag} {typ} {count} {repr(value)} {repr(data)}")
result += self._pack("HHL4s", tag, typ, count, value)
# -- overwrite here for multi-page --
result += b"\0\0\0\0" # end of entries
# pass 3: write auxiliary data to file
for tag, typ, count, value, data in entries:
result += data
if len(data) & 1:
result += b"\0"
return result