diff options
author | 2022-11-13 23:46:45 +0530 | |
---|---|---|
committer | 2022-11-13 23:46:45 +0530 | |
commit | 9468226a9e2e2ab8cdd599f1d8538e860ca86120 (patch) | |
tree | 0a77ada226d6db80639f96b438bf83e4e756edb5 /env/lib/python3.10/site-packages/PIL/ImageFile.py | |
download | idcard-9468226a9e2e2ab8cdd599f1d8538e860ca86120.tar.gz idcard-9468226a9e2e2ab8cdd599f1d8538e860ca86120.tar.bz2 idcard-9468226a9e2e2ab8cdd599f1d8538e860ca86120.zip |
id card generator
Diffstat (limited to 'env/lib/python3.10/site-packages/PIL/ImageFile.py')
-rw-r--r-- | env/lib/python3.10/site-packages/PIL/ImageFile.py | 754 |
1 files changed, 754 insertions, 0 deletions
diff --git a/env/lib/python3.10/site-packages/PIL/ImageFile.py b/env/lib/python3.10/site-packages/PIL/ImageFile.py new file mode 100644 index 0000000..f281b9e --- /dev/null +++ b/env/lib/python3.10/site-packages/PIL/ImageFile.py @@ -0,0 +1,754 @@ +# +# The Python Imaging Library. +# $Id$ +# +# base class for image file handlers +# +# history: +# 1995-09-09 fl Created +# 1996-03-11 fl Fixed load mechanism. +# 1996-04-15 fl Added pcx/xbm decoders. +# 1996-04-30 fl Added encoders. +# 1996-12-14 fl Added load helpers +# 1997-01-11 fl Use encode_to_file where possible +# 1997-08-27 fl Flush output in _save +# 1998-03-05 fl Use memory mapping for some modes +# 1999-02-04 fl Use memory mapping also for "I;16" and "I;16B" +# 1999-05-31 fl Added image parser +# 2000-10-12 fl Set readonly flag on memory-mapped images +# 2002-03-20 fl Use better messages for common decoder errors +# 2003-04-21 fl Fall back on mmap/map_buffer if map is not available +# 2003-10-30 fl Added StubImageFile class +# 2004-02-25 fl Made incremental parser more robust +# +# Copyright (c) 1997-2004 by Secret Labs AB +# Copyright (c) 1995-2004 by Fredrik Lundh +# +# See the README file for information on usage and redistribution. +# + +import io +import itertools +import struct +import sys + +from . import Image +from ._util import is_path + +MAXBLOCK = 65536 + +SAFEBLOCK = 1024 * 1024 + +LOAD_TRUNCATED_IMAGES = False +"""Whether or not to load truncated image files. User code may change this.""" + +ERRORS = { + -1: "image buffer overrun error", + -2: "decoding error", + -3: "unknown error", + -8: "bad configuration", + -9: "out of memory error", +} +""" +Dict of known error codes returned from :meth:`.PyDecoder.decode`, +:meth:`.PyEncoder.encode` :meth:`.PyEncoder.encode_to_pyfd` and +:meth:`.PyEncoder.encode_to_file`. +""" + + +# +# -------------------------------------------------------------------- +# Helpers + + +def raise_oserror(error): + try: + message = Image.core.getcodecstatus(error) + except AttributeError: + message = ERRORS.get(error) + if not message: + message = f"decoder error {error}" + raise OSError(message + " when reading image file") + + +def _tilesort(t): + # sort on offset + return t[2] + + +# +# -------------------------------------------------------------------- +# ImageFile base class + + +class ImageFile(Image.Image): + """Base class for image file format handlers.""" + + def __init__(self, fp=None, filename=None): + super().__init__() + + self._min_frame = 0 + + self.custom_mimetype = None + + self.tile = None + """ A list of tile descriptors, or ``None`` """ + + self.readonly = 1 # until we know better + + self.decoderconfig = () + self.decodermaxblock = MAXBLOCK + + if is_path(fp): + # filename + self.fp = open(fp, "rb") + self.filename = fp + self._exclusive_fp = True + else: + # stream + self.fp = fp + self.filename = filename + # can be overridden + self._exclusive_fp = None + + try: + try: + self._open() + except ( + IndexError, # end of data + TypeError, # end of data (ord) + KeyError, # unsupported mode + EOFError, # got header but not the first frame + struct.error, + ) as v: + raise SyntaxError(v) from v + + if not self.mode or self.size[0] <= 0 or self.size[1] <= 0: + raise SyntaxError("not identified by this driver") + except BaseException: + # close the file only if we have opened it this constructor + if self._exclusive_fp: + self.fp.close() + raise + + def get_format_mimetype(self): + if self.custom_mimetype: + return self.custom_mimetype + if self.format is not None: + return Image.MIME.get(self.format.upper()) + + def verify(self): + """Check file integrity""" + + # raise exception if something's wrong. must be called + # directly after open, and closes file when finished. + if self._exclusive_fp: + self.fp.close() + self.fp = None + + def load(self): + """Load image data based on tile list""" + + if self.tile is None: + raise OSError("cannot load this image") + + pixel = Image.Image.load(self) + if not self.tile: + return pixel + + self.map = None + use_mmap = self.filename and len(self.tile) == 1 + # As of pypy 2.1.0, memory mapping was failing here. + use_mmap = use_mmap and not hasattr(sys, "pypy_version_info") + + readonly = 0 + + # look for read/seek overrides + try: + read = self.load_read + # don't use mmap if there are custom read/seek functions + use_mmap = False + except AttributeError: + read = self.fp.read + + try: + seek = self.load_seek + use_mmap = False + except AttributeError: + seek = self.fp.seek + + if use_mmap: + # try memory mapping + decoder_name, extents, offset, args = self.tile[0] + if ( + decoder_name == "raw" + and len(args) >= 3 + and args[0] == self.mode + and args[0] in Image._MAPMODES + ): + try: + # use mmap, if possible + import mmap + + with open(self.filename) as fp: + self.map = mmap.mmap(fp.fileno(), 0, access=mmap.ACCESS_READ) + if offset + self.size[1] * args[1] > self.map.size(): + # buffer is not large enough + raise OSError + self.im = Image.core.map_buffer( + self.map, self.size, decoder_name, offset, args + ) + readonly = 1 + # After trashing self.im, + # we might need to reload the palette data. + if self.palette: + self.palette.dirty = 1 + except (AttributeError, OSError, ImportError): + self.map = None + + self.load_prepare() + err_code = -3 # initialize to unknown error + if not self.map: + # sort tiles in file order + self.tile.sort(key=_tilesort) + + try: + # FIXME: This is a hack to handle TIFF's JpegTables tag. + prefix = self.tile_prefix + except AttributeError: + prefix = b"" + + # Remove consecutive duplicates that only differ by their offset + self.tile = [ + list(tiles)[-1] + for _, tiles in itertools.groupby( + self.tile, lambda tile: (tile[0], tile[1], tile[3]) + ) + ] + for decoder_name, extents, offset, args in self.tile: + seek(offset) + decoder = Image._getdecoder( + self.mode, decoder_name, args, self.decoderconfig + ) + try: + decoder.setimage(self.im, extents) + if decoder.pulls_fd: + decoder.setfd(self.fp) + err_code = decoder.decode(b"")[1] + else: + b = prefix + while True: + try: + s = read(self.decodermaxblock) + except (IndexError, struct.error) as e: + # truncated png/gif + if LOAD_TRUNCATED_IMAGES: + break + else: + raise OSError("image file is truncated") from e + + if not s: # truncated jpeg + if LOAD_TRUNCATED_IMAGES: + break + else: + raise OSError( + "image file is truncated " + f"({len(b)} bytes not processed)" + ) + + b = b + s + n, err_code = decoder.decode(b) + if n < 0: + break + b = b[n:] + finally: + # Need to cleanup here to prevent leaks + decoder.cleanup() + + self.tile = [] + self.readonly = readonly + + self.load_end() + + if self._exclusive_fp and self._close_exclusive_fp_after_loading: + self.fp.close() + self.fp = None + + if not self.map and not LOAD_TRUNCATED_IMAGES and err_code < 0: + # still raised if decoder fails to return anything + raise_oserror(err_code) + + return Image.Image.load(self) + + def load_prepare(self): + # create image memory if necessary + if not self.im or self.im.mode != self.mode or self.im.size != self.size: + self.im = Image.core.new(self.mode, self.size) + # create palette (optional) + if self.mode == "P": + Image.Image.load(self) + + def load_end(self): + # may be overridden + pass + + # may be defined for contained formats + # def load_seek(self, pos): + # pass + + # may be defined for blocked formats (e.g. PNG) + # def load_read(self, bytes): + # pass + + def _seek_check(self, frame): + if ( + frame < self._min_frame + # Only check upper limit on frames if additional seek operations + # are not required to do so + or ( + not (hasattr(self, "_n_frames") and self._n_frames is None) + and frame >= self.n_frames + self._min_frame + ) + ): + raise EOFError("attempt to seek outside sequence") + + return self.tell() != frame + + +class StubImageFile(ImageFile): + """ + Base class for stub image loaders. + + A stub loader is an image loader that can identify files of a + certain format, but relies on external code to load the file. + """ + + def _open(self): + raise NotImplementedError("StubImageFile subclass must implement _open") + + def load(self): + loader = self._load() + if loader is None: + raise OSError(f"cannot find loader for this {self.format} file") + image = loader.load(self) + assert image is not None + # become the other object (!) + self.__class__ = image.__class__ + self.__dict__ = image.__dict__ + return image.load() + + def _load(self): + """(Hook) Find actual image loader.""" + raise NotImplementedError("StubImageFile subclass must implement _load") + + +class Parser: + """ + Incremental image parser. This class implements the standard + feed/close consumer interface. + """ + + incremental = None + image = None + data = None + decoder = None + offset = 0 + finished = 0 + + def reset(self): + """ + (Consumer) Reset the parser. Note that you can only call this + method immediately after you've created a parser; parser + instances cannot be reused. + """ + assert self.data is None, "cannot reuse parsers" + + def feed(self, data): + """ + (Consumer) Feed data to the parser. + + :param data: A string buffer. + :exception OSError: If the parser failed to parse the image file. + """ + # collect data + + if self.finished: + return + + if self.data is None: + self.data = data + else: + self.data = self.data + data + + # parse what we have + if self.decoder: + + if self.offset > 0: + # skip header + skip = min(len(self.data), self.offset) + self.data = self.data[skip:] + self.offset = self.offset - skip + if self.offset > 0 or not self.data: + return + + n, e = self.decoder.decode(self.data) + + if n < 0: + # end of stream + self.data = None + self.finished = 1 + if e < 0: + # decoding error + self.image = None + raise_oserror(e) + else: + # end of image + return + self.data = self.data[n:] + + elif self.image: + + # if we end up here with no decoder, this file cannot + # be incrementally parsed. wait until we've gotten all + # available data + pass + + else: + + # attempt to open this file + try: + with io.BytesIO(self.data) as fp: + im = Image.open(fp) + except OSError: + # traceback.print_exc() + pass # not enough data + else: + flag = hasattr(im, "load_seek") or hasattr(im, "load_read") + if flag or len(im.tile) != 1: + # custom load code, or multiple tiles + self.decode = None + else: + # initialize decoder + im.load_prepare() + d, e, o, a = im.tile[0] + im.tile = [] + self.decoder = Image._getdecoder(im.mode, d, a, im.decoderconfig) + self.decoder.setimage(im.im, e) + + # calculate decoder offset + self.offset = o + if self.offset <= len(self.data): + self.data = self.data[self.offset :] + self.offset = 0 + + self.image = im + + def __enter__(self): + return self + + def __exit__(self, *args): + self.close() + + def close(self): + """ + (Consumer) Close the stream. + + :returns: An image object. + :exception OSError: If the parser failed to parse the image file either + because it cannot be identified or cannot be + decoded. + """ + # finish decoding + if self.decoder: + # get rid of what's left in the buffers + self.feed(b"") + self.data = self.decoder = None + if not self.finished: + raise OSError("image was incomplete") + if not self.image: + raise OSError("cannot parse this image") + if self.data: + # incremental parsing not possible; reopen the file + # not that we have all data + with io.BytesIO(self.data) as fp: + try: + self.image = Image.open(fp) + finally: + self.image.load() + return self.image + + +# -------------------------------------------------------------------- + + +def _save(im, fp, tile, bufsize=0): + """Helper to save image based on tile list + + :param im: Image object. + :param fp: File object. + :param tile: Tile list. + :param bufsize: Optional buffer size + """ + + im.load() + if not hasattr(im, "encoderconfig"): + im.encoderconfig = () + tile.sort(key=_tilesort) + # FIXME: make MAXBLOCK a configuration parameter + # It would be great if we could have the encoder specify what it needs + # But, it would need at least the image size in most cases. RawEncode is + # a tricky case. + bufsize = max(MAXBLOCK, bufsize, im.size[0] * 4) # see RawEncode.c + try: + fh = fp.fileno() + fp.flush() + _encode_tile(im, fp, tile, bufsize, fh) + except (AttributeError, io.UnsupportedOperation) as exc: + _encode_tile(im, fp, tile, bufsize, None, exc) + if hasattr(fp, "flush"): + fp.flush() + + +def _encode_tile(im, fp, tile, bufsize, fh, exc=None): + for e, b, o, a in tile: + if o > 0: + fp.seek(o) + encoder = Image._getencoder(im.mode, e, a, im.encoderconfig) + try: + encoder.setimage(im.im, b) + if encoder.pushes_fd: + encoder.setfd(fp) + l, s = encoder.encode_to_pyfd() + else: + if exc: + # compress to Python file-compatible object + while True: + l, s, d = encoder.encode(bufsize) + fp.write(d) + if s: + break + else: + # slight speedup: compress to real file object + s = encoder.encode_to_file(fh, bufsize) + if s < 0: + raise OSError(f"encoder error {s} when writing image file") from exc + finally: + encoder.cleanup() + + +def _safe_read(fp, size): + """ + Reads large blocks in a safe way. Unlike fp.read(n), this function + doesn't trust the user. If the requested size is larger than + SAFEBLOCK, the file is read block by block. + + :param fp: File handle. Must implement a <b>read</b> method. + :param size: Number of bytes to read. + :returns: A string containing <i>size</i> bytes of data. + + Raises an OSError if the file is truncated and the read cannot be completed + + """ + if size <= 0: + return b"" + if size <= SAFEBLOCK: + data = fp.read(size) + if len(data) < size: + raise OSError("Truncated File Read") + return data + data = [] + remaining_size = size + while remaining_size > 0: + block = fp.read(min(remaining_size, SAFEBLOCK)) + if not block: + break + data.append(block) + remaining_size -= len(block) + if sum(len(d) for d in data) < size: + raise OSError("Truncated File Read") + return b"".join(data) + + +class PyCodecState: + def __init__(self): + self.xsize = 0 + self.ysize = 0 + self.xoff = 0 + self.yoff = 0 + + def extents(self): + return self.xoff, self.yoff, self.xoff + self.xsize, self.yoff + self.ysize + + +class PyCodec: + def __init__(self, mode, *args): + self.im = None + self.state = PyCodecState() + self.fd = None + self.mode = mode + self.init(args) + + def init(self, args): + """ + Override to perform codec specific initialization + + :param args: Array of args items from the tile entry + :returns: None + """ + self.args = args + + def cleanup(self): + """ + Override to perform codec specific cleanup + + :returns: None + """ + pass + + def setfd(self, fd): + """ + Called from ImageFile to set the Python file-like object + + :param fd: A Python file-like object + :returns: None + """ + self.fd = fd + + def setimage(self, im, extents=None): + """ + Called from ImageFile to set the core output image for the codec + + :param im: A core image object + :param extents: a 4 tuple of (x0, y0, x1, y1) defining the rectangle + for this tile + :returns: None + """ + + # following c code + self.im = im + + if extents: + (x0, y0, x1, y1) = extents + else: + (x0, y0, x1, y1) = (0, 0, 0, 0) + + if x0 == 0 and x1 == 0: + self.state.xsize, self.state.ysize = self.im.size + else: + self.state.xoff = x0 + self.state.yoff = y0 + self.state.xsize = x1 - x0 + self.state.ysize = y1 - y0 + + if self.state.xsize <= 0 or self.state.ysize <= 0: + raise ValueError("Size cannot be negative") + + if ( + self.state.xsize + self.state.xoff > self.im.size[0] + or self.state.ysize + self.state.yoff > self.im.size[1] + ): + raise ValueError("Tile cannot extend outside image") + + +class PyDecoder(PyCodec): + """ + Python implementation of a format decoder. Override this class and + add the decoding logic in the :meth:`decode` method. + + See :ref:`Writing Your Own File Codec in Python<file-codecs-py>` + """ + + _pulls_fd = False + + @property + def pulls_fd(self): + return self._pulls_fd + + def decode(self, buffer): + """ + Override to perform the decoding process. + + :param buffer: A bytes object with the data to be decoded. + :returns: A tuple of ``(bytes consumed, errcode)``. + If finished with decoding return -1 for the bytes consumed. + Err codes are from :data:`.ImageFile.ERRORS`. + """ + raise NotImplementedError() + + def set_as_raw(self, data, rawmode=None): + """ + Convenience method to set the internal image from a stream of raw data + + :param data: Bytes to be set + :param rawmode: The rawmode to be used for the decoder. + If not specified, it will default to the mode of the image + :returns: None + """ + + if not rawmode: + rawmode = self.mode + d = Image._getdecoder(self.mode, "raw", rawmode) + d.setimage(self.im, self.state.extents()) + s = d.decode(data) + + if s[0] >= 0: + raise ValueError("not enough image data") + if s[1] != 0: + raise ValueError("cannot decode image data") + + +class PyEncoder(PyCodec): + """ + Python implementation of a format encoder. Override this class and + add the decoding logic in the :meth:`encode` method. + + See :ref:`Writing Your Own File Codec in Python<file-codecs-py>` + """ + + _pushes_fd = False + + @property + def pushes_fd(self): + return self._pushes_fd + + def encode(self, bufsize): + """ + Override to perform the encoding process. + + :param bufsize: Buffer size. + :returns: A tuple of ``(bytes encoded, errcode, bytes)``. + If finished with encoding return 1 for the error code. + Err codes are from :data:`.ImageFile.ERRORS`. + """ + raise NotImplementedError() + + def encode_to_pyfd(self): + """ + If ``pushes_fd`` is ``True``, then this method will be used, + and ``encode()`` will only be called once. + + :returns: A tuple of ``(bytes consumed, errcode)``. + Err codes are from :data:`.ImageFile.ERRORS`. + """ + if not self.pushes_fd: + return 0, -8 # bad configuration + bytes_consumed, errcode, data = self.encode(0) + if data: + self.fd.write(data) + return bytes_consumed, errcode + + def encode_to_file(self, fh, bufsize): + """ + :param fh: File handle. + :param bufsize: Buffer size. + + :returns: If finished successfully, return 0. + Otherwise, return an error code. Err codes are from + :data:`.ImageFile.ERRORS`. + """ + errcode = 0 + while errcode == 0: + status, errcode, buf = self.encode(bufsize) + if status > 0: + fh.write(buf[status:]) + return errcode |