Python compat.BytesIO类代码示例

    def __init__(self, source):
        '''Construct a `StaticSource` for the data in `source`.

        :Parameters:
            `source` : `Source`
                The source to read and decode audio and video data from.

        '''
        source = source._get_queue_source()
        if source.video_format:
            raise NotImplementedError(
                'Static sources not supported for video yet.')

        self.audio_format = source.audio_format
        if not self.audio_format:
            return

        # Arbitrary: number of bytes to request at a time.
        buffer_size = 1 << 20 # 1 MB

        # Naive implementation.  Driver-specific implementations may override
        # to load static audio data into device (or at least driver) memory. 
        data = BytesIO()
        while True:
            audio_data = source.get_audio_data(buffer_size)
            if not audio_data:
                break
            data.write(audio_data.get_string_data())
        self._data = data.getvalue()

        self._duration = len(self._data) / \
                float(self.audio_format.bytes_per_second)

    def load_texture(self):
        if self.texture_file:
            self.texture_file = join(dirname(__file__), self.texture_file)
            self.original_texture = image.load(self.texture_file).texture

            file = BytesIO()
            self.original_texture.save(self.texture_file, file,
                                       encoder=self.encoder)
            file.seek(0)
            self.saved_texture = image.load(self.texture_file, file).texture

    def load_texture(self):
        print('Drawing scene...')
        self.window.set_visible()
        self.window.dispatch_events()
        self.draw()

        print('Saving depth image...')
        img = image.get_buffer_manager().get_depth_buffer()
        file = BytesIO()
        img.save('buffer.png', file)

        print('Loading depth image as texture...')
        file.seek(0)
        self.saved_texture = image.load('buffer.png', file)

        print('Done.')
        self.window.set_visible(False)

class StaticMemorySource(StaticSource):

    """Helper class for default implementation of `StaticSource`.  Do not use
    directly."""

    def __init__(self, data, audio_format):
        """Construct a memory source over the given data buffer.
        """
        self._file = BytesIO(data)
        self._max_offset = len(data)
        self.audio_format = audio_format
        self._duration = len(data) / float(audio_format.bytes_per_second)

    def seek(self, timestamp):
        offset = int(timestamp * self.audio_format.bytes_per_second)

        # Align to sample
        if self.audio_format.bytes_per_sample == 2:
            offset &= 0xfffffffe
        elif self.audio_format.bytes_per_sample == 4:
            offset &= 0xfffffffc

        self._file.seek(offset)

    def get_audio_data(self, bytes_):
        offset = self._file.tell()
        timestamp = float(offset) / self.audio_format.bytes_per_second

        # Align to sample size
        if self.audio_format.bytes_per_sample == 2:
            bytes_ &= 0xfffffffe
        elif self.audio_format.bytes_per_sample == 4:
            bytes_ &= 0xfffffffc

        data = self._file.read(bytes_)
        if not len(data):
            return None

        duration = float(len(data)) / self.audio_format.bytes_per_second
        return AudioData(data, len(data), timestamp, duration, list())

def load(filename, file=None, decoder=None, batch=None):
    """Load a 3D model from a file.

    :Parameters:
        `filename` : str
            Used to guess the model format, and to load the file if `file` is
            unspecified.
        `file` : file-like object or None
            Source of model data in any supported format.        
        `decoder` : ModelDecoder or None
            If unspecified, all decoders that are registered for the filename
            extension are tried.  If none succeed, the exception from the
            first decoder is raised.
        `batch` : Batch or None
            An optional Batch instance to add this model to. 

    :rtype: Model
    """

    if not file:
        file = open(filename, 'rb')

    if not hasattr(file, 'seek'):
        file = BytesIO(file.read())

    try:
        if decoder:
            return decoder.decode(file, filename, batch)
        else:
            first_exception = None
            for decoder in _codecs.get_decoders(filename):
                try:
                    model = decoder.decode(file, filename, batch)
                    return model
                except _codecs.ModelDecodeException as e:
                    if (not first_exception or
                                first_exception.exception_priority < e.exception_priority):
                        first_exception = e
                    file.seek(0)

            if not first_exception:
                raise _codecs.ModelDecodeException('No decoders are available'
                                                   'for this model format.')
            raise first_exception
    finally:
        file.close()

    def __init__(self, file):
        if not hasattr(file, 'seek'):
            file = BytesIO(file.read())

        super(RIFFFile, self).__init__(file, 0)