Python cStringIO.write方法代码示例

# 需要导入模块: from django.utils.six.moves import cStringIO [as 别名]
# 或者: from django.utils.six.moves.cStringIO import write [as 别名]
def _cache_store_chunks(items, key, expiration):
    """Store a list of items as chunks in the cache.

    The list of items will be combined into chunks and stored in the
    cache as efficiently as possible. Each item in the list will be
    yielded to the caller as it's fetched from the list or generator.
    """
    chunks_data = StringIO()
    chunks_data_len = 0
    read_start = 0
    item_count = 0
    i = 0

    for data, has_item, item in items:
        if has_item:
            yield item
            item_count += 1

        chunks_data.write(data)
        chunks_data_len += len(data)

        if chunks_data_len > CACHE_CHUNK_SIZE:
            # We have enough data to fill a chunk now. Start processing
            # what we've stored and create cache keys for each chunk.
            # Anything remaining will be stored for the next round.
            chunks_data.seek(read_start)
            cached_data = {}

            while chunks_data_len > CACHE_CHUNK_SIZE:
                chunk = chunks_data.read(CACHE_CHUNK_SIZE)
                chunk_len = len(chunk)
                chunks_data_len -= chunk_len
                read_start += chunk_len

                # Note that we wrap the chunk in a list so that the cache
                # backend won't try to perform any conversion on the string.
                cached_data[make_cache_key('%s-%d' % (key, i))] = [chunk]
                i += 1

            # Store the keys in the cache in a single request.
            cache.set_many(cached_data, expiration)

            # Reposition back at the end of the stream.
            chunks_data.seek(0, 2)

    if chunks_data_len > 0:
        # There's one last bit of data to store. Note that this should be
        # less than the size of a chunk,
        assert chunks_data_len <= CACHE_CHUNK_SIZE

        chunks_data.seek(read_start)
        chunk = chunks_data.read()
        cache.set(make_cache_key('%s-%d' % (key, i)), [chunk], expiration)
        i += 1

    cache.set(make_cache_key(key), '%d' % i, expiration)

# 需要导入模块: from django.utils.six.moves import cStringIO [as 别名]
# 或者: from django.utils.six.moves.cStringIO import write [as 别名]
    def parse(self):
        """
        Parses the diff, returning a list of File objects representing each
        file in the diff.
        """
        self.files = []
        i = 0
        preamble = StringIO()

        while i < len(self.lines):
            next_i, file_info, new_diff = self._parse_diff(i)

            if file_info:
                if self.files:
                    self.files[-1].finalize()

                self._ensure_file_has_required_fields(file_info)

                file_info.prepend_data(preamble.getvalue())
                preamble.close()
                preamble = StringIO()

                self.files.append(file_info)
            elif new_diff:
                # We found a diff, but it was empty and has no file entry.
                # Reset the preamble.
                preamble.close()
                preamble = StringIO()
            else:
                preamble.write(self.lines[i])
                preamble.write(b'\n')

            i = next_i

        try:
            if self.files:
                self.files[-1].finalize()
            elif preamble.getvalue().strip() != b'':
                # This is probably not an actual git diff file.
                raise DiffParserError('This does not appear to be a git diff',
                                      0)
        finally:
            preamble.close()

        return self.files

# 需要导入模块: from django.utils.six.moves import cStringIO [as 别名]
# 或者: from django.utils.six.moves.cStringIO import write [as 别名]
class FileStream(object):
    """File stream for streaming reponses

    This buffer intended for use as an argument to StreamingHTTPResponse
    and also as a file for TarFile to write into.

    Files are read in by chunks and written to this buffer through TarFile.
    When there is content to be read from the buffer, it is taken up by
    StreamingHTTPResponse and the buffer is cleared to prevent storing large
    chunks of data in memory.
    """
    def __init__(self):
        self.buffer = StringIO()
        self.offset = 0

    def write(self, s):
        """Write ``s`` to the buffer and adjust the offset."""
        self.buffer.write(s)
        self.offset += len(s)

    def tell(self):
        """Return the current position of the buffer."""
        return self.offset

    def close(self):
        """Close the buffer."""
        self.buffer.close()

    def pop(self):
        """Return the current contents of the buffer then clear it."""
        s = self.buffer.getvalue()
        self.buffer.close()

        self.buffer = StringIO()

        return s