comparison mercurial/util.py @ 26478:a3f7e5461dbd

util.chunkbuffer: special case reading everything

The new code results in simpler logic within the while loop. It is also
faster since we avoid performing operations on the queue and buf
collections. However, there shouldn't be any super hot loops for this
since the whole point of chunkbuffer is to avoid reading large amounts
of data at once. This does, however, make it easier to optimize
chunkbuffer in a subsequent patch.

26477:d69245af4dbe

    def read(self, l=None):
        """Read L bytes of data from the iterator of chunks of data.
        Returns less than L bytes if the iterator runs dry.

        If size parameter is omitted, read everything"""
        left = l
        buf = []
        queue = self._queue
        while left is None or left > 0:
            # refill the queue
            if not queue:
                target = 2**18
                for chunk in self.iter:
                    queue.append(chunk)

                        break
                if not queue:
                    break

            chunk = queue.popleft()
            if left is not None:
                left -= len(chunk)
            if left is not None and left < 0:
                queue.appendleft(chunk[left:])
                buf.append(chunk[:left])
            else:
                buf.append(chunk)

26478:a3f7e5461dbd

    def read(self, l=None):
        """Read L bytes of data from the iterator of chunks of data.
        Returns less than L bytes if the iterator runs dry.

        If size parameter is omitted, read everything"""
        if l is None:
            return ''.join(self.iter)

        left = l
        buf = []
        queue = self._queue
        while left > 0:
            # refill the queue
            if not queue:
                target = 2**18
                for chunk in self.iter:
                    queue.append(chunk)

                        break
                if not queue:
                    break

            chunk = queue.popleft()
            left -= len(chunk)
            if left < 0:
                queue.appendleft(chunk[left:])
                buf.append(chunk[:left])
            else:
                buf.append(chunk)