Revert "Add gsutil 4.13 to telemetry/third_party"

tools/telemetry/third_party/gsutil/gslib/resumable_streaming_upload.py

-# Copyright 2014 Google Inc. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-"""Helper class for streaming resumable uploads."""
-
-import collections
-import os
-
-from gslib.exception import CommandException
-from gslib.util import GetJsonResumableChunkSize
-
-
-class ResumableStreamingJsonUploadWrapper(object):
-  """Wraps an input stream in a buffer for resumable uploads.
-
-  This class takes a non-seekable input stream, buffers it, and exposes it
-  as a stream with limited seek capabilities such that it can be used in a
-  resumable JSON API upload.
-
-  max_buffer_size bytes of buffering is supported.
-  """
-
-  def __init__(self, stream, max_buffer_size, test_small_buffer=False):
-    """Initializes the wrapper.
-
-    Args:
-      stream: Input stream.
-      max_buffer_size: Maximum size of internal buffer; should be >= the chunk
-          size of the resumable upload API to ensure that at least one full
-          chunk write can be replayed in the event of a server error.
-      test_small_buffer: Skip check for buffer size vs. chunk size, for testing.
-    """
-    self._orig_fp = stream
-
-    if not test_small_buffer and max_buffer_size < GetJsonResumableChunkSize():
-      raise CommandException('Resumable streaming upload created with buffer '
-                             'size %s, JSON resumable upload chunk size %s. '
-                             'Buffer size must be >= JSON resumable upload '
-                             'chunk size to ensure that uploads can be '
-                             'resumed.' % (max_buffer_size,
-                                           GetJsonResumableChunkSize()))
-
-    self._max_buffer_size = max_buffer_size
-    self._buffer = collections.deque()
-    self._buffer_start = 0
-    self._buffer_end = 0
-    self._position = 0
-
-  def read(self, size=-1):  # pylint: disable=invalid-name
-    """"Reads from the wrapped stream.
-
-    Args:
-      size: The amount of bytes to read. If omitted or negative, the entire
-          contents of the stream will be read and returned.
-
-    Returns:
-      Bytes from the wrapped stream.
-    """
-    read_all_bytes = size is None or size < 0
-    if read_all_bytes:
-      bytes_remaining = self._max_buffer_size
-    else:
-      bytes_remaining = size
-    data = b''
-    buffered_data = []
-    if self._position < self._buffer_end:
-      # There was a backwards seek, so read from the buffer first.
-
-      # TODO: Performance test to validate if it is worth re-aligning
-      # the buffers in this case.  Also, seeking through the buffer for
-      # each read on a long catch-up is probably not performant, but we'd
-      # need a more complex data structure than a deque to get around this.
-      pos_in_buffer = self._buffer_start
-      buffer_index = 0
-      # First, find the start position in the buffer.
-      while pos_in_buffer + len(self._buffer[buffer_index]) < self._position:
-        # When this loop exits, buffer_index will refer to a buffer that
-        # has at least some overlap with self._position, and
-        # pos_in_buffer will be >= self._position
-        pos_in_buffer += len(self._buffer[buffer_index])
-        buffer_index += 1
-
-      # Read until we've read enough or we're out of buffer.
-      while pos_in_buffer < self._buffer_end and bytes_remaining > 0:
-        buffer_len = len(self._buffer[buffer_index])
-        # This describes how far into the current buffer self._position is.
-        offset_from_position = self._position - pos_in_buffer
-        bytes_available_this_buffer = buffer_len - offset_from_position
-        read_size = min(bytes_available_this_buffer, bytes_remaining)
-        buffered_data.append(
-            self._buffer[buffer_index]
-            [offset_from_position:offset_from_position + read_size])
-        bytes_remaining -= read_size
-        pos_in_buffer += buffer_len
-        buffer_index += 1
-        self._position += read_size
-
-    # At this point we're guaranteed that if there are any bytes left to read,
-    # then self._position == self._buffer_end, and we can read from the
-    # wrapped stream if needed.
-    if read_all_bytes:
-      # TODO: The user is requesting reading until the end of an
-      # arbitrary length stream, which is bad we'll need to return data
-      # with no size limits; if the stream is sufficiently long, we could run
-      # out of memory. We could break this down into smaller reads and
-      # buffer it as we go, but we're still left returning the data all at
-      # once to the caller.  We could raise, but for now trust the caller to
-      # be sane and have enough memory to hold the remaining stream contents.
-      new_data = self._orig_fp.read(size)
-      data_len = len(new_data)
-      if not buffered_data:
-        data = new_data
-      else:
-        buffered_data.append(new_data)
-        data = b''.join(buffered_data)
-      self._position += data_len
-    elif bytes_remaining:
-      new_data = self._orig_fp.read(bytes_remaining)
-      if not buffered_data:
-        data = new_data
-      else:
-        buffered_data.append(new_data)
-        data = b''.join(buffered_data)
-      data_len = len(new_data)
-      if data_len:
-        self._position += data_len
-        self._buffer.append(new_data)
-        self._buffer_end += data_len
-        oldest_data = None
-        while self._buffer_end - self._buffer_start > self._max_buffer_size:
-          oldest_data = self._buffer.popleft()
-          self._buffer_start += len(oldest_data)
-        if oldest_data:
-          refill_amount = self._max_buffer_size - (self._buffer_end -
-                                                   self._buffer_start)
-          if refill_amount:
-            self._buffer.appendleft(oldest_data[-refill_amount:])
-            self._buffer_start -= refill_amount
-    else:
-      data = b''.join(buffered_data) if buffered_data else b''
-
-    return data
-
-  def tell(self):  # pylint: disable=invalid-name
-    """Returns the current stream position."""
-    return self._position
-
-  def seekable(self):  # pylint: disable=invalid-name
-    """Returns true since limited seek support exists."""
-    return True
-
-  def seek(self, offset, whence=os.SEEK_SET):  # pylint: disable=invalid-name
-    """Seeks on the buffered stream.
-
-    Args:
-      offset: The offset to seek to; must be within the buffer bounds.
-      whence: Must be os.SEEK_SET.
-
-    Raises:
-      CommandException if an unsupported seek mode or position is used.
-    """
-    if whence == os.SEEK_SET:
-      if offset < self._buffer_start or offset > self._buffer_end:
-        raise CommandException('Unable to resume upload because of limited '
-                               'buffering available for streaming uploads. '
-                               'Offset %s was requested, but only data from '
-                               '%s to %s is buffered.' %
-                               (offset, self._buffer_start, self._buffer_end))
-      # Move to a position within the buffer.
-      self._position = offset
-    elif whence == os.SEEK_END:
-      if offset > self._max_buffer_size:
-        raise CommandException('Invalid SEEK_END offset %s on streaming '
-                               'upload. Only %s can be buffered.' %
-                               (offset, self._max_buffer_size))
-      # Read to the end and rely on buffering to handle the offset.
-      while self.read(self._max_buffer_size):
-        pass
-      # Now we're at the end.
-      self._position -= offset
-    else:
-      raise CommandException('Invalid seek mode on streaming upload. '
-                             '(mode %s, offset %s)' % (whence, offset))
-
-  def close(self):  # pylint: disable=invalid-name
-    return self._orig_fp.close()