Initial Contributionv1.0

1 files changed, 326 insertions, 0 deletions

diff --git a/froofle/protobuf/internal/input_stream.py b/froofle/protobuf/internal/input_stream.py
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+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+# http://code.google.com/p/protobuf/
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""InputStream is the primitive interface for reading bits from the wire.
+
+All protocol buffer deserialization can be expressed in terms of
+the InputStream primitives provided here.
+"""
+
+__author__ = 'robinson@google.com (Will Robinson)'
+
+import struct
+from array import array
+from froofle.protobuf import message
+from froofle.protobuf.internal import wire_format
+
+
+# Note that much of this code is ported from //net/proto/ProtocolBuffer, and
+# that the interface is strongly inspired by CodedInputStream from the C++
+# proto2 implementation.
+
+
+class InputStreamBuffer(object):
+
+  """Contains all logic for reading bits, and dealing with stream position.
+
+  If an InputStream method ever raises an exception, the stream is left
+  in an indeterminate state and is not safe for further use.
+  """
+
+  def __init__(self, s):
+    # What we really want is something like array('B', s), where elements we
+    # read from the array are already given to us as one-byte integers.  BUT
+    # using array() instead of buffer() would force full string copies to result
+    # from each GetSubBuffer() call.
+    #
+    # So, if the N serialized bytes of a single protocol buffer object are
+    # split evenly between 2 child messages, and so on recursively, using
+    # array('B', s) instead of buffer() would incur an additional N*logN bytes
+    # copied during deserialization.
+    #
+    # The higher constant overhead of having to ord() for every byte we read
+    # from the buffer in _ReadVarintHelper() could definitely lead to worse
+    # performance in many real-world scenarios, even if the asymptotic
+    # complexity is better.  However, our real answer is that the mythical
+    # Python/C extension module output mode for the protocol compiler will
+    # be blazing-fast and will eliminate most use of this class anyway.
+    self._buffer = buffer(s)
+    self._pos = 0
+
+  def EndOfStream(self):
+    """Returns true iff we're at the end of the stream.
+    If this returns true, then a call to any other InputStream method
+    will raise an exception.
+    """
+    return self._pos >= len(self._buffer)
+
+  def Position(self):
+    """Returns the current position in the stream, or equivalently, the
+    number of bytes read so far.
+    """
+    return self._pos
+
+  def GetSubBuffer(self, size=None):
+    """Returns a sequence-like object that represents a portion of our
+    underlying sequence.
+
+    Position 0 in the returned object corresponds to self.Position()
+    in this stream.
+
+    If size is specified, then the returned object ends after the
+    next "size" bytes in this stream.  If size is not specified,
+    then the returned object ends at the end of this stream.
+
+    We guarantee that the returned object R supports the Python buffer
+    interface (and thus that the call buffer(R) will work).
+
+    Note that the returned buffer is read-only.
+
+    The intended use for this method is for nested-message and nested-group
+    deserialization, where we want to make a recursive MergeFromString()
+    call on the portion of the original sequence that contains the serialized
+    nested message.  (And we'd like to do so without making unnecessary string
+    copies).
+
+    REQUIRES: size is nonnegative.
+    """
+    # Note that buffer() doesn't perform any actual string copy.
+    if size is None:
+      return buffer(self._buffer, self._pos)
+    else:
+      if size < 0:
+        raise message.DecodeError('Negative size %d' % size)
+      return buffer(self._buffer, self._pos, size)
+
+  def SkipBytes(self, num_bytes):
+    """Skip num_bytes bytes ahead, or go to the end of the stream, whichever
+    comes first.
+
+    REQUIRES: num_bytes is nonnegative.
+    """
+    if num_bytes < 0:
+      raise message.DecodeError('Negative num_bytes %d' % num_bytes)
+    self._pos += num_bytes
+    self._pos = min(self._pos, len(self._buffer))
+
+  def ReadBytes(self, size):
+    """Reads up to 'size' bytes from the stream, stopping early
+    only if we reach the end of the stream.  Returns the bytes read
+    as a string.
+    """
+    if size < 0:
+      raise message.DecodeError('Negative size %d' % size)
+    s = (self._buffer[self._pos : self._pos + size])
+    self._pos += len(s)  # Only advance by the number of bytes actually read.
+    return s
+
+  def ReadLittleEndian32(self):
+    """Interprets the next 4 bytes of the stream as a little-endian
+    encoded, unsiged 32-bit integer, and returns that integer.
+    """
+    try:
+      i = struct.unpack(wire_format.FORMAT_UINT32_LITTLE_ENDIAN,
+                        self._buffer[self._pos : self._pos + 4])
+      self._pos += 4
+      return i[0]  # unpack() result is a 1-element tuple.
+    except struct.error, e:
+      raise message.DecodeError(e)
+
+  def ReadLittleEndian64(self):
+    """Interprets the next 8 bytes of the stream as a little-endian
+    encoded, unsiged 64-bit integer, and returns that integer.
+    """
+    try:
+      i = struct.unpack(wire_format.FORMAT_UINT64_LITTLE_ENDIAN,
+                        self._buffer[self._pos : self._pos + 8])
+      self._pos += 8
+      return i[0]  # unpack() result is a 1-element tuple.
+    except struct.error, e:
+      raise message.DecodeError(e)
+
+  def ReadVarint32(self):
+    """Reads a varint from the stream, interprets this varint
+    as a signed, 32-bit integer, and returns the integer.
+    """
+    i = self.ReadVarint64()
+    if not wire_format.INT32_MIN <= i <= wire_format.INT32_MAX:
+      raise message.DecodeError('Value out of range for int32: %d' % i)
+    return int(i)
+
+  def ReadVarUInt32(self):
+    """Reads a varint from the stream, interprets this varint
+    as an unsigned, 32-bit integer, and returns the integer.
+    """
+    i = self.ReadVarUInt64()
+    if i > wire_format.UINT32_MAX:
+      raise message.DecodeError('Value out of range for uint32: %d' % i)
+    return i
+
+  def ReadVarint64(self):
+    """Reads a varint from the stream, interprets this varint
+    as a signed, 64-bit integer, and returns the integer.
+    """
+    i = self.ReadVarUInt64()
+    if i > wire_format.INT64_MAX:
+      i -= (1 << 64)
+    return i
+
+  def ReadVarUInt64(self):
+    """Reads a varint from the stream, interprets this varint
+    as an unsigned, 64-bit integer, and returns the integer.
+    """
+    i = self._ReadVarintHelper()
+    if not 0 <= i <= wire_format.UINT64_MAX:
+      raise message.DecodeError('Value out of range for uint64: %d' % i)
+    return i
+
+  def _ReadVarintHelper(self):
+    """Helper for the various varint-reading methods above.
+    Reads an unsigned, varint-encoded integer from the stream and
+    returns this integer.
+
+    Does no bounds checking except to ensure that we read at most as many bytes
+    as could possibly be present in a varint-encoded 64-bit number.
+    """
+    result = 0
+    shift = 0
+    while 1:
+      if shift >= 64:
+        raise message.DecodeError('Too many bytes when decoding varint.')
+      try:
+        b = ord(self._buffer[self._pos])
+      except IndexError:
+        raise message.DecodeError('Truncated varint.')
+      self._pos += 1
+      result |= ((b & 0x7f) << shift)
+      shift += 7
+      if not (b & 0x80):
+        return result
+
+class InputStreamArray(object):
+  def __init__(self, s):
+    self._buffer = array('B', s)
+    self._pos = 0
+
+  def EndOfStream(self):
+    return self._pos >= len(self._buffer)
+
+  def Position(self):
+    return self._pos
+
+  def GetSubBuffer(self, size=None):
+    if size is None:
+      return self._buffer[self._pos : ].tostring()
+    else:
+      if size < 0:
+        raise message.DecodeError('Negative size %d' % size)
+      return self._buffer[self._pos : self._pos + size].tostring()
+
+  def SkipBytes(self, num_bytes):
+    if num_bytes < 0:
+      raise message.DecodeError('Negative num_bytes %d' % num_bytes)
+    self._pos += num_bytes
+    self._pos = min(self._pos, len(self._buffer))
+
+  def ReadBytes(self, size):
+    if size < 0:
+      raise message.DecodeError('Negative size %d' % size)
+    s = self._buffer[self._pos : self._pos + size].tostring()
+    self._pos += len(s)  # Only advance by the number of bytes actually read.
+    return s
+
+  def ReadLittleEndian32(self):
+    try:
+      i = struct.unpack(wire_format.FORMAT_UINT32_LITTLE_ENDIAN,
+                        self._buffer[self._pos : self._pos + 4])
+      self._pos += 4
+      return i[0]  # unpack() result is a 1-element tuple.
+    except struct.error, e:
+      raise message.DecodeError(e)
+
+  def ReadLittleEndian64(self):
+    try:
+      i = struct.unpack(wire_format.FORMAT_UINT64_LITTLE_ENDIAN,
+                        self._buffer[self._pos : self._pos + 8])
+      self._pos += 8
+      return i[0]  # unpack() result is a 1-element tuple.
+    except struct.error, e:
+      raise message.DecodeError(e)
+
+  def ReadVarint32(self):
+    i = self.ReadVarint64()
+    if not wire_format.INT32_MIN <= i <= wire_format.INT32_MAX:
+      raise message.DecodeError('Value out of range for int32: %d' % i)
+    return int(i)
+
+  def ReadVarUInt32(self):
+    i = self.ReadVarUInt64()
+    if i > wire_format.UINT32_MAX:
+      raise message.DecodeError('Value out of range for uint32: %d' % i)
+    return i
+
+  def ReadVarint64(self):
+    i = self.ReadVarUInt64()
+    if i > wire_format.INT64_MAX:
+      i -= (1 << 64)
+    return i
+
+  def ReadVarUInt64(self):
+    i = self._ReadVarintHelper()
+    if not 0 <= i <= wire_format.UINT64_MAX:
+      raise message.DecodeError('Value out of range for uint64: %d' % i)
+    return i
+
+  def _ReadVarintHelper(self):
+    result = 0
+    shift = 0
+    while 1:
+      if shift >= 64:
+        raise message.DecodeError('Too many bytes when decoding varint.')
+      try:
+        b = self._buffer[self._pos]
+      except IndexError:
+        raise message.DecodeError('Truncated varint.')
+      self._pos += 1
+      result |= ((b & 0x7f) << shift)
+      shift += 7
+      if not (b & 0x80):
+        return result
+
+try:
+  buffer("")
+  InputStream = InputStreamBuffer
+except NotImplementedError:
+  # Google App Engine: dev_appserver.py
+  InputStream = InputStreamArray
+except RuntimeError:
+  # Google App Engine: production
+  InputStream = InputStreamArray