mem: Edit proto Packet and enhance the python script

This patch changes the decode script to output the optional fields of
the proto message Packet, namely id and flags. The flags field is set
by the communication monitor.

The id field is useful for CPU trace experiments, e.g. linking the
fetch side to decode side. It had to be renamed because it clashes
with a built in python function id() for getting the "identity" of an
object.

This patch also takes a few common function definitions out from the
multiple scripts and adds them to a protolib python module.

1 files changed, 141 insertions, 0 deletions

diff --git a/util/protolib.py b/util/protolib.py
new file mode 100644
index 000000000..e085a90f2
--- /dev/null
+++ b/util/protolib.py
@@ -0,0 +1,141 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2013 ARM Limited
+# All rights reserved
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# 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 the copyright holders 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.
+#
+# 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.
+#
+# Authors: Andreas Hansson
+#          Radhika Jagtap
+
+# This file is a library of commonly used functions used when interfacing
+# with protobuf python messages. For eg, the decode scripts for different
+# types of proto objects can use the same function to decode a single message
+
+import struct
+
+def DecodeVarint(in_file):
+    """
+    The decoding of the Varint32 is copied from
+    google.protobuf.internal.decoder and is only repeated here to
+    avoid depending on the internal functions in the library. If the
+    end of file is reached, return (0, 0).
+    """
+    result = 0
+    shift = 0
+    pos = 0
+    # Use a 32-bit mask
+    mask = 0xffffffff
+    while 1:
+        c = in_file.read(1)
+        if len(c) == 0:
+            return (0, 0)
+        b = struct.unpack('<B', c)[0]
+        result |= ((b & 0x7f) << shift)
+        pos += 1
+        if not (b & 0x80):
+            if result > 0x7fffffffffffffff:
+                result -= (1 << 64)
+                result |= ~mask
+            else:
+                result &= mask
+                return (result, pos)
+            shift += 7
+            if shift >= 64:
+                raise IOError('Too many bytes when decoding varint.')
+
+def decodeMessage(in_file, message):
+    """
+    Attempt to read a message from the file and decode it. Return
+    False if no message could be read.
+    """
+    try:
+        size, pos = DecodeVarint(in_file)
+        if size == 0:
+            return False
+        buf = in_file.read(size)
+        message.ParseFromString(buf)
+        return True
+    except IOError:
+        return False
+
+def EncodeVarint(out_file, value):
+  """
+  The encoding of the Varint32 is copied from
+  google.protobuf.internal.encoder and is only repeated here to
+  avoid depending on the internal functions in the library.
+  """
+  bits = value & 0x7f
+  value >>= 7
+  while value:
+    out_file.write(struct.pack('<B', 0x80|bits))
+    bits = value & 0x7f
+    value >>= 7
+  out_file.write(struct.pack('<B', bits))
+
+def encodeMessage(out_file, message):
+    """
+    Encoded a message with the length prepended as a 32-bit varint.
+    """
+    out = message.SerializeToString()
+    EncodeVarint(out_file, len(out))
+    out_file.write(out)