Mojom backend: Stop re-computing version info and field packing data.

mojo/public/tools/bindings/pylib/mojom_tests/generate/pack_unittest.py

-# Copyright 2015 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import imp
-import os.path
-import sys
-import unittest
-
-
-def _GetDirAbove(dirname):
-  """Returns the directory "above" this file containing |dirname| (which must
-  also be "above" this file)."""
-  path = os.path.abspath(__file__)
-  while True:
-    path, tail = os.path.split(path)
-    assert tail
-    if tail == dirname:
-      return path
-
-
-try:
-  imp.find_module("mojom")
-except ImportError:
-  sys.path.append(os.path.join(_GetDirAbove("pylib"), "pylib"))
-from mojom.generate import pack
-from mojom.generate import module as mojom
-
-
-# TODO(yzshen): Move tests in pack_tests.py here.
-class PackTest(unittest.TestCase):
-  def _CheckPackSequence(self, kinds, fields, offsets):
-    """Checks the pack order and offsets of a sequence of mojom.Kinds.
-
-    Args:
-      kinds: A sequence of mojom.Kinds that specify the fields that are to be
-      created.
-      fields: The expected order of the resulting fields, with the integer "1"
-      first.
-      offsets: The expected order of offsets, with the integer "0" first.
-    """
-    struct = mojom.Struct('test')
-    index = 1
-    for kind in kinds:
-      struct.AddField('%d' % index, kind)
-      index += 1
-    ps = pack.PackedStruct(struct)
-    num_fields = len(ps.packed_fields)
-    self.assertEquals(len(kinds), num_fields)
-    for i in xrange(num_fields):
-      self.assertEquals('%d' % fields[i], ps.packed_fields[i].field.name)
-      self.assertEquals(offsets[i], ps.packed_fields[i].offset)
-
-  def testMinVersion(self):
-    """Tests that |min_version| is properly set for packed fields."""
-    struct = mojom.Struct('test')
-    struct.AddField('field_2', mojom.BOOL, 2)
-    struct.AddField('field_0', mojom.INT32, 0)
-    struct.AddField('field_1', mojom.INT64, 1)
-    ps = pack.PackedStruct(struct)
-
-    self.assertEquals('field_0', ps.packed_fields[0].field.name)
-    self.assertEquals('field_2', ps.packed_fields[1].field.name)
-    self.assertEquals('field_1', ps.packed_fields[2].field.name)
-
-    self.assertEquals(0, ps.packed_fields[0].min_version)
-    self.assertEquals(0, ps.packed_fields[1].min_version)
-    self.assertEquals(0, ps.packed_fields[2].min_version)
-
-    struct.fields[0].attributes = {'MinVersion': 1}
-    ps = pack.PackedStruct(struct)
-
-    self.assertEquals(0, ps.packed_fields[0].min_version)
-    self.assertEquals(1, ps.packed_fields[1].min_version)
-    self.assertEquals(0, ps.packed_fields[2].min_version)
-
-  def testGetVersionInfoEmptyStruct(self):
-    """Tests that pack.GetVersionInfo() never returns an empty list, even for
-    empty structs.
-    """
-    struct = mojom.Struct('test')
-    ps = pack.PackedStruct(struct)
-
-    versions = pack.GetVersionInfo(ps)
-    self.assertEquals(1, len(versions))
-    self.assertEquals(0, versions[0].version)
-    self.assertEquals(0, versions[0].num_fields)
-    self.assertEquals(8, versions[0].num_bytes)
-
-  def testGetVersionInfoComplexOrder(self):
-    """Tests pack.GetVersionInfo() using a struct whose definition order,
-    ordinal order and pack order for fields are all different.
-    """
-    struct = mojom.Struct('test')
-    struct.AddField('field_3', mojom.BOOL, ordinal=3,
-                    attributes={'MinVersion': 3})
-    struct.AddField('field_0', mojom.INT32, ordinal=0)
-    struct.AddField('field_1', mojom.INT64, ordinal=1,
-                    attributes={'MinVersion': 2})
-    struct.AddField('field_2', mojom.INT64, ordinal=2,
-                    attributes={'MinVersion': 3})
-    ps = pack.PackedStruct(struct)
-
-    versions = pack.GetVersionInfo(ps)
-    self.assertEquals(3, len(versions))
-
-    self.assertEquals(0, versions[0].version)
-    self.assertEquals(1, versions[0].num_fields)
-    self.assertEquals(16, versions[0].num_bytes)
-
-    self.assertEquals(2, versions[1].version)
-    self.assertEquals(2, versions[1].num_fields)
-    self.assertEquals(24, versions[1].num_bytes)
-
-    self.assertEquals(3, versions[2].version)
-    self.assertEquals(4, versions[2].num_fields)
-    self.assertEquals(32, versions[2].num_bytes)
-
-  def testInterfaceAlignment(self):
-    """Tests that interfaces are aligned on 4-byte boundaries, although the size
-    of an interface is 8 bytes.
-    """
-    kinds = (mojom.INT32, mojom.Interface('test_interface'))
-    fields = (1, 2)
-    offsets = (0, 4)
-    self._CheckPackSequence(kinds, fields, offsets)