Example of refactoring using rope library.

tools/telemetry/third_party/rope/rope/base/change.py

Index: tools/telemetry/third_party/rope/rope/base/change.py
diff --git a/tools/telemetry/third_party/rope/rope/base/change.py b/tools/telemetry/third_party/rope/rope/base/change.py
new file mode 100644
index 0000000000000000000000000000000000000000..fe2ebf435adb36e28509d56f82ca5a707f78df1a
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+++ b/tools/telemetry/third_party/rope/rope/base/change.py
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+import datetime
+import difflib
+import os
+import time
+
+import rope.base.fscommands
+from rope.base import taskhandle, exceptions, utils
+
+
+class Change(object):
+    """The base class for changes
+
+    Rope refactorings return `Change` objects.  They can be previewed,
+    committed or undone.
+    """
+
+    def do(self, job_set=None):
+        """Perform the change
+
+        .. note:: Do use this directly.  Use `Project.do()` instead.
+        """
+
+    def undo(self, job_set=None):
+        """Perform the change
+
+        .. note:: Do use this directly.  Use `History.undo()` instead.
+        """
+
+    def get_description(self):
+        """Return the description of this change
+
+        This can be used for previewing the changes.
+        """
+        return str(self)
+
+    def get_changed_resources(self):
+        """Return the list of resources that will be changed"""
+        return []
+
+    @property
+    @utils.saveit
+    def _operations(self):
+        return _ResourceOperations(self.resource.project)
+
+
+class ChangeSet(Change):
+    """A collection of `Change` objects
+
+    This class holds a collection of changes.  This class provides
+    these fields:
+
+    * `changes`: the list of changes
+    * `description`: the goal of these changes
+    """
+
+    def __init__(self, description, timestamp=None):
+        self.changes = []
+        self.description = description
+        self.time = timestamp
+
+    def do(self, job_set=taskhandle.NullJobSet()):
+        try:
+            done = []
+            for change in self.changes:
+                change.do(job_set)
+                done.append(change)
+            self.time = time.time()
+        except Exception:
+            for change in done:
+                change.undo()
+            raise
+
+    def undo(self, job_set=taskhandle.NullJobSet()):
+        try:
+            done = []
+            for change in reversed(self.changes):
+                change.undo(job_set)
+                done.append(change)
+        except Exception:
+            for change in done:
+                change.do()
+            raise
+
+    def add_change(self, change):
+        self.changes.append(change)
+
+    def get_description(self):
+        result = [str(self) + ':\n\n\n']
+        for change in self.changes:
+            result.append(change.get_description())
+            result.append('\n')
+        return ''.join(result)
+
+    def __str__(self):
+        if self.time is not None:
+            date = datetime.datetime.fromtimestamp(self.time)
+            if date.date() == datetime.date.today():
+                string_date = 'today'
+            elif date.date() == (datetime.date.today() -
+                                 datetime.timedelta(1)):
+                string_date = 'yesterday'
+            elif date.year == datetime.date.today().year:
+                string_date = date.strftime('%b %d')
+            else:
+                string_date = date.strftime('%d %b, %Y')
+            string_time = date.strftime('%H:%M:%S')
+            string_time = '%s %s ' % (string_date, string_time)
+            return self.description + ' - ' + string_time
+        return self.description
+
+    def get_changed_resources(self):
+        result = set()
+        for change in self.changes:
+            result.update(change.get_changed_resources())
+        return result
+
+
+def _handle_job_set(function):
+    """A decorator for handling `taskhandle.JobSet`\s
+
+    A decorator for handling `taskhandle.JobSet`\s for `do` and `undo`
+    methods of `Change`\s.
+    """
+    def call(self, job_set=taskhandle.NullJobSet()):
+        job_set.started_job(str(self))
+        function(self)
+        job_set.finished_job()
+    return call
+
+
+class ChangeContents(Change):
+    """A class to change the contents of a file
+
+    Fields:
+
+    * `resource`: The `rope.base.resources.File` to change
+    * `new_contents`: What to write in the file
+    """
+
+    def __init__(self, resource, new_contents, old_contents=None):
+        self.resource = resource
+        # IDEA: Only saving diffs; possible problems when undo/redoing
+        self.new_contents = new_contents
+        self.old_contents = old_contents
+
+    @_handle_job_set
+    def do(self):
+        if self.old_contents is None:
+            self.old_contents = self.resource.read()
+        self._operations.write_file(self.resource, self.new_contents)
+
+    @_handle_job_set
+    def undo(self):
+        if self.old_contents is None:
+            raise exceptions.HistoryError(
+                'Undoing a change that is not performed yet!')
+        self._operations.write_file(self.resource, self.old_contents)
+
+    def __str__(self):
+        return 'Change <%s>' % self.resource.path
+
+    def get_description(self):
+        new = self.new_contents
+        old = self.old_contents
+        if old is None:
+            if self.resource.exists():
+                old = self.resource.read()
+            else:
+                old = ''
+        result = difflib.unified_diff(
+            old.splitlines(True), new.splitlines(True),
+            'a/' + self.resource.path, 'b/' + self.resource.path)
+        return ''.join(list(result))
+
+    def get_changed_resources(self):
+        return [self.resource]
+
+
+class MoveResource(Change):
+    """Move a resource to a new location
+
+    Fields:
+
+    * `resource`: The `rope.base.resources.Resource` to move
+    * `new_resource`: The destination for move; It is the moved
+      resource not the folder containing that resource.
+    """
+
+    def __init__(self, resource, new_location, exact=False):
+        self.project = resource.project
+        self.resource = resource
+        if not exact:
+            new_location = _get_destination_for_move(resource, new_location)
+        if resource.is_folder():
+            self.new_resource = self.project.get_folder(new_location)
+        else:
+            self.new_resource = self.project.get_file(new_location)
+
+    @_handle_job_set
+    def do(self):
+        self._operations.move(self.resource, self.new_resource)
+
+    @_handle_job_set
+    def undo(self):
+        self._operations.move(self.new_resource, self.resource)
+
+    def __str__(self):
+        return 'Move <%s>' % self.resource.path
+
+    def get_description(self):
+        return 'rename from %s\nrename to %s' % (self.resource.path,
+                                                 self.new_resource.path)
+
+    def get_changed_resources(self):
+        return [self.resource, self.new_resource]
+
+
+class CreateResource(Change):
+    """A class to create a resource
+
+    Fields:
+
+    * `resource`: The resource to create
+    """
+
+    def __init__(self, resource):
+        self.resource = resource
+
+    @_handle_job_set
+    def do(self):
+        self._operations.create(self.resource)
+
+    @_handle_job_set
+    def undo(self):
+        self._operations.remove(self.resource)
+
+    def __str__(self):
+        return 'Create Resource <%s>' % (self.resource.path)
+
+    def get_description(self):
+        return 'new file %s' % (self.resource.path)
+
+    def get_changed_resources(self):
+        return [self.resource]
+
+    def _get_child_path(self, parent, name):
+        if parent.path == '':
+            return name
+        else:
+            return parent.path + '/' + name
+
+
+class CreateFolder(CreateResource):
+    """A class to create a folder
+
+    See docs for `CreateResource`.
+    """
+
+    def __init__(self, parent, name):
+        resource = parent.project.get_folder(
+            self._get_child_path(parent, name))
+        super(CreateFolder, self).__init__(resource)
+
+
+class CreateFile(CreateResource):
+    """A class to create a file
+
+    See docs for `CreateResource`.
+    """
+
+    def __init__(self, parent, name):
+        resource = parent.project.get_file(self._get_child_path(parent, name))
+        super(CreateFile, self).__init__(resource)
+
+
+class RemoveResource(Change):
+    """A class to remove a resource
+
+    Fields:
+
+    * `resource`: The resource to be removed
+    """
+
+    def __init__(self, resource):
+        self.resource = resource
+
+    @_handle_job_set
+    def do(self):
+        self._operations.remove(self.resource)
+
+    # TODO: Undoing remove operations
+    @_handle_job_set
+    def undo(self):
+        raise NotImplementedError(
+            'Undoing `RemoveResource` is not implemented yet.')
+
+    def __str__(self):
+        return 'Remove <%s>' % (self.resource.path)
+
+    def get_changed_resources(self):
+        return [self.resource]
+
+
+def count_changes(change):
+    """Counts the number of basic changes a `Change` will make"""
+    if isinstance(change, ChangeSet):
+        result = 0
+        for child in change.changes:
+            result += count_changes(child)
+        return result
+    return 1
+
+
+def create_job_set(task_handle, change):
+    return task_handle.create_jobset(str(change), count_changes(change))
+
+
+class _ResourceOperations(object):
+
+    def __init__(self, project):
+        self.project = project
+        self.fscommands = project.fscommands
+        self.direct_commands = rope.base.fscommands.FileSystemCommands()
+
+    def _get_fscommands(self, resource):
+        if self.project.is_ignored(resource):
+            return self.direct_commands
+        return self.fscommands
+
+    def write_file(self, resource, contents):
+        data = rope.base.fscommands.unicode_to_file_data(contents)
+        fscommands = self._get_fscommands(resource)
+        fscommands.write(resource.real_path, data)
+        for observer in list(self.project.observers):
+            observer.resource_changed(resource)
+
+    def move(self, resource, new_resource):
+        fscommands = self._get_fscommands(resource)
+        fscommands.move(resource.real_path, new_resource.real_path)
+        for observer in list(self.project.observers):
+            observer.resource_moved(resource, new_resource)
+
+    def create(self, resource):
+        if resource.is_folder():
+            self._create_resource(resource.path, kind='folder')
+        else:
+            self._create_resource(resource.path)
+        for observer in list(self.project.observers):
+            observer.resource_created(resource)
+
+    def remove(self, resource):
+        fscommands = self._get_fscommands(resource)
+        fscommands.remove(resource.real_path)
+        for observer in list(self.project.observers):
+            observer.resource_removed(resource)
+
+    def _create_resource(self, file_name, kind='file'):
+        resource_path = self.project._get_resource_path(file_name)
+        if os.path.exists(resource_path):
+            raise exceptions.RopeError('Resource <%s> already exists'
+                                       % resource_path)
+        resource = self.project.get_file(file_name)
+        if not resource.parent.exists():
+            raise exceptions.ResourceNotFoundError(
+                'Parent folder of <%s> does not exist' % resource.path)
+        fscommands = self._get_fscommands(resource)
+        try:
+            if kind == 'file':
+                fscommands.create_file(resource_path)
+            else:
+                fscommands.create_folder(resource_path)
+        except IOError as e:
+            raise exceptions.RopeError(e)
+
+
+def _get_destination_for_move(resource, destination):
+    dest_path = resource.project._get_resource_path(destination)
+    if os.path.isdir(dest_path):
+        if destination != '':
+            return destination + '/' + resource.name
+        else:
+            return resource.name
+    return destination
+
+
+class ChangeToData(object):
+
+    def convertChangeSet(self, change):
+        description = change.description
+        changes = []
+        for child in change.changes:
+            changes.append(self(child))
+        return (description, changes, change.time)
+
+    def convertChangeContents(self, change):
+        return (change.resource.path, change.new_contents, change.old_contents)
+
+    def convertMoveResource(self, change):
+        return (change.resource.path, change.new_resource.path)
+
+    def convertCreateResource(self, change):
+        return (change.resource.path, change.resource.is_folder())
+
+    def convertRemoveResource(self, change):
+        return (change.resource.path, change.resource.is_folder())
+
+    def __call__(self, change):
+        change_type = type(change)
+        if change_type in (CreateFolder, CreateFile):
+            change_type = CreateResource
+        method = getattr(self, 'convert' + change_type.__name__)
+        return (change_type.__name__, method(change))
+
+
+class DataToChange(object):
+
+    def __init__(self, project):
+        self.project = project
+
+    def makeChangeSet(self, description, changes, time=None):
+        result = ChangeSet(description, time)
+        for child in changes:
+            result.add_change(self(child))
+        return result
+
+    def makeChangeContents(self, path, new_contents, old_contents):
+        resource = self.project.get_file(path)
+        return ChangeContents(resource, new_contents, old_contents)
+
+    def makeMoveResource(self, old_path, new_path):
+        resource = self.project.get_file(old_path)
+        return MoveResource(resource, new_path, exact=True)
+
+    def makeCreateResource(self, path, is_folder):
+        if is_folder:
+            resource = self.project.get_folder(path)
+        else:
+            resource = self.project.get_file(path)
+        return CreateResource(resource)
+
+    def makeRemoveResource(self, path, is_folder):
+        if is_folder:
+            resource = self.project.get_folder(path)
+        else:
+            resource = self.project.get_file(path)
+        return RemoveResource(resource)
+
+    def __call__(self, data):
+        method = getattr(self, 'make' + data[0])
+        return method(*data[1])