Stub out caching functionality

TODO.md

@@ -1,6 +1,10 @@
 foo#*.ext for src_filter on input side
   removes extra intermediate rules (*.css only from set)
 
+Caching
+==============================================================
+
+
 
 Stages
 ==============================================================

anvil/cache.py

@@ -0,0 +1,54 @@
+# Copyright 2012 Google Inc. All Rights Reserved.
+
+"""Rule cache.
+"""
+
+__author__ = 'benvanik@google.com (Ben Vanik)'
+
+
+class RuleCache(object):
+  """
+  """
+
+  def __init__(self):
+    """Initializes the rule cache.
+    """
+    pass
+
+  def compute_delta(self, src_paths):
+    """Computes a file delta for the given source paths.
+
+    Args:
+      src_paths: A list of fully-resolved source file paths.
+
+    Returns:
+      A FileDelta with the information from the given paths.
+    """
+    file_delta = FileDelta()
+    file_delta.all_files.extend(src_paths)
+
+    # TODO(benvanik): work
+    file_delta.changed_files.extend(src_paths)
+
+    return file_delta
+
+
+class FileDelta(object):
+  """
+  """
+
+  def __init__(self):
+    """Initializes a file delta.
+    """
+    self.all_files = []
+    self.added_files = []
+    self.removed_files = []
+    self.modified_files = []
+    self.changed_files = []
+
+  def any_changes(self):
+    """
+    Returns:
+      True if any changes occurred.
+    """
+    return len(self.changed_files)

anvil/context.py

@@ -17,6 +17,7 @@ import stat
 
 from anvil import async
 from anvil.async import Deferred
+from anvil import cache
 from anvil import graph
 from anvil import project
 from anvil import task
@@ -120,6 +121,9 @@ class BuildContext(object):
     # Dictionary that should be used to map rule paths to RuleContexts
     self.rule_contexts = {}
 
+    # Cache used to generate file deltas
+    self.cache = cache.RuleCache()
+
   def __enter__(self):
     return self
 
@@ -350,6 +354,8 @@ class RuleContext(object):
     self.build_env = build_context.build_env
     self.rule = rule
 
+    self.file_delta = None
+
     self.deferred = Deferred()
     self.status = Status.WAITING
     self.start_time = None
@@ -404,7 +410,6 @@ class RuleContext(object):
     exclude_filter_list = []
     if apply_src_filter and self.rule.src_exclude_filter:
       exclude_filter_list = self.rule.src_exclude_filter.split('|')
-      print 'got filters %s' % (exclude_filter_list)
 
     base_path = os.path.dirname(self.rule.parent_module.path)
     input_paths = []
@@ -594,6 +599,23 @@ class RuleContext(object):
           return True
     return False
 
+  def _check_if_cached(self):
+    """Checks if all inputs and outputs match their expected values.
+
+    Returns:
+      True if no inputs or outputs have changed.
+    """
+    # If any input changed...
+    if self.file_delta.any_changes():
+      return False
+
+    # If any output is changed...
+    output_delta = self.build_context.cache.compute_delta(self.all_output_files)
+    if output_delta.any_changes():
+      return False
+
+    return True
+
   def begin(self):
     """Begins asynchronous rule execution.
     Custom RuleContext implementations should override this method to perform
@@ -617,6 +639,10 @@ class RuleContext(object):
 
     print '... %20s ~ %s' % (self.rule.rule_name, rel_path)
 
+    # Compute file delta
+    # Note that this could be done async (somehow)
+    self.file_delta = self.build_context.cache.compute_delta(self.src_paths)
+
     return self.deferred
 
   def cascade_failure(self):
@@ -695,19 +721,3 @@ class RuleContext(object):
               break
       self._fail(exception=exception)
     deferred.add_errback_fn(_errback)
-
-
-# class FileDelta(object):
-#   """
-#   TODO(benvanik): move to another module and setup to use cache
-#   """
-
-#   def __init__(self, source_paths=None):
-#     """
-#     Args:
-#       source_paths
-#     """
-#     self.all_files = []
-#     self.added_files = []
-#     self.removed_files = []
-#     self.changed_files = []

anvil/rules/archive_rules.py

@@ -56,6 +56,11 @@ class ArchiveFilesRule(Rule):
       self._ensure_output_exists(os.path.dirname(output_path))
       self._append_output_paths([output_path])
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       # Compute the relative archive path for each file
       paths = []
       for src_path in self.src_paths:

anvil/rules/closure_gss_rules.py

@@ -108,6 +108,11 @@ class ClosureGssLibraryRule(Rule):
 
       args.extend(self.src_paths)
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       jar_path = self._resolve_input_files([self.rule.compiler_jar])[0]
       d = self._run_task_async(JavaExecutableTask(
           self.build_env, jar_path, args))

anvil/rules/closure_js_rules.py

@@ -60,6 +60,11 @@ class ClosureJsLintRule(Rule):
       super(ClosureJsLintRule._Context, self).begin()
       self._append_output_paths(self.src_paths)
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       namespaces = ','.join(self.rule.namespaces)
       args = [
           '--strict',
@@ -69,7 +74,7 @@ class ClosureJsLintRule(Rule):
 
       # TODO(benvanik): only changed paths
       # Exclude any path containing build-*
-      for src_path in self.src_paths:
+      for src_path in self.file_delta.changed_files:
         if (src_path.find('build-out%s' % os.sep) == -1 and
             src_path.find('build-gen%s' % os.sep) == -1):
           args.append(src_path)
@@ -265,6 +270,11 @@ class ClosureJsLibraryRule(Rule):
       self._ensure_output_exists(os.path.dirname(deps_js_path))
       self._append_output_paths([deps_js_path])
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       # Issue dependency scanning to build the deps graph
       d = self._run_task_async(_ScanJsDependenciesTask(
           self.build_env, self.src_paths))

anvil/rules/closure_soy_rules.py

@@ -78,6 +78,11 @@ class ClosureSoyLibraryRule(Rule):
         rel_path = os.path.relpath(src_path, self.build_env.root_path)
         args.append(rel_path)
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       jar_path = self._resolve_input_files([self.rule.compiler_jar])[0]
       d = self._run_task_async(JavaExecutableTask(
           self.build_env, jar_path, args))

anvil/rules/core_rules.py

@@ -90,6 +90,11 @@ class CopyFilesRule(Rule):
         self._append_output_paths([out_path])
         file_pairs.append((src_path, out_path))
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       # Async issue copying task
       d = self._run_task_async(_CopyFilesTask(
           self.build_env, file_pairs))
@@ -147,6 +152,11 @@ class ConcatFilesRule(Rule):
       self._ensure_output_exists(os.path.dirname(output_path))
       self._append_output_paths([output_path])
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       # Async issue concat task
       d = self._run_task_async(_ConcatFilesTask(
           self.build_env, self.src_paths, output_path))
@@ -221,6 +231,11 @@ class TemplateFilesRule(Rule):
         self._append_output_paths([out_path])
         file_pairs.append((src_path, out_path))
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       # Async issue templating task
       d = self._run_task_async(_TemplateFilesTask(
           self.build_env, file_pairs, self.rule.params))
@@ -289,6 +304,11 @@ class StripCommentsRule(Rule):
         self._append_output_paths([out_path])
         file_pairs.append((src_path, out_path))
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       # Async issue stripping task
       d = self._run_task_async(_StripCommentsRuleTask(
           self.build_env, file_pairs))
@@ -355,6 +375,11 @@ class ShellExecuteRule(Rule):
       call_args = self.rule.command[1:]
       call_args.extend(self.src_paths)
 
+      # Skip if cache hit
+      if self._check_if_cached():
+        self._succeed()
+        return
+
       # Async issue copying task
       d = self._run_task_async(ExecutableTask(
           self.build_env, executable_name, call_args))