[Predator] Move ``FilterStackBuffer`` from stack parser to ``AddFilteredStack`` of stacktrace buffe…

appengine/findit/crash/stacktrace.py

Index: appengine/findit/crash/stacktrace.py
diff --git a/appengine/findit/crash/stacktrace.py b/appengine/findit/crash/stacktrace.py
index 4db6faf2f798d0bfe8188ef56e8e13cabd6932f3..ce3bea60d232d92bc8f9169ada69bc5d6a2e2c5a 100644
--- a/appengine/findit/crash/stacktrace.py
+++ b/appengine/findit/crash/stacktrace.py
@@ -5,6 +5,7 @@
 from collections import namedtuple
 import copy
 import logging
+import math
 import re
 
 from crash import parse_util
@@ -314,13 +315,14 @@ class StacktraceBuffer(object):
   Note, to make this class fully mutable, it should contain CallStackBuffer
   list instead of CallStack list.
   """
-  def __init__(self, stacks=None, signature=None):
+  def __init__(self, stacks=None, signature=None, filters=None):
     """Initialize StacktraceBuffer instance.
 
     Args:
       stacks (list of CallStackBuffer): CallStackBuffer objects to
         build stacktrace.
-      signature (str): signagure is used to determine the crash stack.
+      signature (str): The signagure is used to determine the crash stack.

[wrengr, 2016/12/22 22:42:59]

"signagure" -> "signature"

[Sharu Jiang, 2016/12/23 00:26:20]

Done.

+      filters (list of CallStackBuffer): List of filters to filter stack buffer.

[wrengr, 2016/12/22 22:43:00]

Those aren't CallStackBuffers...

"filters to filter" is awkward

[Sharu Jiang, 2016/12/23 00:26:19]

Oops, corrected.

     """
     self.stacks = stacks or []
     if signature:
@@ -331,12 +333,28 @@ class StacktraceBuffer(object):
       self.signature_parts = signature.splitlines()
     else:
       self.signature_parts = None
+    self.filters = filters

[wrengr, 2016/12/22 22:42:59]

should have a blank line before this, iirc

[Sharu Jiang, 2016/12/23 00:26:20]

Done.

 
   def __nonzero__(self):
     """Returns whether this trace buffer is empty."""
     return bool(self.stacks)
   __bool__ = __nonzero__
 
+  def AddFilteredStack(self, stack_buffer):
+    """Filters stack_buffer and add it to stacks if it's not empty."""
+    # If the callstack is the initial one (infinte priority) or empty, return
+    # None.
+    if math.isinf(stack_buffer.priority) or not stack_buffer.frames:
+      return
+
+    if self.filters:
+      for stack_filter in self.filters:

[wrengr, 2016/12/22 22:42:59]

``if filters: for f in filters:...`` -> ``for f in filters or []:...``

[Sharu Jiang, 2016/12/23 00:26:19]

Done.

+        stack_buffer = stack_filter(stack_buffer)
+        if not stack_buffer:
+          return
+
+    self.stacks.append(stack_buffer)
+
   def ToStacktrace(self):
     """Converts to ``Stacktrace`` object."""
     if not self: