Import Cobalt 2.9617 2016-08-17
diff --git a/src/third_party/libvpx/tools/diff.py b/src/third_party/libvpx/tools/diff.py
new file mode 100644
index 0000000..a96c7db
--- /dev/null
+++ b/src/third_party/libvpx/tools/diff.py
@@ -0,0 +1,130 @@
+#!/usr/bin/env python
+## Copyright (c) 2012 The WebM project authors. All Rights Reserved.
+##
+## Use of this source code is governed by a BSD-style license
+## that can be found in the LICENSE file in the root of the source
+## tree. An additional intellectual property rights grant can be found
+## in the file PATENTS. All contributing project authors may
+## be found in the AUTHORS file in the root of the source tree.
+##
+"""Classes for representing diff pieces."""
+
+__author__ = "jkoleszar@google.com"
+
+import re
+
+
+class DiffLines(object):
+ """A container for one half of a diff."""
+
+ def __init__(self, filename, offset, length):
+ self.filename = filename
+ self.offset = offset
+ self.length = length
+ self.lines = []
+ self.delta_line_nums = []
+
+ def Append(self, line):
+ l = len(self.lines)
+ if line[0] != " ":
+ self.delta_line_nums.append(self.offset + l)
+ self.lines.append(line[1:])
+ assert l+1 <= self.length
+
+ def Complete(self):
+ return len(self.lines) == self.length
+
+ def __contains__(self, item):
+ return item >= self.offset and item <= self.offset + self.length - 1
+
+
+class DiffHunk(object):
+ """A container for one diff hunk, consisting of two DiffLines."""
+
+ def __init__(self, header, file_a, file_b, start_a, len_a, start_b, len_b):
+ self.header = header
+ self.left = DiffLines(file_a, start_a, len_a)
+ self.right = DiffLines(file_b, start_b, len_b)
+ self.lines = []
+
+ def Append(self, line):
+ """Adds a line to the DiffHunk and its DiffLines children."""
+ if line[0] == "-":
+ self.left.Append(line)
+ elif line[0] == "+":
+ self.right.Append(line)
+ elif line[0] == " ":
+ self.left.Append(line)
+ self.right.Append(line)
+ elif line[0] == "\\":
+ # Ignore newline messages from git diff.
+ pass
+ else:
+ assert False, ("Unrecognized character at start of diff line "
+ "%r" % line[0])
+ self.lines.append(line)
+
+ def Complete(self):
+ return self.left.Complete() and self.right.Complete()
+
+ def __repr__(self):
+ return "DiffHunk(%s, %s, len %d)" % (
+ self.left.filename, self.right.filename,
+ max(self.left.length, self.right.length))
+
+
+def ParseDiffHunks(stream):
+ """Walk a file-like object, yielding DiffHunks as they're parsed."""
+
+ file_regex = re.compile(r"(\+\+\+|---) (\S+)")
+ range_regex = re.compile(r"@@ -(\d+)(,(\d+))? \+(\d+)(,(\d+))?")
+ hunk = None
+ while True:
+ line = stream.readline()
+ if not line:
+ break
+
+ if hunk is None:
+ # Parse file names
+ diff_file = file_regex.match(line)
+ if diff_file:
+ if line.startswith("---"):
+ a_line = line
+ a = diff_file.group(2)
+ continue
+ if line.startswith("+++"):
+ b_line = line
+ b = diff_file.group(2)
+ continue
+
+ # Parse offset/lengths
+ diffrange = range_regex.match(line)
+ if diffrange:
+ if diffrange.group(2):
+ start_a = int(diffrange.group(1))
+ len_a = int(diffrange.group(3))
+ else:
+ start_a = 1
+ len_a = int(diffrange.group(1))
+
+ if diffrange.group(5):
+ start_b = int(diffrange.group(4))
+ len_b = int(diffrange.group(6))
+ else:
+ start_b = 1
+ len_b = int(diffrange.group(4))
+
+ header = [a_line, b_line, line]
+ hunk = DiffHunk(header, a, b, start_a, len_a, start_b, len_b)
+ else:
+ # Add the current line to the hunk
+ hunk.Append(line)
+
+ # See if the whole hunk has been parsed. If so, yield it and prepare
+ # for the next hunk.
+ if hunk.Complete():
+ yield hunk
+ hunk = None
+
+ # Partial hunks are a parse error
+ assert hunk is None
