Re-land: Change actions.txt to actions.xml

tools/metrics/common/pretty_print_xml.py

+# Copyright 2013 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.
+
+"""Utility file for pretty print xml file.
+
+The function PrettyPrintNode will be used for formatting both histograms.xml
+and actions.xml.
+"""
+
+import logging
+import textwrap
+import xml.dom.minidom
+
+WRAP_COLUMN = 80
+
+
+class Error(Exception):
+  pass
+
+
+def LastLineLength(s):
+  """Returns the length of the last line in s.
+
+  Args:
+    s: A multi-line string, including newlines.
+
+  Returns:
+    The length of the last line in s, in characters.
+  """
+  if s.rfind('\n') == -1: return len(s)
+  return len(s) - s.rfind('\n') - len('\n')
+
+
+def XmlEscape(s):
+  """XML-escapes the given string, replacing magic characters (&<>") with their
+  escaped equivalents."""
+  s = s.replace("&", "&amp;").replace("<", "&lt;")
+  s = s.replace("\"", "&quot;").replace(">", "&gt;")
+  return s
+
+
+class XmlStyle(object):
+  """A class that stores all style specification for an output xml file."""
+
+  def __init__(self, attribute_order, tags_that_have_extra_newline,
+               tags_that_dont_indent, tags_that_allow_single_line):
+    # List of tag names for top-level nodes whose children are not indented.
+    self.attribute_order = attribute_order
+    self.tags_that_have_extra_newline = tags_that_have_extra_newline
+    self.tags_that_dont_indent = tags_that_dont_indent
+    self.tags_that_allow_single_line = tags_that_allow_single_line
+
+  def PrettyPrintNode(self, node, indent=0):
+    """Pretty-prints the given XML node at the given indent level.
+
+    Args:
+      node: The minidom node to pretty-print.
+      indent: The current indent level.
+
+    Returns:
+      The pretty-printed string (including embedded newlines).
+
+    Raises:
+      Error if the XML has unknown tags or attributes.
+    """
+    # Handle the top-level document node.
+    if node.nodeType == xml.dom.minidom.Node.DOCUMENT_NODE:
+      return '\n'.join([self.PrettyPrintNode(n) for n in node.childNodes])
+
+    # Handle text nodes.
+    if node.nodeType == xml.dom.minidom.Node.TEXT_NODE:
+      # Wrap each paragraph in the text to fit in the 80 column limit.
+      wrapper = textwrap.TextWrapper()
+      wrapper.initial_indent = ' ' * indent
+      wrapper.subsequent_indent = ' ' * indent
+      wrapper.break_on_hyphens = False
+      wrapper.break_long_words = False
+      wrapper.width = WRAP_COLUMN
+      text = XmlEscape(node.data)
+      # Remove any common indent.
+      text = textwrap.dedent(text.strip('\n'))
+      lines = text.split('\n')
+      # Split the text into paragraphs at blank line boundaries.
+      paragraphs = [[]]
+      for l in lines:
+        if len(l.strip()) == 0 and len(paragraphs[-1]) > 0:
+          paragraphs.append([])
+        else:
+          paragraphs[-1].append(l)
+      # Remove trailing empty paragraph if present.
+      if len(paragraphs) > 0 and len(paragraphs[-1]) == 0:
+        paragraphs = paragraphs[:-1]
+      # Wrap each paragraph and separate with two newlines.
+      return '\n\n'.join([wrapper.fill('\n'.join(p)) for p in paragraphs])
+
+    # Handle element nodes.
+    if node.nodeType == xml.dom.minidom.Node.ELEMENT_NODE:
+      newlines_after_open, newlines_before_close, newlines_after_close = (
+          self.tags_that_have_extra_newline.get(node.tagName, (1, 1, 0)))
+      # Open the tag.
+      s = ' ' * indent + '<' + node.tagName
+
+      # Calculate how much space to allow for the '>' or '/>'.
+      closing_chars = 1
+      if not node.childNodes:
+        closing_chars = 2
+
+      # Pretty-print the attributes.
+      attributes = node.attributes.keys()
+      if attributes:
+        # Reorder the attributes.
+        if node.tagName not in self.attribute_order:
+          unrecognized_attributes = attributes
+        else:
+          unrecognized_attributes = (
+              [a for a in attributes
+               if a not in self.attribute_order[node.tagName]])
+          attributes = [a for a in self.attribute_order[node.tagName]
+                        if a in attributes]
+
+        for a in unrecognized_attributes:
+          logging.error(
+              'Unrecognized attribute "%s" in tag "%s"' % (a, node.tagName))
+        if unrecognized_attributes:
+          raise Error()
+
+        for a in attributes:
+          value = XmlEscape(node.attributes[a].value)
+          # Replace sequences of whitespace with single spaces.
+          words = value.split()
+          a_str = ' %s="%s"' % (a, ' '.join(words))
+          # Start a new line if the attribute will make this line too long.
+          if LastLineLength(s) + len(a_str) + closing_chars > WRAP_COLUMN:
+            s += '\n' + ' ' * (indent + 3)
+          # Output everything up to the first quote.
+          s += ' %s="' % (a)
+          value_indent_level = LastLineLength(s)
+          # Output one word at a time, splitting to the next line where
+          # necessary.
+          column = value_indent_level
+          for i, word in enumerate(words):
+            # This is slightly too conservative since not every word will be
+            # followed by the closing characters...
+            if i > 0 and (column + len(word) + 1 + closing_chars > WRAP_COLUMN):
+              s = s.rstrip()  # remove any trailing whitespace
+              s += '\n' + ' ' * value_indent_level
+              column = value_indent_level
+            s += word + ' '
+            column += len(word) + 1
+          s = s.rstrip()  # remove any trailing whitespace
+          s += '"'
+        s = s.rstrip()  # remove any trailing whitespace
+
+      # Pretty-print the child nodes.
+      if node.childNodes:
+        s += '>'
+        # Calculate the new indent level for child nodes.
+        new_indent = indent
+        if node.tagName not in self.tags_that_dont_indent:
+          new_indent += 2
+        child_nodes = node.childNodes
+
+        # Recursively pretty-print the child nodes.
+        child_nodes = [self.PrettyPrintNode(n, indent=new_indent)
+                       for n in child_nodes]
+        child_nodes = [c for c in child_nodes if len(c.strip()) > 0]
+
+        # Determine whether we can fit the entire node on a single line.
+        close_tag = '</%s>' % node.tagName
+        space_left = WRAP_COLUMN - LastLineLength(s) - len(close_tag)
+        if (node.tagName in self.tags_that_allow_single_line and
+            len(child_nodes) == 1 and
+            len(child_nodes[0].strip()) <= space_left):
+          s += child_nodes[0].strip()
+        else:
+          s += '\n' * newlines_after_open + '\n'.join(child_nodes)
+          s += '\n' * newlines_before_close + ' ' * indent
+        s += close_tag
+      else:
+        s += '/>'
+      s += '\n' * newlines_after_close
+      return s
+
+    # Handle comment nodes.
+    if node.nodeType == xml.dom.minidom.Node.COMMENT_NODE:
+      return '<!--%s-->\n' % node.data
+
+    # Ignore other node types. This could be a processing instruction
+    # (<? ... ?>) or cdata section (<![CDATA[...]]!>), neither of which are
+    # legal in the histograms XML at present.
+    logging.error('Ignoring unrecognized node data: %s' % node.toxml())
+    raise Error()