| #!/usr/bin/env python |
| # 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. |
| |
| """Pretty-prints the histograms.xml file, alphabetizing tags, wrapping text |
| at 80 chars, enforcing standard attribute ordering, and standardizing |
| indentation. |
| |
| This is quite a bit more complicated than just calling tree.toprettyxml(); |
| we need additional customization, like special attribute ordering in tags |
| and wrapping text nodes, so we implement our own full custom XML pretty-printer. |
| """ |
| |
| from __future__ import with_statement |
| |
| import logging |
| import os |
| import shutil |
| import sys |
| import xml.dom.minidom |
| |
| import print_style |
| |
| sys.path.insert(1, os.path.join(sys.path[0], '..', '..', 'python')) |
| from google import path_utils |
| |
| # Import the metrics/common module. |
| sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common')) |
| import diff_util |
| |
| # Tags whose children we want to alphabetize. The key is the parent tag name, |
| # and the value is a pair of the tag name of the children we want to sort, |
| # and a key function that maps each child node to the desired sort key. |
| ALPHABETIZATION_RULES = { |
| 'histograms': ('histogram', lambda n: n.attributes['name'].value.lower()), |
| 'enums': ('enum', lambda n: n.attributes['name'].value.lower()), |
| 'enum': ('int', lambda n: int(n.attributes['value'].value)), |
| 'histogram_suffixes_list': ( |
| 'histogram_suffixes', lambda n: n.attributes['name'].value.lower()), |
| 'histogram_suffixes': ('affected-histogram', |
| lambda n: n.attributes['name'].value.lower()), |
| # TODO(yiyaoliu): Remove fieldtrial related pieces when it is not used. |
| 'fieldtrials': ('fieldtrial', lambda n: n.attributes['name'].value.lower()), |
| 'fieldtrial': ('affected-histogram', |
| lambda n: n.attributes['name'].value.lower()), |
| } |
| |
| |
| class Error(Exception): |
| pass |
| |
| |
| def unsafeAppendChild(parent, child): |
| """Append child to parent's list of children, ignoring the possibility that it |
| is already in another node's childNodes list. Requires that the previous |
| parent of child is discarded (to avoid non-tree DOM graphs). |
| This can provide a significant speedup as O(n^2) operations are removed (in |
| particular, each child insertion avoids the need to traverse the old parent's |
| entire list of children).""" |
| child.parentNode = None |
| parent.appendChild(child) |
| child.parentNode = parent |
| |
| |
| def TransformByAlphabetizing(node): |
| """Transform the given XML by alphabetizing specific node types according to |
| the rules in ALPHABETIZATION_RULES. |
| |
| Args: |
| node: The minidom node to transform. |
| |
| Returns: |
| The minidom node, with children appropriately alphabetized. Note that the |
| transformation is done in-place, i.e. the original minidom tree is modified |
| directly. |
| """ |
| if node.nodeType != xml.dom.minidom.Node.ELEMENT_NODE: |
| for c in node.childNodes: TransformByAlphabetizing(c) |
| return node |
| |
| # Element node with a tag name that we alphabetize the children of? |
| if node.tagName in ALPHABETIZATION_RULES: |
| # Put subnodes in a list of node,key pairs to allow for custom sorting. |
| subtag, key_function = ALPHABETIZATION_RULES[node.tagName] |
| subnodes = [] |
| last_key = -1 |
| for c in node.childNodes: |
| if (c.nodeType == xml.dom.minidom.Node.ELEMENT_NODE and |
| c.tagName == subtag): |
| last_key = key_function(c) |
| # Subnodes that we don't want to rearrange use the last node's key, |
| # so they stay in the same relative position. |
| subnodes.append( (c, last_key) ) |
| |
| # Sort the subnode list. |
| subnodes.sort(key=lambda pair: pair[1]) |
| |
| # Re-add the subnodes, transforming each recursively. |
| while node.firstChild: |
| node.removeChild(node.firstChild) |
| for (c, _) in subnodes: |
| unsafeAppendChild(node, TransformByAlphabetizing(c)) |
| return node |
| |
| # Recursively handle other element nodes and other node types. |
| for c in node.childNodes: TransformByAlphabetizing(c) |
| return node |
| |
| |
| def PrettyPrint(raw_xml): |
| """Pretty-print the given XML. |
| |
| Args: |
| raw_xml: The contents of the histograms XML file, as a string. |
| |
| Returns: |
| The pretty-printed version. |
| """ |
| tree = xml.dom.minidom.parseString(raw_xml) |
| tree = TransformByAlphabetizing(tree) |
| return print_style.GetPrintStyle().PrettyPrintNode(tree) |
| |
| |
| def main(): |
| logging.basicConfig(level=logging.INFO) |
| |
| presubmit = ('--presubmit' in sys.argv) |
| |
| histograms_filename = 'histograms.xml' |
| histograms_backup_filename = 'histograms.before.pretty-print.xml' |
| |
| # If there is a histograms.xml in the current working directory, use that. |
| # Otherwise, use the one residing in the same directory as this script. |
| histograms_dir = os.getcwd() |
| if not os.path.isfile(os.path.join(histograms_dir, histograms_filename)): |
| histograms_dir = path_utils.ScriptDir() |
| |
| histograms_pathname = os.path.join(histograms_dir, histograms_filename) |
| histograms_backup_pathname = os.path.join(histograms_dir, |
| histograms_backup_filename) |
| |
| logging.info('Loading %s...' % os.path.relpath(histograms_pathname)) |
| with open(histograms_pathname, 'rb') as f: |
| xml = f.read() |
| |
| # Check there are no CR ('\r') characters in the file. |
| if '\r' in xml: |
| logging.info('DOS-style line endings (CR characters) detected - these are ' |
| 'not allowed. Please run dos2unix %s' % histograms_filename) |
| sys.exit(1) |
| |
| logging.info('Pretty-printing...') |
| try: |
| pretty = PrettyPrint(xml) |
| except Error: |
| logging.error('Aborting parsing due to fatal errors.') |
| sys.exit(1) |
| |
| if xml == pretty: |
| logging.info('%s is correctly pretty-printed.' % histograms_filename) |
| sys.exit(0) |
| if presubmit: |
| logging.info('%s is not formatted correctly; run pretty_print.py to fix.' % |
| histograms_filename) |
| sys.exit(1) |
| if not diff_util.PromptUserToAcceptDiff( |
| xml, pretty, |
| 'Is the prettified version acceptable?'): |
| logging.error('Aborting') |
| return |
| |
| logging.info('Creating backup file %s' % histograms_backup_filename) |
| shutil.move(histograms_pathname, histograms_backup_pathname) |
| |
| logging.info('Writing new %s file' % histograms_filename) |
| with open(histograms_pathname, 'wb') as f: |
| f.write(pretty) |
| |
| |
| if __name__ == '__main__': |
| main() |