subversion_file_system.py revision f2477e01787aa58f445919b809d89e252beef54f
1# Copyright (c) 2012 The Chromium Authors. All rights reserved. 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4 5import logging 6import posixpath 7import traceback 8import xml.dom.minidom as xml 9from xml.parsers.expat import ExpatError 10 11from appengine_url_fetcher import AppEngineUrlFetcher 12from docs_server_utils import StringIdentity 13from file_system import ( 14 FileNotFoundError, FileSystem, FileSystemError, StatInfo, ToUnicode) 15from future import Future 16import url_constants 17 18 19def _ParseHTML(html): 20 '''Unfortunately, the viewvc page has a stray </div> tag, so this takes care 21 of all mismatched tags. 22 ''' 23 try: 24 return xml.parseString(html) 25 except ExpatError as e: 26 return _ParseHTML('\n'.join( 27 line for (i, line) in enumerate(html.split('\n')) 28 if e.lineno != i + 1)) 29 30def _InnerText(node): 31 '''Like node.innerText in JS DOM, but strips surrounding whitespace. 32 ''' 33 text = [] 34 if node.nodeValue: 35 text.append(node.nodeValue) 36 if hasattr(node, 'childNodes'): 37 for child_node in node.childNodes: 38 text.append(_InnerText(child_node)) 39 return ''.join(text).strip() 40 41def _CreateStatInfo(html): 42 parent_version = None 43 child_versions = {} 44 45 # Try all of the tables until we find the ones that contain the data (the 46 # directory and file versions are in different tables). 47 for table in _ParseHTML(html).getElementsByTagName('table'): 48 # Within the table there is a list of files. However, there may be some 49 # things beforehand; a header, "parent directory" list, etc. We will deal 50 # with that below by being generous and just ignoring such rows. 51 rows = table.getElementsByTagName('tr') 52 53 for row in rows: 54 cells = row.getElementsByTagName('td') 55 56 # The version of the directory will eventually appear in the soup of 57 # table rows, like this: 58 # 59 # <tr> 60 # <td>Directory revision:</td> 61 # <td><a href=... title="Revision 214692">214692</a> (of...)</td> 62 # </tr> 63 # 64 # So look out for that. 65 if len(cells) == 2 and _InnerText(cells[0]) == 'Directory revision:': 66 links = cells[1].getElementsByTagName('a') 67 if len(links) != 2: 68 raise FileSystemError('ViewVC assumption invalid: directory ' + 69 'revision content did not have 2 <a> ' + 70 ' elements, instead %s' % _InnerText(cells[1])) 71 this_parent_version = _InnerText(links[0]) 72 int(this_parent_version) # sanity check 73 if parent_version is not None: 74 raise FileSystemError('There was already a parent version %s, and ' + 75 ' we just found a second at %s' % 76 (parent_version, this_parent_version)) 77 parent_version = this_parent_version 78 79 # The version of each file is a list of rows with 5 cells: name, version, 80 # age, author, and last log entry. Maybe the columns will change; we're 81 # at the mercy viewvc, but this constant can be easily updated. 82 if len(cells) != 5: 83 continue 84 name_element, version_element, _, __, ___ = cells 85 86 name = _InnerText(name_element) # note: will end in / for directories 87 try: 88 version = int(_InnerText(version_element)) 89 except StandardError: 90 continue 91 child_versions[name] = str(version) 92 93 if parent_version and child_versions: 94 break 95 96 return StatInfo(parent_version, child_versions) 97 98class _AsyncFetchFuture(object): 99 def __init__(self, paths, fetcher, binary, args=None): 100 def apply_args(path): 101 return path if args is None else '%s?%s' % (path, args) 102 # A list of tuples of the form (path, Future). 103 self._fetches = [(path, fetcher.FetchAsync(apply_args(path))) 104 for path in paths] 105 self._value = {} 106 self._error = None 107 self._binary = binary 108 109 def _ListDir(self, directory): 110 dom = xml.parseString(directory) 111 files = [elem.childNodes[0].data for elem in dom.getElementsByTagName('a')] 112 if '..' in files: 113 files.remove('..') 114 return files 115 116 def Get(self): 117 for path, future in self._fetches: 118 try: 119 result = future.Get() 120 except Exception as e: 121 raise FileSystemError('Error fetching %s for Get: %s' % 122 (path, traceback.format_exc())) 123 124 if result.status_code == 404: 125 raise FileNotFoundError('Got 404 when fetching %s for Get, content %s' % 126 (path, result.content)) 127 if result.status_code != 200: 128 raise FileSystemError('Got %s when fetching %s for Get, content %s' % 129 (result.status_code, path, result.content)) 130 131 if path.endswith('/'): 132 self._value[path] = self._ListDir(result.content) 133 elif not self._binary: 134 self._value[path] = ToUnicode(result.content) 135 else: 136 self._value[path] = result.content 137 if self._error is not None: 138 raise self._error 139 return self._value 140 141class SubversionFileSystem(FileSystem): 142 '''Class to fetch resources from src.chromium.org. 143 ''' 144 @staticmethod 145 def Create(branch='trunk', revision=None): 146 if branch == 'trunk': 147 svn_path = 'trunk/src' 148 else: 149 svn_path = 'branches/%s/src' % branch 150 return SubversionFileSystem( 151 AppEngineUrlFetcher('%s/%s' % (url_constants.SVN_URL, svn_path)), 152 AppEngineUrlFetcher('%s/%s' % (url_constants.VIEWVC_URL, svn_path)), 153 svn_path, 154 revision=revision) 155 156 def __init__(self, file_fetcher, stat_fetcher, svn_path, revision=None): 157 self._file_fetcher = file_fetcher 158 self._stat_fetcher = stat_fetcher 159 self._svn_path = svn_path 160 self._revision = revision 161 162 def Read(self, paths, binary=False): 163 args = None 164 if self._revision is not None: 165 # |fetcher| gets from svn.chromium.org which uses p= for version. 166 args = 'p=%s' % self._revision 167 return Future(delegate=_AsyncFetchFuture(paths, 168 self._file_fetcher, 169 binary, 170 args=args)) 171 172 def Refresh(self): 173 return Future(value=()) 174 175 def Stat(self, path): 176 directory, filename = posixpath.split(path) 177 if self._revision is not None: 178 # |stat_fetch| uses viewvc which uses pathrev= for version. 179 directory += '?pathrev=%s' % self._revision 180 181 try: 182 result = self._stat_fetcher.Fetch(directory) 183 except Exception as e: 184 raise FileSystemError('Error fetching %s for Stat: %s' % 185 (path, traceback.format_exc())) 186 187 if result.status_code == 404: 188 raise FileNotFoundError('Got 404 when fetching %s for Stat, content %s' % 189 (path, result.content)) 190 if result.status_code != 200: 191 raise FileNotFoundError('Got %s when fetching %s for Stat, content %s' % 192 (result.status_code, path, result.content)) 193 194 stat_info = _CreateStatInfo(result.content) 195 if stat_info.version is None: 196 raise FileSystemError('Failed to find version of dir %s' % directory) 197 if path == '' or path.endswith('/'): 198 return stat_info 199 if filename not in stat_info.child_versions: 200 raise FileNotFoundError( 201 '%s from %s was not in child versions for Stat' % (filename, path)) 202 return StatInfo(stat_info.child_versions[filename]) 203 204 def GetIdentity(self): 205 # NOTE: no revision here, since it would mess up the caching of reads. It 206 # probably doesn't matter since all the caching classes will use the result 207 # of Stat to decide whether to re-read - and Stat has a ceiling of the 208 # revision - so when the revision changes, so might Stat. That is enough. 209 return '@'.join((self.__class__.__name__, StringIdentity(self._svn_path))) 210