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1 # -*- coding: iso-8859-1 -*- 2 # vim: set ft=python ts=3 sw=3 expandtab: 3 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # 4 # 5 # C E D A R 6 # S O L U T I O N S "Software done right." 7 # S O F T W A R E 8 # 9 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # 10 # 11 # Copyright (c) 2007,2010 Kenneth J. Pronovici. 12 # All rights reserved. 13 # 14 # This program is free software; you can redistribute it and/or 15 # modify it under the terms of the GNU General Public License, 16 # Version 2, as published by the Free Software Foundation. 17 # 18 # This program is distributed in the hope that it will be useful, 19 # but WITHOUT ANY WARRANTY; without even the implied warranty of 20 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 21 # 22 # Copies of the GNU General Public License are available from 23 # the Free Software Foundation website, http://www.gnu.org/. 24 # 25 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # 26 # 27 # Author : Kenneth J. Pronovici <pronovic@ieee.org> 28 # Language : Python (>= 2.5) 29 # Project : Cedar Backup, release 2 30 # Revision : $Id: util.py 1041 2013-05-10 02:05:13Z pronovic $ 31 # Purpose : Implements action-related utilities 32 # 33 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # 34 35 ######################################################################## 36 # Module documentation 37 ######################################################################## 38 39 """ 40 Implements action-related utilities 41 @sort: findDailyDirs 42 @author: Kenneth J. Pronovici <pronovic@ieee.org> 43 """ 44 45 46 ######################################################################## 47 # Imported modules 48 ######################################################################## 49 50 # System modules 51 import os 52 import time 53 import tempfile 54 import logging 55 56 # Cedar Backup modules 57 from CedarBackup2.filesystem import FilesystemList 58 from CedarBackup2.util import changeOwnership 59 from CedarBackup2.util import deviceMounted 60 from CedarBackup2.writers.util import readMediaLabel 61 from CedarBackup2.writers.cdwriter import CdWriter 62 from CedarBackup2.writers.dvdwriter import DvdWriter 63 from CedarBackup2.writers.cdwriter import MEDIA_CDR_74, MEDIA_CDR_80, MEDIA_CDRW_74, MEDIA_CDRW_80 64 from CedarBackup2.writers.dvdwriter import MEDIA_DVDPLUSR, MEDIA_DVDPLUSRW 65 from CedarBackup2.config import DEFAULT_MEDIA_TYPE, DEFAULT_DEVICE_TYPE, REWRITABLE_MEDIA_TYPES 66 from CedarBackup2.actions.constants import INDICATOR_PATTERN 67 68 69 ######################################################################## 70 # Module-wide constants and variables 71 ######################################################################## 72 73 logger = logging.getLogger("CedarBackup2.log.actions.util") 74 MEDIA_LABEL_PREFIX = "CEDAR BACKUP" 75 76 77 ######################################################################## 78 # Public utility functions 79 ######################################################################## 80 81 ########################### 82 # findDailyDirs() function 83 ########################### 8486 """ 87 Returns a list of all daily staging directories that do not contain 88 the indicated indicator file. 89 90 @param stagingDir: Configured staging directory (config.targetDir) 91 92 @return: List of absolute paths to daily staging directories. 93 """ 94 results = FilesystemList() 95 yearDirs = FilesystemList() 96 yearDirs.excludeFiles = True 97 yearDirs.excludeLinks = True 98 yearDirs.addDirContents(path=stagingDir, recursive=False, addSelf=False) 99 for yearDir in yearDirs: 100 monthDirs = FilesystemList() 101 monthDirs.excludeFiles = True 102 monthDirs.excludeLinks = True 103 monthDirs.addDirContents(path=yearDir, recursive=False, addSelf=False) 104 for monthDir in monthDirs: 105 dailyDirs = FilesystemList() 106 dailyDirs.excludeFiles = True 107 dailyDirs.excludeLinks = True 108 dailyDirs.addDirContents(path=monthDir, recursive=False, addSelf=False) 109 for dailyDir in dailyDirs: 110 if os.path.exists(os.path.join(dailyDir, indicatorFile)): 111 logger.debug("Skipping directory [%s]; contains %s." % (dailyDir, indicatorFile)) 112 else: 113 logger.debug("Adding [%s] to list of daily directories." % dailyDir) 114 results.append(dailyDir) # just put it in the list, no fancy operations 115 return results116 117 118 ########################### 119 # createWriter() function 120 ########################### 121123 """ 124 Creates a writer object based on current configuration. 125 126 This function creates and returns a writer based on configuration. This is 127 done to abstract action functionality from knowing what kind of writer is in 128 use. Since all writers implement the same interface, there's no need for 129 actions to care which one they're working with. 130 131 Currently, the C{cdwriter} and C{dvdwriter} device types are allowed. An 132 exception will be raised if any other device type is used. 133 134 This function also checks to make sure that the device isn't mounted before 135 creating a writer object for it. Experience shows that sometimes if the 136 device is mounted, we have problems with the backup. We may as well do the 137 check here first, before instantiating the writer. 138 139 @param config: Config object. 140 141 @return: Writer that can be used to write a directory to some media. 142 143 @raise ValueError: If there is a problem getting the writer. 144 @raise IOError: If there is a problem creating the writer object. 145 """ 146 devicePath = config.store.devicePath 147 deviceScsiId = config.store.deviceScsiId 148 driveSpeed = config.store.driveSpeed 149 noEject = config.store.noEject 150 refreshMediaDelay = config.store.refreshMediaDelay 151 ejectDelay = config.store.ejectDelay 152 deviceType = _getDeviceType(config) 153 mediaType = _getMediaType(config) 154 if deviceMounted(devicePath): 155 raise IOError("Device [%s] is currently mounted." % (devicePath)) 156 if deviceType == "cdwriter": 157 return CdWriter(devicePath, deviceScsiId, driveSpeed, mediaType, noEject, refreshMediaDelay, ejectDelay) 158 elif deviceType == "dvdwriter": 159 return DvdWriter(devicePath, deviceScsiId, driveSpeed, mediaType, noEject, refreshMediaDelay, ejectDelay) 160 else: 161 raise ValueError("Device type [%s] is invalid." % deviceType)162 163 164 ################################ 165 # writeIndicatorFile() function 166 ################################ 167169 """ 170 Writes an indicator file into a target directory. 171 @param targetDir: Target directory in which to write indicator 172 @param indicatorFile: Name of the indicator file 173 @param backupUser: User that indicator file should be owned by 174 @param backupGroup: Group that indicator file should be owned by 175 @raise IOException: If there is a problem writing the indicator file 176 """ 177 filename = os.path.join(targetDir, indicatorFile) 178 logger.debug("Writing indicator file [%s]." % filename) 179 try: 180 open(filename, "w").write("") 181 changeOwnership(filename, backupUser, backupGroup) 182 except Exception, e: 183 logger.error("Error writing [%s]: %s" % (filename, e)) 184 raise e185 186 187 ############################ 188 # getBackupFiles() function 189 ############################ 190192 """ 193 Gets a list of backup files in a target directory. 194 195 Files that match INDICATOR_PATTERN (i.e. C{"cback.store"}, C{"cback.stage"}, 196 etc.) are assumed to be indicator files and are ignored. 197 198 @param targetDir: Directory to look in 199 200 @return: List of backup files in the directory 201 202 @raise ValueError: If the target directory does not exist 203 """ 204 if not os.path.isdir(targetDir): 205 raise ValueError("Target directory [%s] is not a directory or does not exist." % targetDir) 206 fileList = FilesystemList() 207 fileList.excludeDirs = True 208 fileList.excludeLinks = True 209 fileList.excludeBasenamePatterns = INDICATOR_PATTERN 210 fileList.addDirContents(targetDir) 211 return fileList212 213 214 #################### 215 # checkMediaState() 216 #################### 217219 """ 220 Checks state of the media in the backup device to confirm whether it has 221 been initialized for use with Cedar Backup. 222 223 We can tell whether the media has been initialized by looking at its media 224 label. If the media label starts with MEDIA_LABEL_PREFIX, then it has been 225 initialized. 226 227 The check varies depending on whether the media is rewritable or not. For 228 non-rewritable media, we also accept a C{None} media label, since this kind 229 of media cannot safely be initialized. 230 231 @param storeConfig: Store configuration 232 233 @raise ValueError: If media is not initialized. 234 """ 235 mediaLabel = readMediaLabel(storeConfig.devicePath) 236 if storeConfig.mediaType in REWRITABLE_MEDIA_TYPES: 237 if mediaLabel is None: 238 raise ValueError("Media has not been initialized: no media label available") 239 elif not mediaLabel.startswith(MEDIA_LABEL_PREFIX): 240 raise ValueError("Media has not been initialized: unrecognized media label [%s]" % mediaLabel) 241 else: 242 if mediaLabel is None: 243 logger.info("Media has no media label; assuming OK since media is not rewritable.") 244 elif not mediaLabel.startswith(MEDIA_LABEL_PREFIX): 245 raise ValueError("Media has not been initialized: unrecognized media label [%s]" % mediaLabel)246 247 248 ######################### 249 # initializeMediaState() 250 ######################### 251253 """ 254 Initializes state of the media in the backup device so Cedar Backup can 255 recognize it. 256 257 This is done by writing an mostly-empty image (it contains a "Cedar Backup" 258 directory) to the media with a known media label. 259 260 @note: Only rewritable media (CD-RW, DVD+RW) can be initialized. It 261 doesn't make any sense to initialize media that cannot be rewritten (CD-R, 262 DVD+R), since Cedar Backup would then not be able to use that media for a 263 backup. 264 265 @param config: Cedar Backup configuration 266 267 @raise ValueError: If media could not be initialized. 268 @raise ValueError: If the configured media type is not rewritable 269 """ 270 if not config.store.mediaType in REWRITABLE_MEDIA_TYPES: 271 raise ValueError("Only rewritable media types can be initialized.") 272 mediaLabel = buildMediaLabel() 273 writer = createWriter(config) 274 writer.refreshMedia() 275 writer.initializeImage(True, config.options.workingDir, mediaLabel) # always create a new disc 276 tempdir = tempfile.mkdtemp(dir=config.options.workingDir) 277 try: 278 writer.addImageEntry(tempdir, "CedarBackup") 279 writer.writeImage() 280 finally: 281 if os.path.exists(tempdir): 282 try: 283 os.rmdir(tempdir) 284 except: pass285 286 287 #################### 288 # buildMediaLabel() 289 #################### 290292 """ 293 Builds a media label to be used on Cedar Backup media. 294 @return: Media label as a string. 295 """ 296 currentDate = time.strftime("%d-%b-%Y").upper() 297 return "%s %s" % (MEDIA_LABEL_PREFIX, currentDate)298 299 300 ######################################################################## 301 # Private attribute "getter" functions 302 ######################################################################## 303 304 ############################ 305 # _getDeviceType() function 306 ############################ 307309 """ 310 Gets the device type that should be used for storing. 311 312 Use the configured device type if not C{None}, otherwise use 313 L{config.DEFAULT_DEVICE_TYPE}. 314 315 @param config: Config object. 316 @return: Device type to be used. 317 """ 318 if config.store.deviceType is None: 319 deviceType = DEFAULT_DEVICE_TYPE 320 else: 321 deviceType = config.store.deviceType 322 logger.debug("Device type is [%s]" % deviceType) 323 return deviceType324 325 326 ########################### 327 # _getMediaType() function 328 ########################### 329331 """ 332 Gets the media type that should be used for storing. 333 334 Use the configured media type if not C{None}, otherwise use 335 C{DEFAULT_MEDIA_TYPE}. 336 337 Once we figure out what configuration value to use, we return a media type 338 value that is valid in one of the supported writers:: 339 340 MEDIA_CDR_74 341 MEDIA_CDRW_74 342 MEDIA_CDR_80 343 MEDIA_CDRW_80 344 MEDIA_DVDPLUSR 345 MEDIA_DVDPLUSRW 346 347 @param config: Config object. 348 349 @return: Media type to be used as a writer media type value. 350 @raise ValueError: If the media type is not valid. 351 """ 352 if config.store.mediaType is None: 353 mediaType = DEFAULT_MEDIA_TYPE 354 else: 355 mediaType = config.store.mediaType 356 if mediaType == "cdr-74": 357 logger.debug("Media type is MEDIA_CDR_74.") 358 return MEDIA_CDR_74 359 elif mediaType == "cdrw-74": 360 logger.debug("Media type is MEDIA_CDRW_74.") 361 return MEDIA_CDRW_74 362 elif mediaType == "cdr-80": 363 logger.debug("Media type is MEDIA_CDR_80.") 364 return MEDIA_CDR_80 365 elif mediaType == "cdrw-80": 366 logger.debug("Media type is MEDIA_CDRW_80.") 367 return MEDIA_CDRW_80 368 elif mediaType == "dvd+r": 369 logger.debug("Media type is MEDIA_DVDPLUSR.") 370 return MEDIA_DVDPLUSR 371 elif mediaType == "dvd+rw": 372 logger.debug("Media type is MEDIA_DVDPLUSRW.") 373 return MEDIA_DVDPLUSRW 374 else: 375 raise ValueError("Media type [%s] is not valid." % mediaType)376
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