AutoArchive._services.archiver

Archiver Service Component.

Provides services for creating the backup.

Modules

archiver_service_identification

ArchiverServiceIdentification interface.

class AutoArchive._services.archiver.archiver_service_identification.ArchiverServiceIdentification[source]

Bases: IServiceIdentification

Identifies the Archiver service.

Parameters required by the service upon creation:

workDir: Path to a writable directory. The service will use it as persistent storage (type str).

interface

alias of _TarArchiverProviderBase

providerIdentificationInterface

alias of _TarArchiverProviderIdentification

archiver_service_provider_ids

ArchiverServiceProviderIDs enum.

AutoArchive._services.archiver.archiver_service_provider_ids.ArchiverServiceProviderIDs = TarInternal, TarExternal

Implementations of the archiver service.

backup_definition

MIN_COMPRESSION_STRENGTH and MAX_COMPRESSION_STRENGTH constants, BackupTypes, ArchiverFeatures, BackupSubOperations, BackupOperationErrors enums and BackupDefinition class.

class AutoArchive._services.archiver.backup_definition.BackupDefinition[source]

Bases: object

Container class for information needed to create a backup.

property backupId

The backup identifier, typically the name is used.

Return type:

str

property backupType

Type of the backup.

Return type:

BackupTypes

property destination

Path to the directory which contains the backup.

Return type:

str

property excludeFiles

Set of excluded filesystem objects paths relative to root.

Return type:

Set<str>

property includeFiles

Set of source filesystem objects paths relative to root.

Return type:

Set<str>

property root

Path to the root directory of the source content.

Return type:

str

AutoArchive._services.archiver.backup_definition.ArchiverFeatures = CompressionStrength, Incremental

Features that archiver service may support.

AutoArchive._services.archiver.backup_definition.BackupOperationErrors = UnknownError, UnknownOsError, PermissionDenied, SocketIgnored, UnknownTypeIgnored, FileChanged, SomeFilesChanged, DirectoryRenamed

Errors that may occur during backup operation.

AutoArchive._services.archiver.backup_definition.BackupSubOperations = Unknown, UnknownFileOperation, Stat, Open, Read, Finish

Operations executed during backup creation.

AutoArchive._services.archiver.backup_definition.BackupTypes = Tar, TarGz, TarBz2, TarXz, TarZst

Backup types.

AutoArchive._services.archiver.backup_definition.MAX_COMPRESSION_STRENGTH: int = 9

Maximal compression strength value.

AutoArchive._services.archiver.backup_definition.MIN_COMPRESSION_STRENGTH: int = 0

Minimal compression strength value.

_archiver_service_component

ArchiverServiceComponent.

class AutoArchive._services.archiver._archiver_service_component.ArchiverServiceComponent(applicationContext, serviceAccessor)[source]

Bases: IServiceComponent

Service component for archiver services.

Registers service identified by ArchiverServiceIdentification with two providers of _TarArchiverProviderIdentification-like interface.

destroyServices()[source]

See: IServiceComponent.destroyServices()

_tar_archiver_provider_identification

_TarArchiverProviderIdentification.

class AutoArchive._services.archiver._tar_archiver_provider_identification._TarArchiverProviderIdentification(serviceProviderId)[source]

Bases: object

Provides information about services defined in ArchiverServiceProviderIDs.

Parameters:

serviceProviderId (ArchiverServiceProviderIDs.) – Identifier of the service that this instance shall provide information for.

getSupportedBackupTypes()[source]

See: IArchiverProviderIdentification.getSupportedBackupTypes().

getSupportedFeatures(backupType=None)[source]

See: IArchiverProviderIdentification.getSupportedFeatures().

property providerId

See: IArchiverProviderIdentification.providerId().

_tar_archiver_provider_base

_TarArchiverProviderBase class.

class AutoArchive._services.archiver._tar_archiver_provider_base._TarArchiverProviderBase(workDir)[source]

Bases: IService

Base class for tar archiver service providers.

Abstract constructor of this class, should be called from derived constructors. It initializes the workDir_ property.

Parameters:

workDir (str) – Path to a writable directory. The service will use it as persistent storage.

abstract backupFiles(backupDefinition, compressionStrength=None, overwriteAtStart=False)[source]

Creates a backup.

Parameters:

  • backupDefinition (BackupDefinition) – Defines the backup that shall be created. All attributes of the passed instance has to be initialized.

  • compressionStrength (int) – Value from interval <MIN_COMPRESSION_STRENGTH, MAX_COMPRESSION_STRENGTH> representing the strength of compression. It has to be non-None only for backup types that supports compression and compression strength setting.

  • overwriteAtStart (bool) – If True, backups are overwritten at the start of creation; otherwise they are overwritten at the end of creation (new backups are created with temporary name first and renamed when completed).

Returns:

Path to the created backup.

Return type:

str

Raises:

  • RuntimeError – If compressionStrength is non-None and backupDefinition.backupType does not supports compression or compression strength setting. If an unknown error occurred during backup creation.

  • ValueError – If compressionStrength is outside of required interval or if backupDefinition.backupType is not supported by the implementation.

  • OSError – If a system error occurred while making the backup.

Performs basic checks before the backup creation.

Note

Derived classes should call this base method on the beginning of the overridden method.

abstract backupFilesIncrementally(backupDefinition, compressionStrength=None, level=None, overwriteAtStart=False)[source]

Creates an incremental backup.

A backup of specified level or the next level in a row will be created. The maximal backup level will be increased (see getMaxBackupLevel()).

Parameters:

  • backupDefinition (BackupDefinition) – Defines the backup that shall be created. All attributes of the passed instance has to be initialized.

  • compressionStrength (int) – Value from interval <MIN_COMPRESSION_STRENGTH, MAX_COMPRESSION_STRENGTH> representing the strength of compression. It has to be non-None only for backup types that supports compression and compression strength setting.

  • level (int) – Backup level that shall be created. If None, the next level in a row will be created, which is the the one returned by getMaxBackupLevel(). The value has to be from interval <0, getMaxBackupLevel()>.

  • overwriteAtStart (bool) – If True, backups are overwritten at the start of creation; otherwise they are overwritten at the end of creation (new backups are created with temporary name first and renamed when completed).

Returns:

Path to the created backup.

Return type:

str

Raises:

  • RuntimeError – If compressionStrength is non-None and backupDefinition.backupType does not supports compression or compression strength setting. If an unknown error occurred during backup creation.

  • ValueError – If compressionStrength or level is outside of required interval or if backupDefinition.backupType is not supported by the implementation.

  • NotImplementedError – If incremental backup is not supported.

  • OSError – If a system error occurred while making the backup.

Performs basic checks before the incremental backup creation.

Note

Derived classes should call this base method on the beginning of the overridden method.

doesAnyBackupLevelExist(backupDefinition, fromLevel=0, keepingId=None)[source]

Returns True, if one or more backup levels of a backup defined by backupDefinition exists.

Parameters:

  • backupDefinition (BackupDefinition) – Defines the backup which existence shall be queried.

  • fromLevel (int) – The specified backup level and above will be checked for existence. The value has to be >= 0.

  • keepingId (str) – The kept backup with this ID will be checked for existence. None if the actual (not kept) backup will be checked.

Returns:

True if any backup level exists, False otherwise.

Return type:

bool

Raises:

ValueError – If backupDefinition.backupType is not supported by the implementation.

doesBackupExist(backupDefinition, level=None, keepingId=None)[source]

Returns True, if backup exists.

Parameters:

  • backupDefinition (BackupDefinition) – Defines the backup which existence shall be queried.

  • level (int) – The level of backup of which existence shall be checked. If None, existence of non-incremental backup will be checked. The value has to be >= 0.

  • keepingId (str) – The kept backup with this ID will be checked for existence. None if the actual (not kept) backup will be checked.

Returns:

True if the backup exists, False otherwise.

Return type:

bool

Raises:

ValueError – If backupDefinition.backupType is not supported by the implementation.

static getBackupFilePath_(backupId, backupType, destination, level=None, keepingId=None)[source]

Assembles the backup file name and returns a path to it.

Parameters:

  • backupId (str) – ID of the backup for which the path shall be returned.

  • backupType (BackupTypes) – Type of the backup.

  • destination (str) – Path to the directory where the to the backup shall be created.

  • level (int) – Backup level.

  • keepingId (str) – Path of the kept backup with this ID will be returned. None if path of the actual (not kept) backup shall be returned.

Returns:

Path to the backup file.

Return type:

str

getMaxBackupLevel(backupId)[source]

Determines and returns maximal backup level that can be created.

Parameters:

backupId (str) – ID of the backup for which the level shall be determined.

Returns:

The maximal backup level that can be created by backupFilesIncrementally().

Return type:

int

Raises:

  • NotImplementedError – If incremental backup is not supported.

  • OSError – If a system error occurred.

getStoredBackupIds()[source]

Returns iterable of archive IDs which has some data stored in a persistent storage.

See also: purgeStoredBackupData().

Returns:

Iterable of archive names.

Return type:

Iterable<str>

Raises:

OSError – If a system error occurred.

classmethod getSupportedFeatures(backupType=None)[source]

Returns a set of supported features, either all of them or for given backupType.

Parameters:

backupType (BackupTypes) – The backup type for which the features shall be returned or None if all supported features shall be returned.

Returns:

Supported features for given backupType or all supported features.

Return type:

set<ArchiverFeatures>

Raises:

ValueError – If the given backupType is not supported by this service

classmethod getWorkingPath_(properPath)[source]
keepBackup(backupDefinition, keepingId, newKeepingId, level=None)[source]

Keeps a backup with keepingId under the newKeepingId.

See also: doesBackupExist() or doesAnyBackupLevelExist().

Parameters:

  • backupDefinition (BackupDefinition) – Defines the backup that shall be kept.

  • keepingId (str) – The ID under which the backup is currently kept. None if it is not kept yet.

  • newKeepingId (str) – The ID under which the backup is shall be kept.

  • level (int) – The level of backup of which shall be kept. If None, non-incremental backup will be kept. The value has to be >= 0.

Raises:

  • ValueError – If backupDefinition.backupType is not supported by the implementation or if newKeepingId is None or empty string.

  • FileExistsError – If backup with the specified newKeepingId already exists.

  • FileNotFoundError – If backup with the specified keepingId does not exist.

  • OSError – If a system error occurred.

purgeStoredBackupData(backupId)[source]

Removes internal data from a persistent storage for the passed backupId.

See also: getStoredBackupIds().

Parameters:

backupId (str) – ID of the backup of which data shall be purged.

Raises:

OSError – If a system error occurred.

classmethod raiseIfUnsupportedBackupType_(backupType)[source]

Raises an exception if the passed backupType is not supported by the implementation.

See also: _TarArchiverProviderBase.supportedBackupTypes.

Parameters:

backupType (BackupTypes) – The backup type that shall be checked.

Raises:

ValueError – If the passed backupType is not supported by the concrete implementation.

classmethod raiseIfUnsupportedFeature_(backupType, compressionStrength=None, level=None)[source]
removeBackup(backupDefinition, keepingId=None)[source]

Remove a backup.

Backup defined by backupDefinition will be removed.

Parameters:

  • backupDefinition (BackupDefinition) – Defines backup that shall be removed. BackupDefinition.backupId, BackupDefinition.backupType and BackupDefinition.destination attributes of the passed instance has to be initialized.

  • keepingId (str) – The ID under which the backup is currently kept. None if it is not kept.

Raises:

  • ValueError – If backupDefinition.backupType is not supported by the implementation.

  • OSError – If a system error occurred during removing operation.

removeBackupIncrements(backupDefinition, level=None, keepingId=None)[source]

Remove backup increments starting from level.

Backups (increments) of backup level higher or equal than level or higher that the current backup level - in case level is None - will be removed. The maximal backup level (getMaxBackupLevel()) will be set to the value level.

Parameters:

  • backupDefinition (BackupDefinition) – Defines backup that shall be removed. BackupDefinition.backupId, BackupDefinition.backupType and BackupDefinition.destination attributes of the passed instance has to be initialized.

  • level (int) – The first level that shall be removed. All backups of levels higher or equal than level will be removed. If None, backups of levels higher or equal than the one returned by getMaxBackupLevel() will be removed. The value has to be >= 0.

  • keepingId (str) – The ID under which the backup is currently kept. None if it is not kept.

Raises:

  • ValueError – If level is outside of required interval or if backupDefinition.backupType is not supported by the implementation.

  • NotImplementedError – If incremental backup is not supported.

  • OSError – If a system error occurred during removing operation.

backupOperationError = <AutoArchive._infrastructure.py_additions.event object>
fileAdd = <AutoArchive._infrastructure.py_additions.event object>
abstract property supportedBackupTypes

Gets a set of backup types supported by this archiver service.

Return type:

set<BackupTypes>

property workDir_

Gets path to the working directory.

Return type:

str

_external_tar_archiver_provider

_ExternalTarArchiverProvider class.

class AutoArchive._services.archiver._external_tar_archiver_provider._ExternalTarArchiverProvider(workDir)[source]

Bases: _TarArchiverProviderBase

External archiver service provider.

See also: _TarArchiverProviderBase.

Raises:

OSError – If creation of the snapshot directory failed.

backupFiles(backupDefinition, compressionStrength=None, overwriteAtStart=False)[source]

See: _TarArchiverProviderBase.backupFiles().

backupFilesIncrementally(backupDefinition, compressionStrength=None, level=None, overwriteAtStart=False)[source]

See: _TarArchiverProviderBase.backupFilesIncrementally().

doesAnyBackupLevelExist(backupDefinition, fromLevel=0, keepingId=None)[source]

See: _TarArchiverProviderBase.doesAnyBackupLevelExist().

getMaxBackupLevel(backupId)[source]

See: _TarArchiverProviderBase.getMaxBackupLevel().

getStoredBackupIds()[source]

See: _TarArchiverProviderBase.getStoredBackupIds().

classmethod getSupportedFeatures(backupType=None)[source]

See: _TarArchiverProviderBase.getSupportedFeatures().

purgeStoredBackupData(backupId)[source]

See: _TarArchiverProviderBase.purgeStoredBackupData().

removeBackupIncrements(backupDefinition, level=None, keepingId=None)[source]

See: _TarArchiverProviderBase.removeBackupIncrements().

supportedBackupTypes = frozenset({0, 1, 2, 3, 4})

_internal_tar_archiver_provider

_InternalTarArchiverProvider class.

class AutoArchive._services.archiver._internal_tar_archiver_provider._InternalTarArchiverProvider(workDir)[source]

Bases: _TarArchiverProviderBase

Internal archiver service provider.

See also: _TarArchiverProviderBase.

backupFiles(backupDefinition, compressionStrength=None, overwriteAtStart=False)[source]

See: _TarArchiverProviderBase.backupFiles().

backupFilesIncrementally(backupDefinition, compressionStrength=None, level=None, overwriteAtStart=False)[source]

See: _TarArchiverProviderBase.backupFilesIncrementally().

classmethod getSupportedFeatures(backupType=None)[source]

See: _TarArchiverProviderBase.getSupportedFeatures().

supportedBackupTypes = frozenset({0, 1, 2})