swh.objstorage.objstorage module

swh.objstorage.objstorage.compute_hash(content)

Compute the content’s hash.

Parameters

• content (bytes) – The raw content to hash

• hash_name (str) – Hash’s name (default to ID_HASH_ALGO)

Returns

The ID_HASH_ALGO for the content

class swh.objstorage.objstorage.NullCompressor

Bases: object

compress(data)

flush()

class swh.objstorage.objstorage.NullDecompressor

Bases: object

decompress(data)

property unused_data

class swh.objstorage.objstorage.ObjStorage(*, allow_delete=False, **kwargs)

Bases: object

High-level API to manipulate the Software Heritage object storage.

Conceptually, the object storage offers the following methods:

• check_config() check if the object storage is properly configured

• __contains__() check if an object is present, by object id

• add() add a new object, returning an object id

• restore() same as add() but erase an already existed content

• get() retrieve the content of an object, by object id

• check() check the integrity of an object, by object id

• delete() remove an object

And some management methods:

• get_random() get random object id of existing contents (used for the

  content integrity checker).

Some of the methods have available streaming equivalents:

• add_stream() same as add() but with a chunked iterator

• restore_stream() same as add_stream() but erase already existing content

• get_stream() same as get() but returns a chunked iterator

Each implementation of this interface can have a different behavior and its own way to store the contents.

abstract check_config(*, check_write)

Check whether the object storage is properly configured.

Parameters

• check_write (bool) – if True, check if writes to the object storage

• succeed. (can) –

Returns

True if the configuration check worked, an exception if it didn’t.

abstract add(content, obj_id=None, check_presence=True, *args, **kwargs)

Add a new object to the object storage.

Parameters

• content (bytes) – object’s raw content to add in storage.

• obj_id (bytes) – checksum of [bytes] using [ID_HASH_ALGO] algorithm. When given, obj_id will be trusted to match the bytes. If missing, obj_id will be computed on the fly.

• check_presence (bool) – indicate if the presence of the content should be verified before adding the file.

Returns

the id (bytes) of the object into the storage.

add_batch(contents, check_presence=True) → Dict

Add a batch of new objects to the object storage.

Parameters

contents – mapping from obj_id to object contents

Returns

the summary of objects added to the storage (count of object, count of bytes object)

restore(content, obj_id=None, *args, **kwargs)

Restore a content that have been corrupted.

This function is identical to add but does not check if the object id is already in the file system. The default implementation provided by the current class is suitable for most cases.

Parameters

• content (bytes) – object’s raw content to add in storage

• obj_id (bytes) – checksum of bytes as computed by ID_HASH_ALGO. When given, obj_id will be trusted to match bytes. If missing, obj_id will be computed on the fly.

abstract get(obj_id, *args, **kwargs)

Retrieve the content of a given object.

Parameters

obj_id (bytes) – object id.

Returns

the content of the requested object as bytes.

Raises

ObjNotFoundError – if the requested object is missing.

get_batch(obj_ids, *args, **kwargs)

Retrieve objects’ raw content in bulk from storage.

Note: This function does have a default implementation in ObjStorage that is suitable for most cases.

For object storages that needs to do the minimal number of requests possible (ex: remote object storages), that method can be overridden to perform a more efficient operation.

Parameters

([bytes] (obj_ids) – list of object ids.

Returns

list of resulting contents, or None if the content could not be retrieved. Do not raise any exception as a fail for one content will not cancel the whole request.

abstract check(obj_id, *args, **kwargs)

Perform an integrity check for a given object.

Verify that the file object is in place and that the content matches the object id.

Parameters

obj_id (bytes) – object identifier.

Raises

• ObjNotFoundError – if the requested object is missing.

• Error – if the request object is corrupted.

abstract delete(obj_id, *args, **kwargs)

Delete an object.

Parameters

obj_id (bytes) – object identifier.

Raises

ObjNotFoundError – if the requested object is missing.

get_random(batch_size, *args, **kwargs)

Get random ids of existing contents.

This method is used in order to get random ids to perform content integrity verifications on random contents.

Parameters

batch_size (int) – Number of ids that will be given

Yields

An iterable of ids (bytes) of contents that are in the current object storage.

add_stream(content_iter, obj_id, check_presence=True)

Add a new object to the object storage using streaming.

This function is identical to add() except it takes a generator that yields the chunked content instead of the whole content at once.

Parameters

• content (bytes) – chunked generator that yields the object’s raw content to add in storage.

• obj_id (bytes) – object identifier

• check_presence (bool) – indicate if the presence of the content should be verified before adding the file.

Returns

the id (bytes) of the object into the storage.

restore_stream(content_iter, obj_id=None)

Restore a content that have been corrupted using streaming.

This function is identical to restore() except it takes a generator that yields the chunked content instead of the whole content at once. The default implementation provided by the current class is suitable for most cases.

Parameters

• content (bytes) – chunked generator that yields the object’s raw content to add in storage.

• obj_id (bytes) – object identifier

get_stream(obj_id, chunk_size=2097152)

Retrieve the content of a given object as a chunked iterator.

Parameters

obj_id (bytes) – object id.

Returns

the content of the requested object as bytes.

Raises

ObjNotFoundError – if the requested object is missing.

list_content(last_obj_id=None, limit=10000)

Generates known object ids.

Parameters

• last_obj_id (bytes) – object id from which to iterate from (excluded).

• limit (int) – max number of object ids to generate.

Generates:

obj_id (bytes): object ids.