Class _BlockManager

Allocate a new, empty bufferblock in WRITABLE state and return it.

:blockid:
  optional block identifier, otherwise one will be automatically assigned

:starting_capacity:
  optional capacity, otherwise will use default capacity

:owner:
  ArvadosFile that owns this block

Decorators:

• @synchronized

Create a new bufferblock initialized with the content of an existing bufferblock.

:block:
  the buffer block to copy.

:owner:
  ArvadosFile that owns the new block

Decorators:

• @synchronized

Decorators:

• @synchronized

Decorators:

• @synchronized

Shut down and wait for background upload and download threads to finish.

Decorators:

• @synchronized

Packs small blocks together before uploading

Decorators:

• @synchronized

Initiate a background upload of a bufferblock.

:block:
  The block object to upload

:sync:
  If `sync` is True, upload the block synchronously.
  If `sync` is False, upload the block asynchronously.  This will
  return immediately unless the upload queue is at capacity, in
  which case it will wait on an upload queue slot.

Decorators:

• @synchronized

Get a bufferblock 64 MB in size consisting of all zeros, used as padding when using truncate() to extend the size of a file.

For reference (and possible future optimization), the md5sum of the padding block is: 7f614da9329cd3aebf59b91aadc30bf0+67108864

Decorators:

• @synchronized

Decorators:

• @synchronized

Fetch a block.

First checks to see if the locator is a BufferBlock and return that, if not, passes the request through to KeepClient.get().

Commit all outstanding buffer blocks.

This is a synchronous call, and will not return until all buffer blocks are uploaded. Raises KeepWriteError() if any blocks failed to upload.

Initiate a background download of a block.

This assumes that the underlying KeepClient implements a block cache, so repeated requests for the same block will not result in repeated downloads (unless the block is evicted from the cache.) This method does not block.