def reshape(self, manifest: LocalFileManifest) -> LocalFileManifest:
for block, source, destination, write_back, removed_ids in prepare_reshape(
manifest):
data = self.build_data(source)
new_chunk = destination.evolve_as_block(data)
if write_back:
self.write_chunk(new_chunk, data)
manifest = manifest.evolve_single_block(block, new_chunk)
for removed_id in removed_ids:
self.clear_chunk_data(removed_id)
return manifest
async def _manifest_reshape(self,
manifest: LocalFileManifest,
cache_only: bool = False) -> List[BlockAccess]:
"""This internal helper does not perform any locking."""
# Prepare data structures
missing = []
# Perform operations
for block, source, destination, write_back, removed_ids in prepare_reshape(
manifest):
# Build data block
data, extra_missing = await self._build_data(source)
# Missing data
if extra_missing:
missing += extra_missing
continue
# Write data if necessary
new_chunk = destination.evolve_as_block(data)
if write_back:
await self._write_chunk(new_chunk, data)
# Craft the new manifest
manifest = manifest.evolve_single_block(block, new_chunk)
# Set the new manifest, acting as a checkpoint
await self.local_storage.set_manifest(manifest.id,
manifest,
cache_only=True,
removed_ids=removed_ids)
# Flush if necessary
if not cache_only:
await self.local_storage.ensure_manifest_persistent(manifest.id)
# Return missing block ids
return missing
