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Diffstat (limited to 'core/src/main/scala/spark/storage/BlockObjectWriter.scala')
-rw-r--r-- | core/src/main/scala/spark/storage/BlockObjectWriter.scala | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/core/src/main/scala/spark/storage/BlockObjectWriter.scala b/core/src/main/scala/spark/storage/BlockObjectWriter.scala new file mode 100644 index 0000000000..42e2b07d5c --- /dev/null +++ b/core/src/main/scala/spark/storage/BlockObjectWriter.scala @@ -0,0 +1,50 @@ +package spark.storage + +import java.nio.ByteBuffer + + +/** + * An interface for writing JVM objects to some underlying storage. This interface allows + * appending data to an existing block, and can guarantee atomicity in the case of faults + * as it allows the caller to revert partial writes. + * + * This interface does not support concurrent writes. + */ +abstract class BlockObjectWriter(val blockId: String) { + + var closeEventHandler: () => Unit = _ + + def open(): BlockObjectWriter + + def close() { + closeEventHandler() + } + + def isOpen: Boolean + + def registerCloseEventHandler(handler: () => Unit) { + closeEventHandler = handler + } + + /** + * Flush the partial writes and commit them as a single atomic block. Return the + * number of bytes written for this commit. + */ + def commit(): Long + + /** + * Reverts writes that haven't been flushed yet. Callers should invoke this function + * when there are runtime exceptions. + */ + def revertPartialWrites() + + /** + * Writes an object. + */ + def write(value: Any) + + /** + * Size of the valid writes, in bytes. + */ + def size(): Long +} |