/**
* Appends the given deltas to the deltas already stored. Updates the latest snapshot and latest
* version as well. This method will make a copy of the snapshot.
*
* @param updatedSnapshot the snapshot after deltas have been applied
* @param newDeltas the deltas that have been applied since the last call to appendDeltas.
*/
public void appendDeltas(ReadableWaveletData updatedSnapshot, DeltaSequence newDeltas) {
HashedVersion newEndVersion = newDeltas.getEndVersion();
Preconditions.checkArgument(
!newDeltas.isEmpty(), "There were no new deltas passed to appendDeltas");
Preconditions.checkArgument(
updatedSnapshot.getVersion() == newEndVersion.getVersion(),
String.format(
"Version of snapshot %s doesn't match the HashedVersion %s",
updatedSnapshot.getVersion(), newEndVersion));
Preconditions.checkArgument(
areContiguousToCurrentVersion(newDeltas),
String.format(
"Deltas are not contiguous to the current version(%s) %s",
getVersionAfterDeltas(), deltas));
WaveletName updatedWaveletName = WaveletDataUtil.waveletNameOf(updatedSnapshot);
Preconditions.checkArgument(
updatedWaveletName.equals(waveletName),
String.format(
"Updated wavelet doesn't have the same name as with which this class has been "
+ "instantiated. %s != %s",
updatedWaveletName, waveletName));
// TODO(ljvderijk): This should actually be applying the deltas, however
// they do not contain a timestamp at this time.
snapshotAfterDeltas = WaveletDataUtil.copyWavelet(updatedSnapshot);
deltas = DeltaSequence.join(deltas, newDeltas);
}
/**
* Constructs a {@link WaveletAndDeltas} from wavelet data and a tail of the sequence of
* transformed deltas leading to that snapshot. Takes a copy of the WaveletData so that operations
* can happily applied to it.
*
* <p>The resulting version of the last delta must match the snapshot's version.
*
* @param snapshot the state of the wavelet after the deltas have been applied.
* @param deltas the deltas in the order they have been applied to the wavelet.
* @throws OperationException if the operations can not be rolled back to create a snapshot before
* the deltas have been applied.
*/
public static WaveletAndDeltas create(ReadableWaveletData snapshot, DeltaSequence deltas)
throws OperationException {
HashedVersion endVersion =
deltas.isEmpty() ? snapshot.getHashedVersion() : deltas.getEndVersion();
Preconditions.checkArgument(
snapshot.getVersion() == endVersion.getVersion(),
String.format(
"Version of snapshot %s doesn't match the end version %s",
snapshot.getVersion(), endVersion));
ObservableWaveletData preDeltaWavelet = WaveletDataUtil.copyWavelet(snapshot);
rollback(preDeltaWavelet, deltas);
ObservableWaveletData postDeltaWavelet = WaveletDataUtil.copyWavelet(snapshot);
return new WaveletAndDeltas(preDeltaWavelet, postDeltaWavelet, deltas);
}
