@Override
public void synchronize() throws IOException {
if (logger.isDebugEnabled()) {
logger.debug("Synchronizing...");
}
// Detect remote change
List<ChangeRecord> remoteChanges = remoteChange();
// Detect local change
Snapshot standard = stub.storage().get(StorageService.SNAPSHOT);
Snapshot current = stub.snapshot().make();
List<ChangeRecord> localChanges = compare(standard, current);
/*
* First upload then download. Local change has higher priority than
* remote because remote change can be restored while local cannot.
* Recorded uploaded file so later no need to download
*/
Map<String, String> localUploaded = new HashMap<String, String>();
for (ChangeRecord localChange : localChanges) {
synchronize(localChange);
localUploaded.put(localChange.getLocalFile(), localChange.getRemoteFileId());
}
PriorityQueue<ChangeRecord> orderedRemoteChanges =
new PriorityQueue<ChangeRecord>(
50,
new Comparator<ChangeRecord>() {
@Override
public int compare(ChangeRecord o1, ChangeRecord o2) {
if (o1.getOperation().ordinal() < o2.getOperation().ordinal()) {
return -1;
} else if (o1.getOperation().ordinal() > o2.getOperation().ordinal()) {
return 1;
} else {
if (o1.getLocalFile() == null) return -1;
if (o2.getLocalFile() == null) return 1;
return o1.getLocalFile().compareTo(o2.getLocalFile());
}
}
});
for (ChangeRecord remoteChange : remoteChanges) {
if (!localUploaded.containsKey(remoteChange.getLocalFile())) {
synchronize(remoteChange);
if (remoteChange.getOperation() == Operation.REMOTE_INSERT) {
remoteChange.setLocalFile(
stub.storage().remoteToLocal().get(remoteChange.getRemoteFileId()));
}
orderedRemoteChanges.add(remoteChange);
}
}
while (!orderedRemoteChanges.isEmpty()) {
addToSnapshot(current, orderedRemoteChanges.poll());
}
// Retry until all the errors are processed
while (!stub.storage().failedLog().isEmpty()) {
FailedRecord fr = stub.storage().failedLog().remove(0);
// Filter, modify and discard
fr = correct(fr);
if (fr != null) {
synchronize(fr);
}
}
stub.storage().put(StorageService.SNAPSHOT, current);
}
private void synchronize(ChangeRecord record) throws IOException {
try {
switch (record.getOperation()) {
case LOCAL_INSERT:
{
// Get remote id for the parent folder
File local = DriveUtils.absolutePath(record.getLocalFile());
String remoteParent =
stub.storage().localToRemote().get(DriveUtils.relativePath(local.getParentFile()));
if (!StringUtils.isEmpty(remoteParent)
&& !stub.storage().localToRemote().containsKey(record.getLocalFile())) {
// Ignore insert request that doesn't have a parent or
// already have a mapping.
// The insert operation will be accomplished by the topmost
// folder
String remoteId = stub.transmit().upload(remoteParent, local);
record.setRemoteFileId(remoteId);
}
break;
}
case LOCAL_DELETE:
{
if (!StringUtils.isEmpty(record.getRemoteFileId())) {
stub.transmit().delete(record.getRemoteFileId());
} else {
logger.warn(
"Local deletion has no remote reference, make sure the storage is correct.");
}
break;
}
case LOCAL_CHANGE:
{
if (!StringUtils.isEmpty(record.getRemoteFileId())) {
File local = DriveUtils.absolutePath(record.getLocalFile());
stub.transmit().update(record.getRemoteFileId(), local);
} else {
logger.warn(
"Local change has no remote reference, make sure the storage is correct.");
logger.warn("Trying to insert the new record");
// Modify it to a local insert
record.setOperation(Operation.LOCAL_INSERT);
synchronize(record);
}
break;
}
case LOCAL_RENAME:
{
if (!StringUtils.isEmpty(record.getRemoteFileId())) {
stub.transmit().rename(record.getRemoteFileId(), (String) record.getContext()[0]);
} else {
logger.warn(
"Local rename has no remote reference, make sure the storage is correct.");
logger.warn("Trying to insert the new record");
// Modify it to be a local insert
record.setOperation(Operation.LOCAL_INSERT);
synchronize(record);
}
break;
}
case REMOTE_INSERT:
{
if (stub.storage().remoteToLocal().containsKey(record.getRemoteFileId())) {
// This file/folder already had been created
break;
}
com.google.api.services.drive.model.File file = record.getContext(0);
// Depth search of parent that has a local root
List<ParentReference> path = new ArrayList<ParentReference>();
File local = pathToLocal(record.getRemoteFileId(), path);
if (null == local) {
// Check whether this file is trashed
if (file.getLabels().getTrashed()) {
return;
}
if (file.getShared()) {
return;
} else {
throw new IllegalArgumentException("Non-trash file has no known parent");
}
}
File parent = local;
for (ParentReference node : path) {
stub.transmit().download(node.getId(), parent);
parent = DriveUtils.absolutePath(stub.storage().remoteToLocal().get(node.getId()));
}
stub.transmit().download(record.getRemoteFileId(), parent);
record.setLocalFile(stub.storage().remoteToLocal().get(record.getRemoteFileId()));
if (StringUtils.isEmpty(record.getLocalFile())) {
break;
}
break;
}
case REMOTE_DELETE:
{
if (StringUtils.isEmpty(record.getLocalFile())) {
// No local file, remote file should be a trashed one.
if (logger.isDebugEnabled()) {
logger.debug(
"No corresponding local file for deletion. Remote file may be trashed");
}
break;
}
File localFile = DriveUtils.absolutePath(record.getLocalFile());
String localParent = DriveUtils.relativePath(localFile.getParentFile());
// Preserve the original context
record.setContext(new Object[] {record.getContext(0), localParent});
deleteLocalFile(localFile);
if (localFile.exists()) {
if (logger.isDebugEnabled()) {
logger.debug(
MessageFormat.format(
"Failed to delete file {0}. File may have been deleted.",
record.getLocalFile()));
}
}
stub.storage().localToRemote().remove(record.getLocalFile());
stub.storage().remoteToLocal().remove(record.getRemoteFileId());
break;
}
case REMOTE_CHANGE:
{
File local = DriveUtils.absolutePath(record.getLocalFile());
File localParent = local.getParentFile();
com.google.api.services.drive.model.File remote = record.getContext(0);
if (!remote.getTitle().equals(local.getName())) {
local.delete();
stub.storage().localToRemote().remove(record.getLocalFile());
stub.storage().remoteToLocal().remove(record.getRemoteFileId());
}
stub.transmit().download(record.getRemoteFileId(), localParent);
break;
}
case REMOTE_RENAME:
{
File local = DriveUtils.absolutePath(record.getLocalFile());
com.google.api.services.drive.model.File remote = record.getContext(0);
String remoteName = remote.getTitle();
File newName =
new File(local.getParentFile().getAbsolutePath() + File.separator + remoteName);
String relNewName = DriveUtils.relativePath(newName);
record.setContext(new Object[] {record.getContext()[0], relNewName});
local.renameTo(newName);
stub.storage()
.remoteToLocal()
.put(record.getRemoteFileId(), DriveUtils.relativePath(newName));
stub.storage().localToRemote().remove(DriveUtils.relativePath(local));
stub.storage()
.localToRemote()
.put(DriveUtils.relativePath(newName), record.getRemoteFileId());
break;
}
}
} catch (Exception e) {
logger.warn(MessageFormat.format("Exception on Change {0}. Retry later", record), e);
FailedRecord fr = new FailedRecord(record);
if (e instanceof GoogleJsonResponseException) {
GoogleJsonResponseException gjre = (GoogleJsonResponseException) e;
fr.setError(String.valueOf(gjre.getDetails().getCode()));
} else {
fr.setError(e.getMessage());
}
stub.storage().failedLog().add(fr);
}
}
