public void synchronize(boolean manualSync, SyncResult syncResult)
throws URISyntaxException, LocalStorageException, IOException, HttpException, DavException {
// PHASE 1: push local changes to server
int deletedRemotely = pushDeleted(), addedRemotely = pushNew(), updatedRemotely = pushDirty();
syncResult.stats.numEntries = deletedRemotely + addedRemotely + updatedRemotely;
// PHASE 2A: check if there's a reason to do a sync with remote (= forced sync or remote CTag
// changed)
boolean fetchCollection = syncResult.stats.numEntries > 0;
if (manualSync) {
Log.i(TAG, "Synchronization forced");
fetchCollection = true;
}
if (!fetchCollection) {
String currentCTag = remote.getCTag(), lastCTag = local.getCTag();
Log.d(TAG, "Last local CTag = " + lastCTag + "; current remote CTag = " + currentCTag);
if (currentCTag == null || !currentCTag.equals(lastCTag)) fetchCollection = true;
}
if (!fetchCollection) {
Log.i(TAG, "No local changes and CTags match, no need to sync");
return;
}
// PHASE 2B: detect details of remote changes
Log.i(TAG, "Fetching remote resource list");
Set<Resource> remotelyAdded = new HashSet<Resource>(),
remotelyUpdated = new HashSet<Resource>();
Resource[] remoteResources = remote.getMemberETags();
for (Resource remoteResource : remoteResources) {
try {
Resource localResource = local.findByRemoteName(remoteResource.getName(), false);
if (localResource.getETag() == null
|| !localResource.getETag().equals(remoteResource.getETag()))
remotelyUpdated.add(remoteResource);
} catch (RecordNotFoundException e) {
remotelyAdded.add(remoteResource);
}
}
// PHASE 3: pull remote changes from server
syncResult.stats.numInserts = pullNew(remotelyAdded.toArray(new Resource[0]));
syncResult.stats.numUpdates = pullChanged(remotelyUpdated.toArray(new Resource[0]));
syncResult.stats.numEntries += syncResult.stats.numInserts + syncResult.stats.numUpdates;
Log.i(TAG, "Removing non-dirty resources that are not present remotely anymore");
local.deleteAllExceptRemoteNames(remoteResources);
local.commit();
// update collection CTag
Log.i(TAG, "Sync complete, fetching new CTag");
local.setCTag(remote.getCTag());
}
private int pushDirty()
throws URISyntaxException, LocalStorageException, IOException, HttpException {
int count = 0;
long[] dirtyIDs = local.findUpdated();
Log.i(TAG, "Uploading " + dirtyIDs.length + " modified resource(s) (if not changed)");
try {
for (long id : dirtyIDs) {
try {
Resource res = local.findById(id, true);
String eTag = remote.update(res);
if (eTag != null) local.updateETag(res, eTag);
local.clearDirty(res);
count++;
} catch (PreconditionFailedException e) {
Log.i(TAG, "Locally changed resource has been changed on the server in the meanwhile");
} catch (ValidationException e) {
Log.e(TAG, "Couldn't create entity for updating: " + e.toString());
} catch (RecordNotFoundException e) {
Log.e(TAG, "Couldn't read dirty record", e);
}
}
} finally {
local.commit();
}
return count;
}
private int pushNew()
throws URISyntaxException, LocalStorageException, IOException, HttpException {
int count = 0;
long[] newIDs = local.findNew();
Log.i(TAG, "Uploading " + newIDs.length + " new resource(s) (if not existing)");
try {
for (long id : newIDs)
try {
Resource res = local.findById(id, true);
String eTag = remote.add(res);
if (eTag != null) local.updateETag(res, eTag);
local.clearDirty(res);
count++;
} catch (PreconditionFailedException e) {
Log.i(TAG, "Didn't overwrite existing resource with other content");
} catch (ValidationException e) {
Log.e(TAG, "Couldn't create entity for adding: " + e.toString());
} catch (RecordNotFoundException e) {
Log.wtf(TAG, "Couldn't read new record", e);
}
} finally {
local.commit();
}
return count;
}
private int pushDeleted()
throws URISyntaxException, LocalStorageException, IOException, HttpException {
int count = 0;
long[] deletedIDs = local.findDeleted();
try {
Log.i(
TAG, "Remotely removing " + deletedIDs.length + " deleted resource(s) (if not changed)");
for (long id : deletedIDs)
try {
Resource res = local.findById(id, false);
if (res.getName() != null) // is this resource even present remotely?
try {
remote.delete(res);
} catch (NotFoundException e) {
Log.i(TAG, "Locally-deleted resource has already been removed from server");
} catch (PreconditionFailedException e) {
Log.i(
TAG, "Locally-deleted resource has been changed on the server in the meanwhile");
}
// always delete locally so that the record with the DELETED flag doesn't cause another
// deletion attempt
local.delete(res);
count++;
} catch (RecordNotFoundException e) {
Log.wtf(TAG, "Couldn't read locally-deleted record", e);
}
} finally {
local.commit();
}
return count;
}
private int pullChanged(Resource[] resourcesToUpdate)
throws URISyntaxException, LocalStorageException, IOException, HttpException, DavException {
int count = 0;
Log.i(TAG, "Fetching " + resourcesToUpdate.length + " updated remote resource(s)");
for (Resource[] resources : ArrayUtils.partition(resourcesToUpdate, MAX_MULTIGET_RESOURCES))
for (Resource res : remote.multiGet(resources)) {
Log.i(TAG, "Updating " + res.getName());
local.updateByRemoteName(res);
local.commit();
count++;
}
return count;
}
private int pullNew(Resource[] resourcesToAdd)
throws URISyntaxException, LocalStorageException, IOException, HttpException, DavException {
int count = 0;
Log.i(TAG, "Fetching " + resourcesToAdd.length + " new remote resource(s)");
for (Resource[] resources : ArrayUtils.partition(resourcesToAdd, MAX_MULTIGET_RESOURCES))
for (Resource res : remote.multiGet(resources)) {
Log.d(TAG, "Adding " + res.getName());
local.add(res);
local.commit();
count++;
}
return count;
}