@Override
public void readExtraCommitData(byte[] extra) throws IOException {
try {
mHeaderLatch.acquireShared();
try {
readPartial(mCommitNumber & 1, I_EXTRA_DATA, extra, 0, extra.length);
} finally {
mHeaderLatch.releaseShared();
}
} catch (Throwable e) {
throw closeOnFailure(e);
}
}
/** @see _SnapshotPageArray#beginSnapshot */
Snapshot beginSnapshot(_LocalDatabase db) throws IOException {
mHeaderLatch.acquireShared();
try {
long pageCount, redoPos;
long header = p_alloc(MINIMUM_PAGE_SIZE);
try {
mPageArray.readPage(mCommitNumber & 1, header, 0, MINIMUM_PAGE_SIZE);
pageCount = _PageManager.readTotalPageCount(header, I_MANAGER_HEADER);
redoPos = _LocalDatabase.readRedoPosition(header, I_EXTRA_DATA);
} finally {
p_delete(header);
}
return mPageArray.beginSnapshot(db, pageCount, redoPos);
} finally {
mHeaderLatch.releaseShared();
}
}
@Override
public void commit(boolean resume, long header, final CommitCallback callback)
throws IOException {
// Acquire a shared lock to prevent concurrent commits after callback has released
// exclusive lock.
CommitLock.Shared shared = mCommitLock.acquireShared();
try {
mHeaderLatch.acquireShared();
final int commitNumber = mCommitNumber + 1;
mHeaderLatch.releaseShared();
try {
if (!resume) {
mPageManager.commitStart(header, I_MANAGER_HEADER);
}
if (callback != null) {
// Invoke the callback to ensure all dirty pages get written.
callback.prepare(resume, header);
}
} catch (DatabaseException e) {
if (e.isRecoverable()) {
throw e;
} else {
throw closeOnFailure(e);
}
}
try {
commitHeader(header, commitNumber);
mPageManager.commitEnd(header, I_MANAGER_HEADER);
} catch (Throwable e) {
throw closeOnFailure(e);
}
} finally {
shared.release();
}
}