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#include "messagequeue.h"
#include "storage.h"
#include <QDebug>
#include <log.h>
SINK_DEBUG_AREA("messagequeue")
MessageQueue::MessageQueue(const QString &storageRoot, const QString &name) : mStorage(storageRoot, name, Sink::Storage::DataStore::ReadWrite)
{
}
MessageQueue::~MessageQueue()
{
if (mWriteTransaction) {
mWriteTransaction.abort();
}
}
void MessageQueue::enqueue(void const *msg, size_t size)
{
enqueue(QByteArray::fromRawData(static_cast<const char *>(msg), size));
}
void MessageQueue::startTransaction()
{
if (mWriteTransaction) {
return;
}
processRemovals();
mWriteTransaction = mStorage.createTransaction(Sink::Storage::DataStore::ReadWrite);
}
void MessageQueue::commit()
{
mWriteTransaction.commit();
mWriteTransaction = Sink::Storage::DataStore::Transaction();
processRemovals();
emit messageReady();
}
void MessageQueue::enqueue(const QByteArray &value)
{
bool implicitTransaction = false;
if (!mWriteTransaction) {
implicitTransaction = true;
startTransaction();
}
const qint64 revision = Sink::Storage::DataStore::maxRevision(mWriteTransaction) + 1;
const QByteArray key = QString("%1").arg(revision).toUtf8();
mWriteTransaction.openDatabase().write(key, value);
Sink::Storage::DataStore::setMaxRevision(mWriteTransaction, revision);
if (implicitTransaction) {
commit();
}
}
void MessageQueue::processRemovals()
{
if (mWriteTransaction) {
return;
}
auto transaction = mStorage.createTransaction(Sink::Storage::DataStore::ReadWrite);
for (const auto &key : mPendingRemoval) {
transaction.openDatabase().remove(key);
}
transaction.commit();
mPendingRemoval.clear();
}
void MessageQueue::dequeue(const std::function<void(void *ptr, int size, std::function<void(bool success)>)> &resultHandler, const std::function<void(const Error &error)> &errorHandler)
{
dequeueBatch(1, [resultHandler](const QByteArray &value) {
return KAsync::start<void>([&value, resultHandler](KAsync::Future<void> &future) {
resultHandler(const_cast<void *>(static_cast<const void *>(value.data())), value.size(), [&future](bool success) { future.setFinished(); });
});
}).onError([errorHandler](const KAsync::Error &error) { errorHandler(Error("messagequeue", error.errorCode, error.errorMessage.toLatin1())); }).exec();
}
KAsync::Job<void> MessageQueue::dequeueBatch(int maxBatchSize, const std::function<KAsync::Job<void>(const QByteArray &)> &resultHandler)
{
auto resultCount = QSharedPointer<int>::create(0);
return KAsync::start<void>([this, maxBatchSize, resultHandler, resultCount](KAsync::Future<void> &future) {
int count = 0;
QList<KAsync::Future<void>> waitCondition;
mStorage.createTransaction(Sink::Storage::DataStore::ReadOnly)
.openDatabase()
.scan("",
[this, resultHandler, resultCount, &count, maxBatchSize, &waitCondition](const QByteArray &key, const QByteArray &value) -> bool {
if (mPendingRemoval.contains(key)) {
return true;
}
*resultCount += 1;
// We need a copy of the key here, otherwise we can't store it in the lambda (the pointers will become invalid)
mPendingRemoval << QByteArray(key.constData(), key.size());
waitCondition << resultHandler(value).exec();
count++;
if (count < maxBatchSize) {
return true;
}
return false;
},
[](const Sink::Storage::DataStore::Error &error) {
SinkError() << "Error while retrieving value" << error.message;
// errorHandler(Error(error.store, error.code, error.message));
});
// Trace() << "Waiting on " << waitCondition.size() << " results";
KAsync::waitForCompletion(waitCondition)
.then([this, resultCount, &future]() {
processRemovals();
if (*resultCount == 0) {
future.setFinished();
} else {
if (isEmpty()) {
emit this->drained();
}
future.setFinished();
}
})
.exec();
});
}
bool MessageQueue::isEmpty()
{
int count = 0;
auto t = mStorage.createTransaction(Sink::Storage::DataStore::ReadOnly);
auto db = t.openDatabase();
if (db) {
db.scan("",
[&count, this](const QByteArray &key, const QByteArray &value) -> bool {
if (!mPendingRemoval.contains(key)) {
count++;
return false;
}
return true;
},
[](const Sink::Storage::DataStore::Error &error) { SinkError() << "Error while checking if empty" << error.message; });
}
return count == 0;
}
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundefined-reinterpret-cast"
#include "moc_messagequeue.cpp"
#pragma clang diagnostic pop
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