/*
* nheko Copyright (C) 2017 Konstantinos Sideris <siderisk@auth.gr>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdexcept>
#include <QDebug>
#include <QFile>
#include <QStandardPaths>
#include "Cache.h"
#include "RoomState.h"
static const lmdb::val NEXT_BATCH_KEY("next_batch");
static const lmdb::val transactionID("transaction_id");
Cache::Cache(const QString &userId)
: env_{nullptr}
, stateDb_{0}
, roomDb_{0}
, isMounted_{false}
, userId_{userId}
{}
void
Cache::setup()
{
qDebug() << "Setting up cache";
auto statePath = QString("%1/%2/state")
.arg(QStandardPaths::writableLocation(QStandardPaths::CacheLocation))
.arg(QString::fromUtf8(userId_.toUtf8().toHex()));
cacheDirectory_ = QString("%1/%2")
.arg(QStandardPaths::writableLocation(QStandardPaths::CacheLocation))
.arg(QString::fromUtf8(userId_.toUtf8().toHex()));
bool isInitial = !QFile::exists(statePath);
env_ = lmdb::env::create();
env_.set_mapsize(128UL * 1024UL * 1024UL); /* 128 MB */
env_.set_max_dbs(1024UL);
if (isInitial) {
qDebug() << "First time initializing LMDB";
if (!QDir().mkpath(statePath)) {
throw std::runtime_error(
("Unable to create state directory:" + statePath).toStdString().c_str());
}
}
try {
env_.open(statePath.toStdString().c_str());
} catch (const lmdb::error &e) {
if (e.code() != MDB_VERSION_MISMATCH && e.code() != MDB_INVALID) {
throw std::runtime_error("LMDB initialization failed" +
std::string(e.what()));
}
qWarning() << "Resetting cache due to LMDB version mismatch:" << e.what();
QDir stateDir(statePath);
for (const auto &file : stateDir.entryList(QDir::NoDotAndDotDot)) {
if (!stateDir.remove(file))
throw std::runtime_error(
("Unable to delete file " + file).toStdString().c_str());
}
env_.open(statePath.toStdString().c_str());
}
auto txn = lmdb::txn::begin(env_);
stateDb_ = lmdb::dbi::open(txn, "state", MDB_CREATE);
roomDb_ = lmdb::dbi::open(txn, "rooms", MDB_CREATE);
txn.commit();
isMounted_ = true;
}
void
Cache::setState(const QString &nextBatchToken, const QMap<QString, RoomState> &states)
{
if (!isMounted_)
return;
try {
auto txn = lmdb::txn::begin(env_);
setNextBatchToken(txn, nextBatchToken);
for (auto it = states.constBegin(); it != states.constEnd(); ++it)
insertRoomState(txn, it.key(), it.value());
txn.commit();
} catch (const lmdb::error &e) {
qCritical() << "The cache couldn't be updated: " << e.what();
unmount();
deleteData();
}
}
void
Cache::insertRoomState(lmdb::txn &txn, const QString &roomid, const RoomState &state)
{
auto stateEvents = state.serialize();
auto id = roomid.toUtf8();
lmdb::dbi_put(txn, roomDb_, lmdb::val(id.data(), id.size()), lmdb::val(stateEvents));
for (const auto &membership : state.memberships) {
lmdb::dbi membersDb =
lmdb::dbi::open(txn, roomid.toStdString().c_str(), MDB_CREATE);
// The user_id this membership event relates to, is used
// as the index on the membership database.
auto key = membership.second.state_key;
// Serialize membership event.
nlohmann::json data = membership.second;
std::string memberEvent = data.dump();
switch (membership.second.content.membership) {
// We add or update (e.g invite -> join) a new user to the membership
// list.
case mtx::events::state::Membership::Invite:
case mtx::events::state::Membership::Join: {
lmdb::dbi_put(txn, membersDb, lmdb::val(key), lmdb::val(memberEvent));
break;
}
// We remove the user from the membership list.
case mtx::events::state::Membership::Leave:
case mtx::events::state::Membership::Ban: {
lmdb::dbi_del(txn, membersDb, lmdb::val(key), lmdb::val(memberEvent));
break;
}
case mtx::events::state::Membership::Knock: {
qWarning()
<< "Skipping knock membership" << roomid << QString::fromStdString(key);
break;
}
}
}
}
void
Cache::removeRoom(const QString &roomid)
{
if (!isMounted_)
return;
auto txn = lmdb::txn::begin(env_, nullptr, 0);
lmdb::dbi_del(txn, roomDb_, lmdb::val(roomid.toUtf8(), roomid.toUtf8().size()), nullptr);
txn.commit();
}
QMap<QString, RoomState>
Cache::states()
{
QMap<QString, RoomState> states;
auto txn = lmdb::txn::begin(env_, nullptr, MDB_RDONLY);
auto cursor = lmdb::cursor::open(txn, roomDb_);
std::string room;
std::string stateData;
// Retrieve all the room names.
while (cursor.get(room, stateData, MDB_NEXT)) {
auto roomid = QString::fromUtf8(room.data(), room.size());
auto json = nlohmann::json::parse(stateData);
RoomState state;
state.parse(json);
auto memberDb = lmdb::dbi::open(txn, roomid.toStdString().c_str(), MDB_CREATE);
std::map<std::string, mtx::events::StateEvent<mtx::events::state::Member>> members;
auto memberCursor = lmdb::cursor::open(txn, memberDb);
std::string memberId;
std::string memberContent;
while (memberCursor.get(memberId, memberContent, MDB_NEXT)) {
auto userid = QString::fromStdString(memberId);
try {
auto data = nlohmann::json::parse(memberContent);
mtx::events::StateEvent<mtx::events::state::Member> member = data;
members.emplace(memberId, member);
} catch (std::exception &e) {
qWarning() << "Fault while parsing member event" << e.what()
<< QString::fromStdString(memberContent);
continue;
}
}
qDebug() << members.size() << "members for" << roomid;
state.memberships = members;
states.insert(roomid, state);
}
qDebug() << "Retrieved" << states.size() << "rooms";
cursor.close();
txn.commit();
return states;
}
void
Cache::setNextBatchToken(lmdb::txn &txn, const QString &token)
{
auto value = token.toUtf8();
lmdb::dbi_put(txn, stateDb_, NEXT_BATCH_KEY, lmdb::val(value.data(), value.size()));
}
bool
Cache::isInitialized() const
{
auto txn = lmdb::txn::begin(env_, nullptr, MDB_RDONLY);
lmdb::val token;
bool res = lmdb::dbi_get(txn, stateDb_, NEXT_BATCH_KEY, token);
txn.commit();
return res;
}
QString
Cache::nextBatchToken() const
{
auto txn = lmdb::txn::begin(env_, nullptr, MDB_RDONLY);
lmdb::val token;
lmdb::dbi_get(txn, stateDb_, NEXT_BATCH_KEY, token);
txn.commit();
return QString::fromUtf8(token.data(), token.size());
}
void
Cache::deleteData()
{
qInfo() << "Deleting cache data";
if (!cacheDirectory_.isEmpty())
QDir(cacheDirectory_).removeRecursively();
}