/*
* Copyright 2013, Matt Brozowski and Eric Evans
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.opennms.twissandra.persistence.cassandra.internal;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.UUID;
import org.opennms.twissandra.api.Tweet;
import org.opennms.twissandra.api.TweetRepository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.utils.UUIDs;
public class CassandraTweetRepository implements TweetRepository {
private static final String PUBLIC_USERLINE_KEY = "!PUBLIC!";
private static final Logger LOG = LoggerFactory.getLogger(CassandraTweetRepository.class);
private final String m_cassandraHost;
private final int m_cassandraPort;
private final String m_keyspaceName;
private final Cluster cluster;
private final Session session;
public CassandraTweetRepository(String cassandraHost, int cassandraPort, String keyspaceName) {
m_cassandraHost = cassandraHost;
m_cassandraPort = cassandraPort;
m_keyspaceName = keyspaceName;
LOG.info("Connecting to {}:{}...", cassandraHost, cassandraPort);
cluster = Cluster.builder().withPort(m_cassandraPort).addContactPoint(m_cassandraHost).build();
session = cluster.connect(m_keyspaceName);
LOG.info("Connected.");
}
public String getPassword(String username) {
ResultSet queryResult = execute("SELECT password FROM users WHERE username = '%s'", username);
Row row = getOneRow(queryResult);
return row != null ? row.getString("password") : null;
}
public List<String> getFriends(String username) {
ResultSet queryResult = execute("SELECT followed FROM following WHERE username = '%s'", username);
List<String> friends = new ArrayList<String>();
for (Row row : queryResult)
friends.add(row.getString("followed"));
return friends;
}
public List<String> getFollowers(String username) {
ResultSet queryResult = execute("SELECT following FROM followers WHERE username = '%s'", username);
List<String> followers = new ArrayList<String>();
for (Row row : queryResult)
followers.add(row.getString("following"));
return followers;
}
/** {@inheritDoc} */
public List<Tweet> getUserline(String username, Date start, int limit) {
ResultSet queryResult = execute(
"SELECT tweetid, body FROM userline WHERE username = '%s' AND tweetid < maxTimeuuid('%d') ORDER BY tweetid DESC LIMIT %d",
username,
start.getTime(),
limit);
List<Tweet> tweets = new ArrayList<Tweet>();
for (Row row : queryResult) {
UUID id = row.getUUID("tweetid");
tweets.add(new Tweet(username, row.getString("body"), id, fromUUID1(id)));
}
return tweets;
}
/** {@inheritDoc} */
public List<Tweet> getTimeline(String username, Date start, int limit) {
ResultSet queryResult = execute(
"SELECT tweetid, posted_by, body FROM timeline WHERE username = '%s' AND tweetid < maxTimeuuid('%d') ORDER BY tweetid DESC LIMIT %d",
username,
start.getTime(),
limit);
List<Tweet> tweets = new ArrayList<Tweet>();
for (Row row : queryResult) {
UUID id = row.getUUID("tweetid");
tweets.add(new Tweet(row.getString("posted_by"), row.getString("body"), id, fromUUID1(id)));
}
return tweets;
}
public List<Tweet> getTweets(Date start, int limit) {
return getTimeline(PUBLIC_USERLINE_KEY, start, limit);
}
public Tweet getTweet(UUID id) {
Row row = getOneRow(execute("SELECT username, body FROM tweets WHERE tweetid = %s", id.toString()));
return row != null ? new Tweet(row.getString("username"), row.getString("body"), id, fromUUID1(id)) : null;
}
public void saveUser(String username, String password) {
execute("INSERT INTO users (username, password) VALUES ('%s', '%s')", username , password);
}
public Tweet saveTweet(String username, String body) {
UUID id = UUIDs.timeBased();
// Create the tweet in the tweets cf
execute("INSERT INTO tweets (tweetid, username, body) VALUES (%s, '%s', '%s')",
id.toString(),
username,
body);
// Store the tweet in this users userline
execute("INSERT INTO userline (username, tweetid, body) VALUES ('%s', %s, '%s')",
username,
id.toString(),
body);
// Store the tweet in this users timeline
execute("INSERT INTO timeline (username, tweetid, posted_by, body) VALUES ('%s', %s, '%s', '%s')",
username,
id.toString(),
username,
body);
// Store the tweet in the public timeline
execute("INSERT INTO timeline (username, tweetid, posted_by, body) VALUES ('%s', %s, '%s', '%s')",
PUBLIC_USERLINE_KEY,
id.toString(),
username,
body);
// Insert the tweet into follower timelines
for (String follower : getFollowers(username)) {
execute("INSERT INTO timeline (username, tweetid, posted_by, body) VALUES ('%s', %s, '%s', '%s')",
follower,
id.toString(),
username,
body);
}
return new Tweet(username, body, id, fromUUID1(id));
}
public void addFriend(String username, String friend) {
if (username.equals(friend)) {
LOG.warn("Attempted to self-friend {} (no self-loving here, please).", username);
return;
}
execute("INSERT INTO following (username, followed) VALUES ('%s', '%s')", username, friend);
execute("INSERT INTO followers (username, following) VALUES ('%s', '%s')", friend, username);
}
public void removeFriend(String username, String friend) {
execute("DELETE FROM following WHERE username = '%s' AND followed = '%s'", username, friend);
execute("DELETE FROM followers WHERE username = '%s' AND following = '%s'", friend, username);
}
private Row getOneRow(ResultSet result) {
Row row = result.one();
if (!result.isExhausted())
throw new RuntimeException("ResultSet instance contained more than one row!");
return row;
}
private ResultSet execute(String query, Object...parms) {
String cql = String.format(query, parms);
LOG.debug("Executing CQL: {}", cql);
return session.execute(cql);
}
private Date fromUUID1(UUID uuid) {
assert uuid.version() == 1;
return new Date((uuid.timestamp() / 10000) + -12219292800000L); // -12219292800000L is the start epoch
}
}
