public static Database buildsecondary(Database std) {
// Parse database loaded
try {
io.deleteFile("secondarydb");
// SecondaryDatabases started
DatabaseConfig dbConfig = new DatabaseConfig();
dbConfig.setType(DatabaseType.HASH);
dbConfig.setAllowCreate(true);
dbConfig.setUnsortedDuplicates(true);
Database secdb = new Database("secondarydb", null, dbConfig);
// Cursors started
Cursor stdcursor = std.openCursor(null, null);
Cursor secdbcursor = secdb.openCursor(null, null);
// Key and Data started
DatabaseEntry stdkey = new DatabaseEntry();
DatabaseEntry stddata = new DatabaseEntry();
DatabaseEntry seckey = new DatabaseEntry();
DatabaseEntry secdata = new DatabaseEntry();
while (stdcursor.getNext(stdkey, stddata, LockMode.DEFAULT)
== OperationStatus.SUCCESS) { // Writing into secondary db
String[] key = new String(stdkey.getData()).split(",");
String data = new String(stddata.getData());
// DEBUG:
// System.out.println("key 0:" + key[0] + " key 1:" + key[1] + " data:" + data);
seckey.setData(key[1].getBytes());
OperationStatus operation = secdbcursor.getSearchKey(seckey, secdata, LockMode.DEFAULT);
String b = null;
while (operation == OperationStatus.SUCCESS) {
b = new String(secdata.getData());
secdbcursor.delete();
operation = secdbcursor.getNextDup(seckey, secdata, LockMode.DEFAULT);
}
if (b == null) {
seckey.setData(key[1].getBytes());
secdata.setData(("(" + key[0] + "," + data + ")").getBytes());
secdb.put(null, seckey, secdata);
}
if (b != null) {
secdata.setData(b.concat("(" + key[0] + "," + data + ")").getBytes());
secdb.put(null, seckey, secdata);
}
seckey.setData(null);
secdata.setData(null);
stdkey.setData(null);
stddata.setData(null);
}
// io.debugread(secdb);
return secdb;
} catch (Exception e) {
System.out.println("Error creating <user>,<song,rating> secondary table!\n");
System.out.println(e.getMessage());
}
return null; // SHOULD NEVER HAPPEN
}
public void delete(int count) throws DatabaseException {
synchronized (mutex) {
int matches = 0;
Cursor cursor = null;
OperationStatus result;
DatabaseEntry key = new DatabaseEntry();
DatabaseEntry value = new DatabaseEntry();
Transaction txn;
if (resumable) {
txn = env.beginTransaction(null, null);
} else {
txn = null;
}
try {
cursor = urlsDB.openCursor(txn, null);
result = cursor.getFirst(key, value, null);
while (matches < count && result == OperationStatus.SUCCESS) {
cursor.delete();
matches++;
result = cursor.getNext(key, value, null);
}
} catch (DatabaseException e) {
if (txn != null) {
txn.abort();
txn = null;
}
throw e;
} finally {
if (cursor != null) {
cursor.close();
}
if (txn != null) {
txn.commit();
}
}
}
}
public static String top3(String line, Database secdb, Database tdb)
throws DatabaseException, FileNotFoundException {
// configure sqSum db for keeping track of cumulative squaresums
io.deleteFile("sqSumdb");
DatabaseConfig dbConfig = new DatabaseConfig();
dbConfig.setType(DatabaseType.HASH);
dbConfig.setAllowCreate(true);
dbConfig.setUnsortedDuplicates(true);
Database sqSumdb = new Database("sqSumdb", null, dbConfig);
Cursor sqSumCurs = sqSumdb.openCursor(null, null);
DatabaseEntry sqSumKey = new DatabaseEntry();
DatabaseEntry sqSumData = new DatabaseEntry();
Cursor secCurs = secdb.openCursor(null, null);
Cursor tCurs = tdb.openCursor(null, null);
DatabaseEntry secKey = new DatabaseEntry();
DatabaseEntry secData = new DatabaseEntry();
DatabaseEntry tKey = new DatabaseEntry();
DatabaseEntry tData = new DatabaseEntry();
// get input song users and ratings
tKey.setData(line.getBytes());
if (tCurs.getSearchKey(tKey, tData, LockMode.DEFAULT) == OperationStatus.SUCCESS) {
// for each user in input song, get songs and ratings
HashMap<String, String> iRatings = parseBrace(new String(tData.getData()));
for (String user : iRatings.keySet()) {
// get current user's rating for input song
int inputRating = Integer.parseInt(iRatings.get(user));
// get songs and ratings for user
secKey.setData(null);
secData.setData(null);
secKey.setData(user.getBytes());
if (secCurs.getSearchKey(secKey, secData, null) == OperationStatus.SUCCESS) {
// for each song rated by user
HashMap<String, String> currSongs = parseBrace(new String(secData.getData()));
for (String song : currSongs.keySet()) {
// input song should not be compared to itself, otherwise get the users and ratings for
// it
if (song.equals(line)) continue;
// current user's rating for song under inspection
int songRating = Integer.parseInt(currSongs.get(song));
sqSumKey.setData(null);
sqSumData.setData(null);
sqSumKey.setData(song.getBytes());
if (sqSumCurs.getSearchKey(sqSumKey, sqSumData, null) == OperationStatus.SUCCESS) {
// if song is already in sqSum,N db, add to it
String[] sumN = (new String(sqSumData.getData())).split(",");
// add the new square sum to the previous and increment N
int sum = Integer.parseInt(sumN[0]);
int N = Integer.parseInt(sumN[1]);
sum += (inputRating - songRating) * (inputRating - songRating);
N += 1;
String encoded = Integer.toString(sum) + "," + Integer.toString(N);
// remove old entry for current song and replace it with the new one
sqSumCurs.delete();
sqSumKey.setData(null);
sqSumData.setData(null);
sqSumKey.setData(song.getBytes());
sqSumData.setData(encoded.getBytes());
sqSumdb.put(null, sqSumKey, sqSumData);
} else {
// if song in not already in sqSum,N db, create it
int sum = (inputRating - songRating) * (inputRating - songRating);
int N = 1;
String encoded = Integer.toString(sum) + "," + Integer.toString(N);
sqSumKey.setData(null);
sqSumData.setData(null);
sqSumKey.setData(song.getBytes());
sqSumData.setData(encoded.getBytes());
sqSumdb.put(null, sqSumKey, sqSumData);
}
}
} else {
System.out.println("ERROR: user " + user + " not in secondary database.");
}
}
} else {
return line + " has not been rated by any user.";
}
// DEBUG
// io.debugread(sqSumdb);
// calculate distance for each song in, inserting into the top 3 spots as we iterate through
String ranked = rank(sqSumdb);
return line + ", " + ranked;
}
@Test
public void testOpenReadOnly() throws Throwable {
try {
EnvironmentConfig envConfig = TestUtils.initEnvConfig();
envConfig.setTransactional(true);
envConfig.setAllowCreate(true);
env = create(envHome, envConfig);
DatabaseEntry key = new DatabaseEntry();
DatabaseEntry data = new DatabaseEntry();
Transaction txn = env.beginTransaction(null, null);
DatabaseConfig dbConfig = new DatabaseConfig();
dbConfig.setTransactional(true);
dbConfig.setAllowCreate(true);
Database myDb = env.openDatabase(txn, "testDB2", dbConfig);
key.setData(TestUtils.getTestArray(0));
data.setData(TestUtils.getTestArray(0));
try {
myDb.put(txn, key, data);
} catch (DatabaseException DBE) {
fail("unexpected DatabaseException during put");
}
txn.commit();
myDb.close();
dbConfig = new DatabaseConfig();
dbConfig.setTransactional(true);
dbConfig.setReadOnly(true);
txn = env.beginTransaction(null, null);
myDb = env.openDatabase(txn, "testDB2", dbConfig);
assertTrue(myDb.isTransactional());
assertTrue(myDb.getConfig().getTransactional());
key.setData(TestUtils.getTestArray(0));
data.setData(TestUtils.getTestArray(0));
try {
myDb.put(txn, key, data);
fail("expected UnsupportedOperationException " + "because open RDONLY");
} catch (UnsupportedOperationException expected) {
}
key.setData(TestUtils.getTestArray(0));
data.setData(TestUtils.getTestArray(0));
assertEquals(OperationStatus.SUCCESS, myDb.get(txn, key, data, LockMode.DEFAULT));
Cursor cursor = myDb.openCursor(txn, null);
assertEquals(OperationStatus.SUCCESS, cursor.getFirst(key, data, LockMode.DEFAULT));
try {
cursor.delete();
fail("expected Exception from delete on RD_ONLY db");
} catch (UnsupportedOperationException e) {
}
key.setData(TestUtils.getTestArray(1));
data.setData(TestUtils.getTestArray(1));
try {
myDb.put(txn, key, data);
fail("expected UnsupportedOperationException because open RDONLY");
} catch (UnsupportedOperationException expected) {
}
cursor.close();
txn.commit();
myDb.close();
close(env);
} catch (Throwable t) {
t.printStackTrace();
throw t;
}
}
