mirror of
https://code.briarproject.org/briar/briar.git
synced 2026-02-12 18:59:06 +01:00
Initial commit with new directory structure.
This commit is contained in:
akwizgran
209
components/net/sf/briar/db/DatabaseComponentImpl.java
Normal file
209
components/net/sf/briar/db/DatabaseComponentImpl.java
Normal file
@@ -0,0 +1,209 @@
|
||||
package net.sf.briar.db;
|
||||
|
||||
import net.sf.briar.api.db.DatabaseComponent;
|
||||
import net.sf.briar.api.db.DbException;
|
||||
import net.sf.briar.api.db.NeighbourId;
|
||||
import net.sf.briar.api.db.Rating;
|
||||
import net.sf.briar.api.db.Status;
|
||||
import net.sf.briar.api.protocol.AuthorId;
|
||||
import net.sf.briar.api.protocol.Batch;
|
||||
import net.sf.briar.api.protocol.Message;
|
||||
import net.sf.briar.api.protocol.MessageId;
|
||||
|
||||
import com.google.inject.Provider;
|
||||
|
||||
abstract class DatabaseComponentImpl<Txn> implements DatabaseComponent {
|
||||
|
||||
protected final Database<Txn> db;
|
||||
protected final Provider<Batch> batchProvider;
|
||||
|
||||
private final Object spaceLock = new Object();
|
||||
private final Object writeLock = new Object();
|
||||
private long bytesStoredSinceLastCheck = 0L; // Locking: spaceLock
|
||||
private long timeOfLastCheck = 0L; // Locking: spaceLock
|
||||
private volatile boolean writesAllowed = true;
|
||||
|
||||
DatabaseComponentImpl(Database<Txn> db, Provider<Batch> batchProvider) {
|
||||
this.db = db;
|
||||
this.batchProvider = batchProvider;
|
||||
startCleaner();
|
||||
}
|
||||
|
||||
protected abstract void expireMessages(long size) throws DbException;
|
||||
|
||||
// Locking: messages write
|
||||
private int calculateSendability(Txn txn, Message m) throws DbException {
|
||||
int sendability = 0;
|
||||
// One point for a good rating
|
||||
if(getRating(m.getAuthor()) == Rating.GOOD) sendability++;
|
||||
// One point per sendable child (backward inclusion)
|
||||
for(MessageId kid : db.getMessagesByParent(txn, m.getId())) {
|
||||
Integer kidSendability = db.getSendability(txn, kid);
|
||||
assert kidSendability != null;
|
||||
if(kidSendability > 0) sendability++;
|
||||
}
|
||||
return sendability;
|
||||
}
|
||||
|
||||
private void checkFreeSpaceAndClean() throws DbException {
|
||||
long freeSpace = db.getFreeSpace();
|
||||
while(freeSpace < MIN_FREE_SPACE) {
|
||||
// If disk space is critical, disable the storage of new messages
|
||||
if(freeSpace < CRITICAL_FREE_SPACE) {
|
||||
System.out.println("Critical cleanup");
|
||||
writesAllowed = false;
|
||||
} else {
|
||||
System.out.println("Normal cleanup");
|
||||
}
|
||||
expireMessages(BYTES_PER_SWEEP);
|
||||
Thread.yield();
|
||||
freeSpace = db.getFreeSpace();
|
||||
// If disk space is no longer critical, re-enable writes
|
||||
if(freeSpace >= CRITICAL_FREE_SPACE && !writesAllowed) {
|
||||
writesAllowed = true;
|
||||
synchronized(writeLock) {
|
||||
writeLock.notifyAll();
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Locking: messages write, neighbours write
|
||||
protected void removeMessage(Txn txn, MessageId id) throws DbException {
|
||||
Integer sendability = db.getSendability(txn, id);
|
||||
assert sendability != null;
|
||||
if(sendability > 0) updateAncestorSendability(txn, id, false);
|
||||
db.removeMessage(txn, id);
|
||||
}
|
||||
|
||||
private boolean shouldCheckFreeSpace() {
|
||||
synchronized(spaceLock) {
|
||||
long now = System.currentTimeMillis();
|
||||
if(bytesStoredSinceLastCheck > MAX_BYTES_BETWEEN_SPACE_CHECKS) {
|
||||
System.out.println(bytesStoredSinceLastCheck
|
||||
+ " bytes stored since last check");
|
||||
bytesStoredSinceLastCheck = 0L;
|
||||
timeOfLastCheck = now;
|
||||
return true;
|
||||
}
|
||||
if(now - timeOfLastCheck > MAX_MS_BETWEEN_SPACE_CHECKS) {
|
||||
System.out.println((now - timeOfLastCheck)
|
||||
+ " ms since last check");
|
||||
bytesStoredSinceLastCheck = 0L;
|
||||
timeOfLastCheck = now;
|
||||
return true;
|
||||
}
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
private void startCleaner() {
|
||||
Runnable cleaner = new Runnable() {
|
||||
public void run() {
|
||||
try {
|
||||
while(true) {
|
||||
if(shouldCheckFreeSpace()) {
|
||||
checkFreeSpaceAndClean();
|
||||
} else {
|
||||
try {
|
||||
Thread.sleep(CLEANER_SLEEP_MS);
|
||||
} catch(InterruptedException ignored) {}
|
||||
}
|
||||
}
|
||||
} catch(Throwable t) {
|
||||
// FIXME: Work out what to do here
|
||||
t.printStackTrace();
|
||||
System.exit(1);
|
||||
}
|
||||
}
|
||||
};
|
||||
new Thread(cleaner).start();
|
||||
}
|
||||
|
||||
// Locking: messages write, neighbours write
|
||||
protected boolean storeMessage(Txn txn, Message m, NeighbourId sender)
|
||||
throws DbException {
|
||||
boolean added = db.addMessage(txn, m);
|
||||
// Mark the message as seen by the sender
|
||||
MessageId id = m.getId();
|
||||
if(sender != null) db.setStatus(txn, sender, id, Status.SEEN);
|
||||
if(added) {
|
||||
// Mark the message as unseen by other neighbours
|
||||
for(NeighbourId n : db.getNeighbours(txn)) {
|
||||
if(!n.equals(sender)) db.setStatus(txn, n, id, Status.NEW);
|
||||
}
|
||||
// Calculate and store the message's sendability
|
||||
int sendability = calculateSendability(txn, m);
|
||||
db.setSendability(txn, id, sendability);
|
||||
if(sendability > 0) updateAncestorSendability(txn, id, true);
|
||||
// Count the bytes stored
|
||||
synchronized(spaceLock) {
|
||||
bytesStoredSinceLastCheck += m.getSize();
|
||||
}
|
||||
}
|
||||
return added;
|
||||
}
|
||||
|
||||
// Locking: messages write
|
||||
private int updateAncestorSendability(Txn txn, MessageId m,
|
||||
boolean increment) throws DbException {
|
||||
int affected = 0;
|
||||
boolean changed = true;
|
||||
while(changed) {
|
||||
MessageId parent = db.getParent(txn, m);
|
||||
if(parent.equals(MessageId.NONE)) break;
|
||||
if(!db.containsMessage(txn, parent)) break;
|
||||
Integer parentSendability = db.getSendability(txn, parent);
|
||||
assert parentSendability != null;
|
||||
if(increment) {
|
||||
parentSendability++;
|
||||
changed = parentSendability == 1;
|
||||
if(changed) affected++;
|
||||
} else {
|
||||
assert parentSendability > 0;
|
||||
parentSendability--;
|
||||
changed = parentSendability == 0;
|
||||
if(changed) affected++;
|
||||
}
|
||||
db.setSendability(txn, parent, parentSendability);
|
||||
m = parent;
|
||||
}
|
||||
return affected;
|
||||
}
|
||||
|
||||
// Locking: messages write
|
||||
protected void updateAuthorSendability(Txn txn, AuthorId a,
|
||||
boolean increment) throws DbException {
|
||||
int direct = 0, indirect = 0;
|
||||
for(MessageId id : db.getMessagesByAuthor(txn, a)) {
|
||||
int sendability = db.getSendability(txn, id);
|
||||
if(increment) {
|
||||
db.setSendability(txn, id, sendability + 1);
|
||||
if(sendability == 0) {
|
||||
direct++;
|
||||
indirect += updateAncestorSendability(txn, id, true);
|
||||
}
|
||||
} else {
|
||||
assert sendability > 0;
|
||||
db.setSendability(txn, id, sendability - 1);
|
||||
if(sendability == 1) {
|
||||
direct++;
|
||||
indirect += updateAncestorSendability(txn, id, false);
|
||||
}
|
||||
}
|
||||
}
|
||||
System.out.println(direct + " messages affected directly, "
|
||||
+ indirect + " indirectly");
|
||||
}
|
||||
|
||||
protected void waitForPermissionToWrite() {
|
||||
synchronized(writeLock) {
|
||||
while(!writesAllowed) {
|
||||
System.out.println("Waiting for permission to write");
|
||||
try {
|
||||
writeLock.wait();
|
||||
} catch(InterruptedException ignored) {}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user