Examples with Promise com.twitter.util.Promise used on opensource projects

Example 6 with Promise

use of com.twitter.util.Promise in project distributedlog by twitter.

the class TestEntry method testWriteRecords.

@Test(timeout = 20000)
public void testWriteRecords() throws Exception {
    Writer writer = Entry.newEntry("test-write-records", 1024, true, CompressionCodec.Type.NONE, NullStatsLogger.INSTANCE);
    assertEquals("zero bytes", 0, writer.getNumBytes());
    assertEquals("zero records", 0, writer.getNumRecords());
    List<Future<DLSN>> writePromiseList = Lists.newArrayList();
    // write first 5 records
    for (int i = 0; i < 5; i++) {
        LogRecord record = new LogRecord(i, ("record-" + i).getBytes(UTF_8));
        record.setPositionWithinLogSegment(i);
        Promise<DLSN> writePromise = new Promise<DLSN>();
        writer.writeRecord(record, writePromise);
        writePromiseList.add(writePromise);
        assertEquals((i + 1) + " records", (i + 1), writer.getNumRecords());
    }
    // write large record
    LogRecord largeRecord = new LogRecord(1L, new byte[MAX_LOGRECORD_SIZE + 1]);
    try {
        writer.writeRecord(largeRecord, new Promise<DLSN>());
        Assert.fail("Should fail on writing large record");
    } catch (LogRecordTooLongException lrtle) {
    // expected
    }
    assertEquals("5 records", 5, writer.getNumRecords());
    // write another 5 records
    for (int i = 0; i < 5; i++) {
        LogRecord record = new LogRecord(i + 5, ("record-" + (i + 5)).getBytes(UTF_8));
        record.setPositionWithinLogSegment(i + 5);
        Promise<DLSN> writePromise = new Promise<DLSN>();
        writer.writeRecord(record, writePromise);
        writePromiseList.add(writePromise);
        assertEquals((i + 6) + " records", (i + 6), writer.getNumRecords());
    }
    Buffer buffer = writer.getBuffer();
    // Test transmit complete
    writer.completeTransmit(1L, 1L);
    List<DLSN> writeResults = Await.result(Future.collect(writePromiseList));
    for (int i = 0; i < 10; i++) {
        Assert.assertEquals(new DLSN(1L, 1L, i), writeResults.get(i));
    }
    // Test reading from buffer
    Entry recordSet = Entry.newBuilder().setData(buffer.getData(), 0, buffer.size()).setLogSegmentInfo(1L, 1L).setEntryId(0L).build();
    Reader reader = recordSet.reader();
    LogRecordWithDLSN record = reader.nextRecord();
    int numReads = 0;
    long expectedTxid = 0L;
    while (null != record) {
        Assert.assertEquals(expectedTxid, record.getTransactionId());
        Assert.assertEquals(expectedTxid, record.getSequenceId());
        Assert.assertEquals(new DLSN(1L, 0L, expectedTxid), record.getDlsn());
        ++numReads;
        ++expectedTxid;
        record = reader.nextRecord();
    }
    Assert.assertEquals(10, numReads);
}

Example 7 with Promise

use of com.twitter.util.Promise in project distributedlog by twitter.

the class Utils method zkSetData.

/**
     * Set <code>data</code> to zookeeper <code>path</code>.
     *
     * @param zk
     *          zookeeper client
     * @param path
     *          path to set data
     * @param data
     *          data to set
     * @param version
     *          version used to set data
     * @return future representing the version after this operation.
     */
public static Future<ZkVersion> zkSetData(ZooKeeper zk, String path, byte[] data, ZkVersion version) {
    final Promise<ZkVersion> promise = new Promise<ZkVersion>();
    zk.setData(path, data, version.getZnodeVersion(), new AsyncCallback.StatCallback() {

        @Override
        public void processResult(int rc, String path, Object ctx, Stat stat) {
            if (KeeperException.Code.OK.intValue() == rc) {
                promise.updateIfEmpty(new Return<ZkVersion>(new ZkVersion(stat.getVersion())));
                return;
            }
            promise.updateIfEmpty(new Throw<ZkVersion>(KeeperException.create(KeeperException.Code.get(rc))));
            return;
        }
    }, null);
    return promise;
}

Example 8 with Promise

use of com.twitter.util.Promise in project distributedlog by twitter.

the class BKLogHandler method asyncGetFirstLogRecord.

public Future<LogRecordWithDLSN> asyncGetFirstLogRecord() {
    final Promise<LogRecordWithDLSN> promise = new Promise<LogRecordWithDLSN>();
    checkLogStreamExistsAsync().addEventListener(new FutureEventListener<Void>() {

        @Override
        public void onSuccess(Void value) {
            asyncGetFullLedgerList(true, true).addEventListener(new FutureEventListener<List<LogSegmentMetadata>>() {

                @Override
                public void onSuccess(List<LogSegmentMetadata> ledgerList) {
                    if (ledgerList.isEmpty()) {
                        promise.setException(new LogEmptyException("Log " + getFullyQualifiedName() + " has no records"));
                        return;
                    }
                    Future<LogRecordWithDLSN> firstRecord = null;
                    for (LogSegmentMetadata ledger : ledgerList) {
                        if (!ledger.isTruncated() && (ledger.getRecordCount() > 0 || ledger.isInProgress())) {
                            firstRecord = asyncReadFirstUserRecord(ledger, DLSN.InitialDLSN);
                            break;
                        }
                    }
                    if (null != firstRecord) {
                        promise.become(firstRecord);
                    } else {
                        promise.setException(new LogEmptyException("Log " + getFullyQualifiedName() + " has no records"));
                    }
                }

                @Override
                public void onFailure(Throwable cause) {
                    promise.setException(cause);
                }
            });
        }

        @Override
        public void onFailure(Throwable cause) {
            promise.setException(cause);
        }
    });
    return promise;
}

Example 9 with Promise

use of com.twitter.util.Promise in project distributedlog by twitter.

the class BKLogHandler method checkLogStreamExistsAsync.

Future<Void> checkLogStreamExistsAsync() {
    final Promise<Void> promise = new Promise<Void>();
    try {
        final ZooKeeper zk = zooKeeperClient.get();
        zk.sync(logMetadata.getLogSegmentsPath(), new AsyncCallback.VoidCallback() {

            @Override
            public void processResult(int syncRc, String path, Object syncCtx) {
                if (KeeperException.Code.NONODE.intValue() == syncRc) {
                    promise.setException(new LogNotFoundException(String.format("Log %s does not exist or has been deleted", getFullyQualifiedName())));
                    return;
                } else if (KeeperException.Code.OK.intValue() != syncRc) {
                    promise.setException(new ZKException("Error on checking log existence for " + getFullyQualifiedName(), KeeperException.create(KeeperException.Code.get(syncRc))));
                    return;
                }
                zk.exists(logMetadata.getLogSegmentsPath(), false, new AsyncCallback.StatCallback() {

                    @Override
                    public void processResult(int rc, String path, Object ctx, Stat stat) {
                        if (KeeperException.Code.OK.intValue() == rc) {
                            promise.setValue(null);
                        } else if (KeeperException.Code.NONODE.intValue() == rc) {
                            promise.setException(new LogNotFoundException(String.format("Log %s does not exist or has been deleted", getFullyQualifiedName())));
                        } else {
                            promise.setException(new ZKException("Error on checking log existence for " + getFullyQualifiedName(), KeeperException.create(KeeperException.Code.get(rc))));
                        }
                    }
                }, null);
            }
        }, null);
    } catch (InterruptedException ie) {
        LOG.error("Interrupted while reading {}", logMetadata.getLogSegmentsPath(), ie);
        promise.setException(new DLInterruptedException("Interrupted while checking " + logMetadata.getLogSegmentsPath(), ie));
    } catch (ZooKeeperClient.ZooKeeperConnectionException e) {
        promise.setException(e);
    }
    return promise;
}

Example 10 with Promise

use of com.twitter.util.Promise in project distributedlog by twitter.

the class BKLogHandler method asyncGetLedgerList.

protected Future<List<LogSegmentMetadata>> asyncGetLedgerList(final boolean forceFetch, final boolean fetchFullList, final Comparator<LogSegmentMetadata> comparator, final boolean throwOnEmpty) {
    final Promise<List<LogSegmentMetadata>> promise = new Promise<List<LogSegmentMetadata>>();
    final Stopwatch stopwatch = Stopwatch.createStarted();
    final OpStatsLogger statsLogger = fetchFullList ? getFullListStat : getFilteredListStat;
    asyncDoGetLedgerList(forceFetch, fetchFullList, comparator, throwOnEmpty).addEventListener(new FutureEventListener<List<LogSegmentMetadata>>() {

        @Override
        public void onSuccess(List<LogSegmentMetadata> value) {
            statsLogger.registerSuccessfulEvent(stopwatch.stop().elapsed(TimeUnit.MICROSECONDS));
            promise.setValue(value);
        }

        @Override
        public void onFailure(Throwable cause) {
            statsLogger.registerFailedEvent(stopwatch.stop().elapsed(TimeUnit.MICROSECONDS));
            promise.setException(cause);
        }
    });
    return promise;
}