Examples with Visitor org.neo4j.internal.helpers.collection.Visitor used on opensource projects

Example 1 with Visitor

use of org.neo4j.internal.helpers.collection.Visitor in project neo4j by neo4j.

the class TransactionLogsRecoveryTest method writeSomeDataWithVersion.

private void writeSomeDataWithVersion(Path file, Visitor<Pair<LogEntryWriter, Consumer<LogPositionMarker>>, IOException> visitor, KernelVersion version) throws IOException {
    try (LogVersionedStoreChannel versionedStoreChannel = new PhysicalLogVersionedStoreChannel(fileSystem.write(file), logVersion, CURRENT_LOG_FORMAT_VERSION, file, EMPTY_ACCESSOR);
        PositionAwarePhysicalFlushableChecksumChannel writableLogChannel = new PositionAwarePhysicalFlushableChecksumChannel(versionedStoreChannel, new HeapScopedBuffer(1, KibiByte, INSTANCE))) {
        writeLogHeader(writableLogChannel, new LogHeader(logVersion, 2L, StoreId.UNKNOWN));
        writableLogChannel.beginChecksum();
        Consumer<LogPositionMarker> consumer = marker -> {
            try {
                writableLogChannel.getCurrentPosition(marker);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        };
        LogEntryWriter first = new LogEntryWriter(writableLogChannel, version);
        visitor.visit(Pair.of(first, consumer));
    }
}

Example 2 with Visitor

use of org.neo4j.internal.helpers.collection.Visitor in project neo4j by neo4j.

the class NodeStoreTest method scanningRecordsShouldVisitEachInUseRecordOnce.

@Test
void scanningRecordsShouldVisitEachInUseRecordOnce() throws IOException {
    // GIVEN we have a NodeStore with data that spans several pages...
    nodeStore = newNodeStore(fs);
    ThreadLocalRandom rng = ThreadLocalRandom.current();
    final MutableLongSet nextRelSet = new LongHashSet();
    for (int i = 0; i < 10_000; i++) {
        // Enough records to span several pages
        int nextRelCandidate = rng.nextInt(0, Integer.MAX_VALUE);
        if (nextRelSet.add(nextRelCandidate)) {
            long nodeId = nodeStore.nextId(NULL);
            NodeRecord record = new NodeRecord(nodeId).initialize(true, 20, false, nextRelCandidate, 0);
            nodeStore.updateRecord(record, NULL);
            if (rng.nextInt(0, 10) < 3) {
                nextRelSet.remove(nextRelCandidate);
                record.setInUse(false);
                nodeStore.updateRecord(record, NULL);
            }
        }
    }
    // ...WHEN we now have an interesting set of node records, and we
    // visit each and remove that node from our nextRelSet...
    Visitor<NodeRecord, IOException> scanner = record -> {
        // ...THEN we should observe that no nextRel is ever removed twice...
        assertTrue(nextRelSet.remove(record.getNextRel()));
        return false;
    };
    nodeStore.scanAllRecords(scanner, NULL);
    // ...NOR do we have anything left in the set afterwards.
    assertTrue(nextRelSet.isEmpty());
}