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* to you 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
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.pulsar.metadata.bookkeeper;
import java.io.IOException;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.atomic.AtomicInteger;
import lombok.extern.slf4j.Slf4j;
import org.apache.bookkeeper.proto.BookkeeperInternalCallbacks;
import org.apache.bookkeeper.util.StringUtils;
import org.apache.pulsar.metadata.api.MetadataStore;
import org.apache.zookeeper.AsyncCallback;
@Slf4j
abstract class AbstractHierarchicalLedgerManager {
protected final MetadataStore store;
protected final ScheduledExecutorService scheduler;
protected final String ledgerRootPath;
AbstractHierarchicalLedgerManager(MetadataStore store,
ScheduledExecutorService scheduler,
String ledgerRootPath) {
this.store = store;
this.scheduler = scheduler;
this.ledgerRootPath = ledgerRootPath;
}
/**
* regex expression for name of top level parent znode for ledgers (in
* HierarchicalLedgerManager) or znode of a ledger (in FlatLedgerManager).
*
* @return
*/
protected abstract String getLedgerParentNodeRegex();
/**
* whether the child of ledgersRootPath is a top level parent znode for
* ledgers (in HierarchicalLedgerManager) or znode of a ledger (in
* FlatLedgerManager).
*/
public boolean isLedgerParentNode(String path) {
return path.matches(getLedgerParentNodeRegex());
}
/**
* Process hash nodes in a given path.
*/
void asyncProcessLevelNodes(
final String path, final BookkeeperInternalCallbacks.Processor processor,
final AsyncCallback.VoidCallback finalCb, final Object context,
final int successRc, final int failureRc) {
store.getChildren(path)
.thenAccept(levelNodes -> {
if (levelNodes.isEmpty()) {
finalCb.processResult(successRc, null, context);
return;
}
AsyncListProcessor listProcessor = new AsyncListProcessor<>(scheduler);
// process its children
listProcessor.process(levelNodes, processor, finalCb, context, successRc, failureRc);
}).exceptionally(ex -> {
log.error("Error polling hash nodes of {}: {}", path, ex.getMessage());
finalCb.processResult(failureRc, null, context);
return null;
});
}
/**
* Process list one by one in asynchronize way. Process will be stopped immediately
* when error occurred.
*/
private static class AsyncListProcessor {
// use this to prevent long stack chains from building up in callbacks
ScheduledExecutorService scheduler;
/**
* Constructor.
*
* @param scheduler
* Executor used to prevent long stack chains
*/
public AsyncListProcessor(ScheduledExecutorService scheduler) {
this.scheduler = scheduler;
}
/**
* Process list of items.
*
* @param data
* List of data to process
* @param processor
* Callback to process element of list when success
* @param finalCb
* Final callback to be called after all elements in the list are processed
* @param context
* Context of final callback
* @param successRc
* RC passed to final callback on success
* @param failureRc
* RC passed to final callback on failure
*/
public void process(final List data, final BookkeeperInternalCallbacks.Processor processor,
final AsyncCallback.VoidCallback finalCb, final Object context,
final int successRc, final int failureRc) {
if (data == null || data.size() == 0) {
finalCb.processResult(successRc, null, context);
return;
}
final int size = data.size();
final AtomicInteger current = new AtomicInteger(0);
T firstElement = data.get(0);
processor.process(firstElement, new AsyncCallback.VoidCallback() {
@Override
public void processResult(int rc, String path, Object ctx) {
if (rc != successRc) {
// terminal immediately
finalCb.processResult(failureRc, null, context);
return;
}
// process next element
int next = current.incrementAndGet();
if (next >= size) { // reach the end of list
finalCb.processResult(successRc, null, context);
return;
}
final T dataToProcess = data.get(next);
final AsyncCallback.VoidCallback stub = this;
scheduler.execute(() -> processor.process(dataToProcess, stub));
}
});
}
}
// get ledger from all level nodes
long getLedgerId(String... levelNodes) throws IOException {
return StringUtils.stringToHierarchicalLedgerId(levelNodes);
}
/**
* Process ledgers in a single zk node.
*
*
* for each ledger found in this zk node, processor#process(ledgerId) will be triggerred
* to process a specific ledger. after all ledgers has been processed, the finalCb will
* be called with provided context object. The RC passed to finalCb is decided by :
*
* - All ledgers are processed successfully, successRc will be passed.
*
- Either ledger is processed failed, failureRc will be passed.
*
*
*
* @param path
* Zk node path to store ledgers
* @param processor
* Processor provided to process ledger
* @param finalCb
* Callback object when all ledgers are processed
* @param ctx
* Context object passed to finalCb
* @param successRc
* RC passed to finalCb when all ledgers are processed successfully
* @param failureRc
* RC passed to finalCb when either ledger is processed failed
*/
protected void asyncProcessLedgersInSingleNode(
final String path, final BookkeeperInternalCallbacks.Processor processor,
final AsyncCallback.VoidCallback finalCb, final Object ctx,
final int successRc, final int failureRc) {
store.getChildren(path)
.thenAccept(ledgerNodes -> {
Set activeLedgers = HierarchicalLedgerUtils.ledgerListToSet(ledgerNodes,
ledgerRootPath, path);
if (log.isDebugEnabled()) {
log.debug("Processing ledgers: {}", activeLedgers);
}
// no ledgers found, return directly
if (activeLedgers.isEmpty()) {
finalCb.processResult(successRc, null, ctx);
return;
}
BookkeeperInternalCallbacks.MultiCallback
mcb = new BookkeeperInternalCallbacks.MultiCallback(activeLedgers.size(), finalCb, ctx,
successRc, failureRc);
// start loop over all ledgers
scheduler.submit(() -> {
for (Long ledger : activeLedgers) {
processor.process(ledger, mcb);
}
});
}).exceptionally(ex -> {
finalCb.processResult(failureRc, null, ctx);
return null;
});
}
}