BewareMyPower commented on code in PR #21417:
URL: https://github.com/apache/pulsar/pull/21417#discussion_r1519244269
##########
pulsar-client/src/main/java/org/apache/pulsar/client/impl/TableViewImpl.java:
##########
@@ -180,96 +204,154 @@ public void close() throws PulsarClientException {
}
private void handleMessage(Message<T> msg) {
- try {
- if (msg.hasKey()) {
- String key = msg.getKey();
- T cur = msg.size() > 0 ? msg.getValue() : null;
- if (log.isDebugEnabled()) {
- log.debug("Applying message from topic {}. key={}
value={}",
+ readPositions.put(msg.getTopicName(), msg.getMessageId());
+ if (msg.hasKey()) {
+ String key = msg.getKey();
+ T cur = msg.size() > 0 ? msg.getValue() : null;
+ if (log.isDebugEnabled()) {
+ log.debug("Applying message from topic {}. key={} value={}",
+ conf.getTopicName(),
+ key,
+ cur);
+ }
+
+ boolean update = true;
+ if (compactionStrategy != null) {
+ T prev = data.get(key);
+ update = !compactionStrategy.shouldKeepLeft(prev, cur);
+ if (!update) {
+ log.info("Skipped the message from topic {}. key={}
value={} prev={}",
conf.getTopicName(),
key,
- cur);
+ cur,
+ prev);
+ compactionStrategy.handleSkippedMessage(key, cur);
}
+ }
- boolean update = true;
- if (compactionStrategy != null) {
- T prev = data.get(key);
- update = !compactionStrategy.shouldKeepLeft(prev, cur);
- if (!update) {
- log.info("Skipped the message from topic {}. key={}
value={} prev={}",
- conf.getTopicName(),
- key,
- cur,
- prev);
- compactionStrategy.handleSkippedMessage(key, cur);
+ if (update) {
+ try {
+ listenersMutex.lock();
+ if (null == cur) {
+ data.remove(key);
+ } else {
+ data.put(key, cur);
}
- }
- if (update) {
- try {
- listenersMutex.lock();
- if (null == cur) {
- data.remove(key);
- } else {
- data.put(key, cur);
- }
-
- for (BiConsumer<String, T> listener : listeners) {
- try {
- listener.accept(key, cur);
- } catch (Throwable t) {
- log.error("Table view listener raised an
exception", t);
- }
+ for (BiConsumer<String, T> listener : listeners) {
+ try {
+ listener.accept(key, cur);
+ } catch (Throwable t) {
+ log.error("Table view listener raised an
exception", t);
}
- } finally {
- listenersMutex.unlock();
}
+ } finally {
+ listenersMutex.unlock();
}
}
- } finally {
- msg.release();
}
}
- private CompletableFuture<Reader<T>> readAllExistingMessages(Reader<T>
reader) {
+ @Override
+ public CompletableFuture<Void> refreshAsync() {
+ CompletableFuture<Void> completableFuture = new CompletableFuture<>();
+ reader.thenCompose(reader -> buildFreshTask(reader,
completableFuture).thenAccept(lastMessageIds -> {
+ // After get the response of lastMessageIds, put the future and
result into `refreshMap`
+ // and then filter out partitions that has been read to the
lastMessageID.
+ refreshRequests.put(completableFuture, lastMessageIds);
+ filterReceivedMessages(lastMessageIds);
+ // If there is no new messages, the refresh operation could be
completed right now.
+ if (lastMessageIds.isEmpty()) {
+ refreshRequests.remove(completableFuture);
+ completableFuture.complete(null);
+ }
+ }));
+ return completableFuture;
+ }
+
+ @Override
+ public void refresh() throws PulsarClientException {
+ refreshAsync().join();
+ }
+
+ private CompletableFuture<Void> readAllExistingMessages(Reader<T> reader) {
long startTime = System.nanoTime();
AtomicLong messagesRead = new AtomicLong();
- CompletableFuture<Reader<T>> future = new CompletableFuture<>();
- reader.getLastMessageIdsAsync().thenAccept(lastMessageIds -> {
+ CompletableFuture<Void> future = new CompletableFuture<>();
+ buildFreshTask(reader, future).thenAccept(maxMessageIds -> {
+ readAllExistingMessages(reader, future, startTime, messagesRead,
maxMessageIds);
+ });
+ return future;
+ }
+
+ private CompletableFuture<Map<String, TopicMessageId>>
buildFreshTask(Reader<T> reader,
Review Comment:
This method name is hard to understand. Maybe `getLastMessageIds` would be a
better name?
##########
pulsar-client/src/main/java/org/apache/pulsar/client/impl/TableViewImpl.java:
##########
@@ -180,96 +204,154 @@ public void close() throws PulsarClientException {
}
private void handleMessage(Message<T> msg) {
- try {
- if (msg.hasKey()) {
- String key = msg.getKey();
- T cur = msg.size() > 0 ? msg.getValue() : null;
- if (log.isDebugEnabled()) {
- log.debug("Applying message from topic {}. key={}
value={}",
+ readPositions.put(msg.getTopicName(), msg.getMessageId());
+ if (msg.hasKey()) {
+ String key = msg.getKey();
+ T cur = msg.size() > 0 ? msg.getValue() : null;
+ if (log.isDebugEnabled()) {
+ log.debug("Applying message from topic {}. key={} value={}",
+ conf.getTopicName(),
+ key,
+ cur);
+ }
+
+ boolean update = true;
+ if (compactionStrategy != null) {
+ T prev = data.get(key);
+ update = !compactionStrategy.shouldKeepLeft(prev, cur);
+ if (!update) {
+ log.info("Skipped the message from topic {}. key={}
value={} prev={}",
conf.getTopicName(),
key,
- cur);
+ cur,
+ prev);
+ compactionStrategy.handleSkippedMessage(key, cur);
}
+ }
- boolean update = true;
- if (compactionStrategy != null) {
- T prev = data.get(key);
- update = !compactionStrategy.shouldKeepLeft(prev, cur);
- if (!update) {
- log.info("Skipped the message from topic {}. key={}
value={} prev={}",
- conf.getTopicName(),
- key,
- cur,
- prev);
- compactionStrategy.handleSkippedMessage(key, cur);
+ if (update) {
+ try {
+ listenersMutex.lock();
+ if (null == cur) {
+ data.remove(key);
+ } else {
+ data.put(key, cur);
}
- }
- if (update) {
- try {
- listenersMutex.lock();
- if (null == cur) {
- data.remove(key);
- } else {
- data.put(key, cur);
- }
-
- for (BiConsumer<String, T> listener : listeners) {
- try {
- listener.accept(key, cur);
- } catch (Throwable t) {
- log.error("Table view listener raised an
exception", t);
- }
+ for (BiConsumer<String, T> listener : listeners) {
+ try {
+ listener.accept(key, cur);
+ } catch (Throwable t) {
+ log.error("Table view listener raised an
exception", t);
}
- } finally {
- listenersMutex.unlock();
}
+ } finally {
+ listenersMutex.unlock();
}
}
- } finally {
- msg.release();
}
}
- private CompletableFuture<Reader<T>> readAllExistingMessages(Reader<T>
reader) {
+ @Override
+ public CompletableFuture<Void> refreshAsync() {
+ CompletableFuture<Void> completableFuture = new CompletableFuture<>();
+ reader.thenCompose(reader -> buildFreshTask(reader,
completableFuture).thenAccept(lastMessageIds -> {
+ // After get the response of lastMessageIds, put the future and
result into `refreshMap`
+ // and then filter out partitions that has been read to the
lastMessageID.
+ refreshRequests.put(completableFuture, lastMessageIds);
+ filterReceivedMessages(lastMessageIds);
+ // If there is no new messages, the refresh operation could be
completed right now.
+ if (lastMessageIds.isEmpty()) {
+ refreshRequests.remove(completableFuture);
+ completableFuture.complete(null);
+ }
+ }));
+ return completableFuture;
+ }
+
+ @Override
+ public void refresh() throws PulsarClientException {
+ refreshAsync().join();
+ }
+
+ private CompletableFuture<Void> readAllExistingMessages(Reader<T> reader) {
long startTime = System.nanoTime();
AtomicLong messagesRead = new AtomicLong();
- CompletableFuture<Reader<T>> future = new CompletableFuture<>();
- reader.getLastMessageIdsAsync().thenAccept(lastMessageIds -> {
+ CompletableFuture<Void> future = new CompletableFuture<>();
+ buildFreshTask(reader, future).thenAccept(maxMessageIds -> {
+ readAllExistingMessages(reader, future, startTime, messagesRead,
maxMessageIds);
+ });
+ return future;
+ }
+
+ private CompletableFuture<Map<String, TopicMessageId>>
buildFreshTask(Reader<T> reader,
+
CompletableFuture<Void> future) {
+ return reader.getLastMessageIdsAsync().thenApply(lastMessageIds -> {
Map<String, TopicMessageId> maxMessageIds = new
ConcurrentHashMap<>();
lastMessageIds.forEach(topicMessageId -> {
maxMessageIds.put(topicMessageId.getOwnerTopic(),
topicMessageId);
});
- readAllExistingMessages(reader, future, startTime, messagesRead,
maxMessageIds);
+ return maxMessageIds;
}).exceptionally(ex -> {
future.completeExceptionally(ex);
Review Comment:
If `buildFreshTask` failed, it will return a future that completes with null
rather than a future that completes exceptionally. Then NPE might happen in the
caller code like:
```java
// lastMessageIds is null when `reader.getLastMessageIdsAsync()`
completes exceptionally
reader.thenCompose(reader -> buildFreshTask(reader,
completableFuture).thenAccept(lastMessageIds -> {
```
Here is an example that simulates the behavior I described.
```java
private static CompletableFuture<Integer> f(int x) {
final CompletableFuture<Integer> future = new CompletableFuture<>();
if (x == 0) {
future.completeExceptionally(new RuntimeException("failed"));
} else {
future.complete(x);
}
return future;
}
public static void main(String[] args) {
final CompletableFuture<Integer> anotherFuture = new
CompletableFuture<>();
final CompletableFuture<Integer> future = f(0).thenApply(x -> x +
1).exceptionally(e -> {
anotherFuture.completeExceptionally(e);
return null;
});
future.thenAccept(x -> System.out.println(x + 1)).join();
}
```
Why not write a method like
```java
private CompletableFuture<Map<String, TopicMessageId>>
getLastMessageIds(Reader<T> reader) {
return reader.getLastMessageIdsAsync().thenApply(lastMessageIds -> {
Map<String, TopicMessageId> maxMessageIds = new HashMap<>();
/* ... */
});
}
```
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