Github user anmolnar commented on a diff in the pull request:
https://github.com/apache/zookeeper/pull/684#discussion_r230975652
--- Diff:
zookeeper-server/src/main/java/org/apache/zookeeper/server/ServerCnxn.java ---
@@ -68,29 +70,74 @@
private volatile boolean stale = false;
+ final ZooKeeperServer zkServer;
+
+ public ServerCnxn(final ZooKeeperServer zkServer) {
+ this.zkServer = zkServer;
+ }
+
abstract int getSessionTimeout();
abstract void close();
+ public abstract void sendResponse(ReplyHeader h, Record r,
+ String tag, String cacheKey, Stat stat) throws IOException;
+
public void sendResponse(ReplyHeader h, Record r, String tag) throws
IOException {
- ByteArrayOutputStream baos = new ByteArrayOutputStream();
- // Make space for length
+ sendResponse(h, r, tag, null, null);
+ }
+
+ protected byte[] serializeRecord(Record record) throws IOException {
+ ByteArrayOutputStream baos = new ByteArrayOutputStream(
+ ZooKeeperServer.intBufferStartingSizeBytes);
BinaryOutputArchive bos = BinaryOutputArchive.getArchive(baos);
- try {
- baos.write(fourBytes);
- bos.writeRecord(h, "header");
- if (r != null) {
- bos.writeRecord(r, tag);
+ bos.writeRecord(record, null);
+ return baos.toByteArray();
+ }
+
+ protected ByteBuffer[] serialize(ReplyHeader h, Record r, String tag,
+ String cacheKey, Stat stat) throws IOException {
+ byte[] header = serializeRecord(h);
+ byte[] data = null;
+ if (r != null) {
+ ResponseCache cache = zkServer.getReadResponseCache();
+ if (cache != null && stat != null && cacheKey != null &&
+ !cacheKey.endsWith(Quotas.statNode)) {
+ // Use cache to get serialized data.
+ //
+ // NB: Tag is ignored both during cache lookup and
serialization,
+ // since is is not used in read responses, which are being
cached.
+ data = cache.get(cacheKey, stat);
+ if (data == null) {
+ // Cache miss, serialize the response and put it in
cache.
+ data = serializeRecord(r);
--- End diff --
`put()` aquires the write lock anyway, so in my opinion this will cause the
response to be serialized twice and put into the cache twice (second overwrites
first). I think it's fine.
---
