dao-jun commented on PR #22760: URL: https://github.com/apache/pulsar/pull/22760#issuecomment-2125646839
Just add additional context to help understand it quickly. [CopyingEncoder](https://github.com/apache/pulsar/blob/master/pulsar-common/src/main/java/org/apache/pulsar/common/protocol/ByteBufPair.java#L138-L158) is used to handle the case of `SslHandler`. Because `SslHandler` could compose ByteBufs to one(The first input ByteBuf). For instance, we write `buf1`,`buf2`,`buf3` to the handler, it will write `buf2`,`buf3` to `buf1`. If we are enable `EntryCache`, this will pollute the entries. So we use `buf.copy` to make a new instance and copy the bytes to handle the case. However, `buf.copy` is not thread safe, multi thread copying will lead to data corruption. The solution is pass a `ReadOnlyByteBuf` to `SslHandler` to disable ByteBuf compose(write `buf2`,`buf3` to `buf1`), although netty considered the input ByteBuf can be not writable, but it seems there are some problems with the code: ```java private static boolean attemptCopyToCumulation(ByteBuf cumulation, ByteBuf next, int wrapDataSize) { final int inReadableBytes = next.readableBytes(); final int cumulationCapacity = cumulation.capacity(); if (wrapDataSize - cumulation.readableBytes() >= inReadableBytes && // Avoid using the same buffer if next's data would make cumulation exceed the wrapDataSize. // Only copy if there is enough space available and the capacity is large enough, and attempt to // resize if the capacity is small. (cumulation.isWritable(inReadableBytes) && cumulationCapacity >= wrapDataSize || cumulationCapacity < wrapDataSize && ensureWritableSuccess(cumulation.ensureWritable(inReadableBytes, false)))) { cumulation.writeBytes(next); next.release(); return true; } return false; } ``` it should return false immediately if `cumulation.isWritable(inReadableBytes)` == false. Waiting the fix PR https://github.com/netty/netty/pull/14071 merged. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@pulsar.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
