afterincomparableyum commented on code in PR #3748: URL: https://github.com/apache/celeborn/pull/3748#discussion_r3489534548
########## cpp/celeborn/client/tests/CelebornInputStreamTest.cpp: ########## @@ -0,0 +1,40 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file 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 "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <cstdint> +#include <vector> + +#include <gtest/gtest.h> + +#include "celeborn/client/reader/CelebornInputStream.h" + +using namespace celeborn; +using namespace celeborn::client; + +// empty() returns a no-op stream: read() reports EOF (-1) immediately and stays +// at EOF across repeated and larger reads. +TEST(CelebornInputStreamTest, emptyStreamReadsReturnEof) { + auto stream = CelebornInputStream::empty(); + ASSERT_NE(stream, nullptr); + + std::vector<uint8_t> buffer(16, 0); + EXPECT_EQ(stream->read(buffer.data(), 0, buffer.size()), -1); + // No state to advance: a second read still reports EOF. + EXPECT_EQ(stream->read(buffer.data(), 0, buffer.size()), -1); + // A zero-length read is a no-op that returns 0, not EOF. + EXPECT_EQ(stream->read(buffer.data(), 0, 0), 0); Review Comment: Minor / non-blocking parity note: this is a behavioral difference from Java's empty stream. Java's `emptyInputStream.read(b, off, len)` returns `-1` unconditionally, even when `len == 0`, whereas this C++ empty stream returns `0` for a zero-length read because `read()` short-circuits on `len <= 0` before reaching EOF detection. It's internally consistent with the C++ `read()` contract and has no functional impact (real readers always pass `len > 0`), so the assertion here is fine — just flagging it since the stated goal is parity with the Java client. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
