IGNITE-27088 BinaryWriter should use internal String#value - #13529
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nizhikov wants to merge 13 commits into
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IGNITE-27088 BinaryWriter should use internal String#value#13529nizhikov wants to merge 13 commits into
nizhikov wants to merge 13 commits into
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TCBot Test Analysis
Possible Blockers (0)No blockers found. New Tests (4)
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🟡 Changes recommended
A Checkstyle-enforced unused import in StringWriter.java will break the build, and the JMH benchmark’s zeroCopy parameterization is not reliable due to JVM-static initialization of the toggle.
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Pull request overview
Introduces a zero-copy UTF-8 string serialization path for Ignite binary writing, controlled by a new system property, and adds tests/benchmarks to validate and measure the behavior.
Changes:
- Added
StringWriterto serializeStringtoBinaryOutputStreamwithout allocating temporary UTF-8 byte arrays when enabled. - Added
IGNITE_BINARY_STRING_ZERO_COPYsystem property (defaulttrue) and wired it intoBinaryWriterExImpl. - Updated
DirectByteBufferStreamstring encoding/decoding to be explicitly UTF-8 and added coverage/benchmarking for the new string writer.
File summaries
| File | Description |
|---|---|
| modules/core/src/test/java/org/apache/ignite/testsuites/IgniteBinaryObjectsTestSuite.java | Adds the new StringWriterSelfTest to the binary objects test suite. |
| modules/core/src/test/java/org/apache/ignite/internal/binary/StringWriterSelfTest.java | New differential tests ensuring StringWriter output matches UTF-8 String#getBytes serialization. |
| modules/core/src/main/java/org/apache/ignite/internal/direct/stream/DirectByteBufferStream.java | Uses UTF-8 explicitly for string serialization; adds ASCII fast-path via internal string value. |
| modules/commons/src/main/java/org/apache/ignite/IgniteCommonsSystemProperties.java | Adds IGNITE_BINARY_STRING_ZERO_COPY property and default value constant. |
| modules/binary/impl/src/main/java/org/apache/ignite/internal/binary/StringWriter.java | New zero-copy UTF-8 string writer with compact-string and SIMD-negative-scan optimizations when available. |
| modules/binary/impl/src/main/java/org/apache/ignite/internal/binary/BinaryWriterExImpl.java | Enables StringWriter path when IGNITE_BINARY_STRING_ZERO_COPY is enabled. |
| modules/benchmarks/src/main/java/org/apache/ignite/internal/benchmarks/jmh/binary/JmhBinaryStringWriteBenchmark.java | Adds JMH benchmark intended to compare zero-copy vs legacy behavior. |
Review details
- Files reviewed: 7/7 changed files
- Comments generated: 3
- Review effort level: Lite
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| /** | ||
| * Tests that {@link StringWriter} output is byte-identical to serialization of the {@link String#getBytes()} result, | ||
| * which was used before zero-copy string serialization was introduced. | ||
| */ |
zstan
reviewed
Sep 7, 2026
zstan
reviewed
Sep 7, 2026
| byte[] latin1 = latin1Value(val); | ||
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| if (latin1 != null) { | ||
| if (out.hasArray()) { |
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.NET/C++ code goes through hasArray()==false branch as I can see, thus we need carefully bench such a branch too.
zstan
reviewed
Sep 7, 2026
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| str = sb.toString(); | ||
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| out = BinaryStreams.outputStream(4 * len + 64); |
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I try to run it instead of master with fast refactoring for PlatformOutputStreamImpl (C++.Net) like :
and found a bit perf drop (in measurements !!!!) thus real performance test need to be executed.
I changed:
long poolPtr = allocatePool();
long memPtr = allocatePooled(poolPtr, 10_000);
PlatformMemory res = pool.get(memPtr);
out = res.output();
//out = new PlatformAbstractMemory BinaryStreams.outputStream(4 * len + 64);
PR
Benchmark (content) (len) (zeroCopy) Mode Cnt Score Error Units
JmhBinaryStringWriteBenchmark.writeString cyrillic 512 true avgt 5 523.005 ± 13.730 ns/op
JmhBinaryStringWriteBenchmark.writeString:gc.alloc.rate cyrillic 512 true avgt 5 0.001 ± 0.001 MB/sec
master
Benchmark (content) (len) (zeroCopy) Mode Cnt Score Error Units
JmhBinaryStringWriteBenchmark.writeString cyrillic 512 true avgt 5 443.634 ± 11.679 ns/op
JmhBinaryStringWriteBenchmark.writeString:gc.alloc.rate cyrillic 512 true avgt 5 5572.091 ± 145.617 MB/sec
zstan
approved these changes
Sep 7, 2026
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JmhBinaryStringWriteBenchmark on my local machine (less is better).
gc data (less is better):