Optimize writing numeric values. #1635
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vbabanin
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vbabanin
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I like this, it looks similar to my PR at #1629 which try writing byte per byte if there is available space to straight use the same buffer ❤️ |
| * @throws java.nio.BufferOverflowException if there are fewer than 4 bytes remaining in this buffer | ||
| * @throws java.nio.ReadOnlyBufferException if this buffer is read-only | ||
| */ | ||
| ByteBuf putInt(int b); |
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Given that the interface includes the warning:
This interface is not frozen yet, and methods may be added in a minor release, so beware implementing this yourself we are justified in adding new methods to this class.
it is permissible to add new methods to this class.
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Add @since to the javadoc for all the new methods.
| * @throws java.nio.BufferOverflowException if there are fewer than 4 bytes remaining in this buffer | ||
| * @throws java.nio.ReadOnlyBufferException if this buffer is read-only | ||
| */ | ||
| ByteBuf putInt(int b); |
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Add @since to the javadoc for all the new methods.
driver-core/src/main/com/mongodb/internal/connection/ByteBufferBsonOutput.java
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driver-core/src/main/com/mongodb/internal/connection/ByteBufferBsonOutput.java
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driver-core/src/main/com/mongodb/internal/connection/ByteBufferBsonOutput.java
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| class ByteBufTest { | ||
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| static Stream<BufferProvider> bufferProviders() { | ||
| return Stream.of(new ByteBufSpecification.NettyBufferProvider(), new SimpleBufferProvider()); |
driver-core/src/test/unit/com/mongodb/internal/connection/ByteBufTest.java
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…rBsonOutput.java Co-authored-by: Ross Lawley <ross.lawley@gmail.com>
…rBsonOutput.java Co-authored-by: Ross Lawley <ross.lawley@gmail.com>
…rBsonOutput.java Co-authored-by: Ross Lawley <ross.lawley@gmail.com>
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I ran ByteBufferBsonOutputTest with Coverage, and noticed that ByteBufferBsonOutput#write(int absolutePosition, int value) is no longer covered by test due to the optimizations that were introduced. This method should either be covered by tests or removed (it seems like it will never be called)
Here's one way to do it: https://github.com/jyemin/mongo-java-driver/pull/new/jeff-wip
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[Note] As @stIncMale suggested, lets put Evolving annotation here.
Summary
This PR improves BSON encoding by replacing byte manipulations and bound checks with ByteBuffer’s optimized methods (putInt, putLong, putDouble). These methods are optimized for bulk operations and often intrinsified by the JVM using efficient CPU opcodes, leading to reduced overhead and better performance.
Key Changes:
writeInt32(int absolutePosition, int value)from 4 to 1 by preferring a single putInt call when capacity allows, minimizing overhead. Adds a fallback for edge cases (e.g., buffer boundaries) with O(1) buffer switches instead of repeated O(n) lookups.putInt(int),putInt(int, int),putDouble(double), andputLong(long)toByteBuf, implemented inByteBufNIOandNettyByteBuf, with no-op stubs inCompositeByteBuf.ByteBufferBsonOutputto: UseputInt,putLong, andputDoublefor single-call writes when capacity allows, reducing overhead.Performance analysis
To ensure accurate performance comparison and reduce noise, 11 versions (Comparison Versions) were aggregated and compared against a stable region of data around the Base Mainline Version. The percentage difference and z-score of the mean of the Comparison Versions were calculated relative to the Base Mainline Version’s stable region mean.
Perf analyzer results: Link
JAVA-5800