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Disable UTF-8 validity checks in parser for speed#552

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Karolina-Bogacka merged 3 commits intomainfrom
piotr/faster-read-string
Sep 29, 2025
Merged

Disable UTF-8 validity checks in parser for speed#552
Karolina-Bogacka merged 3 commits intomainfrom
piotr/faster-read-string

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@Ostrzyciel
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@Ostrzyciel Ostrzyciel commented Sep 28, 2025

Using readString() any invalid UTF-8 characters are replaced with a UTF replacement char. That's also fine, because we don't actually have a contract saying that we must throw if invalid UTF-8 is encountered. This skips one check, making readString a bit faster:

# JMH version: 1.37
# VM version: JDK 25, Java HotSpot(TM) 64-Bit Server VM, 25+37-LTS-jvmci-b01
# VM invoker: /home/piotr/.jdks/graalvm-jdk-25/bin/java
# VM options: -XX:ThreadPriorityPolicy=1 -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCIProduct -XX:+EnableJVMCI -XX:-UnlockExperimentalVMOptions -Djacoco.skip=true
# Blackhole mode: compiler (auto-detected, use -Djmh.blackhole.autoDetect=false to disable)
# Warmup: 5 iterations, 10 s each
# Measurement: 10 iterations, 10 s each
# Timeout: 10 min per iteration
# Threads: 1 thread, will synchronize iterations
# Benchmark mode: Average time, time/op
# Benchmark: eu.neverblink.jelly.jmh.ReadStringBench.readString

Benchmark                              Mode  Cnt    Score   Error  Units
ReadStringBench.readString             avgt   10  747.251 ± 4.469  ns/op
ReadStringBench.readStringRequireUtf8  avgt   10  793.255 ± 1.196  ns/op

@Ostrzyciel Ostrzyciel force-pushed the piotr/faster-read-string branch from 506ef18 to abc6827 Compare September 28, 2025 18:30
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@Karolina-Bogacka Karolina-Bogacka merged commit f3fbe01 into main Sep 29, 2025
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@Karolina-Bogacka Karolina-Bogacka deleted the piotr/faster-read-string branch September 29, 2025 07:18
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@Karolina-Bogacka Karolina-Bogacka Karolina-Bogacka approved these changes

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@Ostrzyciel @Karolina-Bogacka