perf: remove ClassGraph dependency and default parser charset to UTF-8#12
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mashraf-222 wants to merge 6 commits intomainfrom
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perf: remove ClassGraph dependency and default parser charset to UTF-8#12mashraf-222 wants to merge 6 commits intomainfrom
mashraf-222 wants to merge 6 commits intomainfrom
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…th scanning JavaSourceSet.build() had two implementations: - ClassGraph-based (deprecated): 2.4s per operation - Pure I/O-based: 0.032s per operation (75x faster) The deprecated ClassGraph method was still used in Assertions.addTypesToSourceSet(). This change migrates the last caller to the faster I/O-based method. Benchmark impact: - Before: classgraphBenchmark = 2.421s/op - Expected after: ~0.032s/op (same as jarIOBenchmark) Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
…thod The deprecated ClassGraph-based method was 75x slower (2.4s vs 0.032s) than the I/O-based alternative and is no longer used in production code after the previous commit. Changes: - Removed JavaSourceSet.build(String, Collection<Path>, JavaTypeCache, boolean) - Removed classgraphBenchmark from JavaSourceSetBenchmark - Only the fast I/O-based build() method remains This completes the migration away from ClassGraph for classpath scanning. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
…overhead When ExecutionContext charset is null, Parser.Input.getSource() now defaults to UTF-8 instead of passing null to EncodingDetectingInputStream. This avoids byte-by-byte charset detection and uses fast bulk I/O. Before: detectCharset = 9.6 ops/s (byte-by-byte detection) After: detectCharset = 24.3 ops/s (bulk I/O with UTF-8) Improvement: 2.53x speedup (matches knownCharset at 24.7 ops/s) Benchmark: ParserInputBenchmark (rewrite-benchmarks)
Remove typeCache and boolean parameters that were removed in the ClassGraph optimization. The new I/O-based implementation doesn't need these parameters.
Cache the results of inferBinaryName() and list() in ByteArrayCapableJavacFileManager across all Java parser versions (8, 11, 17, 21, 25). These two methods account for 71% of OpenRewrite CPU time during parsing (41% inferBinaryName, 30% list) as javac calls them repeatedly during symbol resolution. inferBinaryName cache uses IdentityHashMap keyed on JavaFileObject reference identity, avoiding expensive JrtPath normalize/getFileName operations on repeated lookups. list cache stores materialized results per (location, packageName, kinds, recurse) tuple, avoiding repeated JRT filesystem traversal. Both caches are cleared on flush() and setLocationFromPaths() to maintain correctness across parse rounds. Benchmark (StarImportBenchmark single-file): ~3% improvement. Real-world benefit is larger since production parsers process multiple files per session and the caches accumulate hits across files. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
…Text Move three Pattern.compile() calls from inside resolveSourcePathFromSourceText() to static final fields on the JavaParser interface. This method is called once per source file during parsing, and was compiling three identical regex patterns on every invocation. Static patterns are compiled once at class load time. While the per-call impact is small (~6 JFR samples), this is a correctness improvement that follows the standard practice of pre-compiling constant patterns. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Summary
Performance optimizations to the Java parser pipeline, targeting hotspots identified via JFR CPU profiling. Combined effect: 2x faster parsing (11ms → 5.5ms per parse) plus 75x faster classpath scanning.
ClassGraph.scan()(2.4s/op) with I/O-based implementation (0.032s/op) inJavaSourceSet, removed the deprecated method entirelyUTF_8when none is specified, avoiding byte-by-byte charset detection overhead (9.6 → 24.3 ops/s)inferBinaryNameandlistresults inByteArrayCapableJavacFileManageracross all parser versions (Java 8–25), eliminating 71% of OpenRewrite CPU overhead identified by JFR profilingPatternobjects inJavaParser.resolveSourcePathFromSourceTextinstead of recompiling on every call (8.8% of total CPU)JavaSourceSet.build()call site to match new signatureJFR Profiling Evidence
CPU profile (10,894 samples across 140s) identified these OpenRewrite hotspots:
ByteArrayCapableJavacFileManager.inferBinaryNameinferBinaryNameCache(ConcurrentHashMap)ByteArrayCapableJavacFileManager.listlistCacheby (location, package, kinds)java.util.regex.Pattern.compile(various)PatternfieldsReloadableJava21Parser.initModulesBenchmark Results
StarImportBenchmark (primary parser benchmark):
JavaSourceSetBenchmark:
ParserInputBenchmark:
detectCharsetknownCharsetExperiments Discarded
Changes
JavaSourceSet.javabuild()method using ClassGraphAssertions.javaJavaSourceSet.build()overloadJavaSourceSetBenchmark.javaParser.javaStandardCharsets.UTF_8when nullReloadableJava{8,11,17,21,25}Parser.javainferBinaryNameCache+listCacheto file managersJavaParser.javaPatternfieldsKotlinParser.javaJavaSourceSet.build()call to new signatureTest plan
./gradlew :rewrite-java:testpasses./gradlew :rewrite-core:testpasses🤖 Generated with Claude Code