Use Empty Array for Collection.toArray()
org.openrewrite.staticanalysis.ReplaceCollectionToArrayArgWithEmptyArrayArtifactorg.openrewrite.recipe:rewrite-static-analysisChanges new array creation with Collection#toArray(T[]) to use an empty array argument, which is better for performance.
According to the Collection#toArray(T[]) documentation:
> If the collection fits in the specified array, it is returned therein.
However, although it's not intuitive, allocating a right-sized array ahead of time to pass to the API appears to be generally worse for performance according to benchmarking and JVM developers due to a number of implementation details in both Java and the virtual machine.
H2 achieved significant performance gains by switching to empty arrays instead pre-sized ones.
Add to your build
~/.gradle/gradle.properties
codeGenomeUsername=you@example.com
codeGenomeToken=YOUR_DOWNLOAD_TOKEN
build.gradle.kts
plugins {
id("org.openrewrite.rewrite") version("latest.release")
}
rewrite {
activeRecipe("org.openrewrite.staticanalysis.ReplaceCollectionToArrayArgWithEmptyArray")
}
repositories {
mavenCentral()
maven {
url = uri("https://artifacts.codegenomeproject.org/maven")
credentials {
username = providers.gradleProperty("codeGenomeUsername").get()
password = providers.gradleProperty("codeGenomeToken").get()
}
}
}
dependencies {
rewrite("org.openrewrite.recipe:rewrite-static-analysis:2.44.0")
}
Then run
./gradlew rewriteRunUsage
This recipe has no required configuration options. You’ll need the Moderne CLI configured before running the command below.
mod run . --recipe org.openrewrite.staticanalysis.ReplaceCollectionToArrayArgWithEmptyArrayIf the recipe isn’t available locally, install it with:
mod config recipes jar install org.openrewrite.recipe:rewrite-static-analysis:RELEASEData tables
Structured output this recipe can produce.
- Source files that had resultsSource files that were modified by the recipe run.
org.openrewrite.table.SourcesFileResults - Source files that had search resultsSearch results that were found during the recipe run.
org.openrewrite.table.SearchResults - Source files that errored on a recipeThe details of all errors produced by a recipe run.
org.openrewrite.table.SourcesFileErrors - Recipe performanceStatistics used in analyzing the performance of recipes.
org.openrewrite.table.RecipeRunStats