LevelDB for Kotlin Multiplatform

Wrapper for using LevelDB in Kotlin Multiplatform projects and created and designed for use in lamba92/kotlin.document.store.

From google/leveldb repository:

LevelDB is a fast key-value storage library written at Google that provides an ordered mapping from string keys to string values.

google/leveldb is licensed under BSD-3-Clause license, all rights reserved to the original authors.

Index

1. Introduction
   • Overview
   • Supported Platforms
2. Usage
   • Dependency Setup
   • Code Example
   • Snapshots
3. Benchmarks
   • Ubuntu x64 Benchmarks
   • Windows x64 Benchmarks
   • macOS arm64 Benchmarks

Supported Platforms

The library is available for:

• Windows (mingwX64)
• Linux (x64, arm64)
• MacOS (x64, arm64)
• Android Native (arm64-v8a, armeabi-v7a, x86, x86_64)
• iOS (arm64, arm64-simulator, x64, x64-simulator)
• watchOS (arm64, arm64-simulator, x64-simulator)
• tvOS (arm64, arm64-simulator, x64-simulator)
• JVM:
  • Windows (x64, arm64)
  • Linux (x64, arm64)
  • macOS (x64, arm64)
  • Android (arm64-v8a, armeabi-v7a, x86, x86_64)

No JS or WASM, sorry!

LevelDB binaries are built in lamba92/leveldb-builds repository.

Usage

Dependency Setup

See releases for the latest version!

In your build.gradle.kts file:

// Kotlin Multiplatform
kotlin {
    sourceSets {
        commonMain {
            dependencies {
                implementation("com.github.lamba92:kotlin-leveldb:{latest-version}")
            }
        }
    }
}

// Kotlin JVM
dependencies {
    implementation("com.github.lamba92:kotlin-leveldb:{latest-version}")
}

In your code

val db = LevelDB("/path/to/db/as/string")

db.put("key", "value")
val value = db.get("key")
db.delete("key")
db.close()

Snapshots of latest commits

Snapshots of latest commits are available in Sonatype's snapshots repository. Can be used by adding the repository and the dependency:

repositories {
    maven("https://oss.sonatype.org/content/repositories/snapshots/")
}

Use version x.y-SNAPSHOT to get the latest version. Check the current one here.

Benchmarks

Benchmarks are available in the benchmarks module. On each commit, the benchmarks are run and the results are published in the GitHub Actions logs. You can find the latest results here. Benchmarks are executed on fre GitHub Actions runners for Windows x64, macOS arm64 and Linux x64, specs available here. Benchmarks uses Kotlin/Native only, so the JVM version is not tested.

As of December 2024:

Ubuntu x64

Operation	Ops/sec (avg over 10 runs)
Burst Single Put	262.85k
Burst Single Get	735.99k
Burst Single Override Put	257.76k
Burst Single Delete	287.94k
Batch Put	1116.69k

Windows x64

Operation	Ops/sec (avg over 10 runs)
Burst Single Put	315.42k
Burst Single Get	522.96k
Burst Single Override Put	302.40k
Burst Single Delete	358.45k
Batch Put	936.79k
Batch Override Put	918.24k
Batch Delete	1266.11k

macOS arm64

Operation	Ops/sec (avg over 10 runs)
Burst Single Put	290.51k
Burst Single Get	689.45k
Burst Single Override Put	283.43k
Burst Single Delete	349.12k
Batch Put	1392.60k
Batch Override Put	1374.63k
Batch Delete	1919.41k

Quite good, I'd say!