A multiplatform Kotlin library providing basic IO primitives. kotlinx-io is based on Okio but does not preserve backward compatibility with it.

The library is built around Buffer - a mutable sequence of bytes. Buffer works like a queue allowing one to read data from its head or write data to its tail.

Buffer provides functions to read and write data of different built-in types and copy data to or from other buffers. Depending on a target platform, extension functions allowing data exchange with platform-specific types are also provided.

Buffer consists of segments organized as a linked list. Segments allow reducing memory allocations during the buffer's expansion and copying. The latter is achieved by delegating or sharing the ownership over the underlying buffer's segments with other buffers.

The library also provides interfaces representing data sources and destinations - Source and Sink.

In addition to Buffer, the library provides an immutable sequence of bytes - ByteString.

There are two kotlinx-io modules:

• kotlinx-io-bytestring - provides ByteString.
• kotlinx-io-core - provides IO primitives (Buffer, Source, Sink), depends on kotlinx-io-bytestring.

Note that the library is experimental, and the API is subject to change.

Make sure that you have mavenCentral() in the list of repositories:

repositories {
    mavenCentral()
}

Add libraries to dependencies:

dependencies {
    implementation("org.jetbrains.kotlinx:kotlinx-io-core:0.2.0")
    implementation("org.jetbrains.kotlinx:kotlinx-io-bytestring:0.2.0")
}

In multiplatform projects, add a dependency to the commonMain source set dependencies:

kotlin {
    sourceSets {
        commonMain {
            dependencies {
                implementation("org.jetbrains.kotlinx:kotlinx-io-core:0.2.0")
                implementation("org.jetbrains.kotlinx:kotlinx-io-bytestring:0.2.0")
            }
        }
    }
}

Add libraries to dependencies:

<dependency>
    <groupId>org.jetbrains.kotlinx</groupId>
    <artifactId>kotlinx-io-core-jvm</artifactId>
    <version>0.2.0</version>
</dependency>
<dependency>
    <groupId>org.jetbrains.kotlinx</groupId>
    <artifactId>kotlinx-io-bytestring-jvm</artifactId>
    <version>0.2.0</version>
</dependency>

Read the Contributing Guidelines.

This project and the corresponding community are governed by the JetBrains Open Source and Community Code of Conduct. Please make sure you read it.

kotlinx-io is licensed under the Apache 2.0 License.

Thanks to everyone involved in the project.

A honorable mention goes to the developers of Okio that served as the foundation for kotlinx-io and to Jesse Wilson, for the help with Okio adaption, his suggestions, assistance and guidance with kotlinx-io development.