Bytes

This library contains an immutable representation of sequence of bytes: com.avast.bytes.Bytes.

The goal is to provide single immutable representation of bytes that is not dependent on a third-party library (like com.google.protobuf.ByteString). However, multiple implementations of the Bytes interface can be created using third-party libraries to take advantage of their benefits (io.netty.buffer.ByteBuf for example). Implementations that require third-party dependencies will be separated to their own module, while the core module provides only the API and implementations based on Java standard library.

Features of Bytes include:

• reading encapsulated data using random (Bytes.byteAt(int)) and linear (Bytes.newInputStream()) access
• zero copy substring views (Bytes.view(int, int))
• zero copy concat (Bytes.concat(otherBytes))
• utility methods for reading & writing hex strings (Bytes.copyFromHex(someBytes.toHexString))
• reading directly from InputStream (in some implementations, e.g. ByteArrayBytes.readFrom(is) or ByteArrayBytes.readFrom(is, offset, length))

Usage

Parsing Google Protocol Buffer message: Assume NotificationData is a class generated by protoc.

Bytes bytes = ...

try (InputStream bytesStream = bytes.newInputStream()) {
    NotificationData message = NotificationData.parseFrom(bytesStream);
}

Serializing Google Protocol Buffer message to Bytes:

NotificationData message = ...
try (Bytes.BuilderStream builder = ByteBufBytes.newBuilder(message.getSerializedSize())) {
    message.writeTo(builder);
    Bytes bytes = builder.toBytes();
}

...or serialize the message to ByteString as usual and wrap it with ByteStringBytes.

JDK-based implementations

The core module contains two implementations:

• ByteArrayBytes - backed by byte[]
• ByteBufferBytes - backed by java.nio.ByteBuffer

ByteArrayBytes bab = ByteArrayBytes.copyFrom(new byte[]{0, 0, 7});

ByteBufferBytes bbb = ByteBufferBytes.copyFrom(ByteBuffer.allocate(1024)); // the most useless buffer ever

com.google.protobuf.ByteString wrapper

The gpb module provides ByteStringBytes that implements Bytes by wrapping com.google.protobuf.ByteString.

ByteStringBytes bsb = ByteStringBytes.wrap(ByteString.copyFromUtf8("foo"));