Slice is a Java library for efficiently working with Java byte arrays. Slice provides fast and efficient methods such as read a long at an index without having to assemble the long from individual bytes. In addition to reading and writing single private values, there are methods to bulk transfer data to and from primitive arrays.

Slice uses the Vector API for UTF-8 validation, so the JVM must be started with --add-modules jdk.incubator.vector.

Slice provides classes for interacting with InputStreams and OutputStreams. The classes support the same fast single primitive access and bulk transfer methods as the Slice class.

Slice provides a library for interacting UTF-8 data stored in byte arrays. The UTF-8 library provides functions to count code points, substring, trim, case change, and so on.

This library stores multi-byte values in little-endian byte order. This is distinct from the endianness of the CPU running the code.

Previous versions used sun.misc.Unsafe to read and write multi-byte values directly to memory. This bypassed Java's abstractions and assumed the underlying CPU was little-endian. On a big-endian CPU, values would be silently corrupted.

This version uses VarHandles and MemorySegment, which explicitly specify little-endian byte order. These APIs handle the conversion transparently—on a big-endian CPU, Java automatically swaps bytes when reading or writing. The data format remains little-endian for compatibility, but the library now works correctly on any CPU architecture.

The hash functions (XxHash64, Murmur3) also use little-endian byte order, as required by their specifications.

Version of Slice before 2.0 support off-heap memory and can be backed by any Java primitive array type. These features were rarely used, and were removed in version 2.0 to simplify the codebase. If you need these versions, they are available in the release-0.x branch.