lz4.Compressor

The Compressor struct maintains a persistent configuration, memory allocator, and optional dictionary. Reusing a Compressor instance avoids re-initializing configuration tables across multiple compression calls.

pub const Compressor = struct {
    allocator: std.mem.Allocator,
    options: CompressionOptions,
    dict: ?[]const u8 = null,
    // ...
};

---

Methods

init

pub fn init(allocator: std.mem.Allocator, opts: CompressionOptions) Compressor

Initializes a new Compressor instance with the specified allocator and compression options.

Parameters

• allocator: Memory allocator used for allocated compression outputs.
• opts: Configuration options controlling level, block max size, checksums, etc.

---

deinit

pub fn deinit(self: *Compressor) void

Releases any internal resources owned by the compressor.

---

reset

pub fn reset(self: *Compressor, opts: CompressionOptions) void

Resets the compressor options and dictionary without re-allocating the struct itself.

---

attachDictionary

pub fn attachDictionary(self: *Compressor, dict: []const u8) void

Attaches an in-memory dictionary slice for subsequent compression operations.

---

compress

pub fn compress(self: *Compressor, src: []const u8) ![]u8

Compresses src into a newly allocated slice containing a valid LZ4 Frame. The caller owns the returned slice and must free it using self.allocator.

Errors

• error.OutOfMemory: Failed to allocate output frame buffer.
• error.InputTooLarge: Input exceeds MAX_INPUT_SIZE.
• Other CompressionError codes.

---

compressInto

pub fn compressInto(self: *Compressor, src: []const u8, dst: []u8) !usize

Compresses src directly into the caller-provided dst buffer (in LZ4 Frame format). Returns the number of compressed bytes written into dst.

Errors

• error.DestinationBufferTooSmall: dst buffer capacity is insufficient.
• error.InputTooLarge: src exceeds maximum format size.
• Other CompressionError codes.

---

Example Usage

const std = @import("std");
const lz4 = @import("lz4");

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();

    var compressor = lz4.Compressor.init(allocator, .{
        .level = 1,
        .contentChecksum = true,
    });
    defer compressor.deinit();

    const output1 = try compressor.compress("First payload data");
    defer allocator.free(output1);

    const output2 = try compressor.compress("Second payload data");
    defer allocator.free(output2);
}