lz4.DecompressionOptions

DecompressionOptions configures bounds checking, dictionaries, and safety constraints for the decompression engine.

pub const DecompressionOptions = struct {
    maxOutputSize: usize = 128 * 1024 * 1024,
    customDictionary: ?[]const u8 = null,
};

---

Fields

maxOutputSize

• Type: usize
• Default: 128 * 1024 * 1024 (128 MiB)
• Description: Safety cap defining the maximum permitted buffer allocation for uncompressed output.
  • If a compressed stream attempts to decode more bytes than this limit (e.g. from a corrupted header or a malicious "zip bomb" style attack), decompression immediately aborts with error.OutputTooLarge.
  • Set this value according to your application's expected data sizes and memory budget.

customDictionary

• Type: ?[]const u8
• Default: null
• Description: In-memory dictionary slice for decoding payloads that were compressed with a reference dictionary.

---

Example Usage

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

pub fn safeDecompress(allocator: std.mem.Allocator, untrusted_data: []const u8) ![]u8 {
    return lz4.decompressWithOptions(allocator, untrusted_data, .{
        .maxOutputSize = 16 * 1024 * 1024, // 16 MiB max
        .customDictionary = null,
    });
}