Module patch

wow_mpq

Module patch 

Source
Expand description

MPQ patch file support

This module implements support for binary patch files (PTCH format) used in Cataclysm and later WoW expansions. Patch files contain binary diffs that must be applied to base files to reconstruct the final file.

§Automatic Patch Handling

In most cases, you don’t need to use this module directly. The PatchChain automatically detects and applies patch files when reading files from a chain of archives.

use wow_mpq::PatchChain;

let mut chain = PatchChain::new();
chain.add_archive("base.MPQ", 0)?;
chain.add_archive("patch-1.MPQ", 100)?;

// If the file exists as a patch in patch-1.MPQ, it will be automatically
// applied to the base file from base.MPQ
let data = chain.read_file("some/file.txt")?;

§Patch File Format

Patch files use the PTCH format with three main sections:

  1. PTCH Header - Basic metadata (sizes, signatures)
  2. MD5 Block - Checksums for verification
  3. XFRM Block - Patch data (COPY or BSD0 type)

§Patch Types

  • COPY (0x59504f43) - Simple file replacement
  • BSD0 (0x30445342) - Binary diff using bsdiff40 algorithm

§Manual Patch Application

For advanced use cases where you need to manually parse and apply patches:

use wow_mpq::patch::{PatchFile, apply_patch};

// Read patch file data (bypasses normal Archive::read_file rejection)
let patch_data = /* get patch data from archive */
let patch = PatchFile::parse(&patch_data)?;

// Apply patch to base file
let base_data = /* get base file data */
let patched = apply_patch(&patch, &base_data)?;

Structs§

PatchFile
Complete patch file with header and data
PatchHeader
PTCH file header containing all metadata

Enums§

PatchType
Patch file type

Functions§

apply_patch
Apply a patch file to base data