Upload Apkdiff Module Source Code

apkdiff/README.md

@@ -0,0 +1,86 @@
+# apkdiff
+
+APK 增量更新模块，基于 [bsdiff](https://github.com/mendsley/bsdiff) + zlib + minizip。
+
+通过对比新旧 APK 中每个文件的内容差异，生成体积远小于完整 APK 的 patch 文件，在设备端应用 patch 生成新 APK。
+
+## 结构
+
+```
+├── bsdiff.c / bsdiff.h     # bsdiff 核心算法（原库，未修改）
+├── bspatch.c / bspatch.h   # bspatch 核心算法（原库，未修改）
+├── common/
+│   ├── patch_format.h      # Patch 文件格式定义
+│   └── zlib_stream.h/.c    # zlib 压缩/解压，适配 bsdiff/bspatch stream
+├── gen/
+│   ├── CMakeLists.txt      # 构建 gen.exe
+│   └── main.c              # Patch 生成工具入口
+├── jni/
+│   ├── CMakeLists.txt      # NDK CMake 构建
+│   ├── Android.mk          # 备选 ndk-build 构建
+│   ├── Application.mk      # NDK 配置
+│   ├── apkpatch.c          # JNI native 实现
+│   └── Patcher.kt          # Kotlin 包装类
+└── third_party/
+    └── zlib/               # zlib 源码（作为 submodule 或直接包含）
+```
+
+## Patch 文件格式
+
+```
+Header:
+  [16B]  Magic "APKDIFF/1.0\0\0\0"
+  [4B]   uint32_t entry_count
+
+Entry (×entry_count):
+  [2B]   uint16_t path_len
+  [NB]   path
+  [1B]   type  (0=PATCH, 1=NEW, 2=COPY)
+  [8B]   int64_t old_size
+  [8B]   int64_t new_size
+  [4B]   uint32_t compressed_size
+  [NB]   zlib compressed data (COPY 时无数据)
+```
+
+## gen.exe 编译（Windows）
+
+需要 MSVC + CMake：
+
+```bash
+cmake -B gen/build -S gen -G "Visual Studio 18 2026" -A x64
+cmake --build gen/build --config Release
+```
+
+## gen.exe 用法
+
+```bash
+gen.exe <old.apk> <new.apk> <output.patch>
+```
+
+## JNI 编译（Android NDK）
+
+```bash
+cmake -B jni/build/arm64-v8a -S jni \
+  -G "Unix Makefiles" \
+  -DCMAKE_TOOLCHAIN_FILE=<NDK>/build/cmake/android.toolchain.cmake \
+  -DANDROID_ABI=arm64-v8a \
+  -DANDROID_PLATFORM=android-21 \
+  -DCMAKE_BUILD_TYPE=Release \
+  -DCMAKE_MAKE_PROGRAM=<NDK>/prebuilt/windows-x86_64/bin/make.exe
+
+make -C jni/build/arm64-v8a -j8
+```
+
+## Android 端使用
+
+```kotlin
+import love.qz.apkpatcher.Patcher
+
+val oldApk = context.applicationInfo.sourceDir
+val result = Patcher.applyPatch(oldApk, patchPath, newApkPath)
+// result == 0 → 成功
+```
+
+## License
+
+BSD 2-Clause (bsdiff/bspatch), zlib License (zlib/minizip)