api.h

#ifndef UNPACKRAT_API_H
#define UNPACKRAT_API_H

/**
This file is licensed under the GNU LGPLv3.
It includes/modifies code originally from Observer (https://github.com/lazyhamster/Observer).
**/

// The minimum required platform is Windows Vista. WINVER and _WIN32_WINNT (both 0x0600) are
// supplied as compiler definitions by the shared MSBuild toolchain in build/unpackrat-project.props,
// so this header no longer declares the reserved _WIN32_WINNT identifier itself.

// Exclude rarely-used stuff from Windows headers.
#define WIN32_LEAN_AND_MEAN

#include <windows.h>

#define MODULE_EXPORT __stdcall

// Extract progress callbacks
typedef int(CALLBACK *ExtractProgressFunc)(HANDLE, __int64);

#pragma pack(push, 1)

struct ExtractProcessCallbacks
{
    HANDLE signalContext;
    ExtractProgressFunc FileProgress;
};

#define ACTUAL_API_VERSION 6
#define STORAGE_FORMAT_NAME_MAX_LEN 32
#define STORAGE_PARAM_MAX_LEN 64

struct StorageGeneralInfo
{
    wchar_t Format[STORAGE_FORMAT_NAME_MAX_LEN];
    wchar_t Compression[STORAGE_PARAM_MAX_LEN];
    wchar_t Comment[STORAGE_PARAM_MAX_LEN];
    FILETIME Created;
};

struct StorageOpenParams
{
    size_t StructSize;
    const wchar_t *FilePath;
    const char *Password;
    const void *Data;
    size_t DataSize;
};

struct StorageItemInfo
{
    __int64 Size;
    __int64 PackedSize;
    DWORD Attributes;
    FILETIME CreationTime;
    FILETIME ModificationTime;
    WORD NumHardlinks;
    wchar_t Owner[64];
    wchar_t Path[1024];
};

struct ExtractOperationParams
{
    int ItemIndex;
    int Flags;
    const wchar_t *DestPath;
    const char *Password;
    ExtractProcessCallbacks Callbacks;
};

typedef int(MODULE_EXPORT *OpenStorageFunc)(StorageOpenParams params, HANDLE *storage, StorageGeneralInfo *info);

typedef int(MODULE_EXPORT *PrepareFilesFunc)(HANDLE storage);

typedef void(MODULE_EXPORT *CloseStorageFunc)(HANDLE storage);

typedef int(MODULE_EXPORT *GetItemFunc)(HANDLE storage, int item_index, StorageItemInfo *item_info);

typedef int(MODULE_EXPORT *ExtractFunc)(HANDLE storage, ExtractOperationParams params);

struct module_cbs
{
    OpenStorageFunc OpenStorage;
    CloseStorageFunc CloseStorage;
    GetItemFunc GetItem;
    ExtractFunc ExtractItem;
    PrepareFilesFunc PrepareFiles;
};

struct ModuleLoadParameters
{
    // IN
    size_t StructSize;
    const wchar_t *Settings;
    // OUT
    GUID ModuleId;
    DWORD ModuleVersion;
    DWORD ApiVersion;
    module_cbs ApiFuncs;
};

#pragma pack(pop)

// Function that should be exported from modules
typedef int(MODULE_EXPORT *LoadSubModuleFunc)(ModuleLoadParameters *);

typedef void(MODULE_EXPORT *UnloadSubModuleFunc)(void);

#define MAKEMODULEVERSION(mj, mn) (((mj) << 16U) | (mn))
#define STRBUF_SIZE(x) (sizeof(x) / sizeof((x)[0]))

// Open storage return results
#define SOR_INVALID_FILE 0
#define SOR_SUCCESS 1
#define SOR_PASSWORD_REQUIRED 2

// Item retrieval result
#define GET_ITEM_ERROR 0
#define GET_ITEM_OK 1
#define GET_ITEM_NOMOREITEMS 2

// Extract result
#define SER_SUCCESS 0
#define SER_ERROR_WRITE 1
#define SER_ERROR_READ 2
#define SER_ERROR_SYSTEM 3
#define SER_USERABORT 4
#define SER_PASSWORD_REQUIRED 5
#endif