Function UnpackAsset

src/android/android_main.cpp:15–68

#include <vector>

static bool UnpackAsset(const char *pFilename)
{
	char aAssetFilename[IO_MAX_PATH_LENGTH] = "asset_integrity_files/";
	str_append(aAssetFilename, pFilename);

	// This uses SDL_RWFromFile because it can read Android assets,
	// which are files stored in the app's APK file. All data files
	// are stored as assets and unpacked to the external storage.
	SDL_RWops *pAssetFile = SDL_RWFromFile(aAssetFilename, "rb");
	if(!pAssetFile)
	{
		log_error("android", "Failed to open asset '%s' for reading", pFilename);
		return false;
	}

	const long int FileLength = SDL_RWsize(pAssetFile);
	if(FileLength < 0)
	{
		SDL_RWclose(pAssetFile);
		log_error("android", "Failed to determine length of asset '%s'", pFilename);
		return false;
	}

	char *pData = static_cast<char *>(malloc(FileLength));
	const size_t ReadLength = SDL_RWread(pAssetFile, pData, 1, FileLength);
	SDL_RWclose(pAssetFile);

	if(ReadLength != (size_t)FileLength)
	{
		free(pData);
		log_error("android", "Failed to read asset '%s' (read %" PRIzu ", wanted %ld)", pFilename, ReadLength, FileLength);
		return false;
	}

	IOHANDLE TargetFile = io_open(pFilename, IOFLAG_WRITE);
	if(!TargetFile)
	{
		free(pData);
		log_error("android", "Failed to open '%s' for writing", pFilename);
		return false;
	}

	const size_t WriteLength = io_write(TargetFile, pData, FileLength);
	io_close(TargetFile);
	free(pData);

	if(WriteLength != (size_t)FileLength)
	{
		log_error("android", "Failed to write data to '%s' (wrote %" PRIzu ", wanted %ld)", pFilename, WriteLength, FileLength);
		return false;
	}

	return true;
}

constexpr const char *INTEGRITY_INDEX = "integrity.txt";
constexpr const char *INTEGRITY_INDEX_SAVE = "integrity_save.txt";