fs_android.cpp

#define LOG_TAG "HodJni"

#include <android/log.h>
#include <android/asset_manager.h>
#include <android/asset_manager_jni.h>

#include <SDL.h>

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <unistd.h>

#include "fs.h"

static AAssetManager *_assetManager;
static const char *_dataPath;

static int asset_readfn(void *cookie, char *buf, int size) {
	AAsset *asset = (AAsset *)cookie;
	return AAsset_read(asset, buf, size);
}

static int asset_writefn(void *cookie, const char *buf, int size) {
	return -1;
}

static fpos_t asset_seekfn(void *cookie, fpos_t offset, int whence) {
	AAsset *asset = (AAsset *)cookie;
	return AAsset_seek(asset, offset, whence);
}

static int asset_closefn(void *cookie) {
	AAsset *asset = (AAsset *)cookie;
	AAsset_close(asset);
	return 0;
}

void android_setAssetManager(AAssetManager *assetManager) {
	_assetManager = assetManager;
}

FILE *android_fopen(const char *fname, const char *mode) {
	__android_log_print(ANDROID_LOG_INFO, LOG_TAG, "android_fopen '%s' mode '%s'", fname, mode);
	assert(mode[0] == 'r');
	if (1) { // support for gamedata files installed on external storage
		char path[MAXPATHLEN];
		snprintf(path, sizeof(path), "%s/%s", _dataPath, fname);
		struct stat st;
		if (stat(path, &st) == 0 && S_ISREG(st.st_mode)) {
			return fopen(path, mode);
		}
	}
	AAsset *asset = AAssetManager_open(_assetManager, fname, AASSET_MODE_STREAMING);
	if (asset) {
		FILE *fp = funopen(asset, asset_readfn, asset_writefn, asset_seekfn, asset_closefn);
		return fp;
	}
	return fopen(fname, mode);
}

//
// FileSystem
//

FileSystem::FileSystem(const char *dataPath, const char *savePath) {
	JNIEnv *env = (JNIEnv *)SDL_AndroidGetJNIEnv();
	jobject activity = (jobject)SDL_AndroidGetActivity();

	jmethodID methodGetAssets = env->GetMethodID(env->GetObjectClass(activity), "getAssets", "()Landroid/content/res/AssetManager;");
	assert(methodGetAssets);

	jobject localAssetManager = env->CallObjectMethod(activity, methodGetAssets);
	assert(localAssetManager);

	jobject globalAssetManager = env->NewGlobalRef(localAssetManager);
	assert(globalAssetManager);

	_assetManager = AAssetManager_fromJava(env, globalAssetManager);
	_dataPath = dataPath;
	_savePath = savePath;
	__android_log_print(ANDROID_LOG_INFO, LOG_TAG, "dataPath %s _assetManager %p", _dataPath, _assetManager);
}

FileSystem::~FileSystem() {
}

FILE *FileSystem::openAssetFile(const char *filename) {
	char *name = (char *)alloca(strlen(filename) + 1);
	for (int i = 0; i < strlen(filename) + 1; ++i) {
		if (filename[i] >= 'A' && filename[i] <= 'Z') {
			name[i] = 'a' + (filename[i] - 'A');
		} else {
			name[i] = filename[i];
		}
	}
	FILE *fp = android_fopen(name, "rb");
	__android_log_print(ANDROID_LOG_INFO, LOG_TAG, "android_fopen %s %p", name, fp);
	return fp;
}

FILE *FileSystem::openSaveFile(const char *filename, bool write) {
	FILE *fp = 0;
	char *prefPath = SDL_GetPrefPath(ANDROID_PACKAGE_NAME, "hode");
	if (prefPath) {
		char path[MAXPATHLEN];
		snprintf(path, sizeof(path), "%s/%s", prefPath, filename);
		fp = fopen(path, write ? "wb" : "rb");
		SDL_free(prefPath);
	}
	return fp;
}

int FileSystem::closeFile(FILE *fp) {
	const int err = ferror(fp);
	fclose(fp);
	return err;
}