godot/platform/android/file_access_android.cpp

/*************************************************************************/
/*  file_access_android.cpp                                              */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
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#include "file_access_android.h"
#include "core/print_string.h"

AAssetManager *FileAccessAndroid::asset_manager = nullptr;

FileAccess *FileAccessAndroid::create_android() {
	return memnew(FileAccessAndroid);
}

Error FileAccessAndroid::_open(const String &p_path, int p_mode_flags) {
	String path = fix_path(p_path).simplify_path();
	if (path.begins_with("/")) {
		path = path.substr(1, path.length());
	} else if (path.begins_with("res://")) {
		path = path.substr(6, path.length());
	}

	ERR_FAIL_COND_V(p_mode_flags & FileAccess::WRITE, ERR_UNAVAILABLE); //can't write on android..
	asset = AAssetManager_open(asset_manager, path.utf8().get_data(), AASSET_MODE_STREAMING);
	if (!asset) {
		return ERR_CANT_OPEN;
	}
	len = AAsset_getLength(asset);
	pos = 0;
	eof = false;

	return OK;
}

void FileAccessAndroid::close() {
	if (!asset) {
		return;
	}
	AAsset_close(asset);
	asset = nullptr;
}

bool FileAccessAndroid::is_open() const {
	return asset != nullptr;
}

void FileAccessAndroid::seek(uint64_t p_position) {
	ERR_FAIL_NULL(asset);

	AAsset_seek(asset, p_position, SEEK_SET);
	pos = p_position;
	if (pos > len) {
		pos = len;
		eof = true;
	} else {
		eof = false;
	}
}

void FileAccessAndroid::seek_end(int64_t p_position) {
	ERR_FAIL_NULL(asset);
	AAsset_seek(asset, p_position, SEEK_END);
	pos = len + p_position;
}

uint64_t FileAccessAndroid::get_position() const {
	return pos;
}

uint64_t FileAccessAndroid::get_len() const {
	return len;
}

bool FileAccessAndroid::eof_reached() const {
	return eof;
}

uint8_t FileAccessAndroid::get_8() const {
	if (pos >= len) {
		eof = true;
		return 0;
	}

	uint8_t byte;
	AAsset_read(asset, &byte, 1);
	pos++;
	return byte;
}

uint64_t FileAccessAndroid::get_buffer(uint8_t *p_dst, uint64_t p_length) const {
	ERR_FAIL_COND_V(!p_dst && p_length > 0, -1);

	int r = AAsset_read(asset, p_dst, p_length);

	if (pos + p_length > len) {
		eof = true;
	}

	if (r >= 0) {
		pos += r;
		if (pos > len) {
			pos = len;
		}
	}
	return r;
}

Error FileAccessAndroid::get_error() const {
	return eof ? ERR_FILE_EOF : OK; //not sure what else it may happen
}

void FileAccessAndroid::flush() {
	ERR_FAIL();
}

void FileAccessAndroid::store_8(uint8_t p_dest) {
	ERR_FAIL();
}

bool FileAccessAndroid::file_exists(const String &p_path) {
	String path = fix_path(p_path).simplify_path();
	if (path.begins_with("/")) {
		path = path.substr(1, path.length());
	} else if (path.begins_with("res://")) {
		path = path.substr(6, path.length());
	}
	AAsset *at = AAssetManager_open(asset_manager, path.utf8().get_data(), AASSET_MODE_STREAMING);

	if (!at) {
		return false;
	}

	AAsset_close(at);
	return true;
}

FileAccessAndroid::~FileAccessAndroid() {
	close();
}