text: /*************************************************************************/
  /*  file_access.cpp                                                      */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
  /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #include "file_access.h"
  
  #include "core/crypto/crypto_core.h"
  #include "core/io/file_access_pack.h"
  #include "core/io/marshalls.h"
  #include "core/os/os.h"
  #include "core/project_settings.h"
  
  FileAccess::CreateFunc FileAccess::create_func[ACCESS_MAX] = { 0, 0 };
  
  FileAccess::FileCloseFailNotify FileAccess::close_fail_notify = NULL;
  
  bool FileAccess::backup_save = false;
  
  FileAccess *FileAccess::create(AccessType p_access) {
  
  	ERR_FAIL_INDEX_V(p_access, ACCESS_MAX, 0);
  
  	FileAccess *ret = create_func[p_access]();
  	ret->_set_access_type(p_access);
  	return ret;
  }
  
  bool FileAccess::exists(const String &p_name) {
  
  	if (PackedData::get_singleton() && PackedData::get_singleton()->has_path(p_name))
  		return true;
  
  	FileAccess *f = open(p_name, READ);
  	if (!f)
  		return false;
  	memdelete(f);
  	return true;
  }
  
  void FileAccess::_set_access_type(AccessType p_access) {
  
  	_access_type = p_access;
  };
  
  FileAccess *FileAccess::create_for_path(const String &p_path) {
  
  	FileAccess *ret = NULL;
  	if (p_path.begins_with("res://")) {
  
  		ret = create(ACCESS_RESOURCES);
  	} else if (p_path.begins_with("user://")) {
  
  		ret = create(ACCESS_USERDATA);
  
  	} else {
  
  		ret = create(ACCESS_FILESYSTEM);
  	}
  
  	return ret;
  }
  
  Error FileAccess::reopen(const String &p_path, int p_mode_flags) {
  
  	return _open(p_path, p_mode_flags);
  };
  
  FileAccess *FileAccess::open(const String &p_path, int p_mode_flags, Error *r_error) {
  
  	//try packed data first
  
  	FileAccess *ret = NULL;
  	if (!(p_mode_flags & WRITE) && PackedData::get_singleton() && !PackedData::get_singleton()->is_disabled()) {
  		ret = PackedData::get_singleton()->try_open_path(p_path);
  		if (ret) {
  			if (r_error)
  				*r_error = OK;
  			return ret;
  		}
  	}
  
  	ret = create_for_path(p_path);
  	Error err = ret->_open(p_path, p_mode_flags);
  
  	if (r_error)
  		*r_error = err;
  	if (err != OK) {
  
  		memdelete(ret);
  		ret = NULL;
  	}
  
  	return ret;
  }
  
  FileAccess::CreateFunc FileAccess::get_create_func(AccessType p_access) {
  
  	return create_func[p_access];
  };
  
  String FileAccess::fix_path(const String &p_path) const {
  	//helper used by file accesses that use a single filesystem
  
  	String r_path = p_path.replace("\\", "/");
  
  	switch (_access_type) {
  
  		case ACCESS_RESOURCES: {
  
  			if (ProjectSettings::get_singleton()) {
  				if (r_path.begins_with("res://")) {
  
  					String resource_path = ProjectSettings::get_singleton()->get_resource_path();
  					if (resource_path != "") {
  
  						return r_path.replace("res:/", resource_path);
  					};
  					return r_path.replace("res://", "");
  				}
  			}
  
  		} break;
  		case ACCESS_USERDATA: {
  
  			if (r_path.begins_with("user://")) {
  
  				String data_dir = OS::get_singleton()->get_user_data_dir();
  				if (data_dir != "") {
  
  					return r_path.replace("user:/", data_dir);
  				};
  				return r_path.replace("user://", "");
  			}
  
  		} break;
  		case ACCESS_FILESYSTEM: {
  
  			return r_path;
  		} break;
  		case ACCESS_MAX: break; // Can't happen, but silences warning
  	}
  
  	return r_path;
  }
  
  /* these are all implemented for ease of porting, then can later be optimized */
  
  uint16_t FileAccess::get_16() const {
  
  	uint16_t res;
  	uint8_t a, b;
  
  	a = get_8();
  	b = get_8();
  
  	if (endian_swap) {
  
  		SWAP(a, b);
  	}
  
  	res = b;
  	res <<= 8;
  	res |= a;
  
  	return res;
  }
  uint32_t FileAccess::get_32() const {
  
  	uint32_t res;
  	uint16_t a, b;
  
  	a = get_16();
  	b = get_16();
  
  	if (endian_swap) {
  
  		SWAP(a, b);
  	}
  
  	res = b;
  	res <<= 16;
  	res |= a;
  
  	return res;
  }
  uint64_t FileAccess::get_64() const {
  
  	uint64_t res;
  	uint32_t a, b;
  
  	a = get_32();
  	b = get_32();
  
  	if (endian_swap) {
  
  		SWAP(a, b);
  	}
  
  	res = b;
  	res <<= 32;
  	res |= a;
  
  	return res;
  }
  
  float FileAccess::get_float() const {
  
  	MarshallFloat m;
  	m.i = get_32();
  	return m.f;
  };
  
  real_t FileAccess::get_real() const {
  
  	if (real_is_double)
  		return get_double();
  	else
  		return get_float();
  }
  
  double FileAccess::get_double() const {
  
  	MarshallDouble m;
  	m.l = get_64();
  	return m.d;
  };
  
  String FileAccess::get_token() const {
  
  	CharString token;
  
  	CharType c = get_8();
  
  	while (!eof_reached()) {
  
  		if (c <= ' ') {
  			if (token.length())
  				break;
  		} else {
  			token += c;
  		}
  		c = get_8();
  	}
  
  	return String::utf8(token.get_data());
  }
  
  class CharBuffer {
  	std::vector<char> vector;
  	char stack_buffer[256];
  
  	char *buffer;
  	int capacity;
  	int written;
  
  	bool grow() {
  		vector.resize(next_power_of_2(1 + written));
  
  		if (buffer == stack_buffer) { // first chunk?
  
  			for (int i = 0; i < written; i++) {
  
  				vector[i] = stack_buffer[i];
  			}
  		}
  
  		buffer = vector.data();
  		capacity = vector.size();
  		ERR_FAIL_COND_V(written >= capacity, false);
  
  		return true;
  	}
  
  public:
  	_FORCE_INLINE_ CharBuffer() :
  			buffer(stack_buffer),
  			capacity(sizeof(stack_buffer) / sizeof(char)),
  			written(0) {
  	}
  
  	_FORCE_INLINE_ void push_back(char c) {
  
  		if (written >= capacity) {
  
  			ERR_FAIL_COND(!grow());
  		}
  
  		buffer[written++] = c;
  	}
  
  	_FORCE_INLINE_ const char *get_data() const {
  
  		return buffer;
  	}
  };
  
  String FileAccess::get_line() const {
  
  	CharBuffer line;
  
  	CharType c = get_8();
  
  	while (!eof_reached()) {
  
  		if (c == '\n' || c == '\0') {
  			line.push_back(0);
  			return String::utf8(line.get_data());
  		} else if (c != '\r')
  			line.push_back(c);
  
  		c = get_8();
  	}
  	line.push_back(0);
  	return String::utf8(line.get_data());
  }
  
  std::vector<String> FileAccess::get_csv_line(const String &p_delim) const {
  
  	ERR_FAIL_COND_V(p_delim.length() != 1, std::vector<String>());
  
  	String l;
  	int qc = 0;
  	do {
  		if (eof_reached())
  			break;
  
  		l += get_line() + "\n";
  		qc = 0;
  		for (int i = 0; i < l.length(); i++) {
  
  			if (l[i] == '"')
  				qc++;
  		}
  
  	} while (qc % 2);
  
  	l = l.substr(0, l.length() - 1);
  
  	std::vector<String> strings;
  
  	bool in_quote = false;
  	String current;
  	for (int i = 0; i < l.length(); i++) {
  
  		CharType c = l[i];
  		CharType s[2] = { 0, 0 };
  
  		if (!in_quote && c == p_delim[0]) {
  			strings.push_back(current);
  			current = String();
  		} else if (c == '"') {
  			if (l[i + 1] == '"') {
  				s[0] = '"';
  				current += s;
  				i++;
  			} else {
  
  				in_quote = !in_quote;
  			}
  		} else {
  			s[0] = c;
  			current += s;
  		}
  	}
  
  	strings.push_back(current);
  
  	return strings;
  }
  
  int FileAccess::get_buffer(uint8_t *p_dst, int p_length) const {
  
  	int i = 0;
  	for (i = 0; i < p_length && !eof_reached(); i++)
  		p_dst[i] = get_8();
  
  	return i;
  }
  
  String FileAccess::get_as_utf8_string() const {
  	PoolVector<uint8_t> sourcef;
  	int len = get_len();
  	sourcef.resize(len + 1);
  
  	PoolVector<uint8_t>::Write w = sourcef.write();
  	int r = get_buffer(w.ptr(), len);
  	ERR_FAIL_COND_V(r != len, String());
  	w[len] = 0;
  
  	String s;
  	if (s.parse_utf8((const char *)w.ptr())) {
  		return String();
  	}
  	return s;
  }
  
  void FileAccess::store_16(uint16_t p_dest) {
  
  	uint8_t a, b;
  
  	a = p_dest & 0xFF;
  	b = p_dest >> 8;
  
  	if (endian_swap) {
  
  		SWAP(a, b);
  	}
  
  	store_8(a);
  	store_8(b);
  }
  void FileAccess::store_32(uint32_t p_dest) {
  
  	uint16_t a, b;
  
  	a = p_dest & 0xFFFF;
  	b = p_dest >> 16;
  
  	if (endian_swap) {
  
  		SWAP(a, b);
  	}
  
  	store_16(a);
  	store_16(b);
  }
  void FileAccess::store_64(uint64_t p_dest) {
  
  	uint32_t a, b;
  
  	a = p_dest & 0xFFFFFFFF;
  	b = p_dest >> 32;
  
  	if (endian_swap) {
  
  		SWAP(a, b);
  	}
  
  	store_32(a);
  	store_32(b);
  }
  
  void FileAccess::store_real(real_t p_real) {
  
  	if (sizeof(real_t) == 4)
  		store_float(p_real);
  	else
  		store_double(p_real);
  }
  
  void FileAccess::store_float(float p_dest) {
  
  	MarshallFloat m;
  	m.f = p_dest;
  	store_32(m.i);
  };
  
  void FileAccess::store_double(double p_dest) {
  
  	MarshallDouble m;
  	m.d = p_dest;
  	store_64(m.l);
  };
  
  uint64_t FileAccess::get_modified_time(const String &p_file) {
  
  	if (PackedData::get_singleton() && !PackedData::get_singleton()->is_disabled() && PackedData::get_singleton()->has_path(p_file))
  		return 0;
  
  	FileAccess *fa = create_for_path(p_file);
  	ERR_FAIL_COND_V_MSG(!fa, 0, "Cannot create FileAccess for path '" + p_file + "'.");
  
  	uint64_t mt = fa->_get_modified_time(p_file);
  	memdelete(fa);
  	return mt;
  }
  
  uint32_t FileAccess::get_unix_permissions(const String &p_file) {
  
  	if (PackedData::get_singleton() && !PackedData::get_singleton()->is_disabled() && PackedData::get_singleton()->has_path(p_file))
  		return 0;
  
  	FileAccess *fa = create_for_path(p_file);
  	ERR_FAIL_COND_V_MSG(!fa, 0, "Cannot create FileAccess for path '" + p_file + "'.");
  
  	uint32_t mt = fa->_get_unix_permissions(p_file);
  	memdelete(fa);
  	return mt;
  }
  
  Error FileAccess::set_unix_permissions(const String &p_file, uint32_t p_permissions) {
  
  	FileAccess *fa = create_for_path(p_file);
  	ERR_FAIL_COND_V_MSG(!fa, ERR_CANT_CREATE, "Cannot create FileAccess for path '" + p_file + "'.");
  
  	Error err = fa->_set_unix_permissions(p_file, p_permissions);
  	memdelete(fa);
  	return err;
  }
  
  void FileAccess::store_string(const String &p_string) {
  
  	if (p_string.length() == 0)
  		return;
  
  	CharString cs = p_string.utf8();
  	store_buffer((uint8_t *)&cs[0], cs.length());
  }
  
  void FileAccess::store_pascal_string(const String &p_string) {
  
  	CharString cs = p_string.utf8();
  	store_32(cs.length());
  	store_buffer((uint8_t *)&cs[0], cs.length());
  };
  
  String FileAccess::get_pascal_string() {
  
  	uint32_t sl = get_32();
  	CharString cs;
  	cs.resize(sl + 1);
  	get_buffer((uint8_t *)cs.ptr(), sl);
  	cs[sl] = 0;
  
  	String ret;
  	ret.parse_utf8(cs.ptr());
  
  	return ret;
  };
  
  void FileAccess::store_line(const String &p_line) {
  
  	store_string(p_line);
  	store_8('\n');
  }
  
  void FileAccess::store_csv_line(const std::vector<String> &p_values, const String &p_delim) {
  
  	ERR_FAIL_COND(p_delim.length() != 1);
  
  	String line = "";
  	int size = p_values.size();
  	for (int i = 0; i < size; ++i) {
  		String value = p_values[i];
  
  		if (value.find("\"") != -1 || value.find(p_delim) != -1 || value.find("\n") != -1) {
  			value = "\"" + value.replace("\"", "\"\"") + "\"";
  		}
  		if (i < size - 1) {
  			value += p_delim;
  		}
  
  		line += value;
  	}
  
  	store_line(line);
  }
  
  void FileAccess::store_buffer(const uint8_t *p_src, int p_length) {
  
  	for (int i = 0; i < p_length; i++)
  		store_8(p_src[i]);
  }
  
  std::vector<uint8_t> FileAccess::get_file_as_array(const String &p_path, Error *r_error) {
  
  	FileAccess *f = FileAccess::open(p_path, READ, r_error);
  	if (!f) {
  		if (r_error) { // if error requested, do not throw error
  			return std::vector<uint8_t>();
  		}
  		ERR_FAIL_V_MSG(std::vector<uint8_t>(), "Can't open file from path '" + String(p_path) + "'.");
  	}
  	std::vector<uint8_t> data;
  	data.resize(f->get_len());
  	f->get_buffer(data.data(), data.size());
  	memdelete(f);
  	return data;
  }
  
  String FileAccess::get_file_as_string(const String &p_path, Error *r_error) {
  
  	Error err;
  	std::vector<uint8_t> array = get_file_as_array(p_path, &err);
  	if (r_error) {
  		*r_error = err;
  	}
  	if (err != OK) {
  		if (r_error) {
  			return String();
  		}
  		ERR_FAIL_V_MSG(String(), "Can't get file as string from path '" + String(p_path) + "'.");
  	}
  
  	String ret;
  	ret.parse_utf8((const char *)array.data(), array.size());
  	return ret;
  }
  
  String FileAccess::get_md5(const String &p_file) {
  
  	FileAccess *f = FileAccess::open(p_file, READ);
  	if (!f)
  		return String();
  
  	CryptoCore::MD5Context ctx;
  	ctx.start();
  
  	unsigned char step[32768];
  
  	while (true) {
  
  		int br = f->get_buffer(step, 32768);
  		if (br > 0) {
  
  			ctx.update(step, br);
  		}
  		if (br < 4096)
  			break;
  	}
  
  	unsigned char hash[16];
  	ctx.finish(hash);
  
  	memdelete(f);
  
  	return String::md5(hash);
  }
  
  String FileAccess::get_multiple_md5(const std::vector<String> &p_file) {
  
  	CryptoCore::MD5Context ctx;
  	ctx.start();
  
  	for (int i = 0; i < p_file.size(); i++) {
  		FileAccess *f = FileAccess::open(p_file[i], READ);
  		ERR_CONTINUE(!f);
  
  		unsigned char step[32768];
  
  		while (true) {
  
  			int br = f->get_buffer(step, 32768);
  			if (br > 0) {
  
  				ctx.update(step, br);
  			}
  			if (br < 4096)
  				break;
  		}
  		memdelete(f);
  	}
  
  	unsigned char hash[16];
  	ctx.finish(hash);
  
  	return String::md5(hash);
  }
  
  String FileAccess::get_sha256(const String &p_file) {
  
  	FileAccess *f = FileAccess::open(p_file, READ);
  	if (!f)
  		return String();
  
  	CryptoCore::SHA256Context ctx;
  	ctx.start();
  
  	unsigned char step[32768];
  
  	while (true) {
  
  		int br = f->get_buffer(step, 32768);
  		if (br > 0) {
  
  			ctx.update(step, br);
  		}
  		if (br < 4096)
  			break;
  	}
  
  	unsigned char hash[32];
  	ctx.finish(hash);
  
  	memdelete(f);
  	return String::hex_encode_buffer(hash, 32);
  }
  
  FileAccess::FileAccess() {
  
  	endian_swap = false;
  	real_is_double = false;
  	_access_type = ACCESS_FILESYSTEM;
  };
  