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/* <!-- copyright */
/*
* aria2 - The high speed download utility
*
* Copyright (C) 2006 Tatsuhiro Tsujikawa
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of portions of this program with the
* OpenSSL library under certain conditions as described in each
* individual source file, and distribute linked combinations
* including the two.
* You must obey the GNU General Public License in all respects
* for all of the code used other than OpenSSL. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you
* do not wish to do so, delete this exception statement from your
* version. If you delete this exception statement from all source
* files in the program, then also delete it here.
*/
/* copyright --> */
#include "bencode.h"
#include <fstream>
#include <sstream>
#include "StringFormat.h"
#include "DlAbortEx.h"
namespace aria2 {
namespace bencode {
static BDE decodeiter(std::istream& ss);
static void checkdelim(std::istream& ss, const char delim = ':')
{
char d;
if(!(ss.get(d) && d == delim)) {
throw DL_ABORT_EX
(StringFormat("Bencode decoding failed: Delimiter '%c' not found.",
delim).str());
}
}
static std::string decoderawstring(std::istream& ss)
{
int length;
ss >> length;
if(!ss || length < 0) {
throw DL_ABORT_EX("Bencode decoding failed:"
" A positive integer expected but none found.");
}
// TODO check length, it must be less than or equal to INT_MAX
checkdelim(ss);
char* buf = new char[length];
ss.read(buf, length);
std::string str(&buf[0], &buf[length]);
delete [] buf;
if(ss.gcount() != static_cast<int>(length)) {
throw DL_ABORT_EX
(StringFormat("Bencode decoding failed:"
" Expected %lu bytes of data, but only %d read.",
static_cast<unsigned long>(length), ss.gcount()).str());
}
return str;
}
static BDE decodestring(std::istream& ss)
{
return BDE(decoderawstring(ss));
}
static BDE decodeinteger(std::istream& ss)
{
BDE::Integer integer;
ss >> integer;
if(!ss) {
throw DL_ABORT_EX("Bencode decoding failed:"
" Integer expected but none found");
}
checkdelim(ss, 'e');
return BDE(integer);
}
static BDE decodedict(std::istream& ss)
{
BDE dict = BDE::dict();
char c;
while(ss.get(c)) {
if(c == 'e') {
return dict;
} else {
ss.unget();
std::string key = decoderawstring(ss);
dict[key] = decodeiter(ss);
}
}
throw DL_ABORT_EX("Bencode decoding failed:"
" Unexpected EOF in dict context. 'e' expected.");
}
static BDE decodelist(std::istream& ss)
{
BDE list = BDE::list();
char c;
while(ss.get(c)) {
if(c == 'e') {
return list;
} else {
ss.unget();
list << decodeiter(ss);
}
}
throw DL_ABORT_EX("Bencode decoding failed:"
" Unexpected EOF in list context. 'e' expected.");
}
static BDE decodeiter(std::istream& ss)
{
char c;
if(!ss.get(c)) {
throw DL_ABORT_EX("Bencode decoding failed:"
" Unexpected EOF in term context."
" 'd', 'l', 'i' or digit is expected.");
}
if(c == 'd') {
return decodedict(ss);
} else if(c == 'l') {
return decodelist(ss);
} else if(c == 'i') {
return decodeinteger(ss);
} else {
ss.unget();
return decodestring(ss);
}
}
BDE decode(std::istream& in)
{
return decodeiter(in);
}
BDE decode(const std::string& s)
{
if(s.empty()) {
return BDE::none;
}
std::istringstream ss(s);
return decodeiter(ss);
}
BDE decode(const unsigned char* data, size_t length)
{
return decode(std::string(&data[0], &data[length]));
}
BDE decodeFromFile(const std::string& filename)
{
std::ifstream f(filename.c_str(), std::ios::binary);
if(f) {
return decode(f);
} else {
throw DL_ABORT_EX
(StringFormat("Bencode decoding failed:"
" Cannot open file '%s'.", filename.c_str()).str());
}
}
static void encodeIter(std::ostream& o, const BDE& bde)
{
if(bde.isInteger()) {
o << "i" << bde.i() << "e";
} else if(bde.isString()) {
const std::string& s = bde.s();
o << s.size() << ":";
o.write(s.data(), s.size());
} else if(bde.isDict()) {
o << "d";
for(BDE::Dict::const_iterator i = bde.dictBegin(); i != bde.dictEnd(); ++i){
const std::string& key = (*i).first;
o << key.size() << ":";
o.write(key.data(), key.size());
encodeIter(o, (*i).second);
}
o << "e";
} else if(bde.isList()) {
o << "l";
for(BDE::List::const_iterator i = bde.listBegin(); i != bde.listEnd(); ++i){
encodeIter(o, *i);
}
o << "e";
}
}
std::string encode(const BDE& bde)
{
std::ostringstream ss;
encodeIter(ss, bde);
return ss.str();
}
} // namespace bencode
} // namespace aria2
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