1 files changed, 263 insertions, 0 deletions
diff --git a/src/bencode2.cc b/src/bencode2.cc
new file mode 100644
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--- /dev/null
+++ b/src/bencode2.cc
@@ -0,0 +1,263 @@
+/* <!-- copyright */
+/*
+ * aria2 - The high speed download utility
+ *
+ * Copyright (C) 2010 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 "bencode2.h"
+
+#include <fstream>
+#include <sstream>
+
+#include "StringFormat.h"
+#include "DlAbortEx.h"
+
+namespace aria2 {
+
+namespace bencode2 {
+
+static SharedHandle<ValueBase> decodeiter(std::istream& ss, size_t depth);
+
+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 SharedHandle<ValueBase> decodestring(std::istream& ss)
+{
+  return String::g(decoderawstring(ss));
+}
+
+static SharedHandle<ValueBase> decodeinteger(std::istream& ss)
+{
+  Integer::ValueType iv;
+  ss >> iv;
+  if(!ss) {
+    throw DL_ABORT_EX("Bencode decoding failed:"
+                      " Integer expected but none found");
+  }
+  checkdelim(ss, 'e');
+  return Integer::g(iv);
+}
+
+static SharedHandle<ValueBase> decodedict(std::istream& ss, size_t depth)
+{
+  SharedHandle<Dict> dict = Dict::g();
+  char c;
+  while(ss.get(c)) {
+    if(c == 'e') {
+      return dict;
+    } else {
+      ss.unget();
+      std::string key = decoderawstring(ss);
+      dict->put(key, decodeiter(ss, depth));
+    }
+  }
+  throw DL_ABORT_EX("Bencode decoding failed:"
+                    " Unexpected EOF in dict context. 'e' expected.");
+}
+
+static SharedHandle<ValueBase> decodelist(std::istream& ss, size_t depth)
+{
+  SharedHandle<List> list = List::g();
+  char c;
+  while(ss.get(c)) {
+    if(c == 'e') {
+      return list;
+    } else {
+      ss.unget();
+      list->append(decodeiter(ss, depth));
+    }
+  }
+  throw DL_ABORT_EX("Bencode decoding failed:"
+                    " Unexpected EOF in list context. 'e' expected.");
+}
+
+static void checkDepth(size_t depth)
+{
+  if(depth >= MAX_STRUCTURE_DEPTH) {
+    throw DL_ABORT_EX("Bencode decoding failed: Structure is too deep.");
+  }
+}
+
+static SharedHandle<ValueBase> decodeiter(std::istream& ss, size_t depth)
+{
+  checkDepth(depth);
+  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, depth+1);
+  } else if(c == 'l') {
+    return decodelist(ss, depth+1);
+  } else if(c == 'i') {
+    return decodeinteger(ss);
+  } else {
+    ss.unget();
+    return decodestring(ss);
+  }
+}
+
+SharedHandle<ValueBase> decode(std::istream& in)
+{
+  return decodeiter(in, 0);
+}
+
+SharedHandle<ValueBase> decode(const std::string& s)
+{
+  size_t end;
+  return decode(s, end);
+}
+
+SharedHandle<ValueBase> decode(const std::string& s, size_t& end)
+{
+  if(s.empty()) {
+    return SharedHandle<ValueBase>();
+  }
+  std::istringstream ss(s);
+
+  SharedHandle<ValueBase> vlb = decodeiter(ss, 0);
+  end = ss.tellg();
+  return vlb;
+}
+
+SharedHandle<ValueBase> decode(const unsigned char* data, size_t length)
+{
+  return decode(std::string(&data[0], &data[length]));
+}
+
+SharedHandle<ValueBase> decode(const unsigned char* data, size_t length, size_t& end)
+{
+  return decode(std::string(&data[0], &data[length]), end);
+}
+
+SharedHandle<ValueBase> 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());
+  }
+}
+
+std::string encode(const ValueBase* vlb)
+{
+  class BencodeValueBaseVisitor:public ValueBaseVisitor {
+  private:
+    std::ostringstream out_;
+  public:
+    virtual void visit(const String& string)
+    {
+      const std::string& s = string.s();
+      out_ << s.size() << ":";
+      out_.write(s.data(), s.size());
+    }
+
+    virtual void visit(const Integer& integer)
+    {
+      out_ << "i" << integer.i() << "e";
+    }
+
+    virtual void visit(const List& list)
+    {
+      out_ << "l";
+      for(List::ValueType::const_iterator i = list.begin(), eoi = list.end();
+          i != eoi; ++i){
+        (*i)->accept(*this);
+      }
+      out_ << "e";
+    }
+
+    virtual void visit(const Dict& dict)
+    {
+      out_ << "d";
+      for(Dict::ValueType::const_iterator i = dict.begin(), eoi = dict.end();
+          i != eoi; ++i){
+        const std::string& key = (*i).first;
+        out_ << key.size() << ":";
+        out_.write(key.data(), key.size());
+        (*i).second->accept(*this);
+      }
+      out_ << "e";
+    }
+
+    std::string getResult() const
+    {
+      return out_.str();
+    }
+  };
+  BencodeValueBaseVisitor visitor;
+  vlb->accept(visitor);
+  return visitor.getResult();
+}
+
+std::string encode(const SharedHandle<ValueBase>& vlb)
+{
+  return encode(vlb.get());
+}
+
+} // namespace bencode2
+
+} // namespace aria2