src/encoding/block.cpp - ndn-cxx - Gitiles

 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
  * Copyright (c) 2013-2014 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
  * ndn-cxx library is free software: you can redistribute it and/or modify it under the
  * terms of the GNU Lesser General Public License as published by the Free Software
  * Foundation, either version 3 of the License, or (at your option) any later version.
  *
  * ndn-cxx library 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 Lesser General Public License for more details.
  *
  * You should have received copies of the GNU General Public License and GNU Lesser
  * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
  * <http://www.gnu.org/licenses/>.
  *
  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
  *
  * @author Alexander Afanasyev <http://lasr.cs.ucla.edu/afanasyev/index.html>
  */

 #include "common.hpp"

 #include "block.hpp"
 #include "block-helpers.hpp"

 #include "tlv.hpp"
 #include "encoding-buffer.hpp"
 #include "buffer-stream.hpp"

 #include <boost/lexical_cast.hpp>

 namespace ndn {

 const size_t MAX_SIZE_OF_BLOCK_FROM_STREAM = 8800;

 Block::Block()
   : m_type(std::numeric_limits<uint32_t>::max())
 {
 }

 Block::Block(const EncodingBuffer& buffer)
   : m_buffer(buffer.m_buffer)
   , m_begin(buffer.begin())
   , m_end(buffer.end())
   , m_size(m_end - m_begin)
 {
   m_value_begin = m_begin;
   m_value_end   = m_end;

   m_type = Tlv::readType(m_value_begin, m_value_end);
   uint64_t length = Tlv::readVarNumber(m_value_begin, m_value_end);
   if (length != static_cast<uint64_t>(m_value_end - m_value_begin))
     {
       throw Tlv::Error("TLV length doesn't match buffer length");
     }
 }

 Block::Block(const ConstBufferPtr& wire,
              uint32_t type,
              const Buffer::const_iterator& begin, const Buffer::const_iterator& end,
              const Buffer::const_iterator& valueBegin, const Buffer::const_iterator& valueEnd)
   : m_buffer(wire)
   , m_type(type)
   , m_begin(begin)
   , m_end(end)
   , m_size(m_end - m_begin)
   , m_value_begin(valueBegin)
   , m_value_end(valueEnd)
 {
 }

 Block::Block(const ConstBufferPtr& buffer)
   : m_buffer(buffer)
   , m_begin(m_buffer->begin())
   , m_end(m_buffer->end())
   , m_size(m_end - m_begin)
 {
   m_value_begin = m_begin;
   m_value_end   = m_end;

   m_type = Tlv::readType(m_value_begin, m_value_end);

   uint64_t length = Tlv::readVarNumber(m_value_begin, m_value_end);
   if (length != static_cast<uint64_t>(m_value_end - m_value_begin))
     {
       throw Tlv::Error("TLV length doesn't match buffer length");
     }
 }

 Block::Block(const ConstBufferPtr& buffer,
              const Buffer::const_iterator& begin, const Buffer::const_iterator& end,
              bool verifyLength/* = true*/)
   : m_buffer(buffer)
   , m_begin(begin)
   , m_end(end)
   , m_size(m_end - m_begin)
 {
   m_value_begin = m_begin;
   m_value_end   = m_end;

   m_type = Tlv::readType(m_value_begin, m_value_end);
   uint64_t length = Tlv::readVarNumber(m_value_begin, m_value_end);
   if (verifyLength)
     {
       if (length != static_cast<uint64_t>(m_value_end - m_value_begin))
         {
           throw Tlv::Error("TLV length doesn't match buffer length");
         }
     }
 }


 Block::Block(const uint8_t* buffer, size_t maxlength)
 {
   const uint8_t*  tmp_begin = buffer;
   const uint8_t*  tmp_end   = buffer + maxlength;

   m_type = Tlv::readType(tmp_begin, tmp_end);
   uint64_t length = Tlv::readVarNumber(tmp_begin, tmp_end);

   if (length > static_cast<uint64_t>(tmp_end - tmp_begin))
     {
       throw Tlv::Error("Not enough data in the buffer to fully parse TLV");
     }

   m_buffer = make_shared<Buffer>(buffer, (tmp_begin - buffer) + length);

   m_begin = m_buffer->begin();
   m_end = m_buffer->end();
   m_size = m_end - m_begin;

   m_value_begin = m_buffer->begin() + (tmp_begin - buffer);
   m_value_end   = m_buffer->end();
 }

 Block::Block(const void* bufferX, size_t maxlength)
 {
   const uint8_t* buffer = reinterpret_cast<const uint8_t*>(bufferX);

   const uint8_t* tmp_begin = buffer;
   const uint8_t* tmp_end   = buffer + maxlength;

   m_type = Tlv::readType(tmp_begin, tmp_end);
   uint64_t length = Tlv::readVarNumber(tmp_begin, tmp_end);

   if (length > static_cast<uint64_t>(tmp_end - tmp_begin))
     {
       throw Tlv::Error("Not enough data in the buffer to fully parse TLV");
     }

   m_buffer = make_shared<Buffer>(buffer, (tmp_begin - buffer) + length);

   m_begin = m_buffer->begin();
   m_end = m_buffer->end();
   m_size = m_end - m_begin;

   m_value_begin = m_buffer->begin() + (tmp_begin - buffer);
   m_value_end   = m_buffer->end();
 }

 Block::Block(uint32_t type)
   : m_type(type)
 {
 }

 Block::Block(uint32_t type, const ConstBufferPtr& value)
   : m_buffer(value)
   , m_type(type)
   , m_begin(m_buffer->end())
   , m_end(m_buffer->end())
   , m_value_begin(m_buffer->begin())
   , m_value_end(m_buffer->end())
 {
   m_size = Tlv::sizeOfVarNumber(m_type) + Tlv::sizeOfVarNumber(value_size()) + value_size();
 }

 Block::Block(uint32_t type, const Block& value)
   : m_buffer(value.m_buffer)
   , m_type(type)
   , m_begin(m_buffer->end())
   , m_end(m_buffer->end())
   , m_value_begin(value.begin())
   , m_value_end(value.end())
 {
   m_size = Tlv::sizeOfVarNumber(m_type) + Tlv::sizeOfVarNumber(value_size()) + value_size();
 }

 Block
 Block::fromStream(std::istream& is)
 {
   std::istream_iterator<uint8_t> tmp_begin(is);
   std::istream_iterator<uint8_t> tmp_end;

   uint32_t type = Tlv::readType(tmp_begin, tmp_end);
   uint64_t length = Tlv::readVarNumber(tmp_begin, tmp_end);

   if (length > MAX_SIZE_OF_BLOCK_FROM_STREAM)
     throw Tlv::Error("Length of block from stream is too large");

   // We may still have some problem here, if some exception happens,
   // we may completely lose all the bytes extracted from the stream.

   char buf[MAX_SIZE_OF_BLOCK_FROM_STREAM];
   buf[0] = *tmp_begin;
   is.read(buf+1, length-1);

   if (length != static_cast<uint64_t>(is.gcount()) + 1) {
     throw Tlv::Error("Not enough data in the buffer to fully parse TLV");
   }

   return dataBlock(type, buf, length);
 }

 bool
 Block::fromBuffer(const ConstBufferPtr& wire, size_t offset, Block& block)
 {
   Buffer::const_iterator tempBegin = wire->begin() + offset;

   uint32_t type;
   bool isOk = Tlv::readType(tempBegin, wire->end(), type);
   if (!isOk)
     return false;

   uint64_t length;
   isOk = Tlv::readVarNumber(tempBegin, wire->end(), length);
   if (!isOk)
     return false;

   if (length > static_cast<uint64_t>(wire->end() - tempBegin))
     {
       return false;
     }

   block = Block(wire, type,
                 wire->begin() + offset, tempBegin + length,
                 tempBegin, tempBegin + length);

   return true;
 }

 bool
 Block::fromBuffer(const uint8_t* buffer, size_t maxSize, Block& block)
 {
   const uint8_t* tempBegin = buffer;
   const uint8_t* tempEnd = buffer + maxSize;

   uint32_t type = 0;
   bool isOk = Tlv::readType(tempBegin, tempEnd, type);
   if (!isOk)
     return false;

   uint64_t length;
   isOk = Tlv::readVarNumber(tempBegin, tempEnd, length);
   if (!isOk)
     return false;

   if (length > static_cast<uint64_t>(tempEnd - tempBegin))
     {
       return false;
     }

   BufferPtr sharedBuffer = make_shared<Buffer>(buffer, tempBegin + length);
   block = Block(sharedBuffer, type,
                 sharedBuffer->begin(), sharedBuffer->end(),
                 sharedBuffer->begin() + (tempBegin - buffer), sharedBuffer->end());

   return true;
 }

 void
 Block::parse() const
 {
   if (!m_subBlocks.empty() || value_size() == 0)
     return;

   Buffer::const_iterator begin = value_begin();
   Buffer::const_iterator end = value_end();

   while (begin != end)
     {
       Buffer::const_iterator element_begin = begin;

       uint32_t type = Tlv::readType(begin, end);
       uint64_t length = Tlv::readVarNumber(begin, end);

       if (length > static_cast<uint64_t>(end - begin))
         {
           m_subBlocks.clear();
           throw Tlv::Error("TLV length exceeds buffer length");
         }
       Buffer::const_iterator element_end = begin + length;

       m_subBlocks.push_back(Block(m_buffer,
                                   type,
                                   element_begin, element_end,
                                   begin, element_end));

       begin = element_end;
       // don't do recursive parsing, just the top level
     }
 }

 void
 Block::encode()
 {
   if (hasWire())
     return;

   OBufferStream os;
   Tlv::writeVarNumber(os, type());

   if (hasValue())
     {
       Tlv::writeVarNumber(os, value_size());
       os.write(reinterpret_cast<const char*>(value()), value_size());
     }
   else if (m_subBlocks.size() == 0)
     {
       Tlv::writeVarNumber(os, 0);
     }
   else
     {
       size_t valueSize = 0;
       for (element_const_iterator i = m_subBlocks.begin(); i != m_subBlocks.end(); ++i) {
         valueSize += i->size();
       }

       Tlv::writeVarNumber(os, valueSize);

       for (element_const_iterator i = m_subBlocks.begin(); i != m_subBlocks.end(); ++i) {
         if (i->hasWire())
           os.write(reinterpret_cast<const char*>(i->wire()), i->size());
         else if (i->hasValue()) {
           Tlv::writeVarNumber(os, i->type());
           Tlv::writeVarNumber(os, i->value_size());
           os.write(reinterpret_cast<const char*>(i->value()), i->value_size());
         }
         else
           throw Error("Underlying value buffer is empty");
       }
     }

   // now assign correct block

   m_buffer = os.buf();
   m_begin = m_buffer->begin();
   m_end   = m_buffer->end();
   m_size  = m_end - m_begin;

   m_value_begin = m_buffer->begin();
   m_value_end   = m_buffer->end();

   Tlv::readType(m_value_begin, m_value_end);
   Tlv::readVarNumber(m_value_begin, m_value_end);
 }

 Block
 Block::blockFromValue() const
 {
   if (value_size() == 0)
     throw Error("Underlying value buffer is empty");

   Buffer::const_iterator begin = value_begin(),
     end = value_end();

   Buffer::const_iterator element_begin = begin;

   uint32_t type = Tlv::readType(begin, end);
   uint64_t length = Tlv::readVarNumber(begin, end);

   if (length != static_cast<uint64_t>(end - begin))
     throw Tlv::Error("TLV length mismatches buffer length");

   return Block(m_buffer,
                type,
                element_begin, end,
                begin, end);
 }

 const Block&
 Block::get(uint32_t type) const
 {
   for (element_const_iterator i = m_subBlocks.begin();
        i != m_subBlocks.end();
        i++)
     {
       if (i->type() == type)
         {
           return *i;
         }
     }

   throw Error("(Block::get) Requested a non-existed type [" +
               boost::lexical_cast<std::string>(type) + "] from Block");
 }

 } // namespace ndn
	/* -- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -- */
	/**
	* Copyright (c) 2013-2014 Regents of the University of California.
	*
	* This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
	*
	* ndn-cxx library is free software: you can redistribute it and/or modify it under the
	* terms of the GNU Lesser General Public License as published by the Free Software
	* Foundation, either version 3 of the License, or (at your option) any later version.
	*
	* ndn-cxx library 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 Lesser General Public License for more details.
	*
	* You should have received copies of the GNU General Public License and GNU Lesser
	* General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
	* <http://www.gnu.org/licenses/>.
	*
	* See AUTHORS.md for complete list of ndn-cxx authors and contributors.
	*
	* @author Alexander Afanasyev <http://lasr.cs.ucla.edu/afanasyev/index.html>
	*/

	#include "common.hpp"

	#include "block.hpp"
	#include "block-helpers.hpp"

	#include "tlv.hpp"
	#include "encoding-buffer.hpp"
	#include "buffer-stream.hpp"

	#include <boost/lexical_cast.hpp>

	namespace ndn {

	const size_t MAX_SIZE_OF_BLOCK_FROM_STREAM = 8800;

	Block::Block()
	: m_type(std::numeric_limits<uint32_t>::max())
	{
	}

	Block::Block(const EncodingBuffer& buffer)
	: m_buffer(buffer.m_buffer)
	, m_begin(buffer.begin())
	, m_end(buffer.end())
	, m_size(m_end - m_begin)
	{
	m_value_begin = m_begin;
	m_value_end = m_end;

	m_type = Tlv::readType(m_value_begin, m_value_end);
	uint64_t length = Tlv::readVarNumber(m_value_begin, m_value_end);
	if (length != static_cast<uint64_t>(m_value_end - m_value_begin))
	{
	throw Tlv::Error("TLV length doesn't match buffer length");
	}
	}

	Block::Block(const ConstBufferPtr& wire,
	uint32_t type,
	const Buffer::const_iterator& begin, const Buffer::const_iterator& end,
	const Buffer::const_iterator& valueBegin, const Buffer::const_iterator& valueEnd)
	: m_buffer(wire)
	, m_type(type)
	, m_begin(begin)
	, m_end(end)
	, m_size(m_end - m_begin)
	, m_value_begin(valueBegin)
	, m_value_end(valueEnd)
	{
	}

	Block::Block(const ConstBufferPtr& buffer)
	: m_buffer(buffer)
	, m_begin(m_buffer->begin())
	, m_end(m_buffer->end())
	, m_size(m_end - m_begin)
	{
	m_value_begin = m_begin;
	m_value_end = m_end;

	m_type = Tlv::readType(m_value_begin, m_value_end);

	uint64_t length = Tlv::readVarNumber(m_value_begin, m_value_end);
	if (length != static_cast<uint64_t>(m_value_end - m_value_begin))
	{
	throw Tlv::Error("TLV length doesn't match buffer length");
	}
	}

	Block::Block(const ConstBufferPtr& buffer,
	const Buffer::const_iterator& begin, const Buffer::const_iterator& end,
	bool verifyLength/* = true*/)
	: m_buffer(buffer)
	, m_begin(begin)
	, m_end(end)
	, m_size(m_end - m_begin)
	{
	m_value_begin = m_begin;
	m_value_end = m_end;

	m_type = Tlv::readType(m_value_begin, m_value_end);
	uint64_t length = Tlv::readVarNumber(m_value_begin, m_value_end);
	if (verifyLength)
	{
	if (length != static_cast<uint64_t>(m_value_end - m_value_begin))
	{
	throw Tlv::Error("TLV length doesn't match buffer length");
	}
	}
	}


	Block::Block(const uint8_t* buffer, size_t maxlength)
	{
	const uint8_t* tmp_begin = buffer;
	const uint8_t* tmp_end = buffer + maxlength;

	m_type = Tlv::readType(tmp_begin, tmp_end);
	uint64_t length = Tlv::readVarNumber(tmp_begin, tmp_end);

	if (length > static_cast<uint64_t>(tmp_end - tmp_begin))
	{
	throw Tlv::Error("Not enough data in the buffer to fully parse TLV");
	}

	m_buffer = make_shared<Buffer>(buffer, (tmp_begin - buffer) + length);

	m_begin = m_buffer->begin();
	m_end = m_buffer->end();
	m_size = m_end - m_begin;

	m_value_begin = m_buffer->begin() + (tmp_begin - buffer);
	m_value_end = m_buffer->end();
	}

	Block::Block(const void* bufferX, size_t maxlength)
	{
	const uint8_t* buffer = reinterpret_cast<const uint8_t*>(bufferX);

	const uint8_t* tmp_begin = buffer;
	const uint8_t* tmp_end = buffer + maxlength;

	m_type = Tlv::readType(tmp_begin, tmp_end);
	uint64_t length = Tlv::readVarNumber(tmp_begin, tmp_end);

	if (length > static_cast<uint64_t>(tmp_end - tmp_begin))
	{
	throw Tlv::Error("Not enough data in the buffer to fully parse TLV");
	}

	m_buffer = make_shared<Buffer>(buffer, (tmp_begin - buffer) + length);

	m_begin = m_buffer->begin();
	m_end = m_buffer->end();
	m_size = m_end - m_begin;

	m_value_begin = m_buffer->begin() + (tmp_begin - buffer);
	m_value_end = m_buffer->end();
	}

	Block::Block(uint32_t type)
	: m_type(type)
	{
	}

	Block::Block(uint32_t type, const ConstBufferPtr& value)
	: m_buffer(value)
	, m_type(type)
	, m_begin(m_buffer->end())
	, m_end(m_buffer->end())
	, m_value_begin(m_buffer->begin())
	, m_value_end(m_buffer->end())
	{
	m_size = Tlv::sizeOfVarNumber(m_type) + Tlv::sizeOfVarNumber(value_size()) + value_size();
	}

	Block::Block(uint32_t type, const Block& value)
	: m_buffer(value.m_buffer)
	, m_type(type)
	, m_begin(m_buffer->end())
	, m_end(m_buffer->end())
	, m_value_begin(value.begin())
	, m_value_end(value.end())
	{
	m_size = Tlv::sizeOfVarNumber(m_type) + Tlv::sizeOfVarNumber(value_size()) + value_size();
	}

	Block
	Block::fromStream(std::istream& is)
	{
	std::istream_iterator<uint8_t> tmp_begin(is);
	std::istream_iterator<uint8_t> tmp_end;

	uint32_t type = Tlv::readType(tmp_begin, tmp_end);
	uint64_t length = Tlv::readVarNumber(tmp_begin, tmp_end);

	if (length > MAX_SIZE_OF_BLOCK_FROM_STREAM)
	throw Tlv::Error("Length of block from stream is too large");

	// We may still have some problem here, if some exception happens,
	// we may completely lose all the bytes extracted from the stream.

	char buf[MAX_SIZE_OF_BLOCK_FROM_STREAM];
	buf[0] = *tmp_begin;
	is.read(buf+1, length-1);

	if (length != static_cast<uint64_t>(is.gcount()) + 1) {
	throw Tlv::Error("Not enough data in the buffer to fully parse TLV");
	}

	return dataBlock(type, buf, length);
	}

	bool
	Block::fromBuffer(const ConstBufferPtr& wire, size_t offset, Block& block)
	{
	Buffer::const_iterator tempBegin = wire->begin() + offset;

	uint32_t type;
	bool isOk = Tlv::readType(tempBegin, wire->end(), type);
	if (!isOk)
	return false;

	uint64_t length;
	isOk = Tlv::readVarNumber(tempBegin, wire->end(), length);
	if (!isOk)
	return false;

	if (length > static_cast<uint64_t>(wire->end() - tempBegin))
	{
	return false;
	}

	block = Block(wire, type,
	wire->begin() + offset, tempBegin + length,
	tempBegin, tempBegin + length);

	return true;
	}

	bool
	Block::fromBuffer(const uint8_t* buffer, size_t maxSize, Block& block)
	{
	const uint8_t* tempBegin = buffer;
	const uint8_t* tempEnd = buffer + maxSize;

	uint32_t type = 0;
	bool isOk = Tlv::readType(tempBegin, tempEnd, type);
	if (!isOk)
	return false;

	uint64_t length;
	isOk = Tlv::readVarNumber(tempBegin, tempEnd, length);
	if (!isOk)
	return false;

	if (length > static_cast<uint64_t>(tempEnd - tempBegin))
	{
	return false;
	}

	BufferPtr sharedBuffer = make_shared<Buffer>(buffer, tempBegin + length);
	block = Block(sharedBuffer, type,
	sharedBuffer->begin(), sharedBuffer->end(),
	sharedBuffer->begin() + (tempBegin - buffer), sharedBuffer->end());

	return true;
	}

	void
	Block::parse() const
	{
	if (!m_subBlocks.empty() \|\| value_size() == 0)
	return;

	Buffer::const_iterator begin = value_begin();
	Buffer::const_iterator end = value_end();

	while (begin != end)
	{
	Buffer::const_iterator element_begin = begin;

	uint32_t type = Tlv::readType(begin, end);
	uint64_t length = Tlv::readVarNumber(begin, end);

	if (length > static_cast<uint64_t>(end - begin))
	{
	m_subBlocks.clear();
	throw Tlv::Error("TLV length exceeds buffer length");
	}
	Buffer::const_iterator element_end = begin + length;

	m_subBlocks.push_back(Block(m_buffer,
	type,
	element_begin, element_end,
	begin, element_end));

	begin = element_end;
	// don't do recursive parsing, just the top level
	}
	}

	void
	Block::encode()
	{
	if (hasWire())
	return;

	OBufferStream os;
	Tlv::writeVarNumber(os, type());

	if (hasValue())
	{
	Tlv::writeVarNumber(os, value_size());
	os.write(reinterpret_cast<const char*>(value()), value_size());
	}
	else if (m_subBlocks.size() == 0)
	{
	Tlv::writeVarNumber(os, 0);
	}
	else
	{
	size_t valueSize = 0;
	for (element_const_iterator i = m_subBlocks.begin(); i != m_subBlocks.end(); ++i) {
	valueSize += i->size();
	}

	Tlv::writeVarNumber(os, valueSize);

	for (element_const_iterator i = m_subBlocks.begin(); i != m_subBlocks.end(); ++i) {
	if (i->hasWire())
	os.write(reinterpret_cast<const char*>(i->wire()), i->size());
	else if (i->hasValue()) {
	Tlv::writeVarNumber(os, i->type());
	Tlv::writeVarNumber(os, i->value_size());
	os.write(reinterpret_cast<const char*>(i->value()), i->value_size());
	}
	else
	throw Error("Underlying value buffer is empty");
	}
	}

	// now assign correct block

	m_buffer = os.buf();
	m_begin = m_buffer->begin();
	m_end = m_buffer->end();
	m_size = m_end - m_begin;

	m_value_begin = m_buffer->begin();
	m_value_end = m_buffer->end();

	Tlv::readType(m_value_begin, m_value_end);
	Tlv::readVarNumber(m_value_begin, m_value_end);
	}

	Block
	Block::blockFromValue() const
	{
	if (value_size() == 0)
	throw Error("Underlying value buffer is empty");

	Buffer::const_iterator begin = value_begin(),
	end = value_end();

	Buffer::const_iterator element_begin = begin;

	uint32_t type = Tlv::readType(begin, end);
	uint64_t length = Tlv::readVarNumber(begin, end);

	if (length != static_cast<uint64_t>(end - begin))
	throw Tlv::Error("TLV length mismatches buffer length");

	return Block(m_buffer,
	type,
	element_begin, end,
	begin, end);
	}

	const Block&
	Block::get(uint32_t type) const
	{
	for (element_const_iterator i = m_subBlocks.begin();
	i != m_subBlocks.end();
	i++)
	{
	if (i->type() == type)
	{
	return *i;
	}
	}

	throw Error("(Block::get) Requested a non-existed type [" +
	boost::lexical_cast<std::string>(type) + "] from Block");
	}

	} // namespace ndn