helper/ccnx-encoding-helper.cc - ndnSIM - Gitiles

 /* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
 /*
  * Copyright (c) 2011 University of California, Los Angeles
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation;
  *
  * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  * Author:
  */

 #include "ccnx-encoding-helper.h"

 #include "ns3/ccnx-name-components.h"
 #include "ns3/ccnx-interest-header.h"
 #include "ns3/ccnx-content-object-header.h"

 #include <sstream>
 #include <boost/foreach.hpp>

 namespace ns3 {

 #define CCN_TT_BITS 3
 #define CCN_TT_MASK ((1 << CCN_TT_BITS) - 1)
 #define CCN_MAX_TINY ((1 << (7-CCN_TT_BITS)) - 1)
 #define CCN_TT_HBIT ((unsigned char)(1 << 7))

 size_t
 CcnxEncodingHelper::AppendBlockHeader (Buffer::Iterator start, size_t val, CcnbParser::ccn_tt tt)
 {
   unsigned char buf[1+8*((sizeof(val)+6)/7)];
   unsigned char *p = &(buf[sizeof(buf)-1]);
   size_t n = 1;
   p[0] = (CCN_TT_HBIT & ~CcnbParser::CCN_CLOSE) |
   ((val & CCN_MAX_TINY) << CCN_TT_BITS) |
   (CCN_TT_MASK & tt);
   val >>= (7-CCN_TT_BITS);
   while (val != 0) {
     (--p)[0] = (((unsigned char)val) & ~CCN_TT_HBIT) | CcnbParser::CCN_CLOSE;
     n++;
     val >>= 7;
   }
   start.Write (p,n);
   return n;
 }

 size_t
 CcnxEncodingHelper::AppendNumber (Buffer::Iterator start, uint32_t number)
 {
   std::ostringstream os;
   os << number;

   size_t written = 0;
   written += AppendBlockHeader (start, os.str().size(), CcnbParser::CCN_UDATA);
   written += os.str().size();
   start.Write (reinterpret_cast<const unsigned char*>(os.str().c_str()), os.str().size());

   return written;
 }


 size_t
 CcnxEncodingHelper::CcnxEncodingHelper::AppendCloser (Buffer::Iterator start)
 {
   start.WriteU8 (CcnbParser::CCN_CLOSE);
   return 1;
 }

 size_t
 CcnxEncodingHelper::AppendNameComponents (Buffer::Iterator start, const CcnxNameComponents &name)
 {
   size_t written = 0;
   BOOST_FOREACH (const std::string &component, name.GetComponents())
     {
       written += AppendTaggedBlob (start, CcnbParser::CCN_DTAG_Component,
                                    reinterpret_cast<const uint8_t*>(component.c_str()), component.size());
     }
   return written;
 }

 size_t
 CcnxEncodingHelper::AppendTimestampBlob (Buffer::Iterator start, Time time)
 {
   // the original function implements Markers... thought not sure what are these markers for...

   // Determine miminal number of bytes required to store the timestamp
   int required_bytes = 2; // 12 bits for fractions of a second, 4 bits left for seconds. Sometimes it is enough
   intmax_t ts = time.ToInteger (Time::S) >> 4;
   for (;  required_bytes < 7 && ts != 0; ts >>= 8) // not more than 6 bytes?
      required_bytes++;

   size_t len = AppendBlockHeader(start, required_bytes, CcnbParser::CCN_BLOB);

   // write part with seconds
   ts = time.ToInteger (Time::S) >> 4;
   for (int i = 0; i < required_bytes - 2; i++)
     start.WriteU8 ( ts >> (8 * (required_bytes - 3 - i)) );

   /* arithmetic contortions are to avoid overflowing 31 bits */
   ts = ((time.ToInteger (Time::S) & 15) << 12) + ((time.ToInteger (Time::NS) / 5 * 8 + 195312) / 390625);
   for (int i = required_bytes - 2; i < required_bytes; i++)
     start.WriteU8 ( ts >> (8 * (required_bytes - 1 - i)) );

   return len + required_bytes;
 }

 size_t
 CcnxEncodingHelper::AppendTaggedBlob (Buffer::Iterator start, CcnbParser::ccn_dtag dtag,
                   const uint8_t *data, size_t size)
 {
   size_t written = AppendBlockHeader (start, dtag, CcnbParser::CCN_DTAG);
   if (size>0)
     {
       written += AppendBlockHeader (start, size, CcnbParser::CCN_BLOB);
       start.Write (data, size);
       written += size;
     }
   written += AppendCloser (start);

   return written;
 }


 size_t
 CcnxEncodingHelper::Serialize (Buffer::Iterator start, const CcnxInterestHeader &interest)
 {
   size_t written = 0;
   written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Interest, CcnbParser::CCN_DTAG); // <Interest>

   written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Name, CcnbParser::CCN_DTAG); // <Name>
   written += AppendNameComponents (start, interest.GetName());                // <Component>...</Component>...
   written += AppendCloser (start);                               // </Name>

   if (interest.GetMinSuffixComponents() >= 0)
     {
       written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_MinSuffixComponents, CcnbParser::CCN_DTAG);
       written += AppendNumber (start, interest.GetMinSuffixComponents ());
       written += AppendCloser (start);
     }
   if (interest.GetMaxSuffixComponents() >= 0)
     {
       written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_MaxSuffixComponents, CcnbParser::CCN_DTAG);
       written += AppendNumber (start, interest.GetMaxSuffixComponents ());
       written += AppendCloser (start);
     }
   if (interest.GetExclude().size() > 0)
     {
       written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Exclude, CcnbParser::CCN_DTAG); // <Exclude>
       written += AppendNameComponents (start, interest.GetExclude());                // <Component>...</Component>...
       written += AppendCloser (start);                                  // </Exclude>
     }
   if (interest.IsEnabledChildSelector())
     {
       written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_ChildSelector, CcnbParser::CCN_DTAG);
       written += AppendNumber (start, 1);
       written += AppendCloser (start);
     }
   if (interest.IsEnabledAnswerOriginKind())
     {
       written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_AnswerOriginKind, CcnbParser::CCN_DTAG);
       written += AppendNumber (start, 1);
       written += AppendCloser (start);
     }
   if (interest.GetScope() >= 0)
     {
       written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Scope, CcnbParser::CCN_DTAG);
       written += AppendNumber (start, interest.GetScope ());
       written += AppendCloser (start);
     }
   if (!interest.GetInterestLifetime().IsZero())
     {
       written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_InterestLifetime, CcnbParser::CCN_DTAG);
       written += AppendTimestampBlob (start, interest.GetInterestLifetime());
       written += AppendCloser (start);
     }
   if (interest.GetNonce()>0)
     {
       uint32_t nonce = interest.GetNonce();
       written += AppendTaggedBlob (start, CcnbParser::CCN_DTAG_Nonce,
                                    reinterpret_cast<const uint8_t*>(&nonce),
                                    sizeof(nonce));
     }
   written += AppendCloser (start); // </Interest>

   return written;
 }

 size_t
 CcnxEncodingHelper::Serialize (Buffer::Iterator start, const CcnxContentObjectHeader &contentObject)
 {
   size_t written = 0;
   written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_ContentObject, CcnbParser::CCN_DTAG); // <ContentObject>

   // fake signature
   written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Signature, CcnbParser::CCN_DTAG); // <Signature>
   // Signature ::= DigestAlgorithm?
   //               Witness?
   //               SignatureBits
   written += AppendTaggedBlob (start, CcnbParser::CCN_DTAG_SignatureBits, 0, 0);      // <SignatureBits />
   written += AppendCloser (start);                                    // </Signature>

   written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Name, CcnbParser::CCN_DTAG);    // <Name>
   written += AppendNameComponents (start, contentObject.GetName()); //   <Component>...</Component>...
   written += AppendCloser (start);                                  // </Name>

   // fake signature
   written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_SignedInfo, CcnbParser::CCN_DTAG); // <SignedInfo>
   // SignedInfo ::= PublisherPublicKeyDigest
   //                Timestamp
   //                Type?
   //                FreshnessSeconds?
   //                FinalBlockID?
   //                KeyLocator?
   written += AppendTaggedBlob (start, CcnbParser::CCN_DTAG_PublisherPublicKeyDigest, 0, 0); // <PublisherPublicKeyDigest />
   written += AppendCloser (start);                                     // </SignedInfo>

   written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Content, CcnbParser::CCN_DTAG); // <Content>

   // there is no closing tag !!!
   return written;
 }

 } // namespace ns3
	/* -- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -- */
	/*
	* Copyright (c) 2011 University of California, Los Angeles
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation;
	*
	* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	* Author:
	*/

	#include "ccnx-encoding-helper.h"

	#include "ns3/ccnx-name-components.h"
	#include "ns3/ccnx-interest-header.h"
	#include "ns3/ccnx-content-object-header.h"

	#include <sstream>
	#include <boost/foreach.hpp>

	namespace ns3 {

	#define CCN_TT_BITS 3
	#define CCN_TT_MASK ((1 << CCN_TT_BITS) - 1)
	#define CCN_MAX_TINY ((1 << (7-CCN_TT_BITS)) - 1)
	#define CCN_TT_HBIT ((unsigned char)(1 << 7))

	size_t
	CcnxEncodingHelper::AppendBlockHeader (Buffer::Iterator start, size_t val, CcnbParser::ccn_tt tt)
	{
	unsigned char buf[1+8*((sizeof(val)+6)/7)];
	unsigned char *p = &(buf[sizeof(buf)-1]);
	size_t n = 1;
	p[0] = (CCN_TT_HBIT & ~CcnbParser::CCN_CLOSE) \|
	((val & CCN_MAX_TINY) << CCN_TT_BITS) \|
	(CCN_TT_MASK & tt);
	val >>= (7-CCN_TT_BITS);
	while (val != 0) {
	(--p)[0] = (((unsigned char)val) & ~CCN_TT_HBIT) \| CcnbParser::CCN_CLOSE;
	n++;
	val >>= 7;
	}
	start.Write (p,n);
	return n;
	}

	size_t
	CcnxEncodingHelper::AppendNumber (Buffer::Iterator start, uint32_t number)
	{
	std::ostringstream os;
	os << number;

	size_t written = 0;
	written += AppendBlockHeader (start, os.str().size(), CcnbParser::CCN_UDATA);
	written += os.str().size();
	start.Write (reinterpret_cast<const unsigned char*>(os.str().c_str()), os.str().size());

	return written;
	}


	size_t
	CcnxEncodingHelper::CcnxEncodingHelper::AppendCloser (Buffer::Iterator start)
	{
	start.WriteU8 (CcnbParser::CCN_CLOSE);
	return 1;
	}

	size_t
	CcnxEncodingHelper::AppendNameComponents (Buffer::Iterator start, const CcnxNameComponents &name)
	{
	size_t written = 0;
	BOOST_FOREACH (const std::string &component, name.GetComponents())
	{
	written += AppendTaggedBlob (start, CcnbParser::CCN_DTAG_Component,
	reinterpret_cast<const uint8_t*>(component.c_str()), component.size());
	}
	return written;
	}

	size_t
	CcnxEncodingHelper::AppendTimestampBlob (Buffer::Iterator start, Time time)
	{
	// the original function implements Markers... thought not sure what are these markers for...

	// Determine miminal number of bytes required to store the timestamp
	int required_bytes = 2; // 12 bits for fractions of a second, 4 bits left for seconds. Sometimes it is enough
	intmax_t ts = time.ToInteger (Time::S) >> 4;
	for (; required_bytes < 7 && ts != 0; ts >>= 8) // not more than 6 bytes?
	required_bytes++;

	size_t len = AppendBlockHeader(start, required_bytes, CcnbParser::CCN_BLOB);

	// write part with seconds
	ts = time.ToInteger (Time::S) >> 4;
	for (int i = 0; i < required_bytes - 2; i++)
	start.WriteU8 ( ts >> (8 * (required_bytes - 3 - i)) );

	/* arithmetic contortions are to avoid overflowing 31 bits */
	ts = ((time.ToInteger (Time::S) & 15) << 12) + ((time.ToInteger (Time::NS) / 5 * 8 + 195312) / 390625);
	for (int i = required_bytes - 2; i < required_bytes; i++)
	start.WriteU8 ( ts >> (8 * (required_bytes - 1 - i)) );

	return len + required_bytes;
	}

	size_t
	CcnxEncodingHelper::AppendTaggedBlob (Buffer::Iterator start, CcnbParser::ccn_dtag dtag,
	const uint8_t *data, size_t size)
	{
	size_t written = AppendBlockHeader (start, dtag, CcnbParser::CCN_DTAG);
	if (size>0)
	{
	written += AppendBlockHeader (start, size, CcnbParser::CCN_BLOB);
	start.Write (data, size);
	written += size;
	}
	written += AppendCloser (start);

	return written;
	}


	size_t
	CcnxEncodingHelper::Serialize (Buffer::Iterator start, const CcnxInterestHeader &interest)
	{
	size_t written = 0;
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Interest, CcnbParser::CCN_DTAG); // <Interest>

	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Name, CcnbParser::CCN_DTAG); // <Name>
	written += AppendNameComponents (start, interest.GetName()); // <Component>...</Component>...
	written += AppendCloser (start); // </Name>

	if (interest.GetMinSuffixComponents() >= 0)
	{
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_MinSuffixComponents, CcnbParser::CCN_DTAG);
	written += AppendNumber (start, interest.GetMinSuffixComponents ());
	written += AppendCloser (start);
	}
	if (interest.GetMaxSuffixComponents() >= 0)
	{
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_MaxSuffixComponents, CcnbParser::CCN_DTAG);
	written += AppendNumber (start, interest.GetMaxSuffixComponents ());
	written += AppendCloser (start);
	}
	if (interest.GetExclude().size() > 0)
	{
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Exclude, CcnbParser::CCN_DTAG); // <Exclude>
	written += AppendNameComponents (start, interest.GetExclude()); // <Component>...</Component>...
	written += AppendCloser (start); // </Exclude>
	}
	if (interest.IsEnabledChildSelector())
	{
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_ChildSelector, CcnbParser::CCN_DTAG);
	written += AppendNumber (start, 1);
	written += AppendCloser (start);
	}
	if (interest.IsEnabledAnswerOriginKind())
	{
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_AnswerOriginKind, CcnbParser::CCN_DTAG);
	written += AppendNumber (start, 1);
	written += AppendCloser (start);
	}
	if (interest.GetScope() >= 0)
	{
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Scope, CcnbParser::CCN_DTAG);
	written += AppendNumber (start, interest.GetScope ());
	written += AppendCloser (start);
	}
	if (!interest.GetInterestLifetime().IsZero())
	{
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_InterestLifetime, CcnbParser::CCN_DTAG);
	written += AppendTimestampBlob (start, interest.GetInterestLifetime());
	written += AppendCloser (start);
	}
	if (interest.GetNonce()>0)
	{
	uint32_t nonce = interest.GetNonce();
	written += AppendTaggedBlob (start, CcnbParser::CCN_DTAG_Nonce,
	reinterpret_cast<const uint8_t*>(&nonce),
	sizeof(nonce));
	}
	written += AppendCloser (start); // </Interest>

	return written;
	}

	size_t
	CcnxEncodingHelper::Serialize (Buffer::Iterator start, const CcnxContentObjectHeader &contentObject)
	{
	size_t written = 0;
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_ContentObject, CcnbParser::CCN_DTAG); // <ContentObject>

	// fake signature
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Signature, CcnbParser::CCN_DTAG); // <Signature>
	// Signature ::= DigestAlgorithm?
	// Witness?
	// SignatureBits
	written += AppendTaggedBlob (start, CcnbParser::CCN_DTAG_SignatureBits, 0, 0); // <SignatureBits />
	written += AppendCloser (start); // </Signature>

	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Name, CcnbParser::CCN_DTAG); // <Name>
	written += AppendNameComponents (start, contentObject.GetName()); // <Component>...</Component>...
	written += AppendCloser (start); // </Name>

	// fake signature
	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_SignedInfo, CcnbParser::CCN_DTAG); // <SignedInfo>
	// SignedInfo ::= PublisherPublicKeyDigest
	// Timestamp
	// Type?
	// FreshnessSeconds?
	// FinalBlockID?
	// KeyLocator?
	written += AppendTaggedBlob (start, CcnbParser::CCN_DTAG_PublisherPublicKeyDigest, 0, 0); // <PublisherPublicKeyDigest />
	written += AppendCloser (start); // </SignedInfo>

	written += AppendBlockHeader (start, CcnbParser::CCN_DTAG_Content, CcnbParser::CCN_DTAG); // <Content>

	// there is no closing tag !!!
	return written;
	}

	} // namespace ns3