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/* -*- 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: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
*/
#include "wire-ccnb.h"
#include <sstream>
#include <boost/foreach.hpp>
#include "ccnb-parser/common.h"
NDN_NAMESPACE_BEGIN
namespace wire {
//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
#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
Ccnb::AppendBlockHeader (Buffer::Iterator &start, size_t val, uint32_t 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
Ccnb::EstimateBlockHeader (size_t value)
{
value >>= (7-CCN_TT_BITS);
size_t n = 1;
while (value>0)
{
value >>= 7;
n++;
}
return n;
}
size_t
Ccnb::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
Ccnb::EstimateNumber (uint32_t number)
{
std::ostringstream os;
os << number;
return EstimateBlockHeader (os.str ().size ()) + os.str ().size ();
}
size_t
Ccnb::AppendCloser (Buffer::Iterator &start)
{
start.WriteU8 (CcnbParser::CCN_CLOSE);
return 1;
}
size_t
Ccnb::AppendName (Buffer::Iterator &start, const Name &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
Ccnb::EstimateName (const Name &name)
{
size_t written = 0;
BOOST_FOREACH (const std::string &component, name.GetComponents())
{
written += EstimateTaggedBlob (CcnbParser::CCN_DTAG_Component, component.size());
}
return written;
}
size_t
Ccnb::AppendTimestampBlob (Buffer::Iterator &start, const 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) % 1000000000) / 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
Ccnb::EstimateTimestampBlob (const Time &time)
{
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++;
return EstimateBlockHeader (required_bytes) + required_bytes;
}
size_t
Ccnb::AppendTaggedBlob (Buffer::Iterator &start, uint32_t dtag,
const uint8_t *data, size_t size)
{
size_t written = AppendBlockHeader (start, dtag, CcnbParser::CCN_DTAG);
/* 2 */
if (size>0)
{
written += AppendBlockHeader (start, size, CcnbParser::CCN_BLOB);
start.Write (data, size);
written += size;
/* size */
}
written += AppendCloser (start);
/* 1 */
return written;
}
size_t
Ccnb::EstimateTaggedBlob (uint32_t dtag, size_t size)
{
if (size>0)
return EstimateBlockHeader (dtag) + EstimateBlockHeader (size) + size + 1;
else
return EstimateBlockHeader (dtag) + 1;
}
size_t
Ccnb::AppendString (Buffer::Iterator &start, uint32_t dtag,
const std::string &string)
{
size_t written = AppendBlockHeader (start, dtag, CcnbParser::CCN_DTAG);
{
written += AppendBlockHeader (start, string.size (), CcnbParser::CCN_UDATA);
start.Write (reinterpret_cast<const uint8_t*> (string.c_str ()), string.size ());
written += string.size ();
}
written += AppendCloser (start);
return written;
}
size_t
Ccnb::EstimateString (uint32_t dtag, const std::string &string)
{
return EstimateBlockHeader (dtag) + EstimateBlockHeader (string.size ()) + string.size () + 1;
}
} // wire
NDN_NAMESPACE_END