// Copyright (C) 1999,2000 Bruce Guenter <bruceg@em.ca>

//

// 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#include <stdio.h>

#include <unistd.h>

#include "cdb++.h"

#include "internal.h"

#define safeadd(u,v) do{ uint32 newu = u+v; if(newu<u) FAIL; u=newu; }while(0)

#define FAIL do{ abort(); return false; }while(0)

void cdb_writer::abort()

{

  if(!failed) {

    unlink(fntemp.c_str());

    out.close();

    failed = true;

  }

}

cdb_writer::cdb_writer(const mystring& filename, int mode)

  : out(filename.c_str(), fdobuf::excl | fdobuf::create, mode),

    fntemp(filename),

    pos(sizeof cdbm.final),

    failed(false)

{

  if(!out)

    failed = true;

  else {

    if(!out.write(cdbm.final, sizeof cdbm.final))

      abort();

  }

}

cdb_writer::~cdb_writer()

{

  abort();

}

bool cdb_writer::put(const mystring& key, const mystring& data)

{

  if(failed) return 0;

  unsigned char packbuf[8];

  pack(packbuf, key.length());

  pack(packbuf+4, data.length());

  if(!out.write(packbuf, sizeof packbuf)) FAIL;

  uint32 h = hash(key);

  if(!out.write(key.c_str(), key.length()) ||

     !out.write(data.c_str(), data.length()) ||

     !cdbm.add(h, pos))

    FAIL;

  safeadd(pos, 8);

  safeadd(pos, key.length());

  safeadd(pos, data.length());

  return true;

}

bool cdb_writer::end(const mystring& filename)

{

  if(failed) return 0;

  if(!cdbm.split_hashes()) FAIL;

  for(unsigned i = 0; i < 256; i++) {

    uint32 len = cdbm.throw_hash(pos, i);

    for(uint32 u = 0; u < len; u++) {

      unsigned char packbuf[8];

      pack(packbuf, cdbm.hash[u].h);

      pack(packbuf+4, cdbm.hash[u].p);

      if(!out.write(packbuf, sizeof packbuf)) FAIL;

      safeadd(pos, 8);

    }

  }

  if(!out.rewind()) FAIL;

  if(!out.write(cdbm.final, sizeof(cdbm.final))) FAIL;

  if(!out.flush()) FAIL;

  out.close();

  if(rename(fntemp.c_str(), filename.c_str())) FAIL;

  return true;

}