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

     2 //

     3 // This program is free software; you can redistribute it and/or modify

     4 // it under the terms of the GNU General Public License as published by

     5 // the Free Software Foundation; either version 2 of the License, or

     6 // (at your option) any later version.

     7 //

     8 // This program is distributed in the hope that it will be useful,

     9 // but WITHOUT ANY WARRANTY; without even the implied warranty of

    10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    11 // GNU General Public License for more details.

    12 //

    13 // You should have received a copy of the GNU General Public License

    14 // along with this program; if not, write to the Free Software

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

    16 

    17 #include <stdio.h>

    18 #include <unistd.h>

    19 #include "cdb++.h"

    20 #include "internal.h"

    21 

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

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

    24 

    25 void cdb_writer::abort()

    26 {

    27   if(!failed) {

    28     unlink(fntemp.c_str());

    29     out.close();

    30     failed = true;

    31   }

    32 }

    33 

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

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

    36     fntemp(filename),

    37     pos(sizeof cdbm.final),

    38     failed(false)

    39 {

    40   if(!out)

    41     failed = true;

    42   else {

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

    44       abort();

    45   }

    46 }

    47 

    48 cdb_writer::~cdb_writer()

    49 {

    50   abort();

    51 }

    52 

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

    54 {

    55   if(failed) return 0;

    56   unsigned char packbuf[8];

    57   pack(packbuf, key.length());

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

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

    60 

    61   uint32 h = hash(key);

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

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

    64      !cdbm.add(h, pos))

    65     FAIL;

    66   safeadd(pos, 8);

    67   safeadd(pos, key.length());

    68   safeadd(pos, data.length());

    69   return true;

    70 }

    71 

    72 bool cdb_writer::end(const mystring& filename)

    73 {

    74   if(failed) return 0;

    75   if(!cdbm.split_hashes()) FAIL;

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

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

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

    79       unsigned char packbuf[8];

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

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

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

    83       safeadd(pos, 8);

    84     }

    85   }

    86   if(!out.rewind()) FAIL;

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

    88   if(!out.flush()) FAIL;

    89   out.close();

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

    91   return true;

    92 }