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 "cdb++.h"

    18 #include "internal.h"

    19 

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

    21 

    22 inline uint32 max(uint32 a, uint32 b)

    23 {

    24   return a > b ? a : b;

    25 }

    26 

    27 cdb_reader::cdb_reader(const mystring& filename)

    28   : in(filename.c_str()),

    29     failed(!in),

    30     eof(false)

    31 {

    32   firstrec();

    33 }

    34 

    35 cdb_reader::~cdb_reader()

    36 {

    37 }

    38 

    39 void cdb_reader::abort()

    40 {

    41   failed = true;

    42   in.close();

    43 }

    44 

    45 bool cdb_reader::firstrec()

    46 {

    47   if(failed) return false;

    48   if(!in.seek(0) || !in.read(header, 2048)) {

    49     abort();

    50     return false;

    51   }

    52   eof = false;

    53   eod = unpack(header);

    54   pos = 2048;

    55   return true;

    56 }

    57 

    58 datum* cdb_reader::nextrec()

    59 {

    60   if(eof) return 0;

    61   if(pos >= eod) {

    62     eof = true;

    63     return 0;

    64   }

    65   if(failed || eod-pos < 8 || !in.seek(pos)) FAIL;

    66   pos += 8;

    67   unsigned char buf[8];

    68   if(!in.read(buf, 8)) FAIL;

    69   uint32 klen = unpack(buf);

    70   uint32 dlen = unpack(buf+4);

    71   if (eod - pos < klen) FAIL;

    72   pos += klen;

    73   if (eod - pos < dlen) FAIL;

    74   pos += dlen;

    75   char tmp[max(klen, dlen)];

    76   if(!in.read(tmp, klen)) FAIL;

    77   mystring key(tmp, klen);

    78   if(!in.read(tmp, dlen)) FAIL;

    79   mystring data(tmp, dlen);

    80   return new datum(key, data);

    81 }