toolchain/gcc/fastjar/pushback.c

   1 /* $Id: pushback.c 119 2004-10-05 20:38:42Z oyvind $
   2
   3    $Log$
   4    Revision 1.1  2004/10/05 20:31:35  oyvind
   5         * added GCC to repository
   6
   7    Revision 1.2  2000/12/14 18:45:35  ghazi
   8    Warning fixes:
   9
  10         * compress.c: Include stdlib.h and compress.h.
  11         (rcsid): Delete.
  12         (report_str_error): Make static.
  13         (ez_inflate_str): Delete unused variable.  Add parens in if-stmt.
  14         (hrd_inflate_str): Likewise.
  15
  16         * compress.h (init_compression, end_compression, init_inflation,
  17         end_inflation): Prototype void arguments.
  18
  19         * dostime.c (rcsid): Delete.
  20
  21         * jargrep.c: Include ctype.h, stdlib.h, zlib.h and compress.h.
  22         Make functions static.  Cast ctype function argument to `unsigned
  23         char'.  Add parens in if-stmts.  Constify.
  24         (Usage): Change into a macro.
  25         (jargrep): Remove unused parameter.
  26
  27         * jartool.c: Constify.  Add parens in if-stmts.  Align
  28         signed/unsigned char pointers in functions calls using casts.
  29         (rcsid): Delete.
  30         (list_jar): Fix printf format specifier.
  31         (usage): Chop long string into bits.  Reformat.
  32
  33         * pushback.c (rcsid): Delete.
  34
  35    Revision 1.1  2000/12/09 03:08:23  apbianco
  36    2000-12-08  Alexandre Petit-Bianco  <apbianco@cygnus.com>
  37
  38            * fastjar: Imported.
  39
  40    Revision 1.2  2000/08/23 19:42:17  cory
  41    Added support for more Unix platforms.  The following code has been hacked
  42    to work on AIX, Solaris, True 64, and HP-UX.
  43    Added bigendian check.  Probably works on most big and little endian platforms
  44    now.
  45
  46    Revision 1.1.1.1  1999/12/06 03:09:13  toast
  47    initial checkin..
  48
  49
  50
  51    Revision 1.1  1999/05/10 08:32:37  burnsbr
  52    Initial revision
  53
  54 */
  55
  56 /*
  57   pushback.c - code for a pushback buffer to handle file I/O
  58   Copyright (C) 1999  Bryan Burns
  59
  60   This program is free software; you can redistribute it and/or
  61   modify it under the terms of the GNU General Public License
  62   as published by the Free Software Foundation; either version 2
  63   of the License, or (at your option) any later version.
  64
  65   This program is distributed in the hope that it will be useful,
  66   but WITHOUT ANY WARRANTY; without even the implied warranty of
  67   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  68   GNU General Public License for more details.
  69
  70   You should have received a copy of the GNU General Public License
  71   along with this program; if not, write to the Free Software
  72   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  73  */
  74
  75 #include <unistd.h>
  76 #include <string.h>
  77 #include <stdio.h>
  78
  79 #include "jartool.h"
  80 #include "pushback.h"
  81
  82 void pb_init(pb_file *pbf, int fd){
  83   pbf->fd = fd;
  84   pbf->next = pbf->pb_buff;
  85   pbf->buff_amt = 0;
  86 }
  87
  88 int pb_push(pb_file *pbf, void *buff, int amt){
  89   int in_amt;
  90   int wrap = 0;
  91
  92 #ifdef DEBUG
  93   printf("%d bytes being pushed back to the buffer\n", amt);
  94 #endif
  95
  96   /* determine how much we can take */
  97   if((int)(RDSZ - pbf->buff_amt) < amt)
  98     in_amt = RDSZ - pbf->buff_amt;
  99   else
 100     in_amt = amt;
 101
 102   if(in_amt == 0)
 103     return 0;
 104
 105   /* figure out if we need to wrap around, and if so, by how much */
 106   if(((pbf->pb_buff + RDSZ) - pbf->next) < in_amt)
 107     wrap = in_amt - ((pbf->pb_buff + RDSZ) - pbf->next);
 108
 109   /* write everything up til the end of the buffer */
 110   memcpy(pbf->next, buff, (in_amt - wrap));
 111
 112   /* finish writing what's wrapped around */
 113   memcpy(pbf->pb_buff, ((char *)buff + (in_amt - wrap)), wrap);
 114
 115   /* update the buff_amt field */
 116   pbf->buff_amt += in_amt;
 117
 118 #ifdef DEBUG
 119   printf("%d bytes we can't accept\n", (amt - in_amt));
 120 #endif
 121
 122   return in_amt;
 123 }
 124
 125
 126 int pb_read(pb_file *pbf, void *buff, int amt){
 127   int out_amt = 0;
 128   int wrap = 0;
 129   void *bp = buff;
 130   int tmp;
 131
 132 #ifdef DEBUG
 133   printf("%d bytes requested from us\n", amt);
 134 #endif
 135   while(out_amt < amt){
 136     /* if our push-back buffer contains some data */
 137     if(pbf->buff_amt > 0){
 138
 139 #ifdef DEBUG
 140       printf("giving data from buffer\n");
 141 #endif
 142
 143       /* calculate how much we can actually give the caller */
 144       if( (amt - out_amt) < (int)pbf->buff_amt )
 145         tmp = (amt - out_amt);
 146       else
 147         tmp = pbf->buff_amt;
 148
 149       /* Determine if we're going to need to wrap around the buffer */
 150       if(tmp > ((pbf->pb_buff + RDSZ) - pbf->next))
 151         wrap = tmp - ((pbf->pb_buff + RDSZ) - pbf->next);
 152
 153       memcpy(bp, pbf->next, (tmp - wrap));
 154       bp = &(((char *)bp)[tmp - wrap]);
 155
 156       /* If we need to wrap, read from the start of the buffer */
 157       if(wrap > 0){
 158         memcpy(bp, pbf->pb_buff, wrap);
 159         bp = &(((char *)bp)[wrap]);
 160       }
 161
 162       /* update the buff_amt field */
 163       pbf->buff_amt -= tmp;
 164       pbf->next += tmp;
 165
 166 #ifdef DEBUG
 167       printf("%d bytes remaining in buffer\n", pbf->buff_amt);
 168 #endif
 169
 170       /* if the buffer is empty, reset the next header to the front of the
 171          buffer so subsequent pushbacks/reads won't have to wrap */
 172       if(pbf->buff_amt == 0)
 173         pbf->next = pbf->pb_buff;
 174
 175       out_amt += tmp;
 176
 177     } else {
 178 #ifdef DEBUG
 179       printf("Reading from file..\n");
 180 #endif
 181
 182       /* The pushback buffer was empty, so we just need to read from the file */
 183       tmp = read(pbf->fd, bp, (amt - out_amt));
 184       if(tmp == 0)
 185         break;
 186       else
 187         out_amt += tmp;
 188
 189       bp = &(((char *)bp)[tmp]);
 190     }
 191   }
 192
 193 #ifdef DEBUG
 194   printf("managed to read %d bytes\n", out_amt);
 195 #endif
 196   return out_amt;
 197 }