2000-12-08 Alexandre Petit-Bianco <apbianco@cygnus.com>

        * fastjar: Imported.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@38145 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 163 insertions, 0 deletions

diff --git a/fastjar/pushback.c b/fastjar/pushback.c
new file mode 100644
index 00000000000..03cdd651b42
--- /dev/null
+++ b/fastjar/pushback.c
@@ -0,0 +1,163 @@
+/* $Id: pushback.c,v 1.2 2000/08/23 19:42:17 cory Exp $
+
+   $Log: pushback.c,v $
+   Revision 1.2  2000/08/23 19:42:17  cory
+   Added support for more Unix platforms.  The following code has been hacked
+   to work on AIX, Solaris, True 64, and HP-UX.
+   Added bigendian check.  Probably works on most big and little endian platforms
+   now.
+
+   Revision 1.1.1.1  1999/12/06 03:09:13  toast
+   initial checkin..
+
+
+
+   Revision 1.1  1999/05/10 08:32:37  burnsbr
+   Initial revision
+
+*/
+
+/*
+  pushback.c - code for a pushback buffer to handle file I/O
+  Copyright (C) 1999  Bryan Burns
+  
+  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 <unistd.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "jartool.h"
+#include "pushback.h"
+
+static char rcsid[] = "$Id: pushback.c,v 1.2 2000/08/23 19:42:17 cory Exp $";
+
+void pb_init(pb_file *pbf, int fd){
+  pbf->fd = fd;
+  pbf->next = pbf->pb_buff;
+  pbf->buff_amt = 0;
+}
+
+int pb_push(pb_file *pbf, void *buff, int amt){
+  int in_amt;
+  int wrap = 0;
+
+#ifdef DEBUG
+  printf("%d bytes being pushed back to the buffer\n", amt);
+#endif
+
+  /* determine how much we can take */
+  if((RDSZ - pbf->buff_amt) < amt)
+    in_amt = RDSZ - pbf->buff_amt;
+  else
+    in_amt = amt;
+
+  if(in_amt == 0)
+    return 0;
+
+  /* figure out if we need to wrap around, and if so, by how much */
+  if(((pbf->pb_buff + RDSZ) - pbf->next) < in_amt)
+    wrap = in_amt - ((pbf->pb_buff + RDSZ) - pbf->next);
+
+  /* write everything up til the end of the buffer */
+  memcpy(pbf->next, buff, (in_amt - wrap));
+
+  /* finish writing what's wrapped around */
+  memcpy(pbf->pb_buff, ((char *)buff + (in_amt - wrap)), wrap);
+         
+  /* update the buff_amt field */
+  pbf->buff_amt += in_amt;
+
+#ifdef DEBUG
+  printf("%d bytes we can't accept\n", (amt - in_amt));
+#endif
+
+  return in_amt;
+}
+
+
+int pb_read(pb_file *pbf, void *buff, int amt){
+  int out_amt = 0;
+  int wrap = 0;
+  void *bp = buff;
+  int tmp;
+
+#ifdef DEBUG
+  printf("%d bytes requested from us\n", amt);
+#endif
+  while(out_amt < amt){
+    /* if our push-back buffer contains some data */
+    if(pbf->buff_amt > 0){
+      
+#ifdef DEBUG
+      printf("giving data from buffer\n");
+#endif
+      
+      /* calculate how much we can actually give the caller */
+      if( (amt - out_amt) < pbf->buff_amt )
+        tmp = (amt - out_amt);
+      else
+        tmp = pbf->buff_amt;
+      
+      /* Determine if we're going to need to wrap around the buffer */
+      if(tmp > ((pbf->pb_buff + RDSZ) - pbf->next))
+        wrap = tmp - ((pbf->pb_buff + RDSZ) - pbf->next);
+      
+      memcpy(bp, pbf->next, (tmp - wrap));
+      bp = &(((char *)bp)[tmp - wrap]);
+      
+      /* If we need to wrap, read from the start of the buffer */
+      if(wrap > 0){
+        memcpy(bp, pbf->pb_buff, wrap);
+        bp = &(((char *)bp)[wrap]);
+      }
+      
+      /* update the buff_amt field */
+      pbf->buff_amt -= tmp;
+      pbf->next += tmp;
+      
+#ifdef DEBUG
+      printf("%d bytes remaining in buffer\n", pbf->buff_amt);
+#endif
+      
+      /* if the buffer is empty, reset the next header to the front of the
+         buffer so subsequent pushbacks/reads won't have to wrap */
+      if(pbf->buff_amt == 0)
+        pbf->next = pbf->pb_buff;
+      
+      out_amt += tmp;
+
+    } else {
+#ifdef DEBUG
+      printf("Reading from file..\n");
+#endif
+      
+      /* The pushback buffer was empty, so we just need to read from the file */
+      tmp = read(pbf->fd, bp, (amt - out_amt));
+      if(tmp == 0)
+        break;
+      else
+        out_amt += tmp;
+      
+      bp = &(((char *)bp)[tmp]);
+    }
+  }
+
+#ifdef DEBUG
+  printf("managed to read %d bytes\n", out_amt);
+#endif
+  return out_amt;
+}