2.9BSD - /usr/src/ucb/Mail/strings.c

   1: #
   2: 
   3: /*
   4:  * Mail -- a mail program
   5:  *
   6:  * String allocation routines.
   7:  * Strings handed out here are reclaimed at the top of the command
   8:  * loop each time, so they need not be freed.
   9:  */
  10: 
  11: #include "rcv.h"
  12: 
  13: static char *SccsId = "@(#)strings.c	2.1 7/1/81";
  14: 
  15: /*
  16:  * Allocate size more bytes of space and return the address of the
  17:  * first byte to the caller.  An even number of bytes are always
  18:  * allocated so that the space will always be on a word boundary.
  19:  * The string spaces are of exponentially increasing size, to satisfy
  20:  * the occasional user with enormous string size requests.
  21:  */
  22: 
  23: char *
  24: salloc(size)
  25: {
  26:     register char *t;
  27:     register int s;
  28:     register struct strings *sp;
  29:     int index;
  30: 
  31:     s = size;
  32:     s++;
  33:     s &= ~01;
  34:     index = 0;
  35:     for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
  36:         if (sp->s_topFree == NOSTR && (STRINGSIZE << index) >= s)
  37:             break;
  38:         if (sp->s_nleft >= s)
  39:             break;
  40:         index++;
  41:     }
  42:     if (sp >= &stringdope[NSPACE])
  43:         panic("String too large");
  44:     if (sp->s_topFree == NOSTR) {
  45:         index = sp - &stringdope[0];
  46:         sp->s_topFree = (char *) calloc(STRINGSIZE << index,
  47:             (unsigned) 1);
  48:         if (sp->s_topFree == NOSTR) {
  49:             fprintf(stderr, "No room for space %d\n", index);
  50:             panic("Internal error");
  51:         }
  52:         sp->s_nextFree = sp->s_topFree;
  53:         sp->s_nleft = STRINGSIZE << index;
  54:     }
  55:     sp->s_nleft -= s;
  56:     t = sp->s_nextFree;
  57:     sp->s_nextFree += s;
  58:     return(t);
  59: }
  60: 
  61: /*
  62:  * Reset the string area to be empty.
  63:  * Called to free all strings allocated
  64:  * since last reset.
  65:  */
  66: 
  67: sreset()
  68: {
  69:     register struct strings *sp;
  70:     register int index;
  71: 
  72:     if (noreset)
  73:         return;
  74:     minit();
  75:     index = 0;
  76:     for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
  77:         if (sp->s_topFree == NOSTR)
  78:             continue;
  79:         sp->s_nextFree = sp->s_topFree;
  80:         sp->s_nleft = STRINGSIZE << index;
  81:         index++;
  82:     }
  83: }

Defined functions

Defined variables