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 07/01/81"; 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 } 84