ref: 9661fb64092acfcf370688c5e56934e400965822
dir: /appl/lib/readdir.b/
implement Readdir; include "sys.m"; sys: Sys; Dir: import sys; include "readdir.m"; init(path: string, sortkey: int): (array of ref Dir, int) { sys = load Sys Sys->PATH; fd := sys->open(path, Sys->OREAD); if(fd == nil) return (nil, -1); return readall(fd, sortkey); } readall(fd: ref Sys->FD, sortkey: int): (array of ref Dir, int) { sys = load Sys Sys->PATH; dl: list of array of Dir; n := 0; for(;;){ (nr, b) := sys->dirread(fd); if(nr <= 0){ # any error makes the whole directory unreadable if(nr < 0) return (nil, -1); break; } dl = b :: dl; n += nr; } rl := dl; for(dl = nil; rl != nil; rl = tl rl) dl = hd rl :: dl; a := makerefs(dl, n, sortkey & COMPACT); sortkey &= ~COMPACT; if((sortkey & ~DESCENDING) == NONE) return (a, len a); return sortdir(a, sortkey); } makerefs(dl: list of array of Dir, n: int, compact: int): array of ref Dir { a := array[n] of ref Dir; ht: array of list of string; if(compact) ht = array[41] of list of string; j := 0; for(; dl != nil; dl = tl dl){ d := hd dl; for(i := 0; i < len d; i++) if(ht == nil || hashadd(ht, d[i].name)) a[j++] = ref d[i]; } if(j != n) a = a[0:j]; return a; } sortdir(a: array of ref Dir, key: int): (array of ref Dir, int) { mergesort(a, array[len a] of ref Dir, key); return (a, len a); } # mergesort because it's stable. mergesort(a, b: array of ref Dir, key: int) { r := len a; if (r > 1) { m := (r-1)/2 + 1; mergesort(a[0:m], b[0:m], key); mergesort(a[m:], b[m:], key); b[0:] = a; for ((i, j, k) := (0, m, 0); i < m && j < r; k++) { if (greater(b[i], b[j], key)) a[k] = b[j++]; else a[k] = b[i++]; } if (i < m) a[k:] = b[i:m]; else if (j < r) a[k:] = b[j:r]; } } greater(x, y: ref Dir, sortkey: int): int { case (sortkey) { NAME => return(x.name > y.name); ATIME => return(x.atime < y.atime); MTIME => return(x.mtime < y.mtime); SIZE => return(x.length > y.length); NAME|DESCENDING => return(x.name < y.name); ATIME|DESCENDING => return(x.atime > y.atime); MTIME|DESCENDING => return(x.mtime > y.mtime); SIZE|DESCENDING => return(x.length < y.length); } return 0; } # from tcl_strhash.b hashfn(key: string, n : int): int { h := 0; for(i := 0; i < len key; i++){ h = 10*h + key[i]; h = h%n; } return h%n; } hashadd(ht: array of list of string, nm: string): int { idx := hashfn(nm, len ht); for (ent := ht[idx]; ent != nil; ent = tl ent) if (hd ent == nm) return 0; ht[idx] = nm :: ht[idx]; return 1; }