ref: 21947578303cdb0fcb4b0cdfe80aa9dab5f6b447
dir: /appl/acme/disk.b/
implement Diskm; include "common.m"; sys : Sys; acme : Acme; utils : Utils; SZSHORT, Block, Blockincr, Astring : import Dat; error : import utils; init(mods : ref Dat->Mods) { sys = mods.sys; acme = mods.acme; utils = mods.utils; } blist : ref Block; tempfile() : ref Sys->FD { buf := sys->sprint("/tmp/X%d.%.4sacme", sys->pctl(0, nil), utils->getuser()); for(i:='A'; i<='Z'; i++){ buf[5] = i; (ok, nil) := sys->stat(buf); if(ok == 0) continue; fd := sys->create(buf, Sys->ORDWR|Sys->ORCLOSE, 8r600); if(fd != nil) return fd; } return nil; } Disk.init() : ref Disk { d : ref Disk; d = ref Disk; d.free = array[Dat->Maxblock/Dat->Blockincr+1] of ref Block; d.addr = 0; d.fd = tempfile(); if(d.fd == nil){ error(sys->sprint("can't create temp file %r")); acme->acmeexit("temp create"); } return d; } ntosize(n : int) : (int, int) { size : int; if (n > Dat->Maxblock) error("bad assert in ntosize"); size = n; if(size & (Blockincr-1)) size += Blockincr - (size & (Blockincr-1)); # last bucket holds blocks of exactly Maxblock return (size * SZSHORT, size/Blockincr); } Disk.new(d : self ref Disk, n : int) : ref Block { i, j, size : int; b, bl : ref Block; (size, i) = ntosize(n); b = d.free[i]; if(b != nil) d.free[i] = b.next; else{ # allocate in chunks to reduce malloc overhead if(blist == nil){ blist = ref Block; bl = blist; for(j=0; j<100-1; j++) { bl.next = ref Block; bl = bl.next; } } b = blist; blist = b.next; b.addr = d.addr; d.addr += size; } b.n = n; return b; } Disk.release(d : self ref Disk, b : ref Block) { (nil, i) := ntosize(b.n); b.next = d.free[i]; d.free[i] = b; } Disk.write(d : self ref Disk, bp : ref Block, r : string, n : int) : ref Block { size, nsize, i : int; b : ref Block; ab : array of byte; b = bp; (size, i) = ntosize(b.n); (nsize, i) = ntosize(n); if(size != nsize){ d.release(b); b = d.new(n); } if(sys->seek(d.fd, big b.addr, 0) < big 0) error("seek error in temp file"); ab = utils->stob(r, n); if(sys->write(d.fd, ab, len ab) != len ab) error("write error to temp file"); ab = nil; b.n = n; return b; } Disk.read(d : self ref Disk, b : ref Block, r : ref Astring, n : int) { ab : array of byte; if (n > b.n) error("bad assert in Disk.read"); (nil, nil) := ntosize(b.n); if(sys->seek(d.fd, big b.addr, 0) < big 0) error("seek error in temp file"); ab = array[n*SZSHORT] of byte; if(sys->read(d.fd, ab, len ab) != len ab) error("read error from temp file"); utils->btos(ab, r); ab = nil; }