ref: caef73363f896a1405ce6b9b6435f91e47a9b188
dir: /appl/alphabet/fs/unbundle.b/
implement Unbundle, Fsmodule; include "sys.m"; sys: Sys; include "bufio.m"; bufio: Bufio; Iobuf: import bufio; include "string.m"; str: String; include "draw.m"; include "sh.m"; include "alphabet/reports.m"; reports: Reports; Report, quit, report: import reports; include "alphabet/fs.m"; fs: Fs; Value: import fs; Fschan, Fsdata, Entrychan, Entry, Quit, Next, Skip, Down, Option: import Fs; Unbundle: module {}; types(): string { return "xf"; } badmod(p: string) { sys->fprint(sys->fildes(2), "fs: exec: cannot load %s: %r\n", p); raise "fail:bad module"; } init() { sys = load Sys Sys->PATH; fs = load Fs Fs->PATH; if(fs == nil) badmod(Fs->PATH); fs->init(); reports = load Reports Reports->PATH; if(reports == nil) badmod(Reports->PATH); bufio = load Bufio Bufio->PATH; if(bufio == nil) badmod(Bufio->PATH); str = load String String->PATH; if(str == nil) badmod(String->PATH); } run(nil: ref Draw->Context, report: ref Report, nil: list of Option, args: list of ref Value): ref Value { f := (hd args).f().i; c := ref Value.Vx(chan of (Fsdata, chan of int)); spawn unbundleproc((hd args).f().i, nil, c.i, -1, Sys->ATOMICIO, report.start("unbundle")); return c; } # dodgy heuristic... avoid, or using the stat-length of pipes and net connections isseekable(fd: ref Sys->FD): int { (ok, stat) := sys->fstat(fd); if(ok != -1 && stat.dtype == '|' || stat.dtype == 'I') return 0; return 1; } EOF: con "end of archive\n"; unbundleproc(f: chan of ref Sys->FD, iob: ref Iobuf, c: Fschan, seekable, blocksize: int, errorc: chan of string) { if(f != nil){ fd := <-f; if(fd == nil){ sys->pipe(p := array[2] of ref Sys->FD); f <-= p[1]; p[1] = nil; fd = p[0]; }else f <-= nil; if(seekable == -1) seekable = isseekable(fd); iob = bufio->fopen(fd, Sys->OREAD); f = nil; } reply := chan of int; p := iob.gets('\n'); # XXX overall header? if(p == nil || p == EOF){ fs->sendnulldir(c); quit(errorc); } d := header2dir(p); if(d == nil){ fs->sendnulldir(c); report(errorc, sys->sprint("invalid first header %q", p[0:len p - 1])); quit(errorc); } if((d.mode & Sys->DMDIR) == 0){ fs->sendnulldir(c); report(errorc, "first entry is not a directory"); quit(errorc); } c <-= ((d, nil), reply); case r := <-reply { Down => unbundledir(iob, c, 0, seekable, blocksize, errorc); c <-= ((nil, nil), reply); <-reply; Skip or Next => unbundledir(iob, c, 1, seekable, blocksize, errorc); Quit => break; } quit(errorc); } unbundledir(iob: ref Iobuf, c: Fschan, skipping, seekable, blocksize: int, errorc: chan of string): int { reply := chan of int; while((p := iob.gets('\n')) != nil){ if(p == EOF) break; if(p[0] == '\n') break; d := header2dir(p); if(d == nil){ report(errorc, sys->sprint("invalid bundle header %q", p[0:len p - 1])); return -1; } if(d.mode & Sys->DMDIR){ if(skipping) continue; c <-= ((d, nil), reply); case <-reply { Quit => quit(errorc); Down => r := unbundledir(iob, c, 0, seekable, blocksize, errorc); c <-= ((nil, nil), reply); if(<-reply == Quit) quit(errorc); if(r == -1) return -1; Skip => if(unbundledir(iob, c, 1, seekable, blocksize, errorc) == -1) return -1; skipping = 1; Next => if(unbundledir(iob, c, 1, seekable, blocksize, errorc) == -1) return -1; } }else{ if(skipping){ if(skipdata(iob, d.length, seekable) == -1) return -1; }else{ case unbundlefile(iob, d, c, errorc, seekable, blocksize) { -1 => return -1; Skip => skipping = 1; } } } } if(p == nil) report(errorc, "unexpected eof"); return 0; } skipdata(iob: ref Iobuf, length: big, seekable: int): int { if(seekable){ iob.seek(big length, Sys->SEEKRELA); return 0; } buf := array[Sys->ATOMICIO] of byte; for(n := big 0; n < length; ){ nb := Sys->ATOMICIO; if(length - n < big Sys->ATOMICIO) nb = int (length - n); nb = iob.read(buf, nb); if(nb <= 0) return -1; n += big nb; } return 0; } unbundlefile(iob: ref Iobuf, d: ref Sys->Dir, c: Fschan, errorc: chan of string, seekable, blocksize: int): int { reply := chan of int; c <-= ((d, nil), reply); case <-reply { Quit => quit(errorc); Skip => if(skipdata(iob, d.length, seekable) == -1) return -1; return Skip; Next => if(skipdata(iob, d.length, seekable) == -1) return -1; return Next; } length := d.length; for(n := big 0; n < length; ){ nr := blocksize; if(n + big blocksize > length) nr = int (length - n); buf := array[nr] of byte; nr = iob.read(buf, nr); if(nr <= 0){ if(nr < 0) report(errorc, sys->sprint("read error: %r")); else report(errorc, sys->sprint("premature eof")); return -1; }else if(nr < len buf) buf = buf[0:nr]; c <-= ((nil, buf), reply); n += big nr; case <-reply { Quit => quit(errorc); Skip => if(skipdata(iob, length - n, seekable) == -1) return -1; return Next; } } c <-= ((nil, nil), reply); if(<-reply == Quit) quit(errorc); return Next; } header2dir(s: string): ref Sys->Dir { toks := str->unquoted(s); nf := len toks; if(nf != 6) return nil; d := ref Sys->nulldir; (d.name, toks) = (hd toks, tl toks); (d.mode, toks) = (str->toint(hd toks, 8).t0, tl toks); (d.uid, toks) = (hd toks, tl toks); (d.gid, toks) = (hd toks, tl toks); (d.mtime, toks) = (int hd toks, tl toks); (d.length, toks) = (big hd toks, tl toks); return d; }