ref: d09cf07a82cf4ffb846a31d0384e774b4c4661e1
dir: /appl/alphabet/fs/mergewrite.b/
implement Mergewrite, Fsmodule;
include "sys.m";
sys: Sys;
include "draw.m";
include "sh.m";
include "readdir.m";
readdir: Readdir;
include "alphabet/reports.m";
reports: Reports;
Report, report, quit: import reports;
include "alphabet/fs.m";
fs: Fs;
Value: import fs;
Fschan, Fsdata, Entrychan, Entry,
Cmpchan, Option,
Next, Down, Skip, Quit: import Fs;
Mergewrite: module {};
types(): string
{
return "rxsm-v-n";
}
VERBOSE, NOWRITE, ASSUME: con 1<<iota;
init()
{
sys = load Sys Sys->PATH;
readdir = load Readdir Readdir->PATH;
if(readdir == nil){
sys->fprint(sys->fildes(2), "fs: mergewrite: cannot load %s: %r\n", Readdir->PATH);
raise "fail:bad module";
}
readdir->init(nil, 0);
fs = load Fs Fs->PATH;
if(fs == nil){
sys->fprint(sys->fildes(2), "fs: mergewrite: cannot load %s: %r\n", Fs->PATH);
raise "fail:bad module";
}
reports = load Reports Reports->PATH;
if(reports == nil){
sys->fprint(sys->fildes(2), "fs: mergewrite: cannot load %s: %r\n", Reports->PATH);
raise "fail:bad module";
}
}
run(nil: ref Draw->Context, report: ref Report,
opts: list of Option, args: list of ref Value): ref Value
{
sync := chan of string;
flags := 0;
for(; opts != nil; opts = tl opts){
case (hd opts).opt {
'n' =>
flags |= NOWRITE;
'v' =>
flags |= VERBOSE;
}
}
spawn fswriteproc(sync, flags, (hd args).x().i, (hd tl args).s().i, (hd tl tl args).m().i, report.start("mergewrite"));
sync <-= nil;
return ref Value.Vr(sync);
}
fswriteproc(sync: chan of string, flags: int, c: Fschan, root: string, cmp: Cmpchan, errorc: chan of string)
{
sys->pctl(Sys->FORKNS, nil);
<-sync;
if(<-sync != nil){
(<-c).t1 <-= Quit;
quit(errorc);
}
((d, nil), reply) := <-c;
if(root != nil){
d = ref *d;
d.name = root;
}
fswritedir(d.name, cmp, d, reply, c, errorc, flags);
errorc <-= nil;
sync <-= nil; # XXX should return result here...
}
fswritedir(path: string, cmp: Cmpchan, dir: ref Sys->Dir, dreply: chan of int, c: Fschan,
errorc: chan of string, flags: int)
{
fd: ref Sys->FD;
if(dir.mode & Sys->DMDIR){
made := 0;
if(flags&VERBOSE)
report(errorc, sys->sprint("create %q %uo", path, dir.mode));
if(flags&NOWRITE){
if(flags&ASSUME)
made = 1;
else{
fd = sys->open(dir.name, Sys->OREAD);
if(fd == nil){
made = 1;
flags |= ASSUME;
}else if(sys->chdir(dir.name) == -1){
dreply <-= Next;
report(errorc, sys->sprint("cannot cd to %q: %r", path));
return;
}
}
}else{
fd = sys->create(dir.name, Sys->OREAD, dir.mode|8r300);
made = fd != nil;
if(fd == nil && (fd = sys->open(dir.name, Sys->OREAD)) == nil){
dreply <-= Next;
report(errorc, sys->sprint("cannot create %q, mode %uo: %r", path, dir.mode|8r300));
return;
}
# XXX if we haven't just made it, we should chmod the old entry u+w to enable writing.
if(sys->chdir(dir.name) == -1){ # XXX beware of names starting with '#'
dreply <-= Next;
report(errorc, sys->sprint("cannot cd to %q: %r", path));
fd = nil;
sys->remove(dir.name);
return;
}
}
dreply <-= Down;
entries: array of ref Sys->Dir;
if(made == 0)
entries = readdir->readall(fd, Readdir->NAME|Readdir->COMPACT).t0;
i := 0;
eod := 0;
d0, d1: ref Sys->Dir;
reply: chan of int;
path[len path] = '/';
for(;;){
if(!eod && d0 == nil){
((d0, nil), reply) = <-c;
if(d0 == nil){
reply <-= Next;
eod = 1;
}
}
if(d1 == nil && i < len entries)
d1 = entries[i++];
if(d0 == nil && d1 == nil)
break;
(wd0, wd1) := (d0, d1);
if(d0 != nil && d1 != nil && d0.name != d1.name){
if(d0.name < d1.name)
wd1 = nil;
else
wd0 = nil;
}
r := compare(cmp, wd0, wd1);
if(wd1 != nil){
if((r & 2r10) == 0){
if(flags&VERBOSE)
report(errorc, "removing "+path+wd1.name);
if((flags&NOWRITE)==0){
if(wd1.mode & Sys->DMDIR)
rmdir(wd1.name);
else
remove(wd1.name);
}
}
d1 = nil;
}
if(wd0 != nil){
if((r & 2r01) == 0)
reply <-= Next;
else
fswritedir(path + wd0.name, cmp, d0, reply, c, errorc, flags);
d0 = nil;
}
}
if((flags&ASSUME)==0)
sys->chdir("..");
if((flags&NOWRITE)==0){
if((dir.mode & 8r300) != 8r300){
ws := Sys->nulldir;
ws.mode = dir.mode;
if(sys->fwstat(fd, ws) == -1)
report(errorc, sys->sprint("cannot wstat %q: %r", path));
}
}
}else{
if(flags&VERBOSE)
report(errorc, sys->sprint("create %q %uo", path, dir.mode));
if(flags&NOWRITE){
dreply <-= Next;
return;
}
fd = sys->create(dir.name, Sys->OWRITE, dir.mode);
if(fd == nil){
dreply <-= Next;
report(errorc, sys->sprint("cannot create %q, mode %uo: %r", path, dir.mode|8r300));
return;
}
dreply <-= Down;
while((((nil, buf), reply) := <-c).t0.data != nil){
nw := sys->write(fd, buf, len buf);
if(nw < len buf){
if(nw == -1)
errorc <-= sys->sprint("error writing %q: %r", path);
else
errorc <-= sys->sprint("short write");
reply <-= Skip;
break;
}
reply <-= Next;
}
reply <-= Next;
}
}
rmdir(name: string)
{
(d, n) := readdir->init(name, Readdir->NONE|Readdir->COMPACT);
for(i := 0; i < n; i++){
path := name+"/"+d[i].name;
if(d[i].mode & Sys->DMDIR)
rmdir(path);
else
remove(path);
}
remove(name);
}
remove(name: string)
{
if(sys->remove(name) < 0)
sys->fprint(sys->fildes(2), "mergewrite: cannot remove %q: %r\n", name);
}
compare(cmp: Cmpchan, d0, d1: ref Sys->Dir): int
{
mask := (d0 != nil) | (d1 != nil) << 1;
if(cmp == nil)
return mask;
reply := chan of int;
cmp <-= (d0, d1, reply);
return <-reply & mask;
}