ref: 7ce3aecba011c42b3ae9e13230110dc73fa48a28
dir: /cmd.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include "dat.h"
#include "fns.h"
/* stupidest implementation with the least amount of state to keep track of */
Dot dot;
usize totalsz;
static Chunk norris = {.left = &norris, .right = &norris};
static Chunk *held;
static uchar plentyofroom[Iochunksz];
static int cutheld;
static int epfd[2];
static Chunk *
newchunk(usize n)
{
Chunk *c;
assert((n & 3) == 0);
c = emalloc(sizeof *c);
c->bufsz = n;
c->buf = emalloc(c->bufsz);
return c;
}
static Chunk *
clonechunk(void)
{
Chunk *c;
assert(held != nil);
c = newchunk(held->bufsz);
memcpy(c->buf, held->buf, c->bufsz);
return c;
}
static void
freechunk(Chunk *c)
{
if(c == nil)
return;
free(c->buf);
free(c);
}
static void
linkchunk(Chunk *left, Chunk *c)
{
c->right = left->right;
c->left = left;
c->right->left = c;
left->right = c;
}
static void
unlinkchunk(Chunk *c)
{
c->left->right = c->right;
c->right->left = c->left;
c->left = c->right = nil;
}
/* stupidest possible approach for now: minimal bookkeeping */
Chunk *
p2c(usize p, usize *off)
{
Chunk *c;
c = norris.right;
while(p > c->bufsz){
p -= c->bufsz;
c = c->right;
}
if(off != nil)
*off = p;
assert(c != &norris);
return c;
}
static usize
c2p(Chunk *tc)
{
Chunk *c;
usize p;
p = 0;
c = norris.right;
while(c != tc){
p += c->bufsz;
c = c->right;
}
return p;
}
void
setrange(usize from, usize to)
{
dot.from.pos = from;
dot.to.pos = to;
}
int
setpos(usize off)
{
if(off < dot.from.pos || off > dot.to.pos){
werrstr("cannot jump outside of loop bounds\n");
return -1;
}
setrange(0, totalsz);
dot.pos = off;
return 0;
}
void
jump(usize off)
{
dot.pos = off;
}
static int
holdchunk(int cut)
{
if(held != nil){
if(held == p2c(dot.pos, nil))
return 0;
else if(cutheld){
unlinkchunk(held);
freechunk(held);
}
}
held = p2c(dot.from.pos, nil);
cutheld = cut;
if(cut){
setpos(dot.from.pos);
unlinkchunk(held);
}
return 0;
}
static Chunk *
merge(Chunk *left, Chunk *right)
{
if(left->buf == nil || right->buf == nil){
werrstr("can\'t merge self into void");
return nil;
}
if(left->buf != right->buf){
left->buf = erealloc(left->buf, left->bufsz + right->bufsz, left->bufsz);
memmove(left->buf + left->bufsz, right->buf, right->bufsz);
}else
right->buf = nil;
left->bufsz += right->bufsz;
unlinkchunk(right);
freechunk(right);
return 0;
}
static void
splitright(Chunk *c, usize off)
{
usize Δ;
Chunk *nc;
Δ = c->bufsz - off;
nc = newchunk(Δ);
memcpy(nc->buf, c->buf+off, Δ);
linkchunk(c, nc);
c->buf = erealloc(c->buf, off, c->bufsz);
c->bufsz = off;
}
static Chunk *
mergedot(usize *off)
{
usize p;
Chunk *c;
c = p2c(dot.from.pos, &p);
*off = p;
p = dot.from.pos - p;
while(p + c->bufsz < dot.to.pos)
merge(c, c->right);
return c;
}
/* before one may split oneself, one must first merge oneself */
static void
splitdot(void)
{
usize p;
Chunk *c;
c = mergedot(&p);
splitright(c, p + dot.to.pos - dot.from.pos);
splitright(c, p);
}
uchar *
getbuf(Dot d, usize n, uchar *scratch, usize *boff)
{
uchar *bp, *p;
usize Δbuf, Δloop, m, off, Δ;
Chunk *c;
c = p2c(d.pos, &off);
p = c->buf + off;
m = n;
bp = scratch;
while(m > 0){
Δloop = d.to.pos - d.pos;
Δbuf = c->bufsz - off;
if(m < Δloop && m < Δbuf){
Δ = m;
memcpy(bp, p, Δ);
d.pos += Δ;
}else if(Δloop <= Δbuf){
Δ = Δloop;
memcpy(bp, p, Δ);
d.pos = d.from.pos;
c = p2c(d.from.pos, nil);
off = 0;
p = c->buf;
}else{
if(c == &norris)
c = c->right;
Δ = Δbuf;
memcpy(bp, p, Δ);
d.pos += Δ;
c = c->right;
off = 0;
p = c->buf;
}
bp += Δ;
m -= Δ;
}
*boff = n;
return scratch;
}
void
advance(Dot *d, usize n)
{
usize Δ, Δbuf, Δloop, m, off;
Chunk *c;
c = p2c(d->pos, &off);
m = n;
while(m > 0){
Δloop = d->to.pos - d->pos;
Δbuf = c->bufsz - off;
if(m < Δloop && m < Δbuf){
d->pos += m;
break;
}else if(Δloop < Δbuf){
Δ = Δloop;
d->pos = d->from.pos;
c = p2c(d->from.pos, nil);
off = 0;
}else{
Δ = Δbuf;
d->pos += Δ;
c = c->right;
off = 0;
}
m -= Δ;
}
}
static int
paste(char *)
{
Chunk *c, *l, *dotc;
c = clonechunk();
if(dot.from.pos == 0 && dot.to.pos == totalsz){ /* insert */
linkchunk(p2c(dot.pos, nil), c);
setrange(dot.pos, dot.pos + c->bufsz);
totalsz += c->bufsz;
}else{ /* replace */
dotc = p2c(dot.pos, nil);
l = dotc->left;
totalsz -= dotc->bufsz;
unlinkchunk(dotc);
freechunk(dotc);
linkchunk(l, c);
setrange(dot.from.pos, dot.from.pos + c->bufsz);
totalsz += c->bufsz;
}
return 1;
}
static int
copy(char *)
{
splitdot();
holdchunk(0);
return 0;
}
static int
cut(char *)
{
splitdot();
totalsz -= p2c(dot.pos, nil)->bufsz;
holdchunk(1);
return 1;
}
static int
forcemerge(char *)
{
usize p;
mergedot(&p);
return 0;
}
static Chunk *
readintochunks(int fd)
{
int n;
usize off;
Chunk *c, *nc;
c = newchunk(Iochunksz);
linkchunk(&norris, c);
for(off=0;; off+=n){
if(off == Iochunksz){
totalsz += Iochunksz;
nc = newchunk(Iochunksz);
linkchunk(c, nc);
c = nc;
off = 0;
}
if((n = read(fd, c->buf+off, Ioreadsz)) <= 0)
break;
}
close(fd);
if(n < 0)
fprint(2, "readintochunks: %r\n");
c->buf = erealloc(c->buf, off, c->bufsz);
c->bufsz = off;
totalsz += c->bufsz;
return norris.right;
}
static int
writebuf(int fd)
{
usize n, m;
uchar *p;
Dot d;
d.pos = d.from.pos = dot.from.pos;
d.to.pos = dot.to.pos;
for(m=d.to.pos-d.from.pos; m>0;){
n = sizeof plentyofroom < m ? sizeof plentyofroom : m;
if((p = getbuf(d, n, plentyofroom, &n)) == nil){
fprint(2, "writebuf: getbuf won't feed\n");
return -1;
}
if((n = write(fd, p, m)) != n){
fprint(2, "writebuf: short write not %zd\n", n);
return -1;
}
m -= n;
}
return 0;
}
static void
rc(void *s)
{
close(epfd[1]);
dup(epfd[0], 0);
close(epfd[0]);
procexecl(nil, "/bin/rc", "rc", "-c", s, nil);
sysfatal("procexec: %r");
}
static int
pipeto(char *arg)
{
if(pipe(epfd) < 0)
sysfatal("pipe: %r");
if(procrfork(rc, arg, mainstacksize, RFFDG|RFNOTEG|RFNAMEG) < 0)
sysfatal("procrfork: %r");
close(epfd[0]);
writebuf(epfd[1]);
close(epfd[1]);
return 0;
}
/* the entire string is treated as the filename, ie.
* spaces and any other weird characters will be part
* of it */
static int
writeto(char *arg)
{
int r, fd;
if(dot.to.pos - dot.from.pos == 0){
werrstr("writeto: dot isn't a range");
return -1;
}
if((fd = create(arg, OWRITE, 0664)) < 0){
werrstr("writeto: %r");
return -1;
}
r = writebuf(fd);
close(fd);
return r;
}
int
cmd(char *s)
{
int n;
Rune r, r´;
/* FIXME: avoid potential conflicts with keys in main() */
assert(s != nil);
s += chartorune(&r, s);
for(;;){
n = chartorune(&r´, s);
if(r´ == Runeerror){
werrstr("malformed input");
return -1;
}
if(r´ == 0 || r´ != ' ' && r´ != '\t')
break;
s += n;
}
switch(r){
// case '<': return pipefrom(s);
// case '^': return exchange(s);
case '|': return pipeto(s);
case 'c': return copy(s);
case 'd': return cut(s);
case 'm': return forcemerge(s);
case 'p': return paste(s);
// case 'r': return readfrom(s);
case 'w': return writeto(s);
// case 'x': return crop(s);
default: werrstr("unknown command %C", r); break;
}
return -1;
}
int
loadin(int fd)
{
if(readintochunks(fd) == nil)
sysfatal("loadin: %r");
setrange(0, totalsz);
return 0;
}
static void
catch(void *, char *msg)
{
if(strstr(msg, "closed pipe"))
noted(NCONT);
noted(NDFLT);
}
void
initcmd(void)
{
notify(catch);
}