ref: 928e9db52eaf922181c5b5d7e618e66cfd9afb61
dir: /chunk.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include "dat.h"
#include "fns.h"
/* chunk ≡ chain of chunks */
struct Buf{
uchar *buf;
usize bufsz;
Ref;
};
static Chunk *norris;
// FIXME: crazy idea, multisnarf with addressable elements; $n registers; fork pplay to display them → ?
typedef struct Op Op;
struct Op{
Chunk *p1;
Chunk *p2;
Chunk *l;
Chunk *r;
};
static Op *opbuf, *ophead, *opend;
static usize opbufsz;
static struct{
Chunk *from;
usize foff;
Chunk *to;
usize toff;
} hold;
int
Δfmt(Fmt *fmt)
{
Dot *d;
d = va_arg(fmt->args, Dot*);
if(d == nil)
return fmtstrcpy(fmt, "[??:??:??:??]");
return fmtprint(fmt, "[from=%08zux cur=%08zux to=%08zux]",
d->from, d->pos, d->to);
}
int
χfmt(Fmt *fmt)
{
Chunk *c;
c = va_arg(fmt->args, Chunk*);
if(c == nil)
return fmtstrcpy(fmt, "[]");
return fmtprint(fmt, "0x%08p:%08zux::0x%08p:0x%08p", c, c->len, c->left, c->right);
}
static void
printchunks(Chunk *r)
{
usize len;
Chunk *c;
c = r;
len = 0;
do{
fprint(2, "\t%χ\toff=%08zux\n", c, len);
assert(c->right->left == c);
len += c->len;
c = c->right;
}while(c != r);
fprint(2, "\n");
}
void
dprint(Chunk *c, char *fmt, ...)
{
char s[256];
va_list arg;
if(!debug)
return;
va_start(arg, fmt);
vseprint(s, s+sizeof s, fmt, arg);
va_end(arg);
fprint(2, "%s", s);
printchunks(c == nil ? norris : c);
}
static Chunk *
newchunk(Buf *b)
{
Chunk *c;
c = emalloc(sizeof *c);
c->left = c;
c->right = c;
c->b = b;
c->boff = 0;
c->len = b->bufsz;
incref(&b->Ref);
return c;
}
static Chunk *
newbuf(usize n)
{
Buf *b;
assert((n & 3) == 0);
b = emalloc(sizeof *b);
b->bufsz = n;
b->buf = emalloc(b->bufsz);
return newchunk(b);
}
static void
linkchunk(Chunk *left, Chunk *c)
{
c->left->right = left->right;
left->right->left = c->left;
c->left = left;
left->right = c;
}
static void
unlink(Chunk *left, Chunk *right)
{
left->left->right = right->right;
right->right->left = left->left;
left->left = right;
right->right = left;
}
static Chunk *
clonechunk(Chunk *c)
{
Chunk *nc;
assert(c != nil && c->b != nil);
nc = newchunk(c->b);
nc->boff = c->boff;
nc->len = c->len;
incref(c->b);
return nc;
}
static Chunk *
clone(Chunk *left, Chunk *right)
{
Chunk *cl, *c, *nc;
cl = clonechunk(left);
c = cl;
for(; left!=right;){
left = left->right;
nc = clonechunk(left);
linkchunk(c, nc);
c = nc;
}
return cl;
}
static Chunk *
splitchunk(Chunk *p, usize from, usize to)
{
Chunk *c;
/* 0-size chunks are permitted */
assert(to <= p->len && to - from <= p->len);
c = clonechunk(p);
c->boff += from;
c->len = to - from;
c->left = c->right = c;
return c;
}
static void
freebuf(Buf *b)
{
if(b == nil)
return;
free(b->buf);
free(b);
}
static void
freechunk(Chunk *c)
{
if(c == nil)
return;
if(c->b != nil && decref(c->b) == 0)
freebuf(c->b);
free(c);
}
void
freechain(Chunk *c)
{
Chunk *cl, *cp;
if(c == nil)
return;
for(cl=c->right; cl!=c; cl=cp){
cp = cl->right;
unlink(cl, cl);
freechunk(cl);
}
freechunk(c);
}
usize
chainlen(Chunk *c)
{
usize n;
Chunk *cp;
for(cp=c, n=cp->len, cp=cp->right; cp!=c; cp=cp->right)
n += cp->len;
return n;
}
void
checksz(void)
{
usize n;
n = chainlen(norris);
fprint(2, "totalsz %zd %Δ :: chainlen %zd\n", totalsz, &dot, n);
assert(n == totalsz);
assert(dot.from < dot.to);
assert(dot.from <= totalsz);
assert(dot.pos >= dot.from && dot.pos < dot.to);
}
Chunk *
p2c(usize p, usize *off)
{
Chunk *c;
for(c=norris; p>=c->len; c=c->right){
if(c == norris->left){
assert(p == c->len);
break;
}
p -= c->len;
}
if(off != nil)
*off = p;
return c;
}
static void
forgetop(Op *op)
{
freechain(op->l);
}
int
unpop(char *)
{
Op *op;
if(opend == opbuf || ophead == opend)
return 0;
op = ophead++;
dprint(op->p1, "cmd/unpop dot=%Δ P [%χ][%χ] LR [%χ][%χ]\n",
&dot, op->p1, op->p2, op->l, op->r);
totalsz += chainlen(op->l);
linkchunk(op->p1->left, op->l);
unlink(op->p1, op->p2);
totalsz -= chainlen(op->p1);
if(norris == op->p1)
norris = op->l;
dot.from = dot.pos = 0;
dot.to = totalsz;
latchedpos = -1;
return 1;
}
int
popop(char *)
{
Op *op;
if(ophead == opbuf)
return 0;
op = --ophead;
dprint(op->l, "cmd/pop dot=%Δ P [%χ][%χ] LR [%χ][%χ]\n",
&dot, op->p1, op->p2, op->l, op->r);
totalsz += chainlen(op->p1);
linkchunk(op->l->left, op->p1);
unlink(op->l, op->r);
totalsz -= chainlen(op->l);
if(norris == op->l)
norris = op->p1;
dot.from = dot.pos = 0;
dot.to = totalsz;
latchedpos = -1;
return 1;
}
static void
pushop(Chunk *p1, Chunk *p2, Chunk *l, Chunk *r)
{
Op *op;
if(ophead == opbuf + opbufsz){
opbuf = erealloc(opbuf,
(opbufsz + 1024) * sizeof *opbuf,
opbufsz * sizeof *opbuf);
ophead = opbuf + opbufsz;
opend = ophead;
opbufsz += 1024;
}
if(opend > ophead){
for(op=ophead; op<opend; op++)
forgetop(op);
memset(ophead, 0, (opend - ophead) * sizeof *ophead);
}
*ophead++ = (Op){p1, p2, l, r};
opend = ophead;
}
void
ccrop(usize from, usize to)
{
usize n, off;
Chunk *p1, *p2, *l, *r;
assert(from < to && to <= totalsz);
p1 = p2c(from, &off);
if(p1->len - off >= to - from){
l = splitchunk(p1, off, off);
p2 = p1;
r = splitchunk(p2, off, off + to - from);
if(p1 != norris)
p1 = p1->left;
else
p2 = p2->right;
}else{
p1 = p2c(from, &off);
l = splitchunk(p1, off, p1->len);
p2 = p2c(to, &off);
r = splitchunk(p2, 0, off);
}
linkchunk(p1, l);
linkchunk(p2->left, r);
unlink(p2, p1);
n = chainlen(l);
totalsz = n;
pushop(p1, p2, l, r);
norris = l;
dot.from = dot.pos = 0;
dot.to = n;
latchedpos = -1;
}
static int
creplace(usize from, usize to, Chunk *c)
{
usize n, off;
Chunk *p1, *p2, *l, *r;
assert(from < to && to <= totalsz);
p1 = p2c(from, &off);
l = splitchunk(p1, 0, off);
p2 = p2c(to, &off);
r = splitchunk(p2, off, p2->len);
linkchunk(c, r);
linkchunk(l, c);
n = chainlen(l);
totalsz += n;
linkchunk(p1->left, l);
unlink(p1, p2);
totalsz -= chainlen(p1);
pushop(p1, p2, l, r);
if(p1 == norris)
norris = l;
dot.from = dot.pos = from;
dot.to = from + n;
latchedpos = -1;
return 0;
}
// FIXME: use a specific Dot (prep for multibuf); generalize
static int
cinsert(usize pos, Chunk *c)
{
usize n, off;
Chunk *p, *l, *r;
assert(pos <= totalsz);
p = p2c(pos, &off);
l = splitchunk(p, 0, off);
r = splitchunk(p, off, p->len);
linkchunk(c, r);
linkchunk(l, c);
n = chainlen(l);
totalsz += n;
linkchunk(p->left, l);
unlink(p, p);
totalsz -= chainlen(p);
pushop(p, p, l, r);
if(p == norris)
norris = l;
dot.from = dot.pos = pos;
dot.to = pos + n;
latchedpos = -1;
return 0;
}
int
cpaste(usize from, usize to)
{
Chunk *p1, *p2, *l, *r;
if(hold.from == nil || hold.to == nil){
werrstr("cpaste: nothing to paste");
return -1;
}
p1 = hold.from;
p2 = hold.to;
if(p1 == p2)
l = splitchunk(p1, hold.foff, hold.toff);
else{
l = splitchunk(p1, hold.foff, p1->len);
r = splitchunk(p2, 0, hold.toff);
if(p1->right != p2)
linkchunk(l, clone(p1->right, p2->left));
linkchunk(l->left, r);
}
return from == to ? cinsert(from, l) : creplace(from, to, l);
}
void
ccopy(usize from, usize to)
{
hold.from = p2c(from, &hold.foff);
hold.to = p2c(to, &hold.toff);
}
void
chold(Chunk *c)
{
hold.from = hold.to = c;
hold.foff = hold.toff = 0;
}
void
ccut(usize from, usize to)
{
usize n;
Chunk *p1, *p2, *l, *r;
if(from - to == totalsz){
fprint(2, "ccut: not cutting entire buffer\n");
return;
}
assert(from < to && to <= totalsz);
ccopy(from, to);
p1 = hold.from;
p2 = hold.to;
l = splitchunk(p1, 0, hold.foff);
r = splitchunk(p2, hold.toff, p2->len);
linkchunk(l, r);
n = chainlen(l);
totalsz += n;
linkchunk(p1->left, l);
unlink(p1, p2);
totalsz -= chainlen(p1);
pushop(p1, p2, l, r);
if(p1 == norris)
norris = l;
dot.from = dot.pos = from;
dot.to = totalsz;
latchedpos = -1;
}
uchar *
getslice(Dot *d, usize want, usize *have)
{
usize n, off;
Chunk *c;
if(d->pos >= totalsz){
werrstr("out of bounds");
*have = 0;
return nil;
}
c = p2c(d->pos, &off);
n = c->len - off;
*have = want > n ? n : want;
return c->b->buf + c->boff + off;
}
Chunk *
chunkfile(int fd)
{
int n;
Chunk *c;
Buf *b;
c = newbuf(Chunksz);
b = c->b;
for(;;){
if(b->bufsz - c->len < Chunksz){
b->buf = erealloc(c->b->buf, 2 * c->b->bufsz, c->b->bufsz);
b->bufsz *= 2;
}
if((n = readn(fd, b->buf + c->len, Chunksz)) < Chunksz)
break;
c->len += n;
yield();
}
if(n < 0){
fprint(2, "chunkfile: %r\n");
freechunk(c);
return nil;
}else if(c->len == 0){
fprint(2, "chunkfile: nothing read\n");
freechunk(c);
return nil;
}else if(c->len < b->bufsz){
b->buf = erealloc(b->buf, c->len, b->bufsz);
b->bufsz = c->len;
}
return c;
}
void
initbuf(Chunk *c)
{
norris = c;
totalsz = chainlen(c);
dot.pos = dot.from = 0;
dot.to = totalsz;
}