ref: eb7c19d8d04c872c41c397803ea8f97a9a73a82f
parent: 4f2673e8f15a3e15f897a892e1a5cd2b5dde4138
author: qwx <qwx@sciops.net>
date: Thu Nov 24 14:15:37 EST 2022
multiple fixes over bug-prone buffers vs. position tracking
--- a/cmd.c
+++ b/cmd.c
@@ -7,7 +7,7 @@
/* stupidest implementation with the least amount of state to keep track of */
Dot dot;
-usize totalsz;
+usize totalsz_, totalsz;
static Chunk norris = {.left = &norris, .right = &norris};
static Chunk *held;
static uchar plentyofroom[Iochunksz];
@@ -23,7 +23,7 @@
dot.from.pos, dot.pos, dot.to.pos);
c = r;
do{
- fprint(2, "%#p:%zux ", c, c->bufsz);
+ fprint(2, "%#p:%zux:←%#p→%#p - ", c, c->bufsz, c->left, c->right);
assert(c->right->left == c);
c = c->right;
}while(c != r);
@@ -69,9 +69,11 @@
{
Chunk *c;
- totalsz = 0;
+ totalsz_ = 0;
for(c=norris.right; c!=&norris; c=c->right)
- totalsz += c->bufsz;
+ totalsz_ += c->bufsz;
+ assert(totalsz_ == totalsz);
+ assert(dot.to.pos <= totalsz);
}
static void
@@ -81,6 +83,7 @@
left->right->left = c->left;
c->left = left;
left->right = c;
+ totalsz += c->bufsz;
}
static void
@@ -89,8 +92,22 @@
c->left->right = c->right;
c->right->left = c->left;
c->left = c->right = nil;
+ totalsz -= c->bufsz;
}
+static void
+resizechunk(Chunk *c, usize newsz)
+{
+ vlong Δ;
+
+ Δ = newsz - c->bufsz;
+ c->buf = erealloc(c->buf, newsz, c->bufsz);
+ c->bufsz = newsz;
+ if(c->right == &norris && Δ < 0)
+ dot.to.pos += Δ;
+ totalsz += Δ;
+}
+
/* stupidest possible approach for now: minimal bookkeeping */
Chunk *
p2c(usize p, usize *off)
@@ -134,19 +151,21 @@
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);
+ assert(off >= dot.from.pos && off < dot.to.pos);
dot.pos = off;
return 0;
}
-void
+int
jump(usize off)
{
+ if(off < dot.from.pos || off > dot.to.pos){
+ werrstr("cannot jump outside of loop bounds\n");
+ return -1;
+ }
dot.pos = off;
+ return 0;
}
static int
@@ -155,16 +174,14 @@
if(held != nil){
if(held == c)
return 0;
- else if(cutheld){
- unlinkchunk(held);
+ else if(cutheld)
freechunk(held);
- }
}
held = c;
cutheld = cut;
if(cut){
+ unlinkchunk(c);
setpos(dot.from.pos);
- unlinkchunk(held);
}
return 0;
}
@@ -172,16 +189,21 @@
static Chunk *
merge(Chunk *left, Chunk *right)
{
+ usize Δ;
+
+ assert(right != &norris);
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
+ Δ = left->bufsz;
+ resizechunk(left, left->bufsz + right->bufsz);
+ memmove(left->buf + Δ, right->buf, right->bufsz);
+ }else{
right->buf = nil;
- left->bufsz += right->bufsz;
+ left->bufsz += right->bufsz;
+ }
unlinkchunk(right);
freechunk(right);
return 0;
@@ -190,17 +212,16 @@
static Chunk *
splitright(Chunk *left, usize off)
{
- usize p, Δ;
+ usize Δ;
Chunk *c;
Δ = left->bufsz - off;
+ if(off == 0 || Δ == 0)
+ return left;
c = newchunk(Δ);
memcpy(c->buf, left->buf+off, Δ);
+ resizechunk(left, off);
linkchunk(left, c);
- left->buf = erealloc(left->buf, off, left->bufsz);
- left->bufsz = off;
- p = c2p(c);
- setrange(p, p+Δ);
return c;
}
@@ -314,7 +335,6 @@
left = p2c(dot.pos, &p);
splitright(left, p);
linkchunk(left, c);
- recalcsize();
setrange(dot.pos, dot.pos + c->bufsz);
return 1;
}
@@ -334,8 +354,11 @@
{
Chunk *c;
+ if(dot.from.pos == 0 && dot.to.pos == totalsz){
+ werrstr("cut: no range selected");
+ return -1;
+ }
c = splitdot();
- recalcsize();
holdchunk(c, 1);
return 1;
}
@@ -355,7 +378,6 @@
freechunk(right);
right = left->right;
linkchunk(left, c);
- recalcsize();
setrange(dot.from.pos, right != &norris ? c2p(right) : totalsz);
return 1;
}
@@ -388,8 +410,7 @@
if(dot.from.pos > 0){
Δ = c->bufsz - dot.from.pos;
memmove(c->buf, c->buf + dot.from.pos, Δ);
- erealloc(c->buf, Δ, c->bufsz);
- c->bufsz = Δ;
+ resizechunk(c, Δ);
dot.to.pos -= dot.from.pos;
dot.from.pos = 0;
}
@@ -396,16 +417,13 @@
for(Δ=0; c!=&norris; Δ+=c->bufsz, c=c->right)
if(Δ + c->bufsz >= dot.to.pos)
break;
- if(dot.to.pos > 0){
- erealloc(c->buf, dot.to.pos, c->bufsz);
- c->bufsz = dot.to.pos;
- }
+ if(dot.to.pos > 0)
+ resizechunk(c, dot.to.pos);
for(c=c->right; c!=&norris; c=d){
d = c->right;
unlinkchunk(c);
freechunk(c);
}
- recalcsize();
dot.pos = 0;
dot.to.pos = totalsz;
return 1;
@@ -416,6 +434,10 @@
{
usize p;
+ if(dot.from.pos == 0 && dot.to.pos == totalsz){
+ werrstr("merge: won\'t implicitely merge entire buffer\n");
+ return -1;
+ }
mergedot(&p);
return 0;
}
@@ -446,8 +468,9 @@
return nil;
}
}
- c->buf = erealloc(c->buf, off, c->bufsz);
- c->bufsz = off;
+ resizechunk(c, off);
+ if(m < Iochunksz) /* kludge! >:( */
+ totalsz += Iochunksz - c->bufsz;
return rc;
}
@@ -594,6 +617,7 @@
break;
s += n;
}
+ recalcsize();
switch(r){
case '<': return pipefrom(s);
case '^': return pipethrough(s);
@@ -618,7 +642,6 @@
if((c = readintochunks(fd)) == nil)
sysfatal("loadin: %r");
linkchunk(&norris, c);
- recalcsize();
setrange(0, totalsz);
return 0;
}
--- a/fns.h
+++ b/fns.h
@@ -9,7 +9,7 @@
void redraw(int);
void initdrw(void);
void advance(Dot*, usize);
-void jump(usize);
+int jump(usize);
Chunk* p2c(usize, usize*);
void setrange(usize, usize);
int setpos(usize);