ref: fe1eb39db7ae6904924f3ab1f6f9b34416f2eb1b
dir: /sys/src/cmd/acme/file.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <cursor.h>
#include <mouse.h>
#include <keyboard.h>
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
#include "dat.h"
#include "fns.h"
/*
* Structure of Undo list:
* The Undo structure follows any associated data, so the list
* can be read backwards: read the structure, then read whatever
* data is associated (insert string, file name) and precedes it.
* The structure includes the previous value of the modify bit
* and a sequence number; successive Undo structures with the
* same sequence number represent simultaneous changes.
*/
typedef struct Undo Undo;
struct Undo
{
short type; /* Delete, Insert, Filename */
short mod; /* modify bit */
uint seq; /* sequence number */
uint p0; /* location of change (unused in f) */
uint n; /* # runes in string or file name */
};
enum
{
Undosize = sizeof(Undo)/sizeof(Rune),
};
File*
fileaddtext(File *f, Text *t)
{
if(f == nil){
f = emalloc(sizeof(File));
f->unread = TRUE;
}
f->text = realloc(f->text, (f->ntext+1)*sizeof(Text*));
f->text[f->ntext++] = t;
f->curtext = t;
return f;
}
void
filedeltext(File *f, Text *t)
{
int i;
for(i=0; i<f->ntext; i++)
if(f->text[i] == t)
goto Found;
error("can't find text in filedeltext");
Found:
f->ntext--;
if(f->ntext == 0){
fileclose(f);
return;
}
memmove(f->text+i, f->text+i+1, (f->ntext-i)*sizeof(Text*));
if(f->curtext == t)
f->curtext = f->text[0];
}
void
fileinsert(File *f, uint p0, Rune *s, uint ns)
{
if(p0 > f->nc)
error("internal error: fileinsert");
if(f->seq > 0)
fileuninsert(f, &f->delta, p0, ns);
bufinsert(f, p0, s, ns);
if(ns)
f->mod = TRUE;
}
void
fileuninsert(File *f, Buffer *delta, uint p0, uint ns)
{
Undo u;
/* undo an insertion by deleting */
u.type = Delete;
u.mod = f->mod;
u.seq = f->seq;
u.p0 = p0;
u.n = ns;
bufinsert(delta, delta->nc, (Rune*)&u, Undosize);
}
void
filedelete(File *f, uint p0, uint p1)
{
if(!(p0<=p1 && p0<=f->nc && p1<=f->nc))
error("internal error: filedelete");
if(f->seq > 0)
fileundelete(f, &f->delta, p0, p1);
bufdelete(f, p0, p1);
if(p1 > p0)
f->mod = TRUE;
}
void
fileundelete(File *f, Buffer *delta, uint p0, uint p1)
{
Undo u;
Rune *buf;
uint i, n;
/* undo a deletion by inserting */
u.type = Insert;
u.mod = f->mod;
u.seq = f->seq;
u.p0 = p0;
u.n = p1-p0;
buf = fbufalloc();
for(i=p0; i<p1; i+=n){
n = p1 - i;
if(n > RBUFSIZE)
n = RBUFSIZE;
bufread(f, i, buf, n);
bufinsert(delta, delta->nc, buf, n);
}
fbuffree(buf);
bufinsert(delta, delta->nc, (Rune*)&u, Undosize);
}
void
filesetname(File *f, Rune *name, int n)
{
if(f->seq > 0)
fileunsetname(f, &f->delta);
free(f->name);
f->name = runemalloc(n);
runemove(f->name, name, n);
f->nname = n;
f->unread = TRUE;
}
void
fileunsetname(File *f, Buffer *delta)
{
Undo u;
/* undo a file name change by restoring old name */
u.type = Filename;
u.mod = f->mod;
u.seq = f->seq;
u.p0 = 0; /* unused */
u.n = f->nname;
if(f->nname)
bufinsert(delta, delta->nc, f->name, f->nname);
bufinsert(delta, delta->nc, (Rune*)&u, Undosize);
}
uint
fileload(File *f, uint p0, int fd, int *nulls)
{
if(f->seq > 0)
error("undo in file.load unimplemented");
return bufload(f, p0, fd, nulls);
}
/* return sequence number of pending redo */
uint
fileredoseq(File *f)
{
Undo u;
Buffer *delta;
delta = &f->epsilon;
if(delta->nc == 0)
return 0;
bufread(delta, delta->nc-Undosize, (Rune*)&u, Undosize);
return u.seq;
}
void
fileundo(File *f, int isundo, uint *q0p, uint *q1p)
{
Undo u;
Rune *buf;
uint i, j, n, up;
uint stop;
Buffer *delta, *epsilon;
if(isundo){
/* undo; reverse delta onto epsilon, seq decreases */
delta = &f->delta;
epsilon = &f->epsilon;
stop = f->seq;
}else{
/* redo; reverse epsilon onto delta, seq increases */
delta = &f->epsilon;
epsilon = &f->delta;
stop = 0; /* don't know yet */
}
buf = fbufalloc();
while(delta->nc > 0){
up = delta->nc-Undosize;
bufread(delta, up, (Rune*)&u, Undosize);
if(isundo){
if(u.seq < stop){
f->seq = u.seq;
goto Return;
}
}else{
if(stop == 0)
stop = u.seq;
if(u.seq > stop)
goto Return;
}
switch(u.type){
default:
fprint(2, "undo: 0x%ux\n", u.type);
abort();
break;
case Delete:
f->seq = u.seq;
fileundelete(f, epsilon, u.p0, u.p0+u.n);
f->mod = u.mod;
bufdelete(f, u.p0, u.p0+u.n);
for(j=0; j<f->ntext; j++)
textdelete(f->text[j], u.p0, u.p0+u.n, FALSE);
*q0p = u.p0;
*q1p = u.p0;
break;
case Insert:
f->seq = u.seq;
fileuninsert(f, epsilon, u.p0, u.n);
f->mod = u.mod;
up -= u.n;
for(i=0; i<u.n; i+=n){
n = u.n - i;
if(n > RBUFSIZE)
n = RBUFSIZE;
bufread(delta, up+i, buf, n);
bufinsert(f, u.p0+i, buf, n);
for(j=0; j<f->ntext; j++)
textinsert(f->text[j], u.p0+i, buf, n, FALSE);
}
*q0p = u.p0;
*q1p = u.p0+u.n;
break;
case Filename:
f->seq = u.seq;
fileunsetname(f, epsilon);
f->mod = u.mod;
up -= u.n;
free(f->name);
if(u.n == 0)
f->name = nil;
else
f->name = runemalloc(u.n);
bufread(delta, up, f->name, u.n);
f->nname = u.n;
break;
}
bufdelete(delta, up, delta->nc);
}
if(isundo)
f->seq = 0;
Return:
fbuffree(buf);
}
void
filereset(File *f)
{
bufreset(&f->delta);
bufreset(&f->epsilon);
f->seq = 0;
}
void
fileclose(File *f)
{
free(f->name);
f->nname = 0;
f->name = nil;
free(f->text);
f->ntext = 0;
f->text = nil;
bufclose(f);
bufclose(&f->delta);
bufclose(&f->epsilon);
elogclose(f);
free(f);
}
void
filemark(File *f)
{
if(f->epsilon.nc)
bufdelete(&f->epsilon, 0, f->epsilon.nc);
f->seq = seq;
}