More files related to user-level file servers.

Also add acme!

src/cmd/acme/file.c

@@ -0,0 +1,310 @@
+#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->b.nc)
+		error("internal error: fileinsert");
+	if(f->seq > 0)
+		fileuninsert(f, &f->delta, p0, ns);
+	bufinsert(&f->b, 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->b.nc && p1<=f->b.nc))
+		error("internal error: filedelete");
+	if(f->seq > 0)
+		fileundelete(f, &f->delta, p0, p1);
+	bufdelete(&f->b, 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->b, 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->b, 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->b, 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->b, 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->b);
+	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;
+}