More files related to user-level file servers.

Also add acme!

1 files changed, 350 insertions, 0 deletions

diff --git a/src/cmd/acme/elog.c b/src/cmd/acme/elog.c
new file mode 100644
index 00000000..e86af6ec
--- /dev/null
+++ b/src/cmd/acme/elog.c
@@ -0,0 +1,350 @@
+#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"
+#include "edit.h"
+
+static char Wsequence[] = "warning: changes out of sequence\n";
+static int	warned = FALSE;
+
+/*
+ * Log of changes made by editing commands.  Three reasons for this:
+ * 1) We want addresses in commands to apply to old file, not file-in-change.
+ * 2) It's difficult to track changes correctly as things move, e.g. ,x m$
+ * 3) This gives an opportunity to optimize by merging adjacent changes.
+ * It's a little bit like the Undo/Redo log in Files, but Point 3) argues for a
+ * separate implementation.  To do this well, we use Replace as well as
+ * Insert and Delete
+ */
+
+typedef struct Buflog Buflog;
+struct Buflog
+{
+	short	type;		/* Replace, Filename */
+	uint		q0;		/* location of change (unused in f) */
+	uint		nd;		/* # runes to delete */
+	uint		nr;		/* # runes in string or file name */
+};
+
+enum
+{
+	Buflogsize = sizeof(Buflog)/sizeof(Rune),
+};
+
+/*
+ * Minstring shouldn't be very big or we will do lots of I/O for small changes.
+ * Maxstring is RBUFSIZE so we can fbufalloc() once and not realloc elog.r.
+ */
+enum
+{
+	Minstring = 16,		/* distance beneath which we merge changes */
+	Maxstring = RBUFSIZE,	/* maximum length of change we will merge into one */
+};
+
+void
+eloginit(File *f)
+{
+	if(f->elog.type != Empty)
+		return;
+	f->elog.type = Null;
+	if(f->elogbuf == nil)
+		f->elogbuf = emalloc(sizeof(Buffer));
+	if(f->elog.r == nil)
+		f->elog.r = fbufalloc();
+	bufreset(f->elogbuf);
+}
+
+void
+elogclose(File *f)
+{
+	if(f->elogbuf){
+		bufclose(f->elogbuf);
+		free(f->elogbuf);
+		f->elogbuf = nil;
+	}
+}
+
+void
+elogreset(File *f)
+{
+	f->elog.type = Null;
+	f->elog.nd = 0;
+	f->elog.nr = 0;
+}
+
+void
+elogterm(File *f)
+{
+	elogreset(f);
+	if(f->elogbuf)
+		bufreset(f->elogbuf);
+	f->elog.type = Empty;
+	fbuffree(f->elog.r);
+	f->elog.r = nil;
+	warned = FALSE;
+}
+
+void
+elogflush(File *f)
+{
+	Buflog b;
+
+	b.type = f->elog.type;
+	b.q0 = f->elog.q0;
+	b.nd = f->elog.nd;
+	b.nr = f->elog.nr;
+	switch(f->elog.type){
+	default:
+		warning(nil, "unknown elog type 0x%ux\n", f->elog.type);
+		break;
+	case Null:
+		break;
+	case Insert:
+	case Replace:
+		if(f->elog.nr > 0)
+			bufinsert(f->elogbuf, f->elogbuf->nc, f->elog.r, f->elog.nr);
+		/* fall through */
+	case Delete:
+		bufinsert(f->elogbuf, f->elogbuf->nc, (Rune*)&b, Buflogsize);
+		break;
+	}
+	elogreset(f);
+}
+
+void
+elogreplace(File *f, int q0, int q1, Rune *r, int nr)
+{
+	uint gap;
+
+	if(q0==q1 && nr==0)
+		return;
+	eloginit(f);
+	if(f->elog.type!=Null && q0<f->elog.q0){
+		if(warned++ == 0)
+			warning(nil, Wsequence);
+		elogflush(f);
+	}
+	/* try to merge with previous */
+	gap = q0 - (f->elog.q0+f->elog.nd);	/* gap between previous and this */
+	if(f->elog.type==Replace && f->elog.nr+gap+nr<Maxstring){
+		if(gap < Minstring){
+			if(gap > 0){
+				bufread(&f->b, f->elog.q0+f->elog.nd, f->elog.r+f->elog.nr, gap);
+				f->elog.nr += gap;
+			}
+			f->elog.nd += gap + q1-q0;
+			runemove(f->elog.r+f->elog.nr, r, nr);
+			f->elog.nr += nr;
+			return;
+		}
+	}
+	elogflush(f);
+	f->elog.type = Replace;
+	f->elog.q0 = q0;
+	f->elog.nd = q1-q0;
+	f->elog.nr = nr;
+	if(nr > RBUFSIZE)
+		editerror("internal error: replacement string too large(%d)", nr);
+	runemove(f->elog.r, r, nr);
+}
+
+void
+eloginsert(File *f, int q0, Rune *r, int nr)
+{
+	int n;
+
+	if(nr == 0)
+		return;
+	eloginit(f);
+	if(f->elog.type!=Null && q0<f->elog.q0){
+		if(warned++ == 0)
+			warning(nil, Wsequence);
+		elogflush(f);
+	}
+	/* try to merge with previous */
+	if(f->elog.type==Insert && q0==f->elog.q0 && (q0+nr)-f->elog.q0<Maxstring){
+		runemove(f->elog.r+f->elog.nr, r, nr);
+		f->elog.nr += nr;
+		return;
+	}
+	while(nr > 0){
+		elogflush(f);
+		f->elog.type = Insert;
+		f->elog.q0 = q0;
+		n = nr;
+		if(n > RBUFSIZE)
+			n = RBUFSIZE;
+		f->elog.nr = n;
+		runemove(f->elog.r, r, n);
+		r += n;
+		nr -= n;
+	}
+}
+
+void
+elogdelete(File *f, int q0, int q1)
+{
+	if(q0 == q1)
+		return;
+	eloginit(f);
+	if(f->elog.type!=Null && q0<f->elog.q0+f->elog.nd){
+		if(warned++ == 0)
+			warning(nil, Wsequence);
+		elogflush(f);
+	}
+	/* try to merge with previous */
+	if(f->elog.type==Delete && f->elog.q0+f->elog.nd==q0){
+		f->elog.nd += q1-q0;
+		return;
+	}
+	elogflush(f);
+	f->elog.type = Delete;
+	f->elog.q0 = q0;
+	f->elog.nd = q1-q0;
+}
+
+#define tracelog 0
+void
+elogapply(File *f)
+{
+	Buflog b;
+	Rune *buf;
+	uint i, n, up, mod;
+	uint q0, q1, tq0, tq1;
+	Buffer *log;
+	Text *t;
+
+	elogflush(f);
+	log = f->elogbuf;
+	t = f->curtext;
+
+	buf = fbufalloc();
+	mod = FALSE;
+
+	/*
+	 * The edit commands have already updated the selection in t->q0, t->q1.
+	 * (At least, they are supposed to have updated them.
+	 * We still keep finding commands that don't do it right.)
+	 * The textinsert and textdelete calls below will update it again, so save the
+	 * current setting and restore it at the end.
+	 */
+	q0 = t->q0;
+	q1 = t->q1;
+	/*
+	 * We constrain the addresses in here (with textconstrain()) because
+	 * overlapping changes will generate bogus addresses.   We will warn
+	 * about changes out of sequence but proceed anyway; here we must
+	 * keep things in range.
+	 */
+
+	while(log->nc > 0){
+		up = log->nc-Buflogsize;
+		bufread(log, up, (Rune*)&b, Buflogsize);
+		switch(b.type){
+		default:
+			fprint(2, "elogapply: 0x%ux\n", b.type);
+			abort();
+			break;
+
+		case Replace:
+			if(tracelog)
+				warning(nil, "elog replace %d %d\n",
+					b.q0, b.q0+b.nd);
+			if(!mod){
+				mod = TRUE;
+				filemark(f);
+			}
+			textconstrain(t, b.q0, b.q0+b.nd, &tq0, &tq1);
+			textdelete(t, tq0, tq1, TRUE);
+			up -= b.nr;
+			for(i=0; i<b.nr; i+=n){
+				n = b.nr - i;
+				if(n > RBUFSIZE)
+					n = RBUFSIZE;
+				bufread(log, up+i, buf, n);
+				textinsert(t, tq0+i, buf, n, TRUE);
+			}
+			break;
+
+		case Delete:
+			if(tracelog)
+				warning(nil, "elog delete %d %d\n",
+					b.q0, b.q0+b.nd);
+			if(!mod){
+				mod = TRUE;
+				filemark(f);
+			}
+			textconstrain(t, b.q0, b.q0+b.nd, &tq0, &tq1);
+			textdelete(t, tq0, tq1, TRUE);
+			break;
+
+		case Insert:
+			if(tracelog)
+				warning(nil, "elog insert %d %d\n",
+					b.q0, b.q0+b.nr);
+			if(!mod){
+				mod = TRUE;
+				filemark(f);
+			}
+			textconstrain(t, b.q0, b.q0, &tq0, &tq1);
+			up -= b.nr;
+			for(i=0; i<b.nr; i+=n){
+				n = b.nr - i;
+				if(n > RBUFSIZE)
+					n = RBUFSIZE;
+				bufread(log, up+i, buf, n);
+				textinsert(t, tq0+i, buf, n, TRUE);
+			}
+			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(log, up, log->nc);
+	}
+	fbuffree(buf);
+	if(warned){
+		/*
+		 * Changes were out of order, so the q0 and q1
+		 * computed while generating those changes are not
+		 * to be trusted.
+		 */
+		q1 = min(q1, f->b.nc);
+		q0 = min(q0, q1);
+	}
+	elogterm(f);
+
+	/*
+	 * The q0 and q1 are supposed to be fine (see comment
+	 * above, where we saved them), but bad addresses
+	 * will cause bufload to crash, so double check.
+	 */
+	if(q0 > f->b.nc || q1 > f->b.nc || q0 > q1){
+		warning(nil, "elogapply: can't happen %d %d %d\n", q0, q1, f->b.nc);
+		q1 = min(q1, f->b.nc);
+		q0 = min(q0, q1);
+	}
+
+	t->q0 = q0;
+	t->q1 = q1;
+}