Re: [dev] [hack] Having dmenu provide hints about current selected entry

[Christophe-Marie Duquesne]

The following patch does what I proposed. 'seq 1 1000000 | ./dmenu'
just feels as fast as the vanilla dmenu. After each select(), the file
descriptors are read until there is no data left on them (and match()
is called only once all the data in stdin has been read).

Cheers,
Christophe-Marie

diff -r 2b9683c50723 dmenu.c
--- a/dmenu.c	Wed Dec 01 20:25:10 2010 +0000
+++ b/dmenu.c	Tue Dec 07 14:31:01 2010 +0100
@@ -4,6 +4,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <sys/select.h>
 #include <X11/Xlib.h>
 #include <X11/Xatom.h>
 #include <X11/Xutil.h>
@@ -34,6 +36,7 @@
 static size_t nextrune(int incr);
 static void paste(void);
 static void readstdin(void);
+static void readXEvent(void);
 static void run(void);
 static void setup(void);
 static void usage(void);
@@ -59,6 +62,7 @@
 static Item *items = NULL;
 static Item *matches, *sel;
 static Item *prev, *curr, *next;
+static Item **end = &items;
 static Window root, win;
 
 static int (*fstrncmp)(const char *, const char *, size_t) = strncmp;
@@ -102,7 +106,6 @@
 
 	dc = initdc();
 	initfont(dc, font);
-	readstdin();
 	setup();
 	run();
 
@@ -433,9 +436,9 @@
 void
 readstdin(void) {
 	char buf[sizeof text], *p;
-	Item *item, **end;
+	Item *item;
 
-	for(end = &items; fgets(buf, sizeof buf, stdin); *end = item, end = &item->next) {
+	while (fgets(buf, sizeof buf, stdin)) {
 		if((p = strchr(buf, '\n')))
 			*p = '\0';
 		if(!(item = malloc(sizeof *item)))
@@ -444,14 +447,17 @@
 			eprintf("cannot strdup %u bytes\n", strlen(buf)+1);
 		item->next = item->left = item->right = NULL;
 		inputw = MAX(inputw, textw(dc, item->text));
+		*end = item;
+		end = &item->next;
 	}
+	match();
 }
 
 void
-run(void) {
+readXEvent(void) {
 	XEvent ev;
 
-	while(!XNextEvent(dc->dpy, &ev))
+	while(XPending(dc->dpy) && !XNextEvent(dc->dpy, &ev))
 		switch(ev.type) {
 		case Expose:
 			if(ev.xexpose.count == 0)
@@ -472,6 +478,35 @@
 }
 
 void
+run(void) {
+	fd_set fds;
+	int x11_fd, n, nfds, flags;
+	struct timeval tv;
+
+	flags = fcntl(STDIN_FILENO, F_GETFL);
+	flags |= O_NONBLOCK;
+	fcntl(STDIN_FILENO, F_SETFL, flags);
+
+	x11_fd = XConnectionNumber(dc->dpy);
+	nfds = MAX(STDIN_FILENO, x11_fd) + 1;
+	while(1) {
+		tv.tv_sec = 1;
+		tv.tv_usec = 0;
+		FD_ZERO(&fds);
+		if (!feof(stdin))
+			FD_SET(STDIN_FILENO, &fds);
+		FD_SET(x11_fd, &fds);
+		n = select(nfds, &fds, NULL, NULL, &tv);
+		if(n < 0)
+			eprintf("cannot select\n");
+		if (FD_ISSET(STDIN_FILENO, &fds))
+			readstdin();
+		if (FD_ISSET(x11_fd, &fds))
+			readXEvent();
+	}
+}
+
+void
 setup(void) {
 	int x, y, screen;
 	XSetWindowAttributes wa;
@@ -531,7 +566,7 @@
 	promptw = prompt ? textw(dc, prompt) : 0;
 	XMapRaised(dc->dpy, win);
 	text[0] = '\0';
-	match();
+	drawmenu();
 }
 
 void