From: Andre Noll <maan@systemlinux.org>
Date: Fri, 3 Jan 2014 18:16:51 +0000 (+0000)
Subject: gui: Move external command handling out of do_select().
X-Git-Tag: v0.5.3~12^2~17
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=2436fd444428d2549575fe40484ffae9dc11e58e

gui: Move external command handling out of do_select().

This commit moves the part of do_select() that deals with
external commands to separate functions, command_pre_select() and
command_post_select().

This change shortens do_select() considerably and is another step
towards the goal of using the paraslash scheduling system also for
para_gui.

One thing to note is that the new command_post_select() returns -1 if
both both fds are closed, i.e. when the currently running command has
terminated. This value gets translated back to zero in do_select(),
preserving the current semantics.
---

diff --git a/gui.c b/gui.c
index 318418ea..5f51cfce 100644
--- a/gui.c
+++ b/gui.c
@@ -976,6 +976,60 @@ success:
 
 #define COMMAND_BUF_SIZE 32768
 
+static void command_pre_select(int mode, fd_set *rfds, int *max_fileno)
+{
+	/* check command pipe only in COMMAND_MODE */
+	if (mode != COMMAND_MODE)
+		return;
+	if (command_fds[0] >= 0)
+		para_fd_set(command_fds[0], rfds, max_fileno);
+	if (command_fds[1] >= 0)
+		para_fd_set(command_fds[1], rfds, max_fileno);
+}
+
+static int command_post_select(int mode, fd_set *rfds)
+{
+	int i, ret;
+	static char command_buf[2][COMMAND_BUF_SIZE];
+	static int cbo[2]; /* command buf offsets */
+	static unsigned flags[2]; /* for for_each_line() */
+
+	if (mode != COMMAND_MODE)
+		return 0;
+	for (i = 0; i < 2; i++) {
+		size_t sz;
+		if (command_fds[i] < 0)
+			continue;
+		ret = read_nonblock(command_fds[i],
+			command_buf[i] + cbo[i],
+			COMMAND_BUF_SIZE - 1 - cbo[i], rfds, &sz);
+		cbo[i] += sz;
+		sz = cbo[i];
+		cbo[i] = for_each_line(flags[i], command_buf[i], cbo[i],
+			add_output_line, &i);
+		if (sz != cbo[i]) { /* at least one line found */
+			wrefresh(bot.win);
+			flags[i] = 0;
+		}
+		if (ret < 0) {
+			PARA_NOTICE_LOG("closing command fd %d: %s",
+				i, para_strerror(-ret));
+			close(command_fds[i]);
+			command_fds[i] = -1;
+			flags[i] = 0;
+			cbo[i] = 0;
+			if (command_fds[!i] < 0) /* both fds closed */
+				return -1;
+		}
+		if (cbo[i] == COMMAND_BUF_SIZE - 1) {
+			PARA_NOTICE_LOG("discarding overlong line");
+			cbo[i] = 0;
+			flags[i] = FELF_DISCARD_FIRST;
+		}
+	}
+	return 1;
+}
+
 /*
  * This is the core select loop. Besides the (internal) signal
  * pipe, the following other fds are checked according to the mode:
@@ -992,11 +1046,8 @@ success:
 static int do_select(int mode)
 {
 	fd_set rfds;
-	int ret, i, max_fileno;
-	char command_buf[2][COMMAND_BUF_SIZE] = {"", ""};
-	int cbo[2] = {0, 0}; /* command buf offsets */
+	int ret, max_fileno;
 	struct timeval tv;
-	unsigned flags[2] = {0, 0}; /* for for_each_line() */
 
 repeat:
 	tv.tv_sec = conf.timeout_arg  / 1000;
@@ -1007,13 +1058,7 @@ repeat:
 	status_pre_select(&rfds, &max_fileno, &tv);
 	/* signal pipe */
 	para_fd_set(signal_pipe, &rfds, &max_fileno);
-	/* command pipe only for COMMAND_MODE */
-	if (mode == COMMAND_MODE) {
-		if (command_fds[0] >= 0)
-			para_fd_set(command_fds[0], &rfds, &max_fileno);
-		if (command_fds[1] >= 0)
-			para_fd_set(command_fds[1], &rfds, &max_fileno);
-	}
+	command_pre_select(mode, &rfds, &max_fileno);
 	if (mode == GETCH_MODE || mode == COMMAND_MODE)
 		para_fd_set(STDIN_FILENO, &rfds, &max_fileno);
 	ret = para_select(max_fileno + 1, &rfds, NULL, &tv);
@@ -1024,39 +1069,9 @@ repeat:
 	if (ret > 0)
 		handle_signal(ret);
 	/* read command pipe if ready */
-	if (mode == COMMAND_MODE) {
-		for (i = 0; i < 2; i++) {
-			size_t sz;
-			if (command_fds[i] < 0)
-				continue;
-			ret = read_nonblock(command_fds[i],
-				command_buf[i] + cbo[i],
-				COMMAND_BUF_SIZE - 1 - cbo[i], &rfds, &sz);
-			cbo[i] += sz;
-			sz = cbo[i];
-			cbo[i] = for_each_line(flags[i], command_buf[i], cbo[i],
-				add_output_line, &i);
-			if (sz != cbo[i]) { /* at least one line found */
-				wrefresh(bot.win);
-				flags[i] = 0;
-			}
-			if (ret < 0) {
-				PARA_NOTICE_LOG("closing command fd %d: %s\n",
-					i, para_strerror(-ret));
-				close(command_fds[i]);
-				command_fds[i] = -1;
-				flags[i] = 0;
-				cbo[i] = 0;
-				if (command_fds[!i] < 0) /* both fds closed */
-					return 0;
-			}
-			if (cbo[i] == COMMAND_BUF_SIZE - 1) {
-				PARA_NOTICE_LOG("discarding overlong line\n");
-				cbo[i] = 0;
-				flags[i] = FELF_DISCARD_FIRST;
-			}
-		}
-	}
+	ret = command_post_select(mode, &rfds);
+	if (ret < 0)
+		return 0;
 	status_post_select(&rfds);
 check_return:
 	switch (mode) {