gui: Move external command handling out of do_select().
authorAndre Noll <maan@systemlinux.org>
Fri, 3 Jan 2014 18:16:51 +0000 (18:16 +0000)
committerAndre Noll <maan@systemlinux.org>
Sun, 4 May 2014 13:48:54 +0000 (15:48 +0200)
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.

gui.c

diff --git a/gui.c b/gui.c
index 318418e..5f51cfc 100644 (file)
--- 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) {