From 184b2d23b057b35fba7fd4049962a897ef0e3f9d Mon Sep 17 00:00:00 2001 From: Stefan Raspl Date: Fri, 10 Mar 2017 13:40:06 +0100 Subject: [PATCH] tools/kvm_stat: reduce perceived idle time on filter updates MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Whenever a user adds a filter, we * redraw the header immediately for a snappy response * print a message indicating to the user that we're busy while the noticeable delay induced by updating all of the stats objects takes place * update the statistics ASAP (i.e. after 0.25s instead of 3s) to be consistent with behavior on startup To do so, we split the Tui's refresh() method to allow for drawing header and stats separately, and trigger a header refresh whenever we are about to do something that takes a while - like updating filters. Signed-off-by: Stefan Raspl Signed-off-by: Radim Krčmář --- tools/kvm/kvm_stat/kvm_stat | 48 +++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat index 5c4f24879dc4..3e60d93870c0 100755 --- a/tools/kvm/kvm_stat/kvm_stat +++ b/tools/kvm/kvm_stat/kvm_stat @@ -801,6 +801,8 @@ class Stats(object): LABEL_WIDTH = 40 NUMBER_WIDTH = 10 +DELAY_INITIAL = 0.25 +DELAY_REGULAR = 3.0 class Tui(object): @@ -856,13 +858,14 @@ class Tui(object): """Propagates pid selection to stats object.""" self.stats.pid_filter = pid - def refresh(self, sleeptime): - """Refreshes on-screen data.""" + def refresh_header(self, pid=None): + """Refreshes the header.""" + if pid is None: + pid = self.stats.pid_filter self.screen.erase() - if self.stats.pid_filter > 0: + if pid > 0: self.screen.addstr(0, 0, 'kvm statistics - pid {0}' - .format(self.stats.pid_filter), - curses.A_BOLD) + .format(pid), curses.A_BOLD) else: self.screen.addstr(0, 0, 'kvm statistics - summary', curses.A_BOLD) self.screen.addstr(2, 1, 'Event') @@ -870,7 +873,13 @@ class Tui(object): len('Total'), 'Total') self.screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH + 8 - len('Current'), 'Current') + self.screen.addstr(4, 1, 'Collecting data...') + self.screen.refresh() + + def refresh_body(self, sleeptime): row = 3 + self.screen.move(row, 0) + self.screen.clrtobot() stats = self.stats.get() def sortkey(x): @@ -914,10 +923,12 @@ class Tui(object): regex = self.screen.getstr() curses.noecho() if len(regex) == 0: + self.refresh_header() return try: re.compile(regex) self.stats.fields_filter = regex + self.refresh_header() return except re.error: continue @@ -944,37 +955,38 @@ class Tui(object): try: pid = int(pid) - - if pid == 0: - self.update_pid(pid) - break - else: - if not os.path.isdir(os.path.join('/proc/', str(pid))): - continue - else: - self.update_pid(pid) - break + if pid != 0 and not os.path.isdir(os.path.join('/proc/', + str(pid))): + continue + self.refresh_header(pid) + self.update_pid(pid) + break except ValueError: continue def show_stats(self): """Refreshes the screen and processes user input.""" - sleeptime = 0.25 + sleeptime = DELAY_INITIAL + self.refresh_header() while True: - self.refresh(sleeptime) + self.refresh_body(sleeptime) curses.halfdelay(int(sleeptime * 10)) - sleeptime = 3.0 + sleeptime = DELAY_REGULAR try: char = self.screen.getkey() if char == 'x': + self.refresh_header() self.update_drilldown() + sleeptime = DELAY_INITIAL if char == 'q': break if char == 'f': self.show_filter_selection() + sleeptime = DELAY_INITIAL if char == 'p': self.show_vm_selection() + sleeptime = DELAY_INITIAL except KeyboardInterrupt: break except curses.error: -- GitLab