Factor the progress update throttling code into a separate class.

12 files changed, 213 insertions, 19 deletions

diff --git a/src/cmdline/Makefile.am b/src/cmdline/Makefile.am
index f79cf788..383d389b 100644
--- a/src/cmdline/Makefile.am
+++ b/src/cmdline/Makefile.am
@@ -32,6 +32,8 @@ libcmdline_a_SOURCES=\
 	cmdline_progress.h \
 	cmdline_progress_display.cc \
 	cmdline_progress_display.h \
+	cmdline_progress_throttle.cc \
+	cmdline_progress_throttle.h \
 	cmdline_prompt.cc \
 	cmdline_prompt.h \
 	cmdline_resolver.cc \
diff --git a/src/cmdline/SConscript b/src/cmdline/SConscript
index b87f9f79..92db69d3 100644
--- a/src/cmdline/SConscript
+++ b/src/cmdline/SConscript
@@ -28,6 +28,8 @@ src_filenames = [
     'cmdline_progress.h',
     'cmdline_progress_display.cc',
     'cmdline_progress_display.h',
+    'cmdline_progress_throttle.cc',
+    'cmdline_progress_throttle.h',
     'cmdline_prompt.cc',
     'cmdline_prompt.h',
     'cmdline_resolver.cc',
diff --git a/src/cmdline/cmdline_progress_display.cc b/src/cmdline/cmdline_progress_display.cc
index c35b5d6d..7bd5e463 100644
--- a/src/cmdline/cmdline_progress_display.cc
+++ b/src/cmdline/cmdline_progress_display.cc
@@ -53,10 +53,6 @@ namespace aptitude
 
       class progress_display_impl : public progress_display
       {
-        // The last time that we updated; initially set to the
-        // beginning of the epoch.
-        struct timeval last_update_time;
-
         // The last progress that was displayed; we always update the
         // display if the mode or the message changed.
         progress_info last_progress;
@@ -88,16 +84,7 @@ namespace aptitude
         if(progress.get_progress_status() != last_progress.get_progress_status())
           return true;
 
-
-        // Time checking code shamelessly stolen from apt, since we
-        // know theirs works.
-        struct timeval now;
-        gettimeofday(&now, 0);
-        double diff =
-          now.tv_sec - last_update_time.tv_sec +
-          (now.tv_usec - last_update_time.tv_usec)/1000000.0;
-
-        return diff < progress_update_interval;
+        return false;
       }
 
       void progress_display_impl::set_progress(const progress_info &progress,
@@ -128,7 +115,6 @@ namespace aptitude
               }
 
             last_progress = progress;
-            gettimeofday(&last_update_time, 0);
           }
       }
     }
diff --git a/src/cmdline/cmdline_progress_display.h b/src/cmdline/cmdline_progress_display.h
index b8ca1da6..36cd7e35 100644
--- a/src/cmdline/cmdline_progress_display.h
+++ b/src/cmdline/cmdline_progress_display.h
@@ -44,10 +44,6 @@ namespace aptitude
      *  erased.  A "pulse" mode progress_info displays a message with
      *  no percent indicator.  And a "bar" mode progress_info displays
      *  a message with a percent indicator.
-     *
-     *  This object will automatically avoid updating its display too
-     *  frequently.  Specifically, it will update itself only if some
-     *  time interval has passed.
      */
     class progress_display
     {
diff --git a/src/cmdline/cmdline_progress_throttle.cc b/src/cmdline/cmdline_progress_throttle.cc
new file mode 100644
index 00000000..8e793826
--- /dev/null
+++ b/src/cmdline/cmdline_progress_throttle.cc
@@ -0,0 +1,123 @@
+/** \file cmdline_progress_throttle.cc */   // -*-c++-*-
+
+#include "cmdline_progress_throttle.h"
+
+// Local includes:
+#include <loggers.h>
+
+// System includes:
+#include <boost/make_shared.hpp>
+#include <boost/optional.hpp>
+
+#include <generic/util/util.h>
+
+#include <errno.h>
+#include <sys/time.h>
+
+using aptitude::Loggers;
+using boost::make_shared;
+using boost::optional;
+using boost::shared_ptr;
+using logging::LoggerPtr;
+
+namespace aptitude
+{
+  namespace cmdline
+  {
+    namespace
+    {
+      class progress_throttle_impl : public progress_throttle
+      {
+        boost::optional<struct timeval> last_update;
+
+        logging::LoggerPtr logger;
+
+        // Used to ensure that we only warn once about gettimeofday()
+        // failing.
+        bool wrote_time_error;
+
+        static const double update_interval = 0.7;
+
+        void write_time_error(int errnum);
+
+      public:
+        progress_throttle_impl();
+
+        /** \return \b true if the progress display should be updated. */
+        bool update_required();
+
+        /** \brief Reset the timer that controls when the display is
+         *  updated.
+         */
+        void reset_timer();
+      };
+
+      const double progress_throttle_impl::update_interval;
+
+      void progress_throttle_impl::write_time_error(int errnum)
+      {
+        if(!wrote_time_error)
+          {
+            LOG_ERROR(logger,
+                      "gettimeofday() failed: " <<
+                      sstrerror(errnum));
+            wrote_time_error = true;
+          }
+      }
+
+      progress_throttle_impl::progress_throttle_impl()
+        : logger(Loggers::getAptitudeCmdlineThrottle()),
+          wrote_time_error(false)
+      {
+      }
+
+      bool progress_throttle_impl::update_required()
+      {
+        if(!last_update)
+          return true;
+        else
+          {
+            // Time checking code shamelessly stolen from apt, since
+            // we know theirs works.
+            struct timeval now;
+            if(gettimeofday(&now, 0) != 0)
+              {
+                write_time_error(errno);
+                return false;
+              }
+            else
+              {
+                const struct timeval &last_update_time = *last_update;
+                double diff =
+                  now.tv_sec - last_update_time.tv_sec +
+                  (now.tv_usec - last_update_time.tv_usec)/1000000.0;
+
+                bool rval = diff < update_interval;
+
+                return rval;
+              }
+          }
+      }
+
+      void progress_throttle_impl::reset_timer()
+      {
+        LOG_TRACE(logger, "Resetting the update timer.");
+
+        struct timeval now;
+        if(gettimeofday(&now, 0) != 0)
+          write_time_error(errno);
+        else
+          last_update = now;
+      }
+    }
+
+    progress_throttle::~progress_throttle()
+    {
+    }
+
+    shared_ptr<progress_throttle> create_progress_throttle()
+    {
+      return make_shared<progress_throttle_impl>();
+    }
+  }
+}
diff --git a/src/cmdline/cmdline_progress_throttle.h b/src/cmdline/cmdline_progress_throttle.h
new file mode 100644
index 00000000..fbbb9f22
--- /dev/null
+++ b/src/cmdline/cmdline_progress_throttle.h
@@ -0,0 +1,52 @@
+/** \file cmdline_progress_throttle.h */   // -*-c++-*-
+
+// Copyright (C) 2010 Daniel Burrows
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; see the file COPYING.  If not, write to
+// the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+// Boston, MA 02111-1307, USA.
+
+#ifndef CMDLINE_PROGRESS_THROTTLE_H
+#define CMDLINE_PROGRESS_THROTTLE_H
+
+// System includes:
+#include <boost/shared_ptr.hpp>
+
+namespace aptitude
+{
+  namespace cmdline
+  {
+    /** \brief Used to check whether enough time has passed that a
+     *  progress display should be updated.
+     */
+    class progress_throttle
+    {
+    public:
+      virtual ~progress_throttle() = 0;
+
+      /** \return \b true if the progress display should be updated. */
+      virtual bool update_required() = 0;
+
+      /** \brief Reset the timer that controls when the display is
+       *  updated.
+       */
+      virtual void reset_timer() = 0;
+    };
+
+    /** \brief Create a progress_throttle object. */
+    boost::shared_ptr<progress_throttle> create_progress_throttle();
+  }
+}
+
+#endif // CMDLINE_PROGRESS_THROTTLE_H
diff --git a/src/cmdline/cmdline_search.cc b/src/cmdline/cmdline_search.cc
index ad8c1920..0e58a1ba 100644
--- a/src/cmdline/cmdline_search.cc
+++ b/src/cmdline/cmdline_search.cc
@@ -24,6 +24,7 @@
 
 #include "cmdline_common.h"
 #include "cmdline_progress_display.h"
+#include "cmdline_progress_throttle.h"
 #include "cmdline_search_progress.h"
 #include "cmdline_util.h"
 #include "terminal.h"
@@ -62,10 +63,12 @@ using namespace std;
 namespace cw = cwidget;
 using aptitude::Loggers;
 using aptitude::cmdline::create_progress_display;
+using aptitude::cmdline::create_progress_throttle;
 using aptitude::cmdline::create_terminal;
 using aptitude::cmdline::create_terminal_locale;
 using aptitude::cmdline::make_text_progress;
 using aptitude::cmdline::progress_display;
+using aptitude::cmdline::progress_throttle;
 using aptitude::cmdline::search_progress;
 using aptitude::cmdline::terminal;
 using aptitude::cmdline::terminal_locale;
@@ -98,6 +101,8 @@ namespace
 
     const shared_ptr<progress_display> search_progress_display =
       create_progress_display(term, term_locale);
+    const shared_ptr<progress_throttle> search_progress_throttle =
+      create_progress_throttle();
 
     results_list output;
     ref_ptr<search_cache> search_info(search_cache::create());
@@ -113,6 +118,7 @@ namespace
                                    debug,
                                    sigc::bind(sigc::ptr_fun(&search_progress),
                                               search_progress_display,
+                                              search_progress_throttle,
                                               serialize_pattern(*pIt)));
       }
 
diff --git a/src/cmdline/cmdline_search_progress.cc b/src/cmdline/cmdline_search_progress.cc
index 68962860..53e9a802 100644
--- a/src/cmdline/cmdline_search_progress.cc
+++ b/src/cmdline/cmdline_search_progress.cc
@@ -22,6 +22,7 @@
 #include "cmdline_search_progress.h"
 
 #include "cmdline_progress_display.h"
+#include "cmdline_progress_throttle.h"
 
 #include <generic/util/progress_info.h>
 
@@ -44,8 +45,12 @@ namespace aptitude
   {
     void search_progress(const progress_info &info,
                          const shared_ptr<progress_display> &progress_msg,
+                         const shared_ptr<progress_throttle> &throttle,
                          const std::string &pattern)
     {
+      if(!throttle->update_required())
+        return;
+
       // We interpret the progress_info to add a prefix to its message
       // if it has one.
       switch(info.get_type())
@@ -71,6 +76,8 @@ namespace aptitude
                                      false);
           break;
         }
+
+      throttle->reset_timer();
     }
   }
 }
diff --git a/src/cmdline/cmdline_search_progress.h b/src/cmdline/cmdline_search_progress.h
index 8079a2da..9d8384e8 100644
--- a/src/cmdline/cmdline_search_progress.h
+++ b/src/cmdline/cmdline_search_progress.h
@@ -34,9 +34,11 @@ namespace aptitude
   namespace cmdline
   {
     class progress_display;
+    class progress_throttle;
 
     void search_progress(const aptitude::util::progress_info &info,
                          const boost::shared_ptr<progress_display> &progress_msg,
+                         const boost::shared_ptr<progress_throttle> &throttle,
                          const std::string &pattern);
   }
 }
diff --git a/src/cmdline/cmdline_versions.cc b/src/cmdline/cmdline_versions.cc
index b919174b..dce6eb71 100644
--- a/src/cmdline/cmdline_versions.cc
+++ b/src/cmdline/cmdline_versions.cc
@@ -22,6 +22,7 @@
 #include "cmdline_versions.h"
 
 #include "cmdline_progress_display.h"
+#include "cmdline_progress_throttle.h"
 #include "cmdline_search_progress.h"
 #include "cmdline_util.h"
 #include "terminal.h"
@@ -55,13 +56,17 @@ namespace cw = cwidget;
 namespace m = aptitude::matching;
 
 using aptitude::cmdline::create_progress_display;
+using aptitude::cmdline::create_progress_throttle;
 using aptitude::cmdline::create_terminal;
 using aptitude::cmdline::create_terminal_locale;
 using aptitude::cmdline::lessthan_1st;
 using aptitude::cmdline::package_results_lt;
 using aptitude::cmdline::progress_display;
+using aptitude::cmdline::progress_display;
+using aptitude::cmdline::progress_throttle;
 using aptitude::cmdline::search_progress;
 using aptitude::cmdline::search_result_column_parameters;
+using aptitude::cmdline::search_result_column_parameters;
 using aptitude::cmdline::terminal;
 using aptitude::cmdline::terminal_locale;
 using aptitude::cmdline::version_results_eq;
@@ -254,6 +259,8 @@ namespace
 
     const shared_ptr<progress_display> search_progress_display =
       create_progress_display(term, term_locale);
+    const shared_ptr<progress_throttle> search_progress_throttle =
+      create_progress_throttle();
 
     results_list output;
     cw::util::ref_ptr<m::search_cache> search_info(m::search_cache::create());
@@ -271,6 +278,7 @@ namespace
                                             debug,
                                             sigc::bind(sigc::ptr_fun(&search_progress),
                                                        search_progress_display,
+                                                       search_progress_throttle,
                                                        serialize_pattern(*pIt)));
 
         // Warn the user if an exact name pattern didn't produce a
diff --git a/src/loggers.cc b/src/loggers.cc
index bb243658..6d6a97ca 100644
--- a/src/loggers.cc
+++ b/src/loggers.cc
@@ -54,6 +54,11 @@ namespace aptitude
     return Logger::getLogger("aptitude.cmdline.search");
   }
 
+  LoggerPtr Loggers::getAptitudeCmdlineThrottle()
+  {
+    return Logger::getLogger("aptitude.cmdline.throttle");
+  }
+
   LoggerPtr Loggers::getAptitudeDownloadCache()
   {
     return Logger::getLogger("aptitude.downloadCache");
diff --git a/src/loggers.h b/src/loggers.h
index bb56b4bc..a1ee10a2 100644
--- a/src/loggers.h
+++ b/src/loggers.h
@@ -81,6 +81,11 @@ namespace aptitude
      */
     static logging::LoggerPtr getAptitudeCmdlineSearch();
 
+    /** \brief The logger for events having to do with the progress
+     *  display throttler in aptitude's command-line code.
+     */
+    static logging::LoggerPtr getAptitudeCmdlineThrottle();
+
     /** \brief The logger for events having to do with aptitude's
      *  caching of downloaded data (other than package lists and
      *  .debs).