Move the throttle object to src/generic/util.

7 files changed, 241 insertions, 0 deletions

diff --git a/src/generic/util/Makefile.am b/src/generic/util/Makefile.am
index c754e805..6652afc5 100644
--- a/src/generic/util/Makefile.am
+++ b/src/generic/util/Makefile.am
@@ -4,6 +4,8 @@ localedir = $(datadir)/locale
 INCLUDES = -I$(top_builddir) -I$(srcdir) -I$(top_srcdir) -I$(top_srcdir)/src
 DEFS = -DLOCALEDIR=\"$(localedir)\" @DEFS@
 
+SUBDIRS = mocks
+
 noinst_LIBRARIES = libgeneric-util.a
 libgeneric_util_a_SOURCES = \
 	compare3.h \
@@ -40,6 +42,8 @@ libgeneric_util_a_SOURCES = \
 	sqlite.h \
 	temp.cc \
 	temp.h \
+	throttle.cc \
+	throttle.h \
 	undo.cc \
 	undo.h \
 	util.cc \
diff --git a/src/generic/util/SConscript b/src/generic/util/SConscript
index fe9eeaf5..0615eac0 100644
--- a/src/generic/util/SConscript
+++ b/src/generic/util/SConscript
@@ -34,6 +34,8 @@ srcs = map(File, [
     'sqlite.h',
     'temp.cc',
     'temp.h',
+    'throttle.cc',
+    'throttle.h',
     'undo.cc',
     'undo.h',
     'util.cc',
@@ -42,4 +44,6 @@ srcs = map(File, [
 
 programs_env.Dist('Makefile.am', 'SConscript')
 
+SConscript(dirs = [ 'mocks' ])
+
 Return('srcs')
diff --git a/src/generic/util/mocks/Makefile.am b/src/generic/util/mocks/Makefile.am
new file mode 100644
index 00000000..6b88c48d
--- /dev/null
+++ b/src/generic/util/mocks/Makefile.am
@@ -0,0 +1 @@
+EXTRA_DIST = throttle.h
\ No newline at end of file
diff --git a/src/generic/util/mocks/SConscript b/src/generic/util/mocks/SConscript
new file mode 100644
index 00000000..025e0f15
--- /dev/null
+++ b/src/generic/util/mocks/SConscript
@@ -0,0 +1,3 @@
+Import('programs_env')
+
+programs_env.Dist('throttle.h')
diff --git a/src/generic/util/mocks/throttle.h b/src/generic/util/mocks/throttle.h
new file mode 100644
index 00000000..0e852f6e
--- /dev/null
+++ b/src/generic/util/mocks/throttle.h
@@ -0,0 +1,47 @@
+/** \file 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 APTITUDE_UTIL_MOCKS_THROTTLE_H
+#define APTITUDE_UTIL_MOCKS_THROTTLE_H
+
+// Local includes:
+#include <generic/util/throttle.h>
+
+// System includes:
+#include <gmock/gmock.h>
+
+namespace aptitude
+{
+  namespace util
+  {
+    namespace mocks
+    {
+      /** \brief Mock implementation of aptitude::util::throttle. */
+      class throttle : public aptitude::util::throttle
+      {
+      public:
+        MOCK_METHOD0(update_required, bool());
+        MOCK_METHOD0(reset_timer, void());
+      };
+    }
+  }
+}
+
+#endif // APTITUDE_UTIL_MOCKS_THROTTLE_H
diff --git a/src/generic/util/throttle.cc b/src/generic/util/throttle.cc
new file mode 100644
index 00000000..9697df36
--- /dev/null
+++ b/src/generic/util/throttle.cc
@@ -0,0 +1,123 @@
+/** \file throttle.cc */   // -*-c++-*-
+
+#include "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 util
+  {
+    namespace
+    {
+      class throttle_impl : public 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:
+        throttle_impl();
+
+        /** \return \b true if the timer has expired. */
+        bool update_required();
+
+        /** \brief Reset the timer that controls when the display is
+         *  updated.
+         */
+        void reset_timer();
+      };
+
+      const double throttle_impl::update_interval;
+
+      void throttle_impl::write_time_error(int errnum)
+      {
+        if(!wrote_time_error)
+          {
+            LOG_ERROR(logger,
+                      "gettimeofday() failed: " <<
+                      sstrerror(errnum));
+            wrote_time_error = true;
+          }
+      }
+
+      throttle_impl::throttle_impl()
+        : logger(Loggers::getAptitudeCmdlineThrottle()),
+          wrote_time_error(false)
+      {
+      }
+
+      bool 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 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;
+      }
+    }
+
+    throttle::~throttle()
+    {
+    }
+
+    shared_ptr<throttle> create_throttle()
+    {
+      return make_shared<throttle_impl>();
+    }
+  }
+}
diff --git a/src/generic/util/throttle.h b/src/generic/util/throttle.h
new file mode 100644
index 00000000..5535b8a2
--- /dev/null
+++ b/src/generic/util/throttle.h
@@ -0,0 +1,59 @@
+/** \file 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 APTITUDE_UTIL_THROTTLE_H
+#define APTITUDE_UTIL_THROTTLE_H
+
+// System includes:
+#include <boost/shared_ptr.hpp>
+
+namespace aptitude
+{
+  namespace util
+  {
+    /** \brief Used to ensure that an expensive operation (such as
+     *  updating a progress indicator) doesn't run too often.
+     *
+     *  To test code that uses this class, use the mock that's
+     *  available in mocks/.
+     */
+    class throttle
+    {
+    public:
+      virtual ~throttle() = 0;
+
+      /** \return \b true if the timer has expired. */
+      virtual bool update_required() = 0;
+
+      /** \brief Reset the timer that controls when the display is
+       *  updated.
+       */
+      virtual void reset_timer() = 0;
+    };
+
+    /** \brief Create a throttle object.
+     *
+     *  \todo This should take an argument giving the update interval
+     *  in seconds.
+     */
+    boost::shared_ptr<throttle> create_throttle();
+  }
+}
+
+#endif // APTITUDE_UTIL_THROTTLE_H