From 3a5370ddf16f131267f01f63c3b67b7b3b636cd1 Mon Sep 17 00:00:00 2001
From: Paul Beckingham <paul@beckingham.net>
Date: Thu, 14 Jul 2011 00:46:01 -0400
Subject: [PATCH] Filters

- Implemented Command::filter_shortcut to detect when a filter begins
  with "status:pending" and skip the loading/parsing of completed.data.
- Removed obsolete att.t.cpp tests.
- Removed diagnostics from TDB2::TDB2 that were causing a segfault.
  I suppose there is no std::cout available during global ctors?
---
 src/Context.cpp          |  3 ---
 src/TDB2.cpp             | 10 ++++++++--
 src/commands/Command.cpp | 38 ++++++++++++++++++++++++++++++++++----
 src/commands/Command.h   |  1 +
 test/att.t.cpp           |  2 +-
 5 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/src/Context.cpp b/src/Context.cpp
index aa548f558..39c8b691f 100644
--- a/src/Context.cpp
+++ b/src/Context.cpp
@@ -266,9 +266,6 @@ int Context::dispatch (std::string &out)
     return c->execute (out);
   }
 
-  // TODO Need to invoke 'information' when a sequence/filter is present, but
-  //      no command is specified.
-
   return commands["help"]->execute (out);
 }
 
diff --git a/src/TDB2.cpp b/src/TDB2.cpp
index efd1ab0d9..28bac036b 100644
--- a/src/TDB2.cpp
+++ b/src/TDB2.cpp
@@ -316,7 +316,6 @@ TDB2::TDB2 ()
 : _location ("")
 , _id (1)
 {
-  std::cout << "# TDB2::TDB2\n";
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -324,7 +323,6 @@ TDB2::TDB2 ()
 // already called, if data is to be preserved.
 TDB2::~TDB2 ()
 {
-  std::cout << "# TDB2::~TDB2\n";
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -387,6 +385,10 @@ void TDB2::commit ()
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// Scans the pending tasks for any that are completed or deleted, and if so,
+// moves them to the completed.data file.  Returns a count of tasks moved.
+// Now reverts expired waiting tasks to pending.
+// Now cleans up dangling dependencies.
 int TDB2::gc ()
 {
   std::cout << "# TDB2::gc\n";
@@ -407,6 +409,10 @@ int TDB2::gc ()
       completed.remove
       pending.add
 */
+
+  // TODO Remove dangling dependencies
+  // TODO Wake up expired waiting tasks
+
   return 0;
 }
 
diff --git a/src/commands/Command.cpp b/src/commands/Command.cpp
index 788ef95d9..979f79c01 100644
--- a/src/commands/Command.cpp
+++ b/src/commands/Command.cpp
@@ -297,7 +297,6 @@ void Command::filter (std::vector <Task>& output)
   if (f.size ())
   {
     const std::vector <Task>& pending = context.tdb2.pending.get_tasks ();
-    const std::vector <Task>& completed = context.tdb2.completed.get_tasks (); // TODO Optional
 
     Expression e (f);
 
@@ -307,9 +306,15 @@ void Command::filter (std::vector <Task>& output)
       if (e.eval (*task))
         output.push_back (*task);
 
-    for (task = completed.begin (); task != completed.end (); ++task)
-      if (e.eval (*task))
-        output.push_back (*task);
+    if (! filter_shortcut (f))
+    {
+      const std::vector <Task>& completed = context.tdb2.completed.get_tasks (); // TODO Optional
+      for (task = completed.begin (); task != completed.end (); ++task)
+        if (e.eval (*task))
+          output.push_back (*task);
+    }
+    else
+      context.debug ("Command::filter skipping completed.data");
   }
   else
   {
@@ -325,6 +330,31 @@ void Command::filter (std::vector <Task>& output)
   }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// If the filter contains the restriction "status:pending", as the first filter
+// term, then completed.data does not need to be loaded.
+bool Command::filter_shortcut (const Arguments& filter)
+{
+/**/
+  if (filter.size () >= 3)
+  {
+    std::cout << "# filter[0] " << filter[0]._first << "\n"
+              << "# filter[1] " << filter[1]._first << "\n"
+              << "# filter[2] " << filter[2]._first << "\n";
+  }
+/**/
+
+  // Postfix: <status> <"pending"> <=>
+  //                 0           1   2
+  if (filter.size ()                    >= 3                 &&
+      filter[0]._first                  == "status"          &&
+      filter[1]._first.find ("pending") != std::string::npos &&
+      filter[2]._first                  == "=")
+    return true;
+
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Apply the modifications in arguments to the task.
 void Command::modify_task_description_replace (Task& task, Arguments& arguments)
diff --git a/src/commands/Command.h b/src/commands/Command.h
index f54a721b0..a42ff551d 100644
--- a/src/commands/Command.h
+++ b/src/commands/Command.h
@@ -55,6 +55,7 @@ public:
 protected:
   void filter (std::vector <Task>&, std::vector <Task>&);
   void filter (std::vector <Task>&);
+  bool filter_shortcut (const Arguments&);
 
   void modify_task_description_replace (Task&, Arguments&);
   void modify_task_description_prepend (Task&, Arguments&);
diff --git a/test/att.t.cpp b/test/att.t.cpp
index d92c234e8..6428bd755 100644
--- a/test/att.t.cpp
+++ b/test/att.t.cpp
@@ -34,7 +34,7 @@ Context context;
 ////////////////////////////////////////////////////////////////////////////////
 int main (int argc, char** argv)
 {
-  UnitTest t (121);
+  UnitTest t (118);
 
   Att a;
   t.notok (a.valid ("name"),              "Att::valid name           -> fail");