Refactor various apt-related comparison functors to apt.h

The resulting functors:

  - pkg_name_lt
  - pkg_ptr_lt
  - ver_name_lt
  - ver_ptr_lt
  - dep_type_lt

9 files changed, 102 insertions, 124 deletions

diff --git a/src/cmdline/cmdline_prompt.cc b/src/cmdline/cmdline_prompt.cc
index c98a38a4..c65f779e 100644
--- a/src/cmdline/cmdline_prompt.cc
+++ b/src/cmdline/cmdline_prompt.cc
@@ -74,11 +74,6 @@ struct fetchinfo
   }
 };
 
-static bool pkg_byname_compare(const pkgCache::PkgIterator &a, const pkgCache::PkgIterator &b)
-{
-  return strcmp(a.Name(), b.Name())<0;
-}
-
 static bool get_fetchinfo(fetchinfo &f)
 {
   download_signal_log m;
@@ -137,6 +132,8 @@ namespace
   // action.
   struct compare_first_action
   {
+    pkg_name_lt base;
+  public:
     typedef aptitude::why::action action;
     bool operator()(const std::vector<action> &reason1,
 		    const std::vector<action> &reason2)
@@ -146,8 +143,8 @@ namespace
       else if(reason2.empty())
 	return false;
       else
-	return strcmp(reason1.front().get_dep().ParentPkg().Name(),
-		      reason2.front().get_dep().ParentPkg().Name());
+	return base(reason1.front().get_dep().ParentPkg(),
+                    reason2.front().get_dep().ParentPkg());
     }
   };
 
@@ -261,7 +258,7 @@ static void cmdline_show_instinfo(pkgvector &items,
 				  bool showwhy,
                                   const shared_ptr<terminal_metrics> &term_metrics)
 {
-  sort(items.begin(), items.end(), pkg_byname_compare);
+  sort(items.begin(), items.end(), pkg_name_lt());
   strvector output;
 
   for(pkgvector::iterator i=items.begin(); i!=items.end(); ++i)
diff --git a/src/cmdline/cmdline_why.cc b/src/cmdline/cmdline_why.cc
index d03fda8c..a8034c08 100644
--- a/src/cmdline/cmdline_why.cc
+++ b/src/cmdline/cmdline_why.cc
@@ -89,62 +89,11 @@ namespace
 		   dep.TargetPkg().Name());
   }
 
-  struct compare_pkgs
-  {
-    bool operator()(const pkgCache::PkgIterator &p1,
-		    const pkgCache::PkgIterator &p2)
-    {
-      return p1->ID < p2->ID;
-    }
-  };
-
-  struct compare_dep_levels
-  {
-    static int dep_level_to_int(const pkgCache::Dep::DepType dt)
-    {
-      switch(dt)
-	{
-	case pkgCache::Dep::PreDepends:
-	  return 7;
-
-	case pkgCache::Dep::Depends:
-	  return 6;
-
-	case pkgCache::Dep::Recommends:
-	  return 5;
-
-	case pkgCache::Dep::Conflicts:
-	  return 4;
-
-	case pkgCache::Dep::DpkgBreaks:
-	  return 3;
-
-	case pkgCache::Dep::Suggests:
-	  return 2;
-
-	case pkgCache::Dep::Replaces:
-	  return 1;
-
-	case pkgCache::Dep::Obsoletes:
-	  return 0;
-
-	default:
-	  return -1;
-	}
-    }
-
-    bool operator()(const pkgCache::Dep::DepType dt1,
-		    const pkgCache::Dep::DepType dt2) const
-    {
-      return dep_level_to_int(dt1) < dep_level_to_int(dt2);
-    }
-  };
-
   // Place weaker dependencies first, then order alphabetically.
   struct compare_pair_by_dep_type
   {
-    compare_dep_levels dep_type_less_than;
-
+    dep_type_lt dep_type_less_than;
+  public:
     bool operator()(const std::pair<std::string, pkgCache::Dep::DepType> &p1,
 		    const std::pair<std::string, pkgCache::Dep::DepType> &p2) const
     {
@@ -1551,7 +1500,7 @@ namespace aptitude
       if(mode == show_requiring_packages ||
 	 mode == show_requiring_packages_and_strength)
 	{
-	  compare_dep_levels dep_less_than;
+	  dep_type_lt dep_less_than;
 	  // Maps root names to strongest dependency type.
 	  std::map<std::string, pkgCache::Dep::DepType> roots;
 	  for(std::vector<std::vector<action> >::const_iterator it =
diff --git a/src/generic/apt/apt.h b/src/generic/apt/apt.h
index 208542f9..fc6fb64a 100644
--- a/src/generic/apt/apt.h
+++ b/src/generic/apt/apt.h
@@ -318,6 +318,22 @@ public:
   }
 };
 
+/** Compare two packages by memory location (useful for inserting into
+ *  maps when the particular order is uninteresting).
+ *
+ *  It is safe to use < and not std::less here because the pointers
+ *  share an array in the package cache.
+ */
+struct pkg_ptr_lt
+{
+public:
+  bool operator()(const pkgCache::PkgIterator &p1,
+                  const pkgCache::PkgIterator &p2) const
+  {
+    return &*p1 < &*p2;
+  }
+};
+
 /** Sort versions by package name. */
 struct ver_name_lt
 {
@@ -329,6 +345,65 @@ public:
   }
 };
 
+/** Compare two versions by memory location (useful for inserting into
+ *  maps when the particular order is uninteresting).
+ *
+ *  It is safe to use < and not std::less here because the pointers
+ *  share an array in the package cache.
+ */
+struct ver_ptr_lt
+{
+public:
+  bool operator()(const pkgCache::VerIterator &v1,
+		  const pkgCache::VerIterator &v2) const
+  {
+    return &*v1 < &*v2;
+  }
+};
+
+struct dep_type_lt
+{
+  static int dep_type_to_int(const pkgCache::Dep::DepType dt)
+  {
+    switch(dt)
+      {
+      case pkgCache::Dep::PreDepends:
+        return 7;
+
+      case pkgCache::Dep::Depends:
+        return 6;
+
+      case pkgCache::Dep::Recommends:
+        return 5;
+
+      case pkgCache::Dep::Conflicts:
+        return 4;
+
+      case pkgCache::Dep::DpkgBreaks:
+        return 3;
+
+      case pkgCache::Dep::Suggests:
+        return 2;
+
+      case pkgCache::Dep::Replaces:
+        return 1;
+
+      case pkgCache::Dep::Obsoletes:
+        return 0;
+
+      default:
+        return -1;
+      }
+  }
+
+public:
+  bool operator()(const pkgCache::Dep::DepType dt1,
+                  const pkgCache::Dep::DepType dt2) const
+  {
+    return dep_type_to_int(dt1) < dep_type_to_int(dt2);
+  }
+};
+
 /** \return \b true if the given dependency type is Conflicts or
  *  Breaks.
  *
diff --git a/src/generic/apt/infer_reason.cc b/src/generic/apt/infer_reason.cc
index 233ba985..ef283827 100644
--- a/src/generic/apt/infer_reason.cc
+++ b/src/generic/apt/infer_reason.cc
@@ -294,22 +294,13 @@ void infer_reverse_breakage(pkgCache::PkgIterator &pkg,
     }
 }
 
-struct cmp_pkg_mem
-{
-  bool operator()(const pkgCache::PkgIterator &P1,
-		  const pkgCache::PkgIterator &P2) const
-  {
-    return less<const pkgCache::Package *>()(&*P1, &*P2);
-  }
-};
-
 void infer_reverse_breakage(pkgCache::PkgIterator pkg,
 			    set<reason> &reasons)
 {
   for(pkgCache::DepIterator D=pkg.RevDependsList(); !D.end(); ++D)
     infer_reverse_breakage(pkg, D, reasons);
 
-  set<pkgCache::PkgIterator, cmp_pkg_mem> seen;
+  set<pkgCache::PkgIterator, pkg_ptr_lt> seen;
 
   // Look at the list of stuff provided by any version.
   for(pkgCache::VerIterator V=pkg.VersionList(); !V.end(); ++V)
diff --git a/src/generic/apt/log.cc b/src/generic/apt/log.cc
index a2554a65..77c3551a 100644
--- a/src/generic/apt/log.cc
+++ b/src/generic/apt/log.cc
@@ -154,6 +154,7 @@ bool do_log(const string &log,
 
 struct log_sorter
 {
+  pkg_name_lt plt;
 public:
   inline bool operator()(const logitem &a, const logitem &b)
   {
@@ -161,7 +162,8 @@ public:
       return true;
     else if(a.second>b.second)
       return false;
-    else return strcmp(a.first.Name(), b.first.Name())<0;
+    else
+      return plt(a.first, b.first);
   }
 };
 
diff --git a/src/gtk/dashboardtab.cc b/src/gtk/dashboardtab.cc
index 1bdfd208..ce0911de 100644
--- a/src/gtk/dashboardtab.cc
+++ b/src/gtk/dashboardtab.cc
@@ -272,19 +272,6 @@ namespace gui
     upgrades_pkg_view->show_edit_columns_dialog();
   }
 
-  namespace
-  {
-    struct sort_versions_by_package_name
-    {
-      bool operator()(const pkgCache::VerIterator &v1,
-		      const pkgCache::VerIterator &v2)
-      {
-	return strcmp(v1.ParentPkg().Name(),
-		      v2.ParentPkg().Name()) < 0;
-      }
-    };
-  }
-
   // Download all the changelogs and show the new entries.
   void DashboardTab::create_upgrade_summary()
   {
@@ -329,8 +316,7 @@ namespace gui
       p->Done();
     }
 
-    std::sort(versions.begin(), versions.end(),
-	      sort_versions_by_package_name());
+    std::sort(versions.begin(), versions.end(), ver_name_lt());
 
     upgrades_summary_textview->set_buffer(text_buffer);
 
diff --git a/src/gtk/entitysummary.cc b/src/gtk/entitysummary.cc
index c4efc66e..bc651488 100644
--- a/src/gtk/entitysummary.cc
+++ b/src/gtk/entitysummary.cc
@@ -238,10 +238,12 @@ namespace gui
 
     struct compare_provider_lists_by_name
     {
+      pkg_name_lt base;
+    public:
       bool operator()(const std::pair<pkgCache::PkgIterator, std::vector<pkgCache::VerIterator> > &p1,
 		      const std::pair<pkgCache::PkgIterator, std::vector<pkgCache::VerIterator> > &p2) const
       {
-	return strcmp(p1.first.Name(), p2.first.Name()) < 0;
+	return base(p1.first, p2.first);
       }
     };
   }
diff --git a/src/pkg_ver_item.h b/src/pkg_ver_item.h
index 1d2d64e1..ddbd2519 100644
--- a/src/pkg_ver_item.h
+++ b/src/pkg_ver_item.h
@@ -122,16 +122,8 @@ public:
 
 class versort:public cwidget::widgets::sortpolicy
 {
+  pkg_name_lt plt;
 public:
-  inline int compare(const pkg_ver_item *item1, const pkg_ver_item *item2) const
-  {
-    if(item1->get_version().ParentPkg()!=item2->get_version().ParentPkg())
-      return strcmp(item1->get_version().ParentPkg().Name(),
-		    item2->get_version().ParentPkg().Name());
-
-    return _system->VS->CmpVersion(item1->get_version().VerStr(), item2->get_version().VerStr());
-  }
-
   bool operator()(cwidget::widgets::treeitem *item1, cwidget::widgets::treeitem *item2)
   {
     // FIXME: this is horrible.
@@ -139,7 +131,14 @@ public:
     const pkg_ver_item *pitem2=dynamic_cast<const pkg_ver_item *>(item2);
 
     if(pitem1 && pitem2)
-      return (compare(pitem1,pitem2)<0);
+      {
+        if(pitem1->get_version().ParentPkg()!=pitem2->get_version().ParentPkg())
+          return plt(pitem1->get_version().ParentPkg(),
+                     pitem2->get_version().ParentPkg());
+
+        return _system->VS->CmpVersion(pitem1->get_version().VerStr(),
+                                       pitem2->get_version().VerStr()) < 0;
+      }
     else
       return false; // we shouldn't get here!
   }
diff --git a/src/reason_fragment.cc b/src/reason_fragment.cc
index d7f2cd95..03a257c7 100644
--- a/src/reason_fragment.cc
+++ b/src/reason_fragment.cc
@@ -15,7 +15,6 @@
 #include <cwidget/config/colors.h>
 #include <cwidget/fragment.h>
 
-#include <functional>
 #include <set>
 
 using namespace std;
@@ -51,28 +50,6 @@ cw::fragment *depname_frag(pkgCache::DepIterator dep)
   return cw::text_fragment("has an invalid dependency type!", cw::get_style("Error"));
 }
 
-/** Compare two packages by name */
-struct pkg_name_cmp
-{
-  bool operator()(pkgCache::PkgIterator P1,
-		  pkgCache::PkgIterator P2)
-  {
-    return strcmp(P1.Name(), P2.Name())<0;
-  }
-};
-
-/** Compare two versions by memory location (useful for inserting into
- *  maps when the particular order is uninteresting)
- */
-struct ver_ptr_cmp
-{
-  bool operator()(pkgCache::VerIterator V1,
-		   pkgCache::VerIterator V2)
-  {
-    return less<void*>()(&*V1, &*V2);
-  }
-};
-
 /** Generate a cw::fragment describing the packages providing a given package.
  *
  *  \param dep the dependency that the provides are related to;
@@ -100,8 +77,8 @@ cw::fragment *prvfrag(pkgCache::DepIterator dep,
 
   vector<cw::fragment*> fragments;
 
-  set<pkgCache::VerIterator, ver_ptr_cmp> providing_versions;
-  set<pkgCache::PkgIterator, pkg_name_cmp> providing_packages;
+  set<pkgCache::VerIterator, ver_ptr_lt> providing_versions;
+  set<pkgCache::PkgIterator, pkg_name_lt> providing_packages;
 
   pkgCache::VerIterator candver=(*apt_cache_file)[pkg].CandidateVerIter(*apt_cache_file);