commit 964681ca5738ec760b9428e5cce5ef3494b10a25
author Ed Tanous <edtanous@google.com> Fri Jul 08 12:47:24 2022 -0700
committer Brad Bishop <bradleyb@fuzziesquirrel.com> Mon Jul 11 20:08:40 2022 +0000
tree d79372ff167b9f2ac95e151211ade15fccdf0dc2
parent f9d8c18787fafdca34ef5bd625a93f31072fb311

Modernize mapper core types

There's a number of best practices that have evolved in our use of
flat_maps and flat_sets since this code was originally written.

First, add std::less<> to the Compare template argument.  The default
for this is std::less<Key> which limits find() calls (and any lookup for
that matter) to only supporting std::string.  Using std::less<> allows
lookup by std::string_view, which can prevent some copies in some cases.

Next, add std::vector<...> to the types under the AllocatorOrContainer
template arg.  Per our coding standard, this overrides the default of
using boost::vector, and replaces it with std::vector, which, although
it has a very similar interface, tends to optimize better, and be better
supported overall.

The rest of this patch updates a couple places where the various types
were specifically hardcoded, so it moves to using the various using
declarations.

Tested: Unit tests;  Next patch tests this more fully.

Change-Id: I11e8ecb669f31193c55dda344b25d3fa5d191502
Signed-off-by: Ed Tanous <edtanous@google.com>

src/processing.cpp

diff --git a/src/processing.cpp b/src/processing.cpp
index 448830f..561cbde 100644
--- a/src/processing.cpp
+++ b/src/processing.cpp
@@ -142,12 +142,9 @@
     // This is all needed so that mapper operations can be done
     // on the new parent paths.
     using iface_map_iterator = InterfaceMapType::iterator;
-    using iface_map_value_type =
-        boost::container::flat_map<std::string,
-                                   boost::container::flat_set<std::string>>;
-    using name_map_iterator = iface_map_value_type::iterator;
+    using name_map_iterator = InterfaceMapType::mapped_type::iterator;
 
-    static const boost::container::flat_set<std::string> defaultIfaces{
+    static const InterfaceNames defaultIfaces{
         "org.freedesktop.DBus.Introspectable", "org.freedesktop.DBus.Peer",
         "org.freedesktop.DBus.Properties"};
 
@@ -159,11 +156,10 @@
         parent = parent.substr(0, pos);
 
         std::pair<iface_map_iterator, bool> parentEntry =
-            interfaceMap.insert(std::make_pair(parent, iface_map_value_type{}));
+            interfaceMap.try_emplace(parent);
 
         std::pair<name_map_iterator, bool> ifaceEntry =
-            parentEntry.first->second.insert(
-                std::make_pair(wellKnown, defaultIfaces));
+            parentEntry.first->second.try_emplace(wellKnown, defaultIfaces);
 
         if (!ifaceEntry.second)
         {