From b72424fca7a6af6ff7921101c450850fef875152 Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Sun, 6 Mar 2016 13:52:48 +0300
Subject: Support multiple instances of brep in a single Apache instance

---
 brep/database.cxx | 58 ++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 34 insertions(+), 24 deletions(-)

(limited to 'brep/database.cxx')

diff --git a/brep/database.cxx b/brep/database.cxx
index 9177b55..17605c5 100644
--- a/brep/database.cxx
+++ b/brep/database.cxx
@@ -4,40 +4,50 @@
 
 #include <brep/database>
 
+#include <map>
+
 #include <odb/pgsql/database.hxx>
 
 namespace brep
 {
+  namespace options
+  {
+    bool
+    operator< (const db& x, const db& y)
+    {
+      int r;
+      if ((r = x.db_user ().compare (y.db_user ())) != 0 ||
+          (r = x.db_password ().compare (y.db_password ())) != 0 ||
+          (r = x.db_name ().compare (y.db_name ())) != 0 ||
+          (r = x.db_host ().compare (y.db_host ())))
+        return r < 0;
+
+      return x.db_port () < y.db_port ();
+    }
+  }
+
   shared_ptr<odb::database>
   shared_database (const options::db& o)
   {
     using odb::pgsql::database;
-    static weak_ptr<database> db;
 
-    // In C++11, function-static variable initialization is guaranteed to be
-    // thread-safe, thought this doesn't seem to be enough in our case
-    // (because we are re-initializing the weak pointer).
-    //
-    if (shared_ptr<database> d = db.lock ())
-    {
-      if (o.db_user ()     != d->user ()     ||
-          o.db_password () != d->password () ||
-          o.db_name ()     != d->db ()       ||
-          o.db_host ()     != d->host ()     ||
-          o.db_port ()     != d->port ())
-        throw runtime_error ("shared database options mismatch");
-
-      return d;
-    }
-    else
+    static std::map<options::db, weak_ptr<database>> databases;
+
+    auto i (databases.find (o));
+    if (i != databases.end ())
     {
-      d = make_shared<database> (o.db_user (),
-                                 o.db_password (),
-                                 o.db_name (),
-                                 o.db_host (),
-                                 o.db_port ());
-      db = d;
-      return d;
+      if (shared_ptr<database> d = i->second.lock ())
+        return d;
     }
+
+    shared_ptr<database> d (
+      make_shared<database> (o.db_user (),
+                             o.db_password (),
+                             o.db_name (),
+                             o.db_host (),
+                             o.db_port ()));
+
+    databases[o] = d;
+    return d;
   }
 }
-- 
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