Add a unit test for CanProcess

- Delete the copy ctor & operator

include/xrpl/basics/CanProcess.h

@@ -78,6 +78,11 @@ public:
             cleanup_();
     }
 
+    CanProcess(CanProcess const&) = delete;
+
+    CanProcess&
+    operator=(CanProcess const&) = delete;
+
     explicit
     operator bool() const
     {

src/test/basics/CanProcess_test.cpp

@@ -0,0 +1,164 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012-2016 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <xrpl/basics/CanProcess.h>
+#include <xrpl/beast/unit_test.h>
+
+namespace ripple {
+namespace test {
+
+struct CanProcess_test : beast::unit_test::suite
+{
+    template <class Mutex, class Collection, class Item>
+    void
+    test(
+        std::string const& name,
+        Mutex& mtx,
+        Collection& collection,
+        std::vector<Item> const& items)
+    {
+        testcase(name);
+
+        if (!BEAST_EXPECT(!items.empty()))
+            return;
+        if (!BEAST_EXPECT(collection.empty()))
+            return;
+
+        // CanProcess objects can't be copied or moved. To make that easier,
+        // store shared_ptrs
+        std::vector<std::shared_ptr<CanProcess>> trackers;
+        // Fill up the vector with two CanProcess for each Item. The first
+        // inserts the item into the collection and is "good". The second does
+        // not and is "bad".
+        for (int i = 0; i < items.size(); ++i)
+        {
+            {
+                auto const& good = trackers.emplace_back(
+                    std::make_shared<CanProcess>(mtx, collection, items[i]));
+                BEAST_EXPECT(*good);
+            }
+            BEAST_EXPECT(trackers.size() == (2 * i) + 1);
+            BEAST_EXPECT(collection.size() == i + 1);
+            {
+                auto const& bad = trackers.emplace_back(
+                    std::make_shared<CanProcess>(mtx, collection, items[i]));
+                BEAST_EXPECT(!*bad);
+            }
+            BEAST_EXPECT(trackers.size() == 2 * (i + 1));
+            BEAST_EXPECT(collection.size() == i + 1);
+        }
+        BEAST_EXPECT(collection.size() == items.size());
+        // Now remove the items from the vector<CanProcess> two at a time, and
+        // try to get another CanProcess for that item.
+        for (int i = 0; i < items.size(); ++i)
+        {
+            // Remove the "bad" one in the second position
+            // This will have no effect on the collection
+            {
+                auto const iter = trackers.begin() + 1;
+                BEAST_EXPECT(!**iter);
+                trackers.erase(iter);
+            }
+            BEAST_EXPECT(trackers.size() == (2 * items.size()) - 1);
+            BEAST_EXPECT(collection.size() == items.size());
+            {
+                // Append a new "bad" one
+                auto const& bad = trackers.emplace_back(
+                    std::make_shared<CanProcess>(mtx, collection, items[i]));
+                BEAST_EXPECT(!*bad);
+            }
+            BEAST_EXPECT(trackers.size() == 2 * items.size());
+            BEAST_EXPECT(collection.size() == items.size());
+
+            // Remove the "good" one from the front
+            {
+                auto const iter = trackers.begin();
+                BEAST_EXPECT(**iter);
+                trackers.erase(iter);
+            }
+            BEAST_EXPECT(trackers.size() == (2 * items.size()) - 1);
+            BEAST_EXPECT(collection.size() == items.size() - 1);
+            {
+                // Append a new "good" one
+                auto const& good = trackers.emplace_back(
+                    std::make_shared<CanProcess>(mtx, collection, items[i]));
+                BEAST_EXPECT(*good);
+            }
+            BEAST_EXPECT(trackers.size() == 2 * items.size());
+            BEAST_EXPECT(collection.size() == items.size());
+        }
+        // Now remove them all two at a time
+        for (int i = items.size() - 1; i >= 0; --i)
+        {
+            // Remove the "bad" one from the front
+            {
+                auto const iter = trackers.begin();
+                BEAST_EXPECT(!**iter);
+                trackers.erase(iter);
+            }
+            BEAST_EXPECT(trackers.size() == (2 * i) + 1);
+            BEAST_EXPECT(collection.size() == i + 1);
+            // Remove the "good" one now in front
+            {
+                auto const iter = trackers.begin();
+                BEAST_EXPECT(**iter);
+                trackers.erase(iter);
+            }
+            BEAST_EXPECT(trackers.size() == 2 * i);
+            BEAST_EXPECT(collection.size() == i);
+        }
+        BEAST_EXPECT(trackers.empty());
+        BEAST_EXPECT(collection.empty());
+    }
+
+    void
+    run() override
+    {
+        {
+            std::mutex m;
+            std::set<int> collection;
+            std::vector<int> const items{1, 2, 3, 4, 5};
+            test("set of int", m, collection, items);
+        }
+        {
+            std::mutex m;
+            std::set<std::string> collection;
+            std::vector<std::string> const items{
+                "one", "two", "three", "four", "five"};
+            test("set of string", m, collection, items);
+        }
+        {
+            std::mutex m;
+            std::unordered_set<char> collection;
+            std::vector<char> const items{'1', '2', '3', '4', '5'};
+            test("unorderd_set of char", m, collection, items);
+        }
+        {
+            std::mutex m;
+            std::unordered_set<std::uint64_t> collection;
+            std::vector<std::uint64_t> const items{100u, 1000u, 150u, 4u, 0u};
+            test("unordered_set of uint64_t", m, collection, items);
+        }
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(CanProcess, ripple_basics, ripple);
+
+}  // namespace test
+}  // namespace ripple