util/IntrusiveSortedList: new class

2022-11-13 08:51:18 +01:00
parent 85ab89a08b
commit 51769c40d8
4 changed files with 114 additions and 11 deletions
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2020-2022 Max Kellermann <max.kellermann@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "IntrusiveList.hxx"
+
+/**
+ * A variant of #IntrusiveList which is sorted automatically.  There
+ * are obvious scalability problems with this approach, so use with
+ * care.
+ */
+template<typename T, typename Compare=typename T::Compare,
+	 typename HookTraits=IntrusiveListBaseHookTraits<T>,
+	 bool constant_time_size=false>
+class IntrusiveSortedList
+	: public IntrusiveList<T, HookTraits, constant_time_size>
+{
+	using Base = IntrusiveList<T, HookTraits, constant_time_size>;
+
+	[[no_unique_address]]
+	Compare compare;
+
+public:
+	constexpr IntrusiveSortedList() noexcept = default;
+	IntrusiveSortedList(IntrusiveSortedList &&src) noexcept = default;
+
+	using typename Base::reference;
+	using Base::begin;
+	using Base::end;
+
+	void insert(reference item) noexcept {
+		auto position = std::find_if(begin(), end(), [this, &item](const auto &other){
+			return !compare(other, item);
+		});
+
+		Base::insert(position, item);
+	}
+};