feat(new_metrics): merge prometheus-dev into master branch

.licenserc.yaml

@@ -94,6 +94,11 @@ header:
     - 'include/dsn/utility/rand.h'
     - 'include/dsn/utility/math.h'
     - 'include/dsn/utility/defer.h'
+    - 'include/dsn/utility/alloc.h'
+    - 'include/dsn/utility/casts.h'
+    - 'include/dsn/utility/long_adder.h'
+    - 'include/dsn/utility/metrics.h'
+    - 'include/dsn/utility/nth_element.h'
     - 'src/aio/aio_task.cpp'
     - 'src/aio/test/main.cpp'
     - 'src/meta/test/meta_http_service_test.cpp'
@@ -209,6 +214,17 @@ header:
     - 'src/utils/rand.cpp'
     - 'src/utils/throttling_controller.cpp'
     - 'src/utils/output_utils.cpp'
+    - 'src/utils/alloc.cpp'
+    - 'src/utils/long_adder.cpp'
+    - 'src/utils/long_adder_bench/long_adder_bench.cpp'
+    - 'src/utils/metrics.cpp'
+    - 'src/utils/shared_io_service.cpp'
+    - 'src/utils/test/long_adder_test.cpp'
+    - 'src/utils/test/metrics_test.cpp'
+    - 'src/utils/test/nth_element_bench/nth_element_bench.cpp'
+    - 'src/utils/test/nth_element_test.cpp'
+    - 'src/utils/test/nth_element_utils.h'
+    - 'src/utils/test/percentile_utils.h'
     - 'src/common/partition_split.thrift'
     - 'src/common/common.cpp'
     - 'src/common/consensus.thrift'

include/dsn/utility/alloc.h

@@ -0,0 +1,84 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#pragma once
+
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <new>
+
+#include <dsn/c/api_utilities.h>
+#include <dsn/dist/fmt_logging.h>
+#include <dsn/utility/ports.h>
+
+namespace dsn {
+
+#ifdef CACHELINE_SIZE
+
+extern void *cacheline_aligned_alloc(size_t size);
+
+extern void cacheline_aligned_free(void *mem_block);
+
+template <typename T>
+using cacheline_aligned_ptr = typename std::unique_ptr<T, std::function<void(void *)>>;
+
+template <typename T>
+cacheline_aligned_ptr<T> cacheline_aligned_alloc_array(size_t len)
+{
+    void *buffer = cacheline_aligned_alloc(sizeof(T) * len);
+    if (dsn_unlikely(buffer == nullptr)) {
+        return cacheline_aligned_ptr<T>(nullptr, [](void *) {});
+    }
+
+    T *array = new (buffer) T[len];
+
+#ifndef NDEBUG
+    if (sizeof(T) <= CACHELINE_SIZE && (sizeof(T) & (sizeof(T) - 1)) == 0) {
+        for (size_t i = 0; i < len; ++i) {
+            T *elem = &(array[i]);
+            dassert_f((reinterpret_cast<const uintptr_t>(elem) & (sizeof(T) - 1)) == 0,
+                      "unaligned array element for cache line: array={}, length={}, index={}, "
+                      "elem={}, elem_size={}, mask={}, cacheline_size={}",
+                      fmt::ptr(array),
+                      len,
+                      i,
+                      fmt::ptr(elem),
+                      sizeof(T),
+                      sizeof(T) - 1,
+                      CACHELINE_SIZE);
+        }
+    }
+#endif
+
+    return cacheline_aligned_ptr<T>(array, cacheline_aligned_free);
+}
+
+template <typename T>
+cacheline_aligned_ptr<T> cacheline_aligned_alloc_array(size_t len, const T &val)
+{
+    auto array = cacheline_aligned_alloc_array<T>(len);
+    if (array) {
+        std::fill(array.get(), array.get() + len, val);
+    }
+
+    return array;
+}
+
+#endif
+
+} // namespace dsn

include/dsn/utility/casts.h

@@ -0,0 +1,47 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#pragma once
+
+#include <cassert>
+#include <type_traits>
+
+namespace dsn {
+
+// Downcasting is to convert a base-class pointer(reference) to a derived-class
+// pointer(reference). As a usual approach, RTTI (dynamic_cast<>) is not efficient.
+// Instead, we can perform a compile-time assertion check whether one is derived
+// from another; then, just use static_cast<> to do the conversion faster. RTTI is
+// also run in debug mode to do double-check.
+
+template <typename To, typename From>
+inline To down_cast(From *from)
+{
+    // Perform a compile-time assertion to check whether <From> class is derived from <To> class.
+    static_assert(std::is_base_of<typename std::remove_pointer<From>::type,
+                                  typename std::remove_pointer<To>::type>::value,
+                  "<From> class is not derived from <To> class");
+
+    // Use RTTI to do double-check, though in practice the unit tests are seldom built in debug
+    // mode. For example, the unit tests of github CI for both rDSN and Pegasus are built in
+    // release mode.
+    assert(from == NULL || dynamic_cast<To>(from) != NULL);
+
+    return static_cast<To>(from);
+}
+
+} // namespace dsn