Visual Studio compiler warnings clean-up

api/include/opentelemetry/context/context.h

@@ -3,6 +3,7 @@
 #include "opentelemetry/context/context_value.h"
 #include "opentelemetry/nostd/shared_ptr.h"
 #include "opentelemetry/nostd/string_view.h"
+#include <cstring>
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace context
@@ -65,7 +66,7 @@ class Context
     {
       if (key.size() == data->key_length_)
       {
-        if (memcmp(key.data(), data->key_, data->key_length_) == 0)
+        if (std::memcmp(key.data(), data->key_, data->key_length_) == 0)
         {
           return data->value_;
         }
@@ -81,7 +82,7 @@ class Context
     {
       if (key.size() == data->key_length_)
       {
-        if (memcmp(key.data(), data->key_, data->key_length_) == 0)
+        if (std::memcmp(key.data(), data->key_, data->key_length_) == 0)
         {
           return true;
         }

api/include/opentelemetry/nostd/string_view.h

@@ -118,7 +118,12 @@ class string_view
 inline bool operator==(string_view lhs, string_view rhs) noexcept
 {
   return lhs.length() == rhs.length() &&
+#if _MSC_VER == 1900
+         // Avoid SCL error in Visual Studio 2015
+         (std::memcmp(lhs.data(), rhs.data(), lhs.length()) == 0);
+#else
          std::equal(lhs.data(), lhs.data() + lhs.length(), rhs.data());
+#endif
 }
 
 inline bool operator==(string_view lhs, const std::string &rhs) noexcept
@@ -172,3 +177,18 @@ inline std::ostream &operator<<(std::ostream &os, string_view s)
 }
 }  // namespace nostd
 OPENTELEMETRY_END_NAMESPACE
+
+namespace std {
+  template <>
+  struct hash<OPENTELEMETRY_NAMESPACE::nostd::string_view>
+  {
+    std::size_t operator()(const OPENTELEMETRY_NAMESPACE::nostd::string_view& k) const
+    {
+        // TODO: for C++17 that has native support for std::basic_string_view it would
+        // be more performance-efficient to provide a zero-copy hash.
+        auto s = std::string(k.data(), k.size());
+        return std::hash<std::string>{}(s);
+    }
+  };
+}
+#endif

api/include/opentelemetry/version.h

@@ -12,4 +12,7 @@
 
 #define OPENTELEMETRY_END_NAMESPACE \
   }}
+
+#define OPENTELEMETRY_NAMESPACE opentelemetry :: OPENTELEMETRY_CONCAT(v, OPENTELEMETRY_ABI_VERSION_NO)
+
 // clang-format on

api/test/metrics/noop_metrics_test.cc

@@ -5,6 +5,7 @@
 #include "opentelemetry/metrics/sync_instruments.h"
 
 #include <memory>
+#include <array>
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 

api/test/nostd/utility_test.cc

@@ -2,6 +2,7 @@
 
 #include <type_traits>
 #include <vector>
+#include <tuple>
 
 #include <gtest/gtest.h>
 
@@ -20,7 +21,8 @@ TEST(UtilityTest, Data)
   std::vector<int> v = {1, 2, 3};
   int array[3]       = {1, 2, 3};
   std::initializer_list<int> list{1, 2, 3};
-  int x;
+  int x = 0;
+  std::ignore = x;
 
   EXPECT_EQ(opentelemetry::nostd::data(v), v.data());
   EXPECT_EQ(opentelemetry::nostd::data(array), array);
@@ -32,7 +34,8 @@ TEST(UtilityTest, Size)
 {
   std::vector<int> v = {1, 2, 3};
   int array[3]       = {1, 2, 3};
-  int x;
+  int x = 0;
+  std::ignore = x;
 
   EXPECT_EQ(opentelemetry::nostd::size(v), v.size());
   EXPECT_EQ(opentelemetry::nostd::size(array), 3);

api/test/trace/key_value_iterable_view_test.cc

@@ -1,7 +1,7 @@
 #include "opentelemetry/trace/key_value_iterable_view.h"
 
 #include <map>
-
+#include "opentelemetry/nostd/type_traits.h"
 #include <gtest/gtest.h>
 
 using namespace opentelemetry;

ci/do_ci.sh

@@ -106,8 +106,10 @@ elif [[ "$1" == "bazel.test" ]]; then
   bazel test $BAZEL_TEST_OPTIONS //...
   exit 0
 elif [[ "$1" == "bazel.legacy.test" ]]; then
-  bazel build $BAZEL_OPTIONS -- //... -//exporters/otlp/...
-  bazel test $BAZEL_TEST_OPTIONS -- //... -//exporters/otlp/...
+  # we uses C++ future and async() function to test the Prometheus Exporter functionality,
+  # that make this test always fail. ignore Prometheus exporter here.
+  bazel build $BAZEL_OPTIONS -- //... -//exporters/otlp/... -//exporters/prometheus/...
+  bazel test $BAZEL_TEST_OPTIONS -- //... -//exporters/otlp/... -//exporters/prometheus/...
   exit 0
 elif [[ "$1" == "bazel.noexcept" ]]; then
   # there are some exceptions and error handling code from the Prometheus Client

ci/setup_cmake.sh

@@ -4,13 +4,19 @@ set -e
 
 export DEBIAN_FRONTEND=noninteractive
 apt-get update
-apt-get install --no-install-recommends --no-install-suggests -y \
+
+set +e
+echo		\
                 cmake \
                 libbenchmark-dev \
                 libgtest-dev \
                 zlib1g-dev \
                 sudo \
-                libcurl4-openssl-dev
+                libcurl4-openssl-dev \
+                nlohmann-json-dev \
+                nlohmann-json3 \
+                nlohmann-json3-dev | xargs -n 1 apt-get install --ignore-missing --no-install-recommends --no-install-suggests -y
+set -e
 
 # Follows these instructions for setting up gtest
 # https://www.eriksmistad.no/getting-started-with-google-test-on-ubuntu/

ci/setup_windows_ci_environment.ps1

@@ -11,5 +11,10 @@ $VCPKG_DIR=(Get-Item -Path ".\").FullName
 # Patched Google Benchmark can be shared between vs2017 and vs2019 compilers
 ./vcpkg install --overlay-ports="$PSScriptRoot\ports" benchmark:x64-windows
 
+# Google Test
 ./vcpkg install gtest:x64-windows
+
+# nlohmann-json
+./vcpkg install nlohmann-json:x64-windows
+
 Pop-Location

examples/otlp/CMakeLists.txt

@@ -1,6 +1,11 @@
-add_library(foo_library foo_library/foo_library.cc)
-target_link_libraries(foo_library ${CMAKE_THREAD_LIBS_INIT} opentelemetry_api)
+include_directories(
+  ${CMAKE_BINARY_DIR}/generated/third_party/opentelemetry-proto)
+include_directories(${CMAKE_SOURCE_DIR}/exporters/otlp/include)
+
+add_library(otlp_foo_library foo_library/foo_library.cc)
+target_link_libraries(otlp_foo_library ${CMAKE_THREAD_LIBS_INIT}
+                      opentelemetry_api)
 
 add_executable(example_otlp main.cc)
-target_link_libraries(example_otlp ${CMAKE_THREAD_LIBS_INIT} foo_library
-                      opentelemetry_trace)
+target_link_libraries(example_otlp ${CMAKE_THREAD_LIBS_INIT} otlp_foo_library
+                      opentelemetry_trace opentelemetry_exporter_otprotocol)

exporters/ostream/include/opentelemetry/exporters/ostream/metrics_exporter.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <iostream>
+#include <string>
 #include "opentelemetry/sdk/metrics/aggregator/exact_aggregator.h"
 #include "opentelemetry/sdk/metrics/aggregator/gauge_aggregator.h"
 #include "opentelemetry/sdk/metrics/aggregator/histogram_aggregator.h"
@@ -83,7 +84,7 @@ class OStreamMetricsExporter final : public sdkmetrics::MetricsExporter
         else
         {
           auto vec = agg->get_checkpoint();
-          int size = vec.size();
+          size_t size = vec.size();
           int i    = 1;
 
           sout_ << "\n  values      : " << '[';
@@ -104,8 +105,8 @@ class OStreamMetricsExporter final : public sdkmetrics::MetricsExporter
         auto boundaries = agg->get_boundaries();
         auto counts     = agg->get_counts();
 
-        int boundaries_size = boundaries.size();
-        int counts_size     = counts.size();
+        size_t boundaries_size = boundaries.size();
+        size_t counts_size     = counts.size();
 
         sout_ << "\n  buckets     : " << '[';
 
@@ -134,8 +135,8 @@ class OStreamMetricsExporter final : public sdkmetrics::MetricsExporter
         auto boundaries = agg->get_boundaries();
         auto counts     = agg->get_counts();
 
-        int boundaries_size = boundaries.size();
-        int counts_size     = counts.size();
+        size_t boundaries_size = boundaries.size();
+        size_t counts_size     = counts.size();
 
         sout_ << "\n  buckets     : " << '[';
 

exporters/ostream/include/opentelemetry/exporters/ostream/span_exporter.h

@@ -146,8 +146,8 @@ class OStreamSpanExporter final : public sdktrace::SpanExporter
 
   void printAttributes(std::unordered_map<std::string, sdktrace::SpanDataAttributeValue> map)
   {
-    int size = map.size();
-    int i    = 1;
+    size_t size = map.size();
+    size_t i    = 1;
     for (auto kv : map)
     {
       sout_ << kv.first << ": ";

exporters/prometheus/BUILD

@@ -14,6 +14,24 @@
 
 package(default_visibility = ["//visibility:public"])
 
+cc_library(
+    name = "prometheus_collector",
+    srcs = [
+        "src/prometheus_collector.cc",
+    ],
+    hdrs = [
+        "include/opentelemetry/exporters/prometheus/prometheus_collector.h",
+        "include/opentelemetry/exporters/prometheus/prometheus_exporter_utils.h",
+    ],
+    strip_include_prefix = "include",
+    deps = [
+        ":prometheus_utils",
+        "//api",
+        "//sdk:headers",
+        "@com_github_jupp0r_prometheus_cpp//core",
+    ],
+)
+
 cc_library(
     name = "prometheus_utils",
     srcs = [
@@ -30,6 +48,17 @@ cc_library(
     ],
 )
 
+cc_test(
+    name = "prometheus_collector_test",
+    srcs = [
+        "test/prometheus_collector_test.cc",
+    ],
+    deps = [
+        ":prometheus_collector",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
 cc_test(
     name = "prometheus_exporter_utils_test",
     srcs = [

exporters/prometheus/CMakeLists.txt

@@ -15,7 +15,9 @@
 include_directories(include)
 
 find_package(prometheus-cpp CONFIG REQUIRED)
-add_library(prometheus_exporter src/prometheus_exporter_utils.cc)
+
+add_library(prometheus_exporter src/prometheus_collector.cc
+                                src/prometheus_exporter_utils.cc)
 
 if(BUILD_TESTING)
   add_subdirectory(test)

exporters/prometheus/include/opentelemetry/exporters/prometheus/prometheus_collector.h

@@ -0,0 +1,100 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed 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 <memory>
+#include <mutex>
+#include <vector>
+
+#include "opentelemetry/sdk/metrics/record.h"
+#include "prometheus/collectable.h"
+#include "prometheus/metric_family.h"
+#include "prometheus_exporter_utils.h"
+
+namespace prometheus_client = ::prometheus;
+namespace metric_sdk        = opentelemetry::sdk::metrics;
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace exporter
+{
+namespace prometheus
+{
+/**
+ * The Prometheus Collector maintains the intermediate collection in Prometheus Exporter
+ */
+class PrometheusCollector : public prometheus_client::Collectable
+{
+public:
+  /**
+   * Default Constructor.
+   *
+   * This constructor initializes the collection for metrics to export
+   * in this class with default capacity
+   */
+  explicit PrometheusCollector(int max_collection_size = 2048);
+
+  /**
+   * Collects all metrics data from metricsToCollect collection.
+   *
+   * @return all metrics in the metricsToCollect snapshot
+   */
+  std::vector<prometheus_client::MetricFamily> Collect() const override;
+
+  /**
+   * This function is called by export() function and add the collection of
+   * records to the metricsToCollect collection
+   *
+   * @param records a collection of records to add to the metricsToCollect collection
+   */
+  void AddMetricData(const std::vector<metric_sdk::Record> &records);
+
+  /**
+   * Get the current collection in the collector.
+   *
+   * @return the current metricsToCollect collection
+   */
+  std::vector<metric_sdk::Record> GetCollection();
+
+  /**
+   * Gets the maximum size of the collection.
+   *
+   * @return max collection size
+   */
+  int GetMaxCollectionSize() const;
+
+private:
+  /**
+   * Collection of metrics data from the export() function, and to be export
+   * to user when they send a pull request. This collection is a pointer
+   * to a collection so Collect() is able to clear the collection, even
+   * though it is a const function.
+   */
+  std::unique_ptr<std::vector<metric_sdk::Record>> metrics_to_collect_;
+
+  /**
+   * Maximum size of the metricsToCollect collection.
+   */
+  int max_collection_size_;
+
+  /*
+   * Lock when operating the metricsToCollect collection
+   */
+  mutable std::mutex collection_lock_;
+};
+}  // namespace prometheus
+}  // namespace exporter
+OPENTELEMETRY_END_NAMESPACE