Remove protobuf dependency

.gitmodules

@@ -4,6 +4,3 @@
 [submodule "civetweb"]
 path = 3rdparty/civetweb
 url = https://github.com/civetweb/civetweb.git
-[submodule "prometheus_client_model"]
-path = 3rdparty/prometheus_client_model
-url = https://github.com/prometheus/client_model.git

.travis.yml

@@ -17,14 +17,6 @@ install:
  - sudo apt-get update
  - sudo apt-get install -y gcc-5 g++-5
  - sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 1 --slave /usr/bin/g++ g++ /usr/bin/g++-5
- - wget https://github.com/google/protobuf/archive/v3.1.0.tar.gz
- - tar xzf v3.1.0.tar.gz
- - cd protobuf-3.1.0
- - ./autogen.sh
- - ./configure --prefix=/usr
- - make -j 4
- - sudo make install
- - cd ..
  - sudo add-apt-repository -y ppa:webupd8team/java
  - echo "oracle-java8-installer shared/accepted-oracle-license-v1-1 select true" | sudo debconf-set-selections
  - sudo apt-get install -o Dpkg::Options::="--force-confnew" -y oracle-java8-installer

BUILD

@@ -11,7 +11,6 @@ cc_library(
  "lib/handler.h",
  "lib/histogram.cc",
  "lib/histogram_builder.cc",
- "lib/protobuf_delimited_serializer.cc",
  "lib/registry.cc",
  "lib/summary.cc",
  "lib/summary_builder.cc",
@@ -25,7 +24,5 @@ cc_library(
  visibility = ["//visibility:public"],
  deps = [
  "@civetweb//:civetweb",
- "@com_google_protobuf//:protobuf",
- "@prometheus_client_model//:prometheus_client_model",
  ],
 )

CMakeLists.txt

@@ -10,8 +10,10 @@ if(NOT DEFINED CMAKE_CXX_STANDARD AND UNIX)
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
 endif()
 
+set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
+find_package(Threads)
+
 find_package(GoogleBenchmark)
-find_package(Protobuf REQUIRED)
 find_package(ZLIB REQUIRED)
 find_package(Telegraf)
 
@@ -64,6 +66,10 @@ target_include_directories(gmock_main
  3rdparty/googletest/googlemock
 )
 
+target_link_libraries(gmock_main PRIVATE
+ ${CMAKE_THREAD_LIBS_INIT}
+)
+
 # prometheus-cpp
 
 add_subdirectory(lib)

README.md

@@ -66,11 +66,7 @@ the [travis build script](.travis.yml) might help.
 
 ### via CMake
 
-One prerequisite for performing the build using CMake is
-having [Protocol Buffers](https://github.com/google/protobuf) >= 3.0
-installed. See the [travis build script](.travis.yml) for how to build
-it from source, or use your operating systems package manager to
-install it.
+For CMake builds don't forget to fetch the submodules first. Then build as usual.
 
 ``` shell
 # fetch third-party dependencies
@@ -126,8 +122,6 @@ cc_binary(
 When you call `prometheus_cpp_repositories()` in your `WORKSPACE` file,
 you introduce the following dependencies to your project:
 
-* `load_com_google_protobuf()` for Google protobuf
-* `load_prometheus_client_model()` for Prometheus data model artifacts
 * `load_civetweb()` for Civetweb
 * `load_com_google_googletest()` for Google gtest
 * `load_com_google_googlebenchmark()` for Googlebenchmark
@@ -211,17 +205,6 @@ Alpha
 
 ## FAQ
 
-### Why do you not provide a `protobuf` version as a submodule in `3rdparty`?
-
-We opted against the submodule solution for protobuf, because
-otherwise ABI compatibiliy issues would force all consumers of
-`prometheus-cpp` to use exactly the same protobuf version as the one
-inside the submodule if they were using protobuf on its own.
-
-To phrase it differently, this library should not control the exact
-version, but the executable linking against it should determine a
-version that other libraries also link against.
-
 ## License
 
 MIT

include/prometheus/client_metric.h

@@ -0,0 +1,80 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include "prometheus/metric_type.h"
+
+namespace prometheus {
+
+struct ClientMetric {
+
+ // Label
+
+ struct Label {
+ std::string name;
+ std::string value;
+
+ bool operator==(const Label& rhs) const {
+ return std::tie(name, value) == std::tie(rhs.name, rhs.value);
+ }
+ };
+ std::vector<Label> label;
+
+ // Counter
+
+ struct Counter {
+ double value = 0.0;
+ };
+ Counter counter;
+
+ // Gauge
+
+ struct Gauge {
+ double value = 0.0;
+ };
+ Gauge gauge;
+
+ // Summary
+
+ struct Quantile {
+ double quantile = 0.0;
+ double value = 0.0;
+ };
+
+ struct Summary {
+ std::uint64_t sample_count = 0;
+ double sample_sum = 0.0;
+ std::vector<Quantile> quantile;
+ };
+ Summary summary;
+
+ // Histogram
+
+ struct Bucket {
+ std::uint64_t cumulative_count = 0;
+ double upper_bound = 0.0;
+ };
+
+ struct Histogram {
+ std::uint64_t sample_count = 0;
+ double sample_sum = 0.0;
+ std::vector<Bucket> bucket;
+ };
+ Histogram histogram;
+
+ // Untyped
+
+ struct Untyped {
+ double value = 0;
+ };
+ Untyped untyped;
+
+ // Timestamp
+
+ std::int64_t timestamp_ms = 0;
+};
+
+} // namespace prometheus

include/prometheus/collectable.h

@@ -2,19 +2,15 @@
 
 #include <vector>
 
-namespace io {
 namespace prometheus {
-namespace client {
-class MetricFamily;
-}
-}
+struct MetricFamily;
 }
 
 namespace prometheus {
 
 class Collectable {
  public:
  virtual ~Collectable() = default;
- virtual std::vector<io::prometheus::client::MetricFamily> Collect() = 0;
+ virtual std::vector<MetricFamily> Collect() = 0;
 };
 }

include/prometheus/counter.h

@@ -2,22 +2,20 @@
 
 #include <atomic>
 
-#include "metrics.pb.h"
-
+#include "prometheus/client_metric.h"
 #include "prometheus/gauge.h"
 #include "prometheus/metric.h"
 
 namespace prometheus {
-class Counter : Metric {
+class Counter {
  public:
- static const io::prometheus::client::MetricType metric_type =
- io::prometheus::client::COUNTER;
+ static const MetricType metric_type = MetricType::Counter;
 
  void Increment();
  void Increment(double);
  double Value() const;
 
- io::prometheus::client::Metric Collect();
+ ClientMetric Collect();
 
  private:
  Gauge gauge_;

include/prometheus/family.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <algorithm>
+#include <cassert>
 #include <functional>
 #include <map>
 #include <memory>
@@ -15,6 +16,7 @@
 #include "gauge_builder.h"
 #include "histogram_builder.h"
 #include "metric.h"
+#include "metric_family.h"
 
 namespace prometheus {
 
@@ -32,7 +34,7 @@ class Family : public Collectable {
  void Remove(T* metric);
 
  // Collectable
- std::vector<io::prometheus::client::MetricFamily> Collect() override;
+ std::vector<MetricFamily> Collect() override;
 
  private:
  std::unordered_map<std::size_t, std::unique_ptr<T>> metrics_;
@@ -44,7 +46,7 @@ class Family : public Collectable {
  const std::map<std::string, std::string> constant_labels_;
  std::mutex mutex_;
 
- io::prometheus::client::Metric CollectMetric(std::size_t hash, T* metric);
+ ClientMetric CollectMetric(std::size_t hash, T* metric);
 
  static std::size_t hash_labels(
  const std::map<std::string, std::string>& labels);
@@ -116,27 +118,27 @@ void Family<T>::Remove(T* metric) {
 }
 
 template <typename T>
-std::vector<io::prometheus::client::MetricFamily> Family<T>::Collect() {
+std::vector<MetricFamily> Family<T>::Collect() {
  std::lock_guard<std::mutex> lock{mutex_};
- auto family = io::prometheus::client::MetricFamily{};
- family.set_name(name_);
- family.set_help(help_);
- family.set_type(T::metric_type);
+ auto family = MetricFamily{};
+ family.name = name_;
+ family.help = help_;
+ family.type = T::metric_type;
  for (const auto& m : metrics_) {
- *family.add_metric() = std::move(CollectMetric(m.first, m.second.get()));
+ family.metric.push_back(std::move(CollectMetric(m.first, m.second.get())));
  }
  return {family};
 }
 
 template <typename T>
-io::prometheus::client::Metric Family<T>::CollectMetric(std::size_t hash,
- T* metric) {
+ClientMetric Family<T>::CollectMetric(std::size_t hash, T* metric) {
  auto collected = metric->Collect();
  auto add_label =
  [&collected](const std::pair<std::string, std::string>& label_pair) {
- auto pair = collected.add_label();
- pair->set_name(label_pair.first);
- pair->set_value(label_pair.second);
+ auto label = ClientMetric::Label{};
+ label.name = label_pair.first;
+ label.value = label_pair.second;
+ collected.label.push_back(std::move(label));
  };
  std::for_each(constant_labels_.cbegin(), constant_labels_.cend(), add_label);
  const auto& metric_labels = labels_.at(hash);

include/prometheus/gauge.h

@@ -2,17 +2,15 @@
 
 #include <atomic>
 
+#include "prometheus/client_metric.h"
 #include "prometheus/collectable.h"
 #include "prometheus/metric.h"
 
-#include "metrics.pb.h"
-
 namespace prometheus {
 
-class Gauge : public Metric {
+class Gauge {
  public:
- static const io::prometheus::client::MetricType metric_type =
- io::prometheus::client::GAUGE;
+ static const MetricType metric_type = MetricType::Gauge;
 
  Gauge();
  Gauge(double);
@@ -24,7 +22,7 @@ class Gauge : public Metric {
  void SetToCurrentTime();
  double Value() const;
 
- io::prometheus::client::Metric Collect();
+ ClientMetric Collect();
 
  private:
  void Change(double);

include/prometheus/histogram.h

@@ -2,23 +2,21 @@
 
 #include <vector>
 
+#include "prometheus/client_metric.h"
 #include "prometheus/counter.h"
 
-#include "metrics.pb.h"
-
 namespace prometheus {
-class Histogram : public Metric {
+class Histogram {
  public:
  using BucketBoundaries = std::vector<double>;
 
- static const io::prometheus::client::MetricType metric_type =
- io::prometheus::client::HISTOGRAM;
+ static const MetricType metric_type = MetricType::Histogram;
 
  Histogram(const BucketBoundaries& buckets);
 
  void Observe(double value);
 
- io::prometheus::client::Metric Collect();
+ ClientMetric Collect();
 
  private:
  const BucketBoundaries bucket_boundaries_;

include/prometheus/metric.h

@@ -1,12 +1,12 @@
 #pragma once
 
-#include "metrics.pb.h"
+#include "prometheus/client_metric.h"
 
 namespace prometheus {
 
 class Metric {
  public:
  virtual ~Metric() = default;
- virtual io::prometheus::client::Metric Collect() = 0;
+ virtual ClientMetric Collect() = 0;
 };
 }

include/prometheus/metric_family.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "prometheus/client_metric.h"
+#include "prometheus/metric_type.h"
+
+namespace prometheus {
+
+struct MetricFamily {
+ std::string name;
+ std::string help;
+ MetricType type = MetricType::Untyped;
+ std::vector<ClientMetric> metric;
+};
+} // namespace prometheus