Initial commit

Author: Vincent Thiery

LICENSE.md

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+MIT License
+
+Copyright (c) 2017 Vincent Thiery
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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+# C++ StatsD Client
+
+A header-only StatsD client implemented in C++.
+The client allows:
+- batching,
+- change of configuration at runtime,
+- user-define frequency rate.
+
+## Usage
+A simple example of how to use the client:
+
+```
+#include "StatsdClient.hpp"
+using namespace Statsd;
+
+int main()
+{
+    // Define the client
+    StatsdClient client{ "127.0.0.1", 5005, "myPrefix_", true };
+
+    // Increment "coco"
+    client.increment("coco");
+
+    // Decrement "kiki"
+    client.decrement("kiki");
+
+    // Adjusts "toto" by +3
+    client.count("toto", 2, 0.1f);
+
+    // Record a gauge "titi" to 3
+    client.gauge("titi", 3);
+
+    // Record a timing of 2ms for "myTiming"
+    client.timing("myTiming", 2, 0.1f);
+
+    // Send a metric explicitly
+    client.send("tutu", 4, "c", 2.0f);
+}
+```
+
+## License
+This extension is under MIT license.

src/StatsdClient.hpp

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+#ifndef STATSD_CLIENT_HPP
+#define STATSD_CLIENT_HPP
+
+#include <experimental/optional>
+#include <string>
+#include "UDPSender.hpp"
+
+namespace Statsd
+{
+/*!
+ *
+ * Statsd client
+ *
+ * This is the Statsd client, exposing the classic methods
+ * and relying on a UDP sender for the actual sending.
+ *
+ * The sampling frequency can be input, as well as the
+ * batching size. The latter is optional and shall not be
+ * set if batching is not desired.
+ *
+ */
+class StatsdClient
+{
+public:
+
+    //!@name Constructor and destructor
+    //!@{
+
+    //! Constructor
+    StatsdClient(
+        const std::string& host,
+        const uint16_t port,
+        const std::string& prefix,
+        const std::experimental::optional<uint64_t> batchsize = std::experimental::nullopt) noexcept;
+
+    //! Default destructor
+    ~StatsdClient() = default;
+
+    //!@}
+
+    //!@name Methods
+    //!@{
+
+    //! Sets a configuration { host, port, prefix }
+    inline void setConfig(const std::string& host, const uint16_t port, const std::string& prefix) noexcept;
+
+    //! Returns the error message as an optional std::string
+    inline std::experimental::optional<std::string> errorMessage() const noexcept;
+
+    //! Increments the key, at a given frequency rate
+    inline void increment(const std::string& key, const float frequency = 1.0f) const noexcept;
+
+    //! Increments the key, at a given frequency rate
+    inline void decrement(const std::string& key, const float frequency = 1.0f) const noexcept;
+
+    //! Adjusts the specified key by a given delta, at a given frequency rate
+    inline void count(const std::string& key, const int delta, const float frequency = 1.0f) const noexcept;
+
+    //! Records a gauge for the key, with a given value, at a given frequency rate
+    inline void gauge(const std::string& key, const unsigned int value, const float frequency = 1.0f) const noexcept;
+
+    //! Records a timing for a key, at a given frequency
+    inline void timing(const std::string& key, const unsigned int ms, const float frequency = 1.0f) const noexcept;
+
+    //! Send a value for a key, according to its type, at a given frequency
+    void send(const std::string& key, const int value, const std::string& type, const float frequency = 1.0f) const noexcept;
+
+    //!@}
+
+private:
+
+    // @name Private methods
+    // @{
+
+    //! Returns a cleaned key
+    inline std::string clean(const std::string& key) const noexcept;
+
+    // @}
+
+private:
+
+    //! The prefix to be used for metrics
+    std::string m_prefix;
+
+    //! The UDP sender to be used for actual sending
+    mutable UDPSender m_sender;
+};
+
+StatsdClient::
+StatsdClient(
+    const std::string& host,
+    const uint16_t port,
+    const std::string& prefix,
+    const std::experimental::optional<uint64_t> batchsize) noexcept
+: m_prefix(prefix)
+, m_sender(host, port, batchsize)
+{
+    // Initialize the randorm generator to be used for sampling
+    srandom(time(NULL));
+}
+
+void
+StatsdClient::
+setConfig(const std::string& host, const uint16_t port, const std::string& prefix) noexcept
+{
+    m_prefix = prefix;
+    m_sender.setConfig(host, port);
+}
+
+std::experimental::optional<std::string>
+StatsdClient::
+errorMessage() const noexcept
+{
+    return m_sender.errorMessage();
+}
+
+void
+StatsdClient::
+decrement(const std::string& key, const float frequency) const noexcept
+{
+    return count(key, -1, frequency);
+}
+
+void
+StatsdClient::
+increment(const std::string& key, const float frequency) const noexcept
+{
+    return count(key, 1, frequency);
+}
+
+void
+StatsdClient::
+count(const std::string& key, const int delta, const float frequency) const noexcept
+{
+    return send(key, delta, "c", frequency);
+}
+
+void
+StatsdClient::
+gauge(const std::string& key, const unsigned int value, const float frequency) const noexcept
+{
+    return send(key, value, "g", frequency);
+}
+
+void
+StatsdClient::
+timing(const std::string& key, const unsigned int ms, const float frequency) const noexcept
+{
+    return send(key, ms, "ms", frequency);
+}
+
+void
+StatsdClient::
+send(const std::string& key, const int value, const std::string& type, const float frequency) const noexcept
+{
+    const auto isFrequencyOne = [](const float frequency) noexcept
+    {
+        constexpr float epsilon{ 0.0001f };
+        return std::fabs(frequency - 1.0f) < epsilon;
+    };
+
+    // Test if one should send or not, according to the frequency rate
+    if (!isFrequencyOne(frequency))
+    {
+        if (frequency < (float)random() / RAND_MAX)
+        {
+            return;
+        }
+    }
+
+    // Clean the key
+    clean(key);
+
+    // Prepare the buffer, with a sampling rate if specified different from 1.0f
+    char buffer[256];
+    if (isFrequencyOne(frequency))
+    {
+        // Sampling rate is 1.0f, no need to specify it
+        snprintf(buffer, sizeof(buffer), "%s%s:%zd|%s", m_prefix.c_str(), key.c_str(), static_cast<signed size_t>(value), type.c_str());
+    }
+    else
+    {
+        // Sampling rate is different from 1.0f, hence specify it
+        snprintf(buffer, sizeof(buffer), "%s%s:%zd|%s|@%.2f", m_prefix.c_str(), key.c_str(), static_cast<signed size_t>(value), type.c_str(), frequency);
+    }
+
+    // Send the message via the UDP sender
+    m_sender.send(buffer);
+}
+
+std::string
+StatsdClient::
+clean(const std::string& key) const noexcept
+{
+    std::string cleanKey = key;
+    size_t pos = key.find_first_of(":|@");
+
+    // Add the '_' appropriately to the key
+    while (pos != std::string::npos)
+    {
+        cleanKey[pos] = '_';
+        pos = cleanKey.find_first_of(":|@");
+    }
+    return cleanKey;
+}
+
+}
+
+#endif