Use std random and modernize some code (#2)

* Use std::srand and std::rand instead of direct call to srandom and random
* Modernize the way errors are handled

Author: vthiery

src/StatsdClient.hpp

@@ -1,6 +1,7 @@
 #ifndef STATSD_CLIENT_HPP
 #define STATSD_CLIENT_HPP
 
+#include <cstdlib>
 #include <experimental/optional>
 #include <string>
 #include "UDPSender.hpp"
@@ -33,9 +34,6 @@ class StatsdClient
         const std::string& prefix,
         const std::experimental::optional<uint64_t> batchsize = std::experimental::nullopt) noexcept;
 
-    //! Default destructor
-    ~StatsdClient() = default;
-
     //!@}
 
     //!@name Methods
@@ -96,7 +94,7 @@ StatsdClient(
 , m_sender(host, port, batchsize)
 {
     // Initialize the randorm generator to be used for sampling
-    srandom(time(NULL));
+    std::srand(time(nullptr));
 }
 
 void
@@ -162,7 +160,7 @@ send(const std::string& key, const int value, const std::string& type, const flo
     // Test if one should send or not, according to the frequency rate
     if (!isFrequencyOne(frequency))
     {
-        if (frequency < (float)random() / RAND_MAX)
+        if (frequency < static_cast<float>(std::rand()) / RAND_MAX)
         {
             return;
         }

src/UDPSender.hpp

@@ -232,6 +232,8 @@ bool
 UDPSender::
 initialize() noexcept
 {
+    using namespace std::string_literals;
+
     if (m_isInitialized)
     {
         return true;
@@ -241,9 +243,7 @@ initialize() noexcept
     m_socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
     if (m_socket == -1)
     {
-        char buffer[256];
-        snprintf(buffer, sizeof(buffer), "Could not create socket, err=%m");
-        m_errorMessage = std::string(buffer);
+        m_errorMessage = "Could not create socket, err="s + std::strerror(errno);
         return false;
     }
 
@@ -263,17 +263,13 @@ initialize() noexcept
 
         // Get the address info using the hints
         struct addrinfo* results = nullptr;
-        const int ret = getaddrinfo(m_host.c_str(), nullptr, &hints, &results);
+        const int ret{ getaddrinfo(m_host.c_str(), nullptr, &hints, &results) };
         if (ret != 0)
         {
             // An error code has been returned by getaddrinfo
             close(m_socket);
             m_socket = -1;
-
-            char buffer[256];
-            snprintf(buffer, sizeof(buffer), "getaddrinfo failed: error=%d, msg=%s", ret, gai_strerror(ret));
-            m_errorMessage = std::string(buffer);
-
+            m_errorMessage = "getaddrinfo failed: error="s + std::to_string(ret) + ", msg=" + gai_strerror(ret);
             return false;
         }
 
@@ -286,7 +282,6 @@ initialize() noexcept
     }
 
     m_isInitialized = true;
-
     return true;
 }
 
@@ -301,12 +296,11 @@ sendToDaemon(const std::string& message) noexcept
     }
 
     // Try sending the message
-    const int ret = sendto(m_socket, message.data(), message.size(), 0, (struct sockaddr *)&m_server, sizeof(m_server));
+    const long int ret{ sendto(m_socket, message.data(), message.size(), 0, (struct sockaddr *)&m_server, sizeof(m_server)) };
     if (ret == -1)
     {
-        char buffer[256];
-        snprintf(buffer, sizeof(buffer), "sendto server failed: host=%s:%d, err=%m", m_host.c_str(), m_port);
-        m_errorMessage = std::string(buffer);
+        using namespace std::string_literals;
+        m_errorMessage = "sendto server failed: host="s + m_host + ":" + std::to_string(m_port) + ", err=" + std::strerror(errno);
     }
 }