MXS-2208 Add init/finish functions for mxb::http

Init/finish needed, as curl otherwise will leak memory.

maxutils/maxbase/include/maxbase/http.hh

@@ -24,6 +24,37 @@ namespace maxbase
 namespace http
 {
 
+/**
+ * Initialize the http library.
+ *
+ * @return True if successful, false otherwise.
+ */
+bool init();
+
+/**
+ * Finalize the http library.
+ */
+void finish();
+
+/**
+ * RAII class for initializing the http functionality.
+ */
+class Init
+{
+public:
+    Init()
+    {
+        if (!mxb::http::init())
+        {
+            throw std::runtime_error("Could not initialize mxb::http.");
+        }
+    }
+    ~Init()
+    {
+        mxb::http::finish();
+    }
+};
+
 enum
 {
     DEFAULT_CONNECT_TIMEOUT = 10, // @see https://curl.haxx.se/libcurl/c/CURLOPT_CONNECTTIMEOUT.html

maxutils/maxbase/src/http.cc

@@ -33,6 +33,14 @@ using std::vector;
 namespace
 {
 
+static struct THIS_UNIT
+{
+    int nInits;
+} this_unit =
+{
+    0
+};
+
 using namespace mxb;
 using namespace mxb::http;
 
@@ -421,6 +429,38 @@ namespace maxbase
 namespace http
 {
 
+bool init()
+{
+    bool rv = true;
+
+    if (this_unit.nInits == 0)
+    {
+        CURLcode code = curl_global_init(CURL_GLOBAL_ALL);
+
+        if (code == CURLE_OK)
+        {
+            this_unit.nInits = 1;
+        }
+        else
+        {
+            MXB_ERROR("Failed to initialize CURL library: %s", curl_easy_strerror(code));
+            rv = false;
+        }
+    }
+
+    return rv;
+}
+
+void finish()
+{
+    mxb_assert(this_unit.nInits > 0);
+
+    if (--this_unit.nInits == 0)
+    {
+        curl_global_cleanup();
+    }
+}
+
 Async::Imp::~Imp()
 {
 }

maxutils/maxbase/src/test/test_http.cc

@@ -160,6 +160,8 @@ int main()
     long start;
     long stop;
 
+    mxb::http::Init init;
+
     start = time_since_epoch_ms();
     rv += test_http();
     stop = time_since_epoch_ms();