Introduced UNL update control message. (#169)

src/unl.cpp

@@ -0,0 +1,92 @@
+#include "util/util.hpp"
+#include "hplog.hpp"
+#include "unl.hpp"
+
+/**
+ * Manages the UNL public keys of this node.
+ */
+namespace unl
+{
+    std::set<std::string> list; // List of binary pubkeys of UNL.
+    std::string json_list;      // Stringified json array of UNL. (To be fed into the contract args)
+    std::shared_mutex unl_mutex;
+
+    size_t count()
+    {
+        std::shared_lock lock(unl_mutex);
+        return list.size();
+    }
+
+    std::set<std::string> get()
+    {
+        std::shared_lock lock(unl_mutex);
+        return list;
+    }
+
+    std::string get_json()
+    {
+        std::shared_lock lock(unl_mutex);
+        return json_list;
+    }
+
+    bool exists(const std::string &bin_pubkey)
+    {
+        std::shared_lock lock(unl_mutex);
+        return list.find(bin_pubkey) != list.end();
+    }
+
+    void add(const std::vector<std::string> &additions)
+    {
+        if (additions.empty())
+            return;
+
+        std::unique_lock lock(unl_mutex);
+
+        for (const std::string &pubkey : additions)
+            list.emplace(pubkey);
+
+        update_json_list();
+    }
+
+    void update(const std::vector<std::string> &additions, const std::vector<std::string> &removals)
+    {
+        if (additions.empty() && removals.empty())
+            return;
+
+        std::unique_lock lock(unl_mutex);
+
+        for (const std::string &pubkey : additions)
+            list.emplace(pubkey);
+
+        for (const std::string &pubkey : removals)
+            list.erase(pubkey);
+
+        update_json_list();
+
+        LOG_INFO << "UNL updated. Count:" << list.size();
+        ;
+    }
+
+    void update_json_list()
+    {
+        std::ostringstream os;
+        os << "[";
+        for (auto pk = list.begin(); pk != list.end(); pk++)
+        {
+            if (pk != list.begin())
+                os << ","; // Trailing comma separator for previous element.
+
+            // Convert binary pubkey into hex.
+            std::string pubkeyhex;
+            util::bin2hex(
+                pubkeyhex,
+                reinterpret_cast<const unsigned char *>(pk->data()) + 1,
+                pk->length() - 1);
+
+            os << "\"" << pubkeyhex << "\"";
+        }
+        os << "]";
+        json_list = os.str();
+    }
+
+} // namespace unl