Adding ZeroMQ Sub for chain events

src/rpc/daemon_pub.cpp

@@ -0,0 +1,83 @@
+// Copyright (c) 2020, The Monero Project
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "daemon_pub.h"
+
+#include "wire/crypto.h"
+#include "wire/error.h"
+#include "wire/field.h"
+#include "wire/traits.h"
+#include "wire/json/read.h"
+
+namespace
+{
+  struct dummy_chain_array
+  {
+    using value_type = crypto::hash;
+
+    std::uint64_t count;
+    std::reference_wrapper<crypto::hash> id;
+
+    void clear() noexcept {}
+    void reserve(std::size_t) noexcept {}
+
+    crypto::hash& back() noexcept { return id; }
+    void emplace_back() { ++count; }
+  };
+}
+
+namespace wire
+{
+  template<>
+  struct is_array<dummy_chain_array>
+    : std::true_type
+  {};
+}
+
+namespace lws
+{
+namespace rpc
+{
+  static void read_bytes(wire::json_reader& src, minimal_chain_pub& self)
+  {
+    dummy_chain_array chain{0, std::ref(self.top_block_id)};
+    wire::object(src,
+      wire::field("first_height", std::ref(self.top_block_height)),
+      wire::field("ids", std::ref(chain))
+    );
+
+    self.top_block_height += chain.count - 1;
+    if (chain.count == 0)
+      WIRE_DLOG_THROW(wire::error::schema::binary, "expected at least one block hash");
+  }
+
+  expect<minimal_chain_pub> minimal_chain_pub::from_json(std::string&& source)
+  {
+    return wire::json::from_bytes<minimal_chain_pub>(std::move(source));
+  }
+}
+}