Add defer_validation/confirmation.

include/bitcoin/node/chasers/chaser_confirm.hpp

@@ -69,8 +69,9 @@ class BCN_API chaser_confirm
         size_t top) NOEXCEPT;
     void announce(const header_link& link, height_t height) NOEXCEPT;
 
-    // This is thread safe.
+    // These are thread safe.
     const bool filter_;
+    const bool defer_;
 };
 
 } // namespace node

include/bitcoin/node/chasers/chaser_validate.hpp

@@ -89,6 +89,7 @@ class BCN_API chaser_validate
     const size_t maximum_backlog_;
     const bool node_witness_;
     const bool filter_;
+    const bool defer_;
 };
 
 } // namespace node

include/bitcoin/node/settings.hpp

@@ -74,6 +74,8 @@ class BCN_API settings
     bool headers_first;
     bool thread_priority;
     bool memory_priority;
+    bool defer_validation;
+    bool defer_confirmation;
     float allowed_deviation;
     uint16_t announcement_cache;
     uint16_t allocation_multiple;

src/chasers/chaser_confirm.cpp

@@ -35,7 +35,8 @@ BC_PUSH_WARNING(NO_THROW_IN_NOEXCEPT)
 
 chaser_confirm::chaser_confirm(full_node& node) NOEXCEPT
   : chaser(node),
-    filter_(node.archive().filter_enabled())
+    filter_(node.archive().filter_enabled()),
+    defer_(node.config().node.defer_confirmation)
 {
 }
 
@@ -49,7 +50,11 @@ code chaser_confirm::start() NOEXCEPT
         LOGN("Node is current at startup block [" << position() << "].");
     }
 
-    SUBSCRIBE_EVENTS(handle_event, _1, _2, _3);
+    if (!defer_)
+    {
+        SUBSCRIBE_EVENTS(handle_event, _1, _2, _3);
+    }
+
     return error::success;
 }
 

src/chasers/chaser_validate.cpp

@@ -44,7 +44,8 @@ chaser_validate::chaser_validate(full_node& node) NOEXCEPT
     initial_subsidy_(node.config().bitcoin.initial_subsidy()),
     maximum_backlog_(node.config().node.maximum_concurrency_()),
     node_witness_(node.config().network.witness_node()),
-    filter_(node.archive().filter_enabled())
+    filter_(node.archive().filter_enabled()),
+    defer_(node.config().node.defer_validation)
 {
 }
 
@@ -170,12 +171,13 @@ void chaser_validate::do_bumped(height_t height) NOEXCEPT
         if (ec == database::error::unassociated)
             return;
 
-        const auto bypass = is_under_checkpoint(height) ||
+        const auto bypass = defer_ || is_under_checkpoint(height) ||
             query.is_milestone(link);
 
         if (bypass)
         {
-            if (filter_)
+            // Filters will be set on subsequent unsupressed run.
+            if (filter_ && !defer_)
             {
                 post_block(link, bypass);
             }
@@ -350,9 +352,15 @@ void chaser_validate::complete_block(const code& ec, const header_link& link,
     }
 
     // VALID BLOCK
+    // Under deferral there is no state change, but downloads will stall unless
+    // he window is closed out, so notify the check chaser of the increment.
     notify(ec, chase::valid, possible_wide_cast<height_t>(height));
-    fire(events::block_validated, height);
-    LOGV("Block validated: " << height << (bypass ? " (bypass)" : ""));
+
+    if (!defer_)
+    {
+        fire(events::block_validated, height);
+        LOGV("Block validated: " << height << (bypass ? " (bypass)" : ""));
+    }
 }
 
 // Overrides due to independent priority thread pool

src/parser.cpp

@@ -1029,6 +1029,16 @@ options_metadata parser::load_settings() THROWS
         value<bool>(&configured.node.delay_inbound),
         "Delay accepting inbound connections until node is current, defaults to 'true'."
     )
+    (
+        "node.defer_validation",
+        value<bool>(&configured.node.defer_validation),
+        "Defer validation, defaults to 'false'."
+    )
+    (
+        "node.defer_confirmation",
+        value<bool>(&configured.node.defer_confirmation),
+        "Defer confirmation, defaults to 'false'."
+    )
     ////(
     ////    "node.headers_first",
     ////    value<bool>(&configured.node.headers_first),

src/settings.cpp

@@ -85,6 +85,8 @@ settings::settings() NOEXCEPT
     headers_first{ true },
     memory_priority{ true },
     thread_priority{ true },
+    defer_validation{ false },
+    defer_confirmation{ false },
     allowed_deviation{ 1.5 },
     announcement_cache{ 42 },
     allocation_multiple{ 20 },

test/settings.cpp

@@ -58,6 +58,8 @@ BOOST_AUTO_TEST_CASE(settings__node__default_context__expected)
     BOOST_REQUIRE_EQUAL(node.thread_priority, true);
     BOOST_REQUIRE_EQUAL(node.delay_inbound, true);
     BOOST_REQUIRE_EQUAL(node.headers_first, true);
+    BOOST_REQUIRE_EQUAL(node.defer_validation, false);
+    BOOST_REQUIRE_EQUAL(node.defer_confirmation, false);
     BOOST_REQUIRE_EQUAL(node.allowed_deviation, 1.5);
     BOOST_REQUIRE_EQUAL(node.announcement_cache, 42_u16);
     BOOST_REQUIRE_EQUAL(node.allocation_multiple, 20_u16);