Add modify function to OpenLedger::accept

src/ripple/app/ledger/OpenLedger.h

@@ -57,6 +57,20 @@ private:
     std::shared_ptr<OpenView const> current_;
 
 public:
+    /** Signature for modification functions.
+
+        The modification function is called during
+        apply and modify with an OpenView to accumulate
+        changes and the Journal to use for logging.
+
+        A return value of `true` informs OpenLedger
+        that changes were made. Always returning
+        `true` won't cause harm, but it may be
+        sub-optimal.
+    */
+    using modify_type = std::function<
+        bool(OpenView&, beast::Journal)>;
+
     OpenLedger() = delete;
     OpenLedger (OpenLedger const&) = delete;
     OpenLedger& operator= (OpenLedger const&) = delete;
@@ -105,17 +119,13 @@ public:
         Thread safety:
             Can be called concurrently from any thread.
 
-        `f` will be called as
-            bool(ReadView&)
-
         If `f` returns `true`, the changes made in the
         OpenView will be published to the open ledger.
 
         @return `true` if the open view was changed
     */
     bool
-    modify (std::function<
-        bool(OpenView&, beast::Journal)> const& f);
+    modify (modify_type const& f);
 
     /** Accept a new ledger.
 
@@ -135,6 +145,12 @@ public:
             The list of local transactions are applied
             to the new open view.
 
+            The optional modify function f is called
+            to perform further modifications to the
+            open view, atomically. Changes made in
+            the modify function are not visible to
+            callers until accept() returns.
+
             Any failed, retriable transactions are left
             in `retries` for the caller.
 
@@ -150,7 +166,8 @@ public:
             OrderedTxs const& locals, bool retriesFirst,
                 OrderedTxs& retries, ApplyFlags flags,
                     HashRouter& router,
-                        std::string const& suffix = "");
+                        std::string const& suffix = "",
+                            modify_type const& f = {});
 
     /** Algorithm for applying transactions.
 

src/ripple/app/ledger/impl/OpenLedger.cpp

@@ -54,8 +54,7 @@ OpenLedger::current() const
 }
 
 bool
-OpenLedger::modify (std::function<
-    bool(OpenView&, beast::Journal)> const& f)
+OpenLedger::modify (modify_type const& f)
 {
     std::lock_guard<
         std::mutex> lock1(modify_mutex_);
@@ -77,7 +76,8 @@ OpenLedger::accept(Application& app, Rules const& rules,
     std::shared_ptr<Ledger const> const& ledger,
         OrderedTxs const& locals, bool retriesFirst,
             OrderedTxs& retries, ApplyFlags flags,
-                HashRouter& router, std::string const& suffix)
+                HashRouter& router, std::string const& suffix,
+                    modify_type const& f)
 {
     JLOG(j_.trace) <<
         "accept ledger " << ledger->seq() << " " << suffix;
@@ -112,6 +112,9 @@ OpenLedger::accept(Application& app, Rules const& rules,
     for (auto const& item : locals)
         ripple::apply(app, *next,
             *item.second, flags, j_);
+    // Call the modifier
+    if (f)
+        f(*next, j_);
     // Switch to the new open view
     std::lock_guard<
         std::mutex> lock2(current_mutex_);

src/ripple/app/tests/Offer.test.cpp

@@ -56,7 +56,7 @@ public:
 
             // ledger close times have a dynamic resolution depending on network
             // conditions it appears the resolution in test is 10 seconds
-            env.close (tp);
+            env.close (tp, {});
 
             NetClock::time_point const pct (
                 std::chrono::seconds (env.open ()->info ().parentCloseTime));

src/ripple/test/jtx/Env.h

@@ -195,7 +195,8 @@ public:
             The Env clock is set to the new time.
     */
     void
-    close (NetClock::time_point const& closeTime);
+    close (NetClock::time_point const& closeTime,
+        OpenLedger::modify_type const& f = {});
 
     /** Close and advance the ledger.
 
@@ -205,10 +206,11 @@ public:
     template <class Rep, class Period>
     void
     close (std::chrono::duration<
-        Rep, Period> const& elapsed)
+        Rep, Period> const& elapsed,
+        OpenLedger::modify_type const& f = {})
     {
         stopwatch_.advance(elapsed);
-        close (clock.now() + elapsed);
+        close (clock.now() + elapsed, f);
     }
 
     /** Close and advance the ledger.
@@ -217,9 +219,9 @@ public:
         the previous ledger closing time.
     */
     void
-    close()
+    close(OpenLedger::modify_type const& f = {})
     {
-        close (std::chrono::seconds(5));
+        close (std::chrono::seconds(5), f);
     }
 
     /** Turn on JSON tracing.

src/ripple/test/jtx/impl/Env.cpp

@@ -104,7 +104,8 @@ Env::closed() const
 }
 
 void
-Env::close(NetClock::time_point const& closeTime)
+Env::close(NetClock::time_point const& closeTime,
+    OpenLedger::modify_type const& f)
 {
     clock.set(closeTime);
     // VFALCO TODO Fix the Ledger constructor
@@ -134,7 +135,7 @@ Env::close(NetClock::time_point const& closeTime)
         ledgerPossibleTimeResolutions[0], false, app().config());
     OrderedTxs locals({});
     openLedger.accept(app(), next->rules(), next,
-        locals, false, retries, applyFlags(), *router);
+        locals, false, retries, applyFlags(), *router, "", f);
     closed_ = next;
     cachedSLEs_.expire();
 }