Tx queue enhancements and RPC info (RIPD-1205, RIPD-1206):

* Account-related queue stats (RIPD-1205). Boolean "queue" parameter to
  account_info only if requesting the open ledger.
* Account for the TxQ when autofilling sequence in sign-and-submit (RIPD-1206)
* Tweak TxQ::accept edge case when choosing which tx to try next.
* Labels for experimental "x_" submit parameters use correct separator.

=== Release Notes ===
==== New features ====

When requesting `account_info` for the open ledger, include the `queue :
true` to get extra information about any queued transactions for this
account. (RIPD-1205).

==== Bug fixes ====

When using sign-and-submit mode to autofill a transaction's sequence
number, the logic will not reuse a sequence number that is in the queue
for this account. (RIPD-1206).

Labels for experimental "x_queue_okay" and "x_assume_tx" parameters to
`sign` and `submit` updated to use correct separator.

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

@@ -865,9 +865,8 @@ void LedgerConsensusImp::accept (std::shared_ptr<SHAMap> set)
                     });
             }
             // Update fee computations.
-            app_.getTxQ().processValidatedLedger(app_, accum,
+            app_.getTxQ().processClosedLedger(app_, accum,
                 roundTime_ > 5s);
-
             accum.apply(*buildLCL);
         }
 

src/ripple/app/misc/NetworkOPs.cpp

@@ -1409,7 +1409,7 @@ void NetworkOPsImp::switchLastClosedLedger (
 
     // Update fee computations.
     // TODO: Needs an open ledger
-    //app_.getTxQ().processValidatedLedger(app_, *newLCL, true);
+    //app_.getTxQ().processClosedLedger(app_, *newLCL, true);
 
     // Caller must own master lock
     {

src/ripple/app/misc/TxQ.h

@@ -90,6 +90,13 @@ public:
         std::uint64_t expFeeLevel;        // Estimated fee level to get in next ledger
     };
 
+    struct AccountTxDetails
+    {
+        uint64_t feeLevel;
+        boost::optional<LedgerIndex const> lastValid;
+        boost::optional<TxConsequences const> consequences;
+    };
+
     TxQ(Setup const& setup,
         beast::Journal j);
 
@@ -120,19 +127,33 @@ public:
     accept(Application& app, OpenView& view);
 
     /**
-        A new ledger has been validated. Update and clean up the
+        Update stats and clean up the queue in preparation for
-        queue.
+        the next ledger.
     */
     void
-    processValidatedLedger(Application& app,
+    processClosedLedger(Application& app,
         OpenView const& view, bool timeLeap);
 
     /** Returns fee metrics in reference fee level units.
+
+        @returns Uninitialized @ref optional if the FeeEscalation
+        amendment is not enabled.
     */
     boost::optional<Metrics>
     getMetrics(Config const& config, OpenView const& view,
         std::uint32_t txCountPadding = 0) const;
 
+    /** Returns information about the transactions currently
+        in the queue for the account.
+
+        @returns Uninitialized @ref optional if the FeeEscalation
+        amendment is not enabled, OR if the account has no transactions
+        in the queue.
+    */
+    boost::optional<std::map<TxSeq, AccountTxDetails>>
+    getAccountTxs(AccountID const& account, Config const& config,
+        ReadView const& view) const;
+
     /** Packages up fee metrics for the `fee` RPC command.
     */
     Json::Value
@@ -215,7 +236,6 @@ private:
         scaleFeeLevel(OpenView const& view, std::uint32_t txCountPadding = 0) const;
     };
 
-    // Alternate name: MaybeTx
     class MaybeTx
     {
     public:

src/ripple/app/misc/impl/TxQ.cpp

@@ -356,9 +356,11 @@ TxQ::eraseAndAdvance(TxQ::FeeMultiSet::const_iterator_type candidateIter)
             the latter case, continue through the fee queue anyway
             to head off potential ordering manipulation problems.
     */
+    auto feeNextIter = std::next(candidateIter);
     bool useAccountNext = accountNextIter != txQAccount.transactions.end() &&
         accountNextIter->first == candidateIter->sequence + 1 &&
-            accountNextIter->second.feeLevel > candidateIter->feeLevel;
+            (feeNextIter == byFee_.end() ||
+                accountNextIter->second.feeLevel > feeNextIter->feeLevel);
     auto candidateNextIter = byFee_.erase(candidateIter);
     txQAccount.transactions.erase(accountIter);
     return useAccountNext ?
@@ -917,7 +919,7 @@ TxQ::apply(Application& app, OpenView& view,
 
 */
 void
-TxQ::processValidatedLedger(Application& app,
+TxQ::processClosedLedger(Application& app,
     OpenView const& view, bool timeLeap)
 {
     auto const allowEscalation =
@@ -1145,6 +1147,38 @@ TxQ::getMetrics(Config const& config, OpenView const& view,
     return result;
 }
 
+auto
+TxQ::getAccountTxs(AccountID const& account, Config const& config,
+    ReadView const& view) const
+        -> boost::optional<std::map<TxSeq, AccountTxDetails>>
+{
+    auto const allowEscalation =
+        (view.rules().enabled(featureFeeEscalation,
+            config.features));
+    if (!allowEscalation)
+        return boost::none;
+
+    std::lock_guard<std::mutex> lock(mutex_);
+
+    auto accountIter = byAccount_.find(account);
+    if (accountIter == byAccount_.end() ||
+        accountIter->second.transactions.empty())
+        return boost::none;
+
+    std::map<TxSeq, AccountTxDetails> result;
+
+    for (auto const& tx : accountIter->second.transactions)
+    {
+        auto& resultTx = result[tx.first];
+        resultTx.feeLevel = tx.second.feeLevel;
+        if(tx.second.lastValid)
+            resultTx.lastValid.emplace(*tx.second.lastValid);
+        if(tx.second.consequences)
+            resultTx.consequences.emplace(*tx.second.consequences);
+    }
+    return result;
+}
+
 Json::Value
 TxQ::doRPC(Application& app) const
 {

src/ripple/app/tests/TxQ_test.cpp

@@ -403,6 +403,33 @@ public:
         env(noop(daria), fee(7000), queued);
         env(noop(edgar), fee(7000), queued);
         checkMetrics(env, 5, boost::none, 3, 2, 256);
+        {
+            auto& txQ = env.app().getTxQ();
+            auto aliceStat = txQ.getAccountTxs(alice.id(),
+                env.app().config(), *env.current());
+            if (BEAST_EXPECT(aliceStat))
+            {
+                BEAST_EXPECT(aliceStat->size() == 1);
+                BEAST_EXPECT(aliceStat->begin()->second.feeLevel == 256);
+                BEAST_EXPECT(aliceStat->begin()->second.lastValid &&
+                    *aliceStat->begin()->second.lastValid == 8);
+                BEAST_EXPECT(!aliceStat->begin()->second.consequences);
+            }
+
+            auto bobStat = txQ.getAccountTxs(bob.id(),
+                env.app().config(), *env.current());
+            if (BEAST_EXPECT(bobStat))
+            {
+                BEAST_EXPECT(bobStat->size() == 1);
+                BEAST_EXPECT(bobStat->begin()->second.feeLevel = 7000 * 256 / 10);
+                BEAST_EXPECT(!bobStat->begin()->second.lastValid);
+                BEAST_EXPECT(!bobStat->begin()->second.consequences);
+            }
+
+            auto noStat = txQ.getAccountTxs(Account::master.id(),
+                env.app().config(), *env.current());
+            BEAST_EXPECT(!noStat);
+        }
 
         env.close();
         checkMetrics(env, 1, 6, 4, 3, 256);
@@ -719,6 +746,30 @@ public:
             ++aliceSeq;
         }
         checkMetrics(env, 8, 8, 5, 4, 257);
+        {
+            auto& txQ = env.app().getTxQ();
+            auto aliceStat = txQ.getAccountTxs(alice.id(),
+                env.app().config(), *env.current());
+            std::int64_t fee = 10;
+            auto seq = env.seq(alice);
+            if (BEAST_EXPECT(aliceStat))
+            {
+                BEAST_EXPECT(aliceStat->size() == 7);
+                for (auto const& tx : *aliceStat)
+                {
+                    BEAST_EXPECT(tx.first == seq);
+                    BEAST_EXPECT(tx.second.feeLevel == mulDiv(fee, 256, 10).second);
+                    BEAST_EXPECT(tx.second.lastValid);
+                    BEAST_EXPECT((tx.second.consequences &&
+                        tx.second.consequences->fee == drops(fee) &&
+                        tx.second.consequences->potentialSpend == drops(0) &&
+                        tx.second.consequences->category == TxConsequences::normal) ||
+                        tx.first == env.seq(alice) + 6);
+                    ++seq;
+                    fee = (fee + 1) * 125 / 100;
+                }
+            }
+        }
 
         // Alice attempts to add another item to the queue,
         // but you can't force your own earlier txn off the
@@ -1557,11 +1608,47 @@ public:
                 !RPC::contains_error(fee[jss::result])))
             {
                 auto const& result = fee[jss::result];
-                BEAST_EXPECT(result.isMember(jss::drops));
-                BEAST_EXPECT(result.isMember(jss::levels));
                 BEAST_EXPECT(result.isMember(jss::current_ledger_size));
                 BEAST_EXPECT(result.isMember(jss::current_queue_size));
                 BEAST_EXPECT(result.isMember(jss::expected_ledger_size));
+                BEAST_EXPECT(!result.isMember(jss::max_queue_size));
+                BEAST_EXPECT(result.isMember(jss::drops));
+                auto const& drops = result[jss::drops];
+                BEAST_EXPECT(drops.isMember(jss::base_fee));
+                BEAST_EXPECT(drops.isMember(jss::median_fee));
+                BEAST_EXPECT(drops.isMember(jss::minimum_fee));
+                BEAST_EXPECT(drops.isMember(jss::open_ledger_fee));
+                BEAST_EXPECT(result.isMember(jss::levels));
+                auto const& levels = result[jss::levels];
+                BEAST_EXPECT(levels.isMember(jss::median_level));
+                BEAST_EXPECT(levels.isMember(jss::minimum_level));
+                BEAST_EXPECT(levels.isMember(jss::open_ledger_level));
+                BEAST_EXPECT(levels.isMember(jss::reference_level));
+            }
+
+            env.close();
+
+            fee = env.rpc("fee");
+
+            if (BEAST_EXPECT(fee.isMember(jss::result) &&
+                !RPC::contains_error(fee[jss::result])))
+            {
+                auto const& result = fee[jss::result];
+                BEAST_EXPECT(result.isMember(jss::current_ledger_size));
+                BEAST_EXPECT(result.isMember(jss::current_queue_size));
+                BEAST_EXPECT(result.isMember(jss::expected_ledger_size));
+                BEAST_EXPECT(result.isMember(jss::max_queue_size));
+                auto const& drops = result[jss::drops];
+                BEAST_EXPECT(drops.isMember(jss::base_fee));
+                BEAST_EXPECT(drops.isMember(jss::median_fee));
+                BEAST_EXPECT(drops.isMember(jss::minimum_fee));
+                BEAST_EXPECT(drops.isMember(jss::open_ledger_fee));
+                BEAST_EXPECT(result.isMember(jss::levels));
+                auto const& levels = result[jss::levels];
+                BEAST_EXPECT(levels.isMember(jss::median_level));
+                BEAST_EXPECT(levels.isMember(jss::minimum_level));
+                BEAST_EXPECT(levels.isMember(jss::open_ledger_level));
+                BEAST_EXPECT(levels.isMember(jss::reference_level));
             }
         }
 
@@ -1668,6 +1755,422 @@ public:
         BEAST_EXPECT(env.seq(alice) == aliceSeq + 4);
     }
 
+    void testSignAndSubmitSequence()
+    {
+        testcase("Autofilled sequence should account for TxQ");
+        using namespace jtx;
+        Env env(*this, makeConfig({ {"minimum_txn_in_ledger_standalone", "6"} }),
+            features(featureFeeEscalation));
+        Env_ss envs(env);
+        auto const& txQ = env.app().getTxQ();
+
+        auto const alice = Account("alice");
+        auto const bob = Account("bob");
+        env.fund(XRP(100000), alice, bob);
+
+        auto params = Json::Value(Json::objectValue);
+        // Max fee = 50k drops
+        params[jss::fee_mult_max] = 100;
+        params["x_queue_okay"] = true;
+
+        fillQueue(env, alice);
+        checkMetrics(env, 0, boost::none, 7, 6, 256);
+
+        // Queue up several transactions for alice sign-and-submit
+        auto const aliceSeq = env.seq(alice);
+        auto const lastLedgerSeq = env.current()->info().seq + 2;
+
+        for (int i = 0; i < 5; ++i)
+        {
+            if (i == 2)
+                envs(noop(alice), fee(none), seq(none),
+                    json(jss::LastLedgerSequence, lastLedgerSeq),
+                        ter(terQUEUED))(params);
+            else
+                envs(noop(alice), fee(none), seq(none),
+                    ter(terQUEUED))(params);
+        }
+        checkMetrics(env, 5, boost::none, 7, 6, 256);
+        {
+            auto aliceStat = txQ.getAccountTxs(alice.id(),
+                env.app().config(), *env.current());
+            if (BEAST_EXPECT(aliceStat))
+            {
+                auto seq = aliceSeq;
+                BEAST_EXPECT(aliceStat->size() == 5);
+                for (auto const& tx : *aliceStat)
+                {
+                    BEAST_EXPECT(tx.first == seq);
+                    BEAST_EXPECT(tx.second.feeLevel == 25600);
+                    if(seq == aliceSeq + 2)
+                    {
+                        BEAST_EXPECT(tx.second.lastValid &&
+                            *tx.second.lastValid == lastLedgerSeq);
+                    }
+                    else
+                    {
+                        BEAST_EXPECT(!tx.second.lastValid);
+                    }
+                    ++seq;
+                }
+            }
+        }
+        // Put some txs in the queue for bob.
+        // Give them a higher fee so they'll beat alice's.
+        for (int i = 0; i < 8; ++i)
+            envs(noop(bob), fee(2000), seq(none), ter(terQUEUED))();
+        checkMetrics(env, 13, boost::none, 7, 6, 256);
+
+        env.close();
+        checkMetrics(env, 5, 14, 8, 7, 256);
+        // Put some more txs in the queue for bob.
+        // Give them a higher fee so they'll beat alice's.
+        fillQueue(env, bob);
+        for(int i = 0; i < 9; ++i)
+            envs(noop(bob), fee(2000), seq(none), ter(terQUEUED))();
+        checkMetrics(env, 14, 14, 8, 7, 25601);
+        env.close();
+        // Put some more txs in the queue for bob.
+        // Give them a higher fee so they'll beat alice's.
+        fillQueue(env, bob);
+        for (int i = 0; i < 10; ++i)
+            envs(noop(bob), fee(2000), seq(none), ter(terQUEUED))();
+        checkMetrics(env, 15, 16, 9, 8, 256);
+        env.close();
+        checkMetrics(env, 4, 18, 10, 9, 256);
+        {
+            // Bob has nothing left in the queue.
+            auto bobStat = txQ.getAccountTxs(bob.id(),
+                env.app().config(), *env.current());
+            BEAST_EXPECT(!bobStat);
+        }
+        // Verify alice's tx got dropped as we BEAST_EXPECT, and that there's
+        // a gap in her queued txs.
+        {
+            auto aliceStat = txQ.getAccountTxs(alice.id(),
+                env.app().config(), *env.current());
+            if (BEAST_EXPECT(aliceStat))
+            {
+                auto seq = aliceSeq;
+                BEAST_EXPECT(aliceStat->size() == 4);
+                for (auto const& tx : *aliceStat)
+                {
+                    // Skip over the missing one.
+                    if (seq == aliceSeq + 2)
+                        ++seq;
+
+                    BEAST_EXPECT(tx.first == seq);
+                    BEAST_EXPECT(tx.second.feeLevel == 25600);
+                    BEAST_EXPECT(!tx.second.lastValid);
+                    ++seq;
+                }
+            }
+        }
+        // Now, fill the gap.
+        envs(noop(alice), fee(none), seq(none), ter(terQUEUED))(params);
+        checkMetrics(env, 5, 18, 10, 9, 256);
+        {
+            auto aliceStat = txQ.getAccountTxs(alice.id(),
+                env.app().config(), *env.current());
+            if (BEAST_EXPECT(aliceStat))
+            {
+                auto seq = aliceSeq;
+                BEAST_EXPECT(aliceStat->size() == 5);
+                for (auto const& tx : *aliceStat)
+                {
+                    BEAST_EXPECT(tx.first == seq);
+                    BEAST_EXPECT(tx.second.feeLevel == 25600);
+                    BEAST_EXPECT(!tx.second.lastValid);
+                    ++seq;
+                }
+            }
+        }
+
+        env.close();
+        checkMetrics(env, 0, 20, 5, 10, 256);
+        {
+            // Bob's data has been cleaned up.
+            auto bobStat = txQ.getAccountTxs(bob.id(),
+                env.app().config(), *env.current());
+            BEAST_EXPECT(!bobStat);
+        }
+        {
+            auto aliceStat = txQ.getAccountTxs(alice.id(),
+                env.app().config(), *env.current());
+            BEAST_EXPECT(!aliceStat);
+        }
+    }
+
+    void testAccountInfo()
+    {
+        using namespace jtx;
+        Env env(*this, makeConfig({ { "minimum_txn_in_ledger_standalone", "3" } }),
+            features(featureFeeEscalation));
+        Env_ss envs(env);
+
+        Account const alice{ "alice" };
+        env.fund(XRP(1000000), alice);
+        env.close();
+
+        auto const withQueue =
+            R"({ "account": ")" + alice.human() +
+            R"(", "queue": true })";
+        auto const withoutQueue =
+            R"({ "account": ")" + alice.human() +
+            R"("})";
+        auto const prevLedgerWithQueue =
+            R"({ "account": ")" + alice.human() +
+            R"(", "queue": true, "ledger_index": 3 })";
+        BEAST_EXPECT(env.current()->info().seq > 3);
+
+        auto submitParams = Json::Value(Json::objectValue);
+        // Max fee = 100 drops
+        submitParams[jss::fee_mult_max] = 10;
+        submitParams["x_queue_okay"] = true;
+
+        {
+            // account_info without the "queue" argument.
+            auto const info = env.rpc("json", "account_info", withoutQueue);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
+            BEAST_EXPECT(!info[jss::result].isMember(jss::queue_data));
+        }
+        {
+            // account_info with the "queue" argument.
+            auto const info = env.rpc("json", "account_info", withQueue);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
+            auto const& result = info[jss::result];
+            BEAST_EXPECT(result.isMember(jss::queue_data));
+            auto const& queue_data = result[jss::queue_data];
+            BEAST_EXPECT(queue_data.isObject());
+            BEAST_EXPECT(queue_data.isMember(jss::txn_count));
+            BEAST_EXPECT(queue_data[jss::txn_count] == 0);
+            BEAST_EXPECT(!queue_data.isMember(jss::lowest_sequence));
+            BEAST_EXPECT(!queue_data.isMember(jss::highest_sequence));
+            BEAST_EXPECT(!queue_data.isMember(jss::auth_change_queued));
+            BEAST_EXPECT(!queue_data.isMember(jss::max_spend_drops_total));
+            BEAST_EXPECT(!queue_data.isMember(jss::transactions));
+        }
+        checkMetrics(env, 0, 6, 0, 3, 256);
+
+        fillQueue(env, alice);
+        checkMetrics(env, 0, 6, 4, 3, 256);
+
+        {
+            auto const info = env.rpc("json", "account_info", withQueue);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
+            auto const& result = info[jss::result];
+            BEAST_EXPECT(result.isMember(jss::queue_data));
+            auto const& queue_data = result[jss::queue_data];
+            BEAST_EXPECT(queue_data.isObject());
+            BEAST_EXPECT(queue_data.isMember(jss::txn_count));
+            BEAST_EXPECT(queue_data[jss::txn_count] == 0);
+            BEAST_EXPECT(!queue_data.isMember(jss::lowest_sequence));
+            BEAST_EXPECT(!queue_data.isMember(jss::highest_sequence));
+            BEAST_EXPECT(!queue_data.isMember(jss::auth_change_queued));
+            BEAST_EXPECT(!queue_data.isMember(jss::max_spend_drops_total));
+            BEAST_EXPECT(!queue_data.isMember(jss::transactions));
+        }
+
+        envs(noop(alice), fee(none), seq(none), ter(terQUEUED))(submitParams);
+        envs(noop(alice), fee(none), seq(none), ter(terQUEUED))(submitParams);
+        envs(noop(alice), fee(none), seq(none), ter(terQUEUED))(submitParams);
+        envs(noop(alice), fee(none), seq(none), ter(terQUEUED))(submitParams);
+        checkMetrics(env, 4, 6, 4, 3, 256);
+
+        {
+            auto const info = env.rpc("json", "account_info", withQueue);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
+            auto const& result = info[jss::result];
+            auto const& data = result[jss::account_data];
+            BEAST_EXPECT(result.isMember(jss::queue_data));
+            auto const& queue_data = result[jss::queue_data];
+            BEAST_EXPECT(queue_data.isObject());
+            BEAST_EXPECT(queue_data.isMember(jss::txn_count));
+            BEAST_EXPECT(queue_data[jss::txn_count] == 4);
+            BEAST_EXPECT(queue_data.isMember(jss::lowest_sequence));
+            BEAST_EXPECT(queue_data[jss::lowest_sequence] == data[jss::Sequence]);
+            BEAST_EXPECT(queue_data.isMember(jss::highest_sequence));
+            BEAST_EXPECT(queue_data[jss::highest_sequence] ==
+                data[jss::Sequence].asUInt() +
+                    queue_data[jss::txn_count].asUInt() - 1);
+            BEAST_EXPECT(!queue_data.isMember(jss::auth_change_queued));
+            BEAST_EXPECT(!queue_data.isMember(jss::max_spend_drops_total));
+            BEAST_EXPECT(queue_data.isMember(jss::transactions));
+            auto const& queued = queue_data[jss::transactions];
+            BEAST_EXPECT(queued.size() == queue_data[jss::txn_count]);
+            for (unsigned i = 0; i < queued.size(); ++i)
+            {
+                auto const& item = queued[i];
+                BEAST_EXPECT(item[jss::seq] == data[jss::Sequence].asInt() + i);
+                BEAST_EXPECT(item[jss::fee_level] == "2560");
+                BEAST_EXPECT(!item.isMember(jss::LastLedgerSequence));
+
+                if (i == queued.size() - 1)
+                {
+                    BEAST_EXPECT(!item.isMember(jss::fee));
+                    BEAST_EXPECT(!item.isMember(jss::max_spend_drops));
+                    BEAST_EXPECT(!item.isMember(jss::auth_change));
+                }
+                else
+                {
+                    BEAST_EXPECT(item.isMember(jss::fee));
+                    BEAST_EXPECT(item[jss::fee] == "100");
+                    BEAST_EXPECT(item.isMember(jss::max_spend_drops));
+                    BEAST_EXPECT(item[jss::max_spend_drops] == "100");
+                    BEAST_EXPECT(item.isMember(jss::auth_change));
+                    BEAST_EXPECT(!item[jss::auth_change].asBool());
+                }
+
+            }
+        }
+
+        // Queue up a blocker
+        envs(fset(alice, asfAccountTxnID), fee(none), seq(none),
+            json(jss::LastLedgerSequence, 10),
+                ter(terQUEUED))(submitParams);
+        checkMetrics(env, 5, 6, 4, 3, 256);
+
+        {
+            auto const info = env.rpc("json", "account_info", withQueue);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
+            auto const& result = info[jss::result];
+            auto const& data = result[jss::account_data];
+            BEAST_EXPECT(result.isMember(jss::queue_data));
+            auto const& queue_data = result[jss::queue_data];
+            BEAST_EXPECT(queue_data.isObject());
+            BEAST_EXPECT(queue_data.isMember(jss::txn_count));
+            BEAST_EXPECT(queue_data[jss::txn_count] == 5);
+            BEAST_EXPECT(queue_data.isMember(jss::lowest_sequence));
+            BEAST_EXPECT(queue_data[jss::lowest_sequence] == data[jss::Sequence]);
+            BEAST_EXPECT(queue_data.isMember(jss::highest_sequence));
+            BEAST_EXPECT(queue_data[jss::highest_sequence] ==
+                data[jss::Sequence].asUInt() +
+                    queue_data[jss::txn_count].asUInt() - 1);
+            BEAST_EXPECT(!queue_data.isMember(jss::auth_change_queued));
+            BEAST_EXPECT(!queue_data.isMember(jss::max_spend_drops_total));
+            BEAST_EXPECT(queue_data.isMember(jss::transactions));
+            auto const& queued = queue_data[jss::transactions];
+            BEAST_EXPECT(queued.size() == queue_data[jss::txn_count]);
+            for (unsigned i = 0; i < queued.size(); ++i)
+            {
+                auto const& item = queued[i];
+                BEAST_EXPECT(item[jss::seq] == data[jss::Sequence].asInt() + i);
+                BEAST_EXPECT(item[jss::fee_level] == "2560");
+
+                if (i == queued.size() - 1)
+                {
+                    BEAST_EXPECT(!item.isMember(jss::fee));
+                    BEAST_EXPECT(!item.isMember(jss::max_spend_drops));
+                    BEAST_EXPECT(!item.isMember(jss::auth_change));
+                    BEAST_EXPECT(item.isMember(jss::LastLedgerSequence));
+                    BEAST_EXPECT(item[jss::LastLedgerSequence] == 10);
+                }
+                else
+                {
+                    BEAST_EXPECT(item.isMember(jss::fee));
+                    BEAST_EXPECT(item[jss::fee] == "100");
+                    BEAST_EXPECT(item.isMember(jss::max_spend_drops));
+                    BEAST_EXPECT(item[jss::max_spend_drops] == "100");
+                    BEAST_EXPECT(item.isMember(jss::auth_change));
+                    BEAST_EXPECT(!item[jss::auth_change].asBool());
+                    BEAST_EXPECT(!item.isMember(jss::LastLedgerSequence));
+                }
+
+            }
+        }
+
+        envs(noop(alice), fee(none), seq(none), ter(telCAN_NOT_QUEUE))(submitParams);
+        checkMetrics(env, 5, 6, 4, 3, 256);
+
+        {
+            auto const info = env.rpc("json", "account_info", withQueue);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
+            auto const& result = info[jss::result];
+            auto const& data = result[jss::account_data];
+            BEAST_EXPECT(result.isMember(jss::queue_data));
+            auto const& queue_data = result[jss::queue_data];
+            BEAST_EXPECT(queue_data.isObject());
+            BEAST_EXPECT(queue_data.isMember(jss::txn_count));
+            BEAST_EXPECT(queue_data[jss::txn_count] == 5);
+            BEAST_EXPECT(queue_data.isMember(jss::lowest_sequence));
+            BEAST_EXPECT(queue_data[jss::lowest_sequence] == data[jss::Sequence]);
+            BEAST_EXPECT(queue_data.isMember(jss::highest_sequence));
+            BEAST_EXPECT(queue_data[jss::highest_sequence] ==
+                data[jss::Sequence].asUInt() +
+                    queue_data[jss::txn_count].asUInt() - 1);
+            BEAST_EXPECT(queue_data.isMember(jss::auth_change_queued));
+            BEAST_EXPECT(queue_data[jss::auth_change_queued].asBool());
+            BEAST_EXPECT(queue_data.isMember(jss::max_spend_drops_total));
+            BEAST_EXPECT(queue_data[jss::max_spend_drops_total] == "500");
+            BEAST_EXPECT(queue_data.isMember(jss::transactions));
+            auto const& queued = queue_data[jss::transactions];
+            BEAST_EXPECT(queued.size() == queue_data[jss::txn_count]);
+            for (unsigned i = 0; i < queued.size(); ++i)
+            {
+                auto const& item = queued[i];
+                BEAST_EXPECT(item[jss::seq] == data[jss::Sequence].asInt() + i);
+                BEAST_EXPECT(item[jss::fee_level] == "2560");
+
+                if (i == queued.size() - 1)
+                {
+                    BEAST_EXPECT(item.isMember(jss::fee));
+                    BEAST_EXPECT(item[jss::fee] == "100");
+                    BEAST_EXPECT(item.isMember(jss::max_spend_drops));
+                    BEAST_EXPECT(item[jss::max_spend_drops] == "100");
+                    BEAST_EXPECT(item.isMember(jss::auth_change));
+                    BEAST_EXPECT(item[jss::auth_change].asBool());
+                    BEAST_EXPECT(item.isMember(jss::LastLedgerSequence));
+                    BEAST_EXPECT(item[jss::LastLedgerSequence] == 10);
+                }
+                else
+                {
+                    BEAST_EXPECT(item.isMember(jss::fee));
+                    BEAST_EXPECT(item[jss::fee] == "100");
+                    BEAST_EXPECT(item.isMember(jss::max_spend_drops));
+                    BEAST_EXPECT(item[jss::max_spend_drops] == "100");
+                    BEAST_EXPECT(item.isMember(jss::auth_change));
+                    BEAST_EXPECT(!item[jss::auth_change].asBool());
+                    BEAST_EXPECT(!item.isMember(jss::LastLedgerSequence));
+                }
+
+            }
+        }
+
+        {
+            auto const info = env.rpc("json", "account_info", prevLedgerWithQueue);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                RPC::contains_error(info[jss::result]));
+        }
+
+        env.close();
+        checkMetrics(env, 1, 8, 5, 4, 256);
+        env.close();
+        checkMetrics(env, 0, 10, 1, 5, 256);
+
+        {
+            auto const info = env.rpc("json", "account_info", withQueue);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
+            auto const& result = info[jss::result];
+            BEAST_EXPECT(result.isMember(jss::queue_data));
+            auto const& queue_data = result[jss::queue_data];
+            BEAST_EXPECT(queue_data.isObject());
+            BEAST_EXPECT(queue_data.isMember(jss::txn_count));
+            BEAST_EXPECT(queue_data[jss::txn_count] == 0);
+            BEAST_EXPECT(!queue_data.isMember(jss::lowest_sequence));
+            BEAST_EXPECT(!queue_data.isMember(jss::highest_sequence));
+            BEAST_EXPECT(!queue_data.isMember(jss::auth_change_queued));
+            BEAST_EXPECT(!queue_data.isMember(jss::max_spend_drops_total));
+            BEAST_EXPECT(!queue_data.isMember(jss::transactions));
+        }
+    }
+
     void run()
     {
         testQueue();
@@ -1687,6 +2190,8 @@ public:
         testConsequences();
         testRPC();
         testExpirationReplacement();
+        testSignAndSubmitSequence();
+        testAccountInfo();
     }
 };
 

src/ripple/protocol/JsonFields.h

@@ -83,6 +83,8 @@ JSS ( amendments );                 // in: AccountObjects, out: NetworkOPs
 JSS ( asks );                       // out: Subscribe
 JSS ( assets );                     // out: GatewayBalances
 JSS ( authorized );                 // out: AccountLines
+JSS ( auth_change );                // out: AccountInfo
+JSS ( auth_change_queued );         // out: AccountInfo
 JSS ( balance );                    // out: AccountLines
 JSS ( balances );                   // out: GatewayBalances
 JSS ( base );                       // out: LogLevel
@@ -162,6 +164,7 @@ JSS ( features );                   // out: Feature
 JSS ( fee );                        // out: NetworkOPs, Peers
 JSS ( fee_base );                   // out: NetworkOPs
 JSS ( fee_div_max );                // in: TransactionSign
+JSS ( fee_level );                  // out: AccountInfo
 JSS ( fee_mult_max );               // in: TransactionSign
 JSS ( fee_ref );                    // out: NetworkOPs
 JSS ( fetch_pack );                 // out: NetworkOPs
@@ -184,6 +187,7 @@ JSS ( hashes );                     // in: AccountObjects
 JSS ( have_header );                // out: InboundLedger
 JSS ( have_state );                 // out: InboundLedger
 JSS ( have_transactions );          // out: InboundLedger
+JSS ( highest_sequence );           // out: AccountInfo
 JSS ( hostid );                     // out: NetworkOPs
 JSS ( hotwallet );                  // in: GatewayBalances
 JSS ( id );                         // websocket.
@@ -243,6 +247,7 @@ JSS ( load_factor_net );            // out: NetworkOPs
 JSS ( load_fee );                   // out: LoadFeeTrackImp, NetworkOPs
 JSS ( local );                      // out: resource/Logic.h
 JSS ( local_txs );                  // out: GetCounts
+JSS ( lowest_sequence );            // out: AccountInfo
 JSS ( majority );                   // out: RPC feature
 JSS ( marker );                     // in/out: AccountTx, AccountOffers,
                                     //         AccountLines, AccountObjects,
@@ -253,6 +258,8 @@ JSS ( master_seed );                // out: WalletPropose
 JSS ( master_seed_hex );            // out: WalletPropose
 JSS ( max_ledger );                 // in/out: LedgerCleaner
 JSS ( max_queue_size );             // out: TxQ
+JSS ( max_spend_drops );            // out: AccountInfo
+JSS ( max_spend_drops_total );      // out: AccountInfo
 JSS ( median_fee );                 // out: TxQ
 JSS ( median_level );               // out: TxQ
 JSS ( message );                    // error.
@@ -317,6 +324,8 @@ JSS ( published_ledger );           // out: NetworkOPs
 JSS ( quality );                    // out: NetworkOPs
 JSS ( quality_in );                 // out: AccountLines
 JSS ( quality_out );                // out: AccountLines
+JSS ( queue );                      // in: AccountInfo
+JSS ( queue_data );                 // out: AccountInfo
 JSS ( random );                     // out: Random
 JSS ( raw_meta );                   // out: AcceptedLedgerTx
 JSS ( receive_currencies );         // out: AccountCurrencies

src/ripple/rpc/handlers/AccountInfo.cpp

@@ -20,6 +20,7 @@
 #include <BeastConfig.h>
 
 #include <ripple/app/main/Application.h>
+#include <ripple/app/misc/TxQ.h>
 #include <ripple/json/json_value.h>
 #include <ripple/ledger/ReadView.h>
 #include <ripple/protocol/ErrorCodes.h>
@@ -39,6 +40,11 @@ namespace ripple {
 //   ledger_index : <ledger_index>
 //   signer_lists : <bool> // optional (default false)
 //                         //   if true return SignerList(s).
+//   queue : <bool>        // optional (default false)
+//                         //   if true return information about transactions
+//                         //   in the current TxQ, only if the requested
+//                         //   ledger is open. Otherwise if true, returns an
+//                         //   error.
 // }
 
 // TODO(tom): what is that "default"?
@@ -46,17 +52,20 @@ Json::Value doAccountInfo (RPC::Context& context)
 {
     auto& params = context.params;
 
+    std::string strIdent;
+    if (params.isMember(jss::account))
+        strIdent = params[jss::account].asString();
+    else if (params.isMember(jss::ident))
+        strIdent = params[jss::ident].asString();
+    else
+        return RPC::missing_field_error (jss::account);
+
     std::shared_ptr<ReadView const> ledger;
     auto result = RPC::lookupLedger (ledger, context);
 
     if (!ledger)
         return result;
 
-    if (!params.isMember (jss::account) && !params.isMember (jss::ident))
-        return RPC::missing_field_error (jss::account);
-
-    std::string strIdent = params.isMember (jss::account)
-            ? params[jss::account].asString () : params[jss::ident].asString ();
     bool bStrict = params.isMember (jss::strict) && params[jss::strict].asBool ();
     AccountID accountID;
 
@@ -70,6 +79,17 @@ Json::Value doAccountInfo (RPC::Context& context)
     auto const sleAccepted = ledger->read(keylet::account(accountID));
     if (sleAccepted)
     {
+        auto const queue = params.isMember(jss::queue) &&
+            params[jss::queue].asBool();
+
+        if (queue && !ledger->open())
+        {
+            // It doesn't make sense to request the queue
+            // with any closed or validated ledger.
+            RPC::inject_error(rpcINVALID_PARAMS, result);
+            return result;
+        }
+
         RPC::injectSLE(jvAccepted, *sleAccepted);
         result[jss::account_data] = jvAccepted;
 
@@ -79,14 +99,80 @@ Json::Value doAccountInfo (RPC::Context& context)
         {
             // We put the SignerList in an array because of an anticipated
             // future when we support multiple signer lists on one account.
-            auto& jvSignerList = result[jss::account_data][jss::signer_lists];
+            Json::Value jvSignerList = Json::arrayValue;
-            jvSignerList = Json::arrayValue;
 
             // This code will need to be revisited if in the future we support
             // multiple SignerLists on one account.
             auto const sleSigners = ledger->read (keylet::signers (accountID));
             if (sleSigners)
                 jvSignerList.append (sleSigners->getJson (0));
+
+            result[jss::account_data][jss::signer_lists] =
+                std::move(jvSignerList);
+        }
+        // Return queue info if that is requested
+        if (queue)
+        {
+            Json::Value jvQueueData = Json::objectValue;
+
+            auto const txs = context.app.getTxQ().getAccountTxs(
+                accountID, context.app.config(), *ledger);
+            if (txs && !txs->empty())
+            {
+                jvQueueData[jss::txn_count] = static_cast<Json::UInt>(txs->size());
+                jvQueueData[jss::lowest_sequence] = txs->begin()->first;
+                jvQueueData[jss::highest_sequence] = txs->rbegin()->first;
+
+                auto& jvQueueTx = jvQueueData[jss::transactions];
+                jvQueueTx = Json::arrayValue;
+
+                boost::optional<bool> anyAuthChanged(false);
+                boost::optional<XRPAmount> totalSpend(0);
+
+                for (auto const& tx : *txs)
+                {
+                    Json::Value jvTx = Json::objectValue;
+
+                    jvTx[jss::seq] = tx.first;
+                    jvTx[jss::fee_level] = to_string(tx.second.feeLevel);
+                    if (tx.second.lastValid)
+                        jvTx[jss::LastLedgerSequence] = *tx.second.lastValid;
+                    if (tx.second.consequences)
+                    {
+                        jvTx[jss::fee] = to_string(
+                            tx.second.consequences->fee);
+                        auto spend = tx.second.consequences->potentialSpend +
+                            tx.second.consequences->fee;
+                        jvTx[jss::max_spend_drops] = to_string(spend);
+                        if (totalSpend)
+                            *totalSpend += spend;
+                        auto authChanged = tx.second.consequences->category ==
+                            TxConsequences::blocker;
+                        if (authChanged)
+                            anyAuthChanged.emplace(authChanged);
+                        jvTx[jss::auth_change] = authChanged;
+                    }
+                    else
+                    {
+                        if (anyAuthChanged && !*anyAuthChanged)
+                            anyAuthChanged.reset();
+                        totalSpend.reset();
+                    }
+
+                    jvQueueTx.append(std::move(jvTx));
+                }
+
+                if (anyAuthChanged)
+                    jvQueueData[jss::auth_change_queued] =
+                        *anyAuthChanged;
+                if (totalSpend)
+                    jvQueueData[jss::max_spend_drops_total] =
+                        to_string(*totalSpend);
+            }
+            else
+                jvQueueData[jss::txn_count] = 0u;
+
+            result[jss::queue_data] = std::move(jvQueueData);
         }
     }
     else

src/ripple/rpc/impl/TransactionSign.cpp

@@ -428,7 +428,21 @@ transactionPreProcessImpl (
 
                 return rpcError (rpcSRC_ACT_NOT_FOUND);
             }
-            tx_json[jss::Sequence] = (*sle)[sfSequence];
+
+            auto seq = (*sle)[sfSequence];
+            auto const queued = app.getTxQ().getAccountTxs(srcAddressID,
+                app.config(), *ledger);
+            // If the account has any txs in the TxQ, skip those sequence
+            // numbers (accounting for possible gaps).
+            if(queued)
+                for(auto const& tx : *queued)
+                {
+                    if (tx.first == seq)
+                        ++seq;
+                    else if (tx.first > seq)
+                        break;
+                }
+            tx_json[jss::Sequence] = seq;
         }
 
         if (!tx_json.isMember (jss::Flags))
@@ -680,9 +694,9 @@ Json::Value checkFee (
             ledger->fees().base, ledger->fees().units, isUnlimited (role));
     std::uint64_t fee = loadFee;
     {
-        auto const assumeTx = request.isMember("x-assume-tx") &&
+        auto const assumeTx = request.isMember("x_assume_tx") &&
-            request["x-assume-tx"].isConvertibleTo(Json::uintValue) ?
+            request["x_assume_tx"].isConvertibleTo(Json::uintValue) ?
-                request["x-assume-tx"].asUInt() : 0;
+                request["x_assume_tx"].asUInt() : 0;
         auto const metrics = txQ.getMetrics(config, *ledger, assumeTx);
         if(metrics)
         {
@@ -702,9 +716,9 @@ Json::Value checkFee (
         mult, div);
 
     if (fee > limit && fee != loadFee &&
-        request.isMember("x-queue-okay") &&
+        request.isMember("x_queue_okay") &&
-            request["x-queue-okay"].isBool() &&
+            request["x_queue_okay"].isBool() &&
-                request["x-queue-okay"].asBool())
+                request["x_queue_okay"].asBool())
     {
         fee = std::max(loadFee, limit);
     }

src/ripple/rpc/tests/AccountInfo_test.cpp

@@ -74,12 +74,16 @@ public:
         {
             // account_info without the "signer_lists" argument.
             auto const info = env.rpc ("json", "account_info", withoutSigners);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
             BEAST_EXPECT(! info[jss::result][jss::account_data].
                 isMember (jss::signer_lists));
         }
         {
             // account_info with the "signer_lists" argument.
             auto const info = env.rpc ("json", "account_info", withSigners);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
             auto const& data = info[jss::result][jss::account_data];
             BEAST_EXPECT(data.isMember (jss::signer_lists));
             auto const& signerLists = data[jss::signer_lists];
@@ -95,12 +99,16 @@ public:
         {
             // account_info without the "signer_lists" argument.
             auto const info = env.rpc ("json", "account_info", withoutSigners);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
             BEAST_EXPECT(! info[jss::result][jss::account_data].
                 isMember (jss::signer_lists));
         }
         {
             // account_info with the "signer_lists" argument.
             auto const info = env.rpc ("json", "account_info", withSigners);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
             auto const& data = info[jss::result][jss::account_data];
             BEAST_EXPECT(data.isMember (jss::signer_lists));
             auto const& signerLists = data[jss::signer_lists];
@@ -131,6 +139,8 @@ public:
         {
             // account_info with the "signer_lists" argument.
             auto const info = env.rpc ("json", "account_info", withSigners);
+            BEAST_EXPECT(info.isMember(jss::result) &&
+                info[jss::result].isMember(jss::account_data));
             auto const& data = info[jss::result][jss::account_data];
             BEAST_EXPECT(data.isMember (jss::signer_lists));
             auto const& signerLists = data[jss::signer_lists];

src/ripple/rpc/tests/JSONRPC.test.cpp

@@ -1950,7 +1950,7 @@ public:
             Json::Value req;
             Json::Reader ().parse (R"({
                 "fee_mult_max" : 1000,
-                "x-queue-okay" : false,
+                "x_queue_okay" : false,
                 "tx_json" : { }
             })", req);
             Json::Value result =
@@ -1968,7 +1968,7 @@ public:
             Json::Value req;
             Json::Reader().parse(R"({
                 "fee_mult_max" : 1000,
-                "x-queue-okay" : true,
+                "x_queue_okay" : true,
                 "tx_json" : { }
             })", req);
             Json::Value result =
@@ -1986,7 +1986,7 @@ public:
             Json::Value req;
             Json::Reader().parse(R"({
                 "fee_mult_max" : 1000,
-                "x-assume-tx" : 4,
+                "x_assume_tx" : 4,
                 "tx_json" : { }
             })", req);
             Json::Value result =
@@ -2004,8 +2004,8 @@ public:
             Json::Value req;
             Json::Reader().parse(R"({
                 "fee_mult_max" : 1000,
-                "x-assume-tx" : 4,
+                "x_assume_tx" : 4,
-                "x-queue-okay" : true,
+                "x_queue_okay" : true,
                 "tx_json" : { }
             })", req);
             Json::Value result =
@@ -2041,7 +2041,7 @@ public:
             Json::Value req;
             Json::Reader().parse(R"({
                 "fee_mult_max" : 5,
-                "x-queue-okay" : true,
+                "x_queue_okay" : true,
                 "tx_json" : { }
             })", req);
             Json::Value result =
@@ -2059,8 +2059,8 @@ public:
             Json::Value req;
             Json::Reader().parse(R"({
                 "fee_mult_max" : 5,
-                "x-assume-tx" : 4,
+                "x_assume_tx" : 4,
-                "x-queue-okay" : false,
+                "x_queue_okay" : false,
                 "tx_json" : { }
             })", req);
             Json::Value result =
@@ -2077,8 +2077,8 @@ public:
             Json::Value req;
             Json::Reader().parse(R"({
                 "fee_mult_max" : 5,
-                "x-assume-tx" : 4,
+                "x_assume_tx" : 4,
-                "x-queue-okay" : true,
+                "x_queue_okay" : true,
                 "tx_json" : { }
             })", req);
             Json::Value result =
@@ -2097,8 +2097,8 @@ public:
             Json::Reader().parse(R"({
                 "fee_mult_max" : 1000,
                 "fee_div_max" : 3,
-                "x-assume-tx" : 4,
+                "x_assume_tx" : 4,
-                "x-queue-okay" : true,
+                "x_queue_okay" : true,
                 "tx_json" : { }
             })", req);
             Json::Value result =