Validators work (RIPD-703):

This replaces the experimental validators module with foundational
code to implement a new system for tracking validators, validations and
the UNL. The code is turned off by default, in BeastConfig.h

* Remove obsolete public Manager interfaces
* Remove obsolete database methods
* Remove obsolete ChosenList concept
* Remove obsolete code
* Add missing includes
* Tidy up STValidation.h
* Move factory function to Validators::make_Manager
* Add Connection object for tracking STValidations

src/ripple/validators/impl/Logic.cpp

@@ -0,0 +1,148 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012, 2013 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <ripple/validators/impl/ConnectionImp.h>
+#include <ripple/validators/impl/Logic.h>
+
+/*
+
+Questions the code should answer:
+
+Most important thing that we do:
+    Determine the new last fully validated ledger
+
+
+
+- Are we robustly connected to the Ripple network?
+
+- Given a new recent validation for a ledger with a sequence number higher
+  than the last fully validated ledger, do we have a new last fully validated
+  ledger?
+
+- What's the latest fully validated ledger?
+
+    Sequence number must always be known to set a fully validated ledger
+
+    Accumulate validations from nodes you trust at least a little bit,
+    and that aren't stale.
+
+    If you have a last fully validated ledger then validations for ledgers
+    with lower sequence numbers can be ignored.
+
+    Flow of validations recent in time for sequence numbers greater or equal than
+    the last fully validated ledger.
+
+- What ledger is the current consenus round built on?
+
+- Determine when the current consensus round is over?
+    Criteria: Number of validations for a ledger that comes after.
+
+*/
+
+namespace ripple {
+namespace Validators {
+    
+Logic::Logic (Store& store, beast::Journal journal)
+    : /*store_ (store)
+    , */journal_ (journal)
+    , ledgers_(get_seconds_clock())
+{
+}
+
+void
+Logic::stop()
+{
+}
+
+void
+Logic::load()
+{
+}
+
+void
+Logic::add (ConnectionImp& c)
+{
+    std::lock_guard<std::mutex> lock(mutex_);
+    connections_.insert(&c);
+}
+
+void
+Logic::remove (ConnectionImp& c)
+{
+    std::lock_guard<std::mutex> lock(mutex_);
+    connections_.erase(&c);
+}
+
+bool
+Logic::isStale (STValidation const& v)
+{
+    return false;
+}
+
+void
+Logic::onTimer()
+{
+    std::lock_guard<std::mutex> lock(mutex_);
+    beast::expire(ledgers_, std::chrono::minutes(5));
+}
+
+void
+Logic::onValidation (STValidation const& v)
+{
+    assert(v.isFieldPresent (sfLedgerSequence));
+    auto const seq_no =
+        v.getFieldU32 (sfLedgerSequence);
+    auto const key = v.getSignerPublic();
+    auto const ledger = v.getLedgerHash();
+
+    std::lock_guard<std::mutex> lock(mutex_);
+    if (journal_.trace) journal_.trace <<
+        "onValidation: " << ledger;
+    auto const result = ledgers_.emplace (std::piecewise_construct,
+        std::make_tuple(ledger), std::make_tuple());
+    auto& meta = result.first->second;
+    assert(result.second || seq_no == meta.seq_no);
+    if (result.second)
+        meta.seq_no = seq_no;
+    meta.keys.insert (v.getSignerPublic());
+    if (meta.seq_no > latest_.second.seq_no)
+    {
+        if (policy_.acceptLedgerMeta (*result.first))
+        {
+            //ledgers_.clear();
+            latest_ = *result.first;
+            if (journal_.info) journal_.info <<
+                "Accepted " << latest_.second.seq_no <<
+                    " (" << ledger << ")";
+            for (auto& _ : connections_)
+                _->onLedger(latest_.first);
+        }
+    }
+}
+
+void
+Logic::onLedgerClosed (LedgerIndex index,
+    LedgerHash const& hash, LedgerHash const& parent)
+{
+    if (journal_.info) journal_.info <<
+        "onLedgerClosed: " << index << " " << hash << " (parent " << parent << ")";
+}
+
+}
+}