Extend peer shard info

Builds/CMake/RippledCore.cmake

@@ -509,6 +509,7 @@ target_sources (rippled PRIVATE
   src/ripple/nodestore/impl/ManagerImp.cpp
   src/ripple/nodestore/impl/NodeObject.cpp
   src/ripple/nodestore/impl/Shard.cpp
+  "../../src/ripple/nodestore/impl/ShardInfo.cpp"
   src/ripple/nodestore/impl/TaskQueue.cpp
   #[===============================[
      main sources:

src/ripple/basics/RangeSet.h

@@ -98,18 +98,15 @@ template <class T>
 std::string
 to_string(RangeSet<T> const& rs)
 {
-    using ripple::to_string;
-
     if (rs.empty())
         return "empty";
-    std::string res = "";
+
+    std::string s;
     for (auto const& interval : rs)
-    {
-        if (!res.empty())
-            res += ",";
-        res += to_string(interval);
-    }
-    return res;
+        s += ripple::to_string(interval) + ",";
+    s.pop_back();
+
+    return s;
 }
 
 /** Convert the given styled string to a RangeSet.

src/ripple/nodestore/DatabaseShard.h

@@ -21,8 +21,8 @@
 #define RIPPLE_NODESTORE_DATABASESHARD_H_INCLUDED
 
 #include <ripple/app/ledger/Ledger.h>
-#include <ripple/basics/RangeSet.h>
 #include <ripple/nodestore/Database.h>
+#include <ripple/nodestore/ShardInfo.h>
 #include <ripple/nodestore/Types.h>
 
 #include <boost/optional.hpp>
@@ -61,7 +61,7 @@ class DatabaseShard : public Database
 
         @return `true` if the database initialized without error
     */
-    virtual bool
+    virtual [[nodiscard]] bool
     init() = 0;
 
     /** Prepare to store a new ledger in the shard being acquired
@@ -75,7 +75,7 @@ class DatabaseShard : public Database
                 between requests.
         @implNote adds a new writable shard if necessary
     */
-    virtual boost::optional<std::uint32_t>
+    virtual [[nodiscard]] boost::optional<std::uint32_t>
     prepareLedger(std::uint32_t validLedgerSeq) = 0;
 
     /** Prepare one or more shard indexes to be imported into the database
@@ -118,7 +118,7 @@ class DatabaseShard : public Database
         @param seq The sequence of the ledger
         @return The ledger if found, nullptr otherwise
     */
-    virtual std::shared_ptr<Ledger>
+    virtual [[nodiscard]] std::shared_ptr<Ledger>
     fetchLedger(uint256 const& hash, std::uint32_t seq) = 0;
 
     /** Notifies the database that the given ledger has been
@@ -129,12 +129,12 @@ class DatabaseShard : public Database
     virtual void
     setStored(std::shared_ptr<Ledger const> const& ledger) = 0;
 
-    /** Query which complete shards are stored
+    /** Query information about shards held
 
-        @return the indexes of complete shards
+        @return Information about shards held by this node
     */
-    virtual std::string
-    getCompleteShards() = 0;
+    virtual [[nodiscard]] std::unique_ptr<ShardInfo>
+    getShardInfo() = 0;
 
     /** @return The maximum number of ledgers stored in a shard
      */
@@ -187,7 +187,7 @@ seqToShardIndex(
     return (ledgerSeq - 1) / ledgersPerShard;
 }
 
-extern std::unique_ptr<DatabaseShard>
+extern [[nodiscard]] std::unique_ptr<DatabaseShard>
 make_ShardStore(
     Application& app,
     Stoppable& parent,

src/ripple/nodestore/ShardInfo.h

@@ -0,0 +1,67 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2020 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.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_NODESTORE_SHARDINFO_H_INCLUDED
+#define RIPPLE_NODESTORE_SHARDINFO_H_INCLUDED
+
+#include <ripple/basics/RangeSet.h>
+#include <ripple/nodestore/Types.h>
+#include <ripple/nodestore/impl/Shard.h>
+#include <ripple/protocol/messages.h>
+
+namespace ripple {
+namespace NodeStore {
+
+/* Contains information on the status of shards for a node
+ */
+class ShardInfo
+{
+public:
+    struct Incomplete
+    {
+        Incomplete() = delete;
+        Incomplete(State state_, float progress_)
+            : state(state_), progress(progress_)
+        {
+        }
+
+        State const state;
+        float const progress;
+    };
+
+    [[nodiscard]] std::string
+    finalToString() const;
+
+    [[nodiscard]] std::string
+    incompleteToString() const;
+
+    [[nodiscard]] protocol::TMPeerShardInfoV2
+    makeMessage(Application& app) const;
+
+    // Complete and verified immutable shards
+    RangeSet<std::uint32_t> final;
+
+    // Incomplete shards being acquired or verified
+    std::map<std::uint32_t, Incomplete> incomplete;
+};
+
+}  // namespace NodeStore
+}  // namespace ripple
+
+#endif

src/ripple/nodestore/Types.h

@@ -53,6 +53,21 @@ enum Status {
 /** A batch of NodeObjects to write at once. */
 using Batch = std::vector<std::shared_ptr<NodeObject>>;
 
+/** Shard states. */
+enum class State {
+    acquire,     // Being acquired
+    complete,    // Backend contains all ledgers, requires finalizing
+    finalizing,  // Being finalized
+    final,       // Database verified, shard is immutable
+    queued       // Queued to be finalized
+};
+
+static constexpr State acquire = State::acquire;
+static constexpr State complete = State::complete;
+static constexpr State finalizing = State::finalizing;
+static constexpr State final = State::final;
+static constexpr State queued = State::queued;
+
 }  // namespace NodeStore
 }  // namespace ripple