MOVEONLY: Move BaseIndex to its own file.

src/Makefile.am

@@ -107,6 +107,7 @@ BITCOIN_CORE_H = \
   fs.h \
   httprpc.h \
   httpserver.h \
+  index/base.h \
   index/txindex.h \
   indirectmap.h \
   init.h \
@@ -208,6 +209,7 @@ libbitcoin_server_a_SOURCES = \
   consensus/tx_verify.cpp \
   httprpc.cpp \
   httpserver.cpp \
+  index/base.cpp \
   index/txindex.cpp \
   init.cpp \
   dbwrapper.cpp \

src/index/base.cpp

@@ -0,0 +1,258 @@
+// Copyright (c) 2017-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <chainparams.h>
+#include <index/base.h>
+#include <init.h>
+#include <tinyformat.h>
+#include <ui_interface.h>
+#include <util.h>
+#include <validation.h>
+#include <warnings.h>
+
+constexpr int64_t SYNC_LOG_INTERVAL = 30; // seconds
+constexpr int64_t SYNC_LOCATOR_WRITE_INTERVAL = 30; // seconds
+
+template<typename... Args>
+static void FatalError(const char* fmt, const Args&... args)
+{
+    std::string strMessage = tfm::format(fmt, args...);
+    SetMiscWarning(strMessage);
+    LogPrintf("*** %s\n", strMessage);
+    uiInterface.ThreadSafeMessageBox(
+        "Error: A fatal internal error occurred, see debug.log for details",
+        "", CClientUIInterface::MSG_ERROR);
+    StartShutdown();
+}
+
+BaseIndex::~BaseIndex()
+{
+    Interrupt();
+    Stop();
+}
+
+bool BaseIndex::Init()
+{
+    CBlockLocator locator;
+    if (!GetDB().ReadBestBlock(locator)) {
+        locator.SetNull();
+    }
+
+    LOCK(cs_main);
+    m_best_block_index = FindForkInGlobalIndex(chainActive, locator);
+    m_synced = m_best_block_index.load() == chainActive.Tip();
+    return true;
+}
+
+static const CBlockIndex* NextSyncBlock(const CBlockIndex* pindex_prev)
+{
+    AssertLockHeld(cs_main);
+
+    if (!pindex_prev) {
+        return chainActive.Genesis();
+    }
+
+    const CBlockIndex* pindex = chainActive.Next(pindex_prev);
+    if (pindex) {
+        return pindex;
+    }
+
+    return chainActive.Next(chainActive.FindFork(pindex_prev));
+}
+
+void BaseIndex::ThreadSync()
+{
+    const CBlockIndex* pindex = m_best_block_index.load();
+    if (!m_synced) {
+        auto& consensus_params = Params().GetConsensus();
+
+        int64_t last_log_time = 0;
+        int64_t last_locator_write_time = 0;
+        while (true) {
+            if (m_interrupt) {
+                WriteBestBlock(pindex);
+                return;
+            }
+
+            {
+                LOCK(cs_main);
+                const CBlockIndex* pindex_next = NextSyncBlock(pindex);
+                if (!pindex_next) {
+                    WriteBestBlock(pindex);
+                    m_best_block_index = pindex;
+                    m_synced = true;
+                    break;
+                }
+                pindex = pindex_next;
+            }
+
+            int64_t current_time = GetTime();
+            if (last_log_time + SYNC_LOG_INTERVAL < current_time) {
+                LogPrintf("Syncing %s with block chain from height %d\n",
+                          GetName(), pindex->nHeight);
+                last_log_time = current_time;
+            }
+
+            if (last_locator_write_time + SYNC_LOCATOR_WRITE_INTERVAL < current_time) {
+                WriteBestBlock(pindex);
+                last_locator_write_time = current_time;
+            }
+
+            CBlock block;
+            if (!ReadBlockFromDisk(block, pindex, consensus_params)) {
+                FatalError("%s: Failed to read block %s from disk",
+                           __func__, pindex->GetBlockHash().ToString());
+                return;
+            }
+            if (!WriteBlock(block, pindex)) {
+                FatalError("%s: Failed to write block %s to index database",
+                           __func__, pindex->GetBlockHash().ToString());
+                return;
+            }
+        }
+    }
+
+    if (pindex) {
+        LogPrintf("%s is enabled at height %d\n", GetName(), pindex->nHeight);
+    } else {
+        LogPrintf("%s is enabled\n", GetName());
+    }
+}
+
+bool BaseIndex::WriteBestBlock(const CBlockIndex* block_index)
+{
+    LOCK(cs_main);
+    if (!GetDB().WriteBestBlock(chainActive.GetLocator(block_index))) {
+        return error("%s: Failed to write locator to disk", __func__);
+    }
+    return true;
+}
+
+void BaseIndex::BlockConnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex,
+                               const std::vector<CTransactionRef>& txn_conflicted)
+{
+    if (!m_synced) {
+        return;
+    }
+
+    const CBlockIndex* best_block_index = m_best_block_index.load();
+    if (!best_block_index) {
+        if (pindex->nHeight != 0) {
+            FatalError("%s: First block connected is not the genesis block (height=%d)",
+                       __func__, pindex->nHeight);
+            return;
+        }
+    } else {
+        // Ensure block connects to an ancestor of the current best block. This should be the case
+        // most of the time, but may not be immediately after the sync thread catches up and sets
+        // m_synced. Consider the case where there is a reorg and the blocks on the stale branch are
+        // in the ValidationInterface queue backlog even after the sync thread has caught up to the
+        // new chain tip. In this unlikely event, log a warning and let the queue clear.
+        if (best_block_index->GetAncestor(pindex->nHeight - 1) != pindex->pprev) {
+            LogPrintf("%s: WARNING: Block %s does not connect to an ancestor of " /* Continued */
+                      "known best chain (tip=%s); not updating index\n",
+                      __func__, pindex->GetBlockHash().ToString(),
+                      best_block_index->GetBlockHash().ToString());
+            return;
+        }
+    }
+
+    if (WriteBlock(*block, pindex)) {
+        m_best_block_index = pindex;
+    } else {
+        FatalError("%s: Failed to write block %s to index",
+                   __func__, pindex->GetBlockHash().ToString());
+        return;
+    }
+}
+
+void BaseIndex::ChainStateFlushed(const CBlockLocator& locator)
+{
+    if (!m_synced) {
+        return;
+    }
+
+    const uint256& locator_tip_hash = locator.vHave.front();
+    const CBlockIndex* locator_tip_index;
+    {
+        LOCK(cs_main);
+        locator_tip_index = LookupBlockIndex(locator_tip_hash);
+    }
+
+    if (!locator_tip_index) {
+        FatalError("%s: First block (hash=%s) in locator was not found",
+                   __func__, locator_tip_hash.ToString());
+        return;
+    }
+
+    // This checks that ChainStateFlushed callbacks are received after BlockConnected. The check may fail
+    // immediately after the sync thread catches up and sets m_synced. Consider the case where
+    // there is a reorg and the blocks on the stale branch are in the ValidationInterface queue
+    // backlog even after the sync thread has caught up to the new chain tip. In this unlikely
+    // event, log a warning and let the queue clear.
+    const CBlockIndex* best_block_index = m_best_block_index.load();
+    if (best_block_index->GetAncestor(locator_tip_index->nHeight) != locator_tip_index) {
+        LogPrintf("%s: WARNING: Locator contains block (hash=%s) not on known best " /* Continued */
+                  "chain (tip=%s); not writing index locator\n",
+                  __func__, locator_tip_hash.ToString(),
+                  best_block_index->GetBlockHash().ToString());
+        return;
+    }
+
+    if (!GetDB().WriteBestBlock(locator)) {
+        error("%s: Failed to write locator to disk", __func__);
+    }
+}
+
+bool BaseIndex::BlockUntilSyncedToCurrentChain()
+{
+    AssertLockNotHeld(cs_main);
+
+    if (!m_synced) {
+        return false;
+    }
+
+    {
+        // Skip the queue-draining stuff if we know we're caught up with
+        // chainActive.Tip().
+        LOCK(cs_main);
+        const CBlockIndex* chain_tip = chainActive.Tip();
+        const CBlockIndex* best_block_index = m_best_block_index.load();
+        if (best_block_index->GetAncestor(chain_tip->nHeight) == chain_tip) {
+            return true;
+        }
+    }
+
+    LogPrintf("%s: %s is catching up on block notifications\n", __func__, GetName());
+    SyncWithValidationInterfaceQueue();
+    return true;
+}
+
+void BaseIndex::Interrupt()
+{
+    m_interrupt();
+}
+
+void BaseIndex::Start()
+{
+    // Need to register this ValidationInterface before running Init(), so that
+    // callbacks are not missed if Init sets m_synced to true.
+    RegisterValidationInterface(this);
+    if (!Init()) {
+        FatalError("%s: %s failed to initialize", __func__, GetName());
+        return;
+    }
+
+    m_thread_sync = std::thread(&TraceThread<std::function<void()>>, GetName(),
+                                std::bind(&BaseIndex::ThreadSync, this));
+}
+
+void BaseIndex::Stop()
+{
+    UnregisterValidationInterface(this);
+
+    if (m_thread_sync.joinable()) {
+        m_thread_sync.join();
+    }
+}

src/index/base.h

@@ -0,0 +1,84 @@
+// Copyright (c) 2017-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_INDEX_BASE_H
+#define BITCOIN_INDEX_BASE_H
+
+#include <primitives/block.h>
+#include <primitives/transaction.h>
+#include <threadinterrupt.h>
+#include <txdb.h>
+#include <uint256.h>
+#include <validationinterface.h>
+
+class CBlockIndex;
+
+/**
+ * Base class for indices of blockchain data. This implements
+ * CValidationInterface and ensures blocks are indexed sequentially according
+ * to their position in the active chain.
+ */
+class BaseIndex : public CValidationInterface
+{
+private:
+    /// Whether the index is in sync with the main chain. The flag is flipped
+    /// from false to true once, after which point this starts processing
+    /// ValidationInterface notifications to stay in sync.
+    std::atomic<bool> m_synced{false};
+
+    /// The last block in the chain that the index is in sync with.
+    std::atomic<const CBlockIndex*> m_best_block_index{nullptr};
+
+    std::thread m_thread_sync;
+    CThreadInterrupt m_interrupt;
+
+    /// Sync the index with the block index starting from the current best block.
+    /// Intended to be run in its own thread, m_thread_sync, and can be
+    /// interrupted with m_interrupt. Once the index gets in sync, the m_synced
+    /// flag is set and the BlockConnected ValidationInterface callback takes
+    /// over and the sync thread exits.
+    void ThreadSync();
+
+    /// Write the current chain block locator to the DB.
+    bool WriteBestBlock(const CBlockIndex* block_index);
+
+protected:
+    void BlockConnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex,
+                        const std::vector<CTransactionRef>& txn_conflicted) override;
+
+    void ChainStateFlushed(const CBlockLocator& locator) override;
+
+    /// Initialize internal state from the database and block index.
+    virtual bool Init();
+
+    /// Write update index entries for a newly connected block.
+    virtual bool WriteBlock(const CBlock& block, const CBlockIndex* pindex) { return true; }
+
+    virtual BaseIndexDB& GetDB() const = 0;
+
+    /// Get the name of the index for display in logs.
+    virtual const char* GetName() const = 0;
+
+public:
+    /// Destructor interrupts sync thread if running and blocks until it exits.
+    virtual ~BaseIndex();
+
+    /// Blocks the current thread until the index is caught up to the current
+    /// state of the block chain. This only blocks if the index has gotten in
+    /// sync once and only needs to process blocks in the ValidationInterface
+    /// queue. If the index is catching up from far behind, this method does
+    /// not block and immediately returns false.
+    bool BlockUntilSyncedToCurrentChain();
+
+    void Interrupt();
+
+    /// Start initializes the sync state and registers the instance as a
+    /// ValidationInterface so that it stays in sync with blockchain updates.
+    void Start();
+
+    /// Stops the instance from staying in sync with blockchain updates.
+    void Stop();
+};
+
+#endif // BITCOIN_INDEX_BASE_H

src/index/txindex.cpp

@@ -2,40 +2,14 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <chainparams.h>
 #include <index/txindex.h>
-#include <init.h>
-#include <tinyformat.h>
-#include <ui_interface.h>
 #include <util.h>
 #include <validation.h>
-#include <warnings.h>
-
-constexpr int64_t SYNC_LOG_INTERVAL = 30; // seconds
-constexpr int64_t SYNC_LOCATOR_WRITE_INTERVAL = 30; // seconds
 
 std::unique_ptr<TxIndex> g_txindex;
 
-template<typename... Args>
-static void FatalError(const char* fmt, const Args&... args)
-{
-    std::string strMessage = tfm::format(fmt, args...);
-    SetMiscWarning(strMessage);
-    LogPrintf("*** %s\n", strMessage);
-    uiInterface.ThreadSafeMessageBox(
-        "Error: A fatal internal error occurred, see debug.log for details",
-        "", CClientUIInterface::MSG_ERROR);
-    StartShutdown();
-}
-
 TxIndex::TxIndex(std::unique_ptr<TxIndexDB> db) : m_db(std::move(db)) {}
 
-BaseIndex::~BaseIndex()
-{
-    Interrupt();
-    Stop();
-}
-
 bool TxIndex::Init()
 {
     LOCK(cs_main);
@@ -50,94 +24,6 @@ bool TxIndex::Init()
     return BaseIndex::Init();
 }
 
-bool BaseIndex::Init()
-{
-    CBlockLocator locator;
-    if (!GetDB().ReadBestBlock(locator)) {
-        locator.SetNull();
-    }
-
-    LOCK(cs_main);
-    m_best_block_index = FindForkInGlobalIndex(chainActive, locator);
-    m_synced = m_best_block_index.load() == chainActive.Tip();
-    return true;
-}
-
-static const CBlockIndex* NextSyncBlock(const CBlockIndex* pindex_prev)
-{
-    AssertLockHeld(cs_main);
-
-    if (!pindex_prev) {
-        return chainActive.Genesis();
-    }
-
-    const CBlockIndex* pindex = chainActive.Next(pindex_prev);
-    if (pindex) {
-        return pindex;
-    }
-
-    return chainActive.Next(chainActive.FindFork(pindex_prev));
-}
-
-void BaseIndex::ThreadSync()
-{
-    const CBlockIndex* pindex = m_best_block_index.load();
-    if (!m_synced) {
-        auto& consensus_params = Params().GetConsensus();
-
-        int64_t last_log_time = 0;
-        int64_t last_locator_write_time = 0;
-        while (true) {
-            if (m_interrupt) {
-                WriteBestBlock(pindex);
-                return;
-            }
-
-            {
-                LOCK(cs_main);
-                const CBlockIndex* pindex_next = NextSyncBlock(pindex);
-                if (!pindex_next) {
-                    WriteBestBlock(pindex);
-                    m_best_block_index = pindex;
-                    m_synced = true;
-                    break;
-                }
-                pindex = pindex_next;
-            }
-
-            int64_t current_time = GetTime();
-            if (last_log_time + SYNC_LOG_INTERVAL < current_time) {
-                LogPrintf("Syncing %s with block chain from height %d\n",
-                          GetName(), pindex->nHeight);
-                last_log_time = current_time;
-            }
-
-            if (last_locator_write_time + SYNC_LOCATOR_WRITE_INTERVAL < current_time) {
-                WriteBestBlock(pindex);
-                last_locator_write_time = current_time;
-            }
-
-            CBlock block;
-            if (!ReadBlockFromDisk(block, pindex, consensus_params)) {
-                FatalError("%s: Failed to read block %s from disk",
-                           __func__, pindex->GetBlockHash().ToString());
-                return;
-            }
-            if (!WriteBlock(block, pindex)) {
-                FatalError("%s: Failed to write block %s to index database",
-                           __func__, pindex->GetBlockHash().ToString());
-                return;
-            }
-        }
-    }
-
-    if (pindex) {
-        LogPrintf("%s is enabled at height %d\n", GetName(), pindex->nHeight);
-    } else {
-        LogPrintf("%s is enabled\n", GetName());
-    }
-}
-
 bool TxIndex::WriteBlock(const CBlock& block, const CBlockIndex* pindex)
 {
     CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
@@ -152,115 +38,6 @@ bool TxIndex::WriteBlock(const CBlock& block, const CBlockIndex* pindex)
 
 BaseIndexDB& TxIndex::GetDB() const { return *m_db; }
 
-bool BaseIndex::WriteBestBlock(const CBlockIndex* block_index)
-{
-    LOCK(cs_main);
-    if (!GetDB().WriteBestBlock(chainActive.GetLocator(block_index))) {
-        return error("%s: Failed to write locator to disk", __func__);
-    }
-    return true;
-}
-
-void BaseIndex::BlockConnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex,
-                               const std::vector<CTransactionRef>& txn_conflicted)
-{
-    if (!m_synced) {
-        return;
-    }
-
-    const CBlockIndex* best_block_index = m_best_block_index.load();
-    if (!best_block_index) {
-        if (pindex->nHeight != 0) {
-            FatalError("%s: First block connected is not the genesis block (height=%d)",
-                       __func__, pindex->nHeight);
-            return;
-        }
-    } else {
-        // Ensure block connects to an ancestor of the current best block. This should be the case
-        // most of the time, but may not be immediately after the sync thread catches up and sets
-        // m_synced. Consider the case where there is a reorg and the blocks on the stale branch are
-        // in the ValidationInterface queue backlog even after the sync thread has caught up to the
-        // new chain tip. In this unlikely event, log a warning and let the queue clear.
-        if (best_block_index->GetAncestor(pindex->nHeight - 1) != pindex->pprev) {
-            LogPrintf("%s: WARNING: Block %s does not connect to an ancestor of " /* Continued */
-                      "known best chain (tip=%s); not updating index\n",
-                      __func__, pindex->GetBlockHash().ToString(),
-                      best_block_index->GetBlockHash().ToString());
-            return;
-        }
-    }
-
-    if (WriteBlock(*block, pindex)) {
-        m_best_block_index = pindex;
-    } else {
-        FatalError("%s: Failed to write block %s to index",
-                   __func__, pindex->GetBlockHash().ToString());
-        return;
-    }
-}
-
-void BaseIndex::ChainStateFlushed(const CBlockLocator& locator)
-{
-    if (!m_synced) {
-        return;
-    }
-
-    const uint256& locator_tip_hash = locator.vHave.front();
-    const CBlockIndex* locator_tip_index;
-    {
-        LOCK(cs_main);
-        locator_tip_index = LookupBlockIndex(locator_tip_hash);
-    }
-
-    if (!locator_tip_index) {
-        FatalError("%s: First block (hash=%s) in locator was not found",
-                   __func__, locator_tip_hash.ToString());
-        return;
-    }
-
-    // This checks that ChainStateFlushed callbacks are received after BlockConnected. The check may fail
-    // immediately after the sync thread catches up and sets m_synced. Consider the case where
-    // there is a reorg and the blocks on the stale branch are in the ValidationInterface queue
-    // backlog even after the sync thread has caught up to the new chain tip. In this unlikely
-    // event, log a warning and let the queue clear.
-    const CBlockIndex* best_block_index = m_best_block_index.load();
-    if (best_block_index->GetAncestor(locator_tip_index->nHeight) != locator_tip_index) {
-        LogPrintf("%s: WARNING: Locator contains block (hash=%s) not on known best " /* Continued */
-                  "chain (tip=%s); not writing index locator\n",
-                  __func__, locator_tip_hash.ToString(),
-                  best_block_index->GetBlockHash().ToString());
-        return;
-    }
-
-    if (!GetDB().WriteBestBlock(locator)) {
-        error("%s: Failed to write locator to disk", __func__);
-    }
-}
-
-bool BaseIndex::BlockUntilSyncedToCurrentChain()
-{
-    AssertLockNotHeld(cs_main);
-
-    if (!m_synced) {
-        return false;
-    }
-
-    {
-        // Skip the queue-draining stuff if we know we're caught up with
-        // chainActive.Tip().
-        LOCK(cs_main);
-        const CBlockIndex* chain_tip = chainActive.Tip();
-        const CBlockIndex* best_block_index = m_best_block_index.load();
-        if (best_block_index->GetAncestor(chain_tip->nHeight) == chain_tip) {
-            return true;
-        }
-    }
-
-    LogPrintf("%s: %s is catching up on block notifications\n", __func__, GetName());
-    SyncWithValidationInterfaceQueue();
-    return true;
-}
-
 bool TxIndex::FindTx(const uint256& tx_hash, uint256& block_hash, CTransactionRef& tx) const
 {
     CDiskTxPos postx;
@@ -288,31 +65,3 @@ bool TxIndex::FindTx(const uint256& tx_hash, uint256& block_hash, CTransactionRe
     block_hash = header.GetHash();
     return true;
 }
-
-void BaseIndex::Interrupt()
-{
-    m_interrupt();
-}
-
-void BaseIndex::Start()
-{
-    // Need to register this ValidationInterface before running Init(), so that
-    // callbacks are not missed if Init sets m_synced to true.
-    RegisterValidationInterface(this);
-    if (!Init()) {
-        FatalError("%s: %s failed to initialize", __func__, GetName());
-        return;
-    }
-
-    m_thread_sync = std::thread(&TraceThread<std::function<void()>>, GetName(),
-                                std::bind(&BaseIndex::ThreadSync, this));
-}
-
-void BaseIndex::Stop()
-{
-    UnregisterValidationInterface(this);
-
-    if (m_thread_sync.joinable()) {
-        m_thread_sync.join();
-    }
-}

src/index/txindex.h

@@ -5,81 +5,7 @@
 #ifndef BITCOIN_INDEX_TXINDEX_H
 #define BITCOIN_INDEX_TXINDEX_H
 
-#include <primitives/block.h>
+#include <index/base.h>
-#include <primitives/transaction.h>
-#include <threadinterrupt.h>
-#include <txdb.h>
-#include <uint256.h>
-#include <validationinterface.h>
-
-class CBlockIndex;
-
-/**
- * Base class for indices of blockchain data. This implements
- * CValidationInterface and ensures blocks are indexed sequentially according
- * to their position in the active chain.
- */
-class BaseIndex : public CValidationInterface
-{
-private:
-    /// Whether the index is in sync with the main chain. The flag is flipped
-    /// from false to true once, after which point this starts processing
-    /// ValidationInterface notifications to stay in sync.
-    std::atomic<bool> m_synced{false};
-
-    /// The last block in the chain that the index is in sync with.
-    std::atomic<const CBlockIndex*> m_best_block_index{nullptr};
-
-    std::thread m_thread_sync;
-    CThreadInterrupt m_interrupt;
-
-    /// Sync the index with the block index starting from the current best block.
-    /// Intended to be run in its own thread, m_thread_sync, and can be
-    /// interrupted with m_interrupt. Once the index gets in sync, the m_synced
-    /// flag is set and the BlockConnected ValidationInterface callback takes
-    /// over and the sync thread exits.
-    void ThreadSync();
-
-    /// Write the current chain block locator to the DB.
-    bool WriteBestBlock(const CBlockIndex* block_index);
-
-protected:
-    void BlockConnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex,
-                        const std::vector<CTransactionRef>& txn_conflicted) override;
-
-    void ChainStateFlushed(const CBlockLocator& locator) override;
-
-    /// Initialize internal state from the database and block index.
-    virtual bool Init();
-
-    /// Write update index entries for a newly connected block.
-    virtual bool WriteBlock(const CBlock& block, const CBlockIndex* pindex) { return true; }
-
-    virtual BaseIndexDB& GetDB() const = 0;
-
-    /// Get the name of the index for display in logs.
-    virtual const char* GetName() const = 0;
-
-public:
-    /// Destructor interrupts sync thread if running and blocks until it exits.
-    virtual ~BaseIndex();
-
-    /// Blocks the current thread until the index is caught up to the current
-    /// state of the block chain. This only blocks if the index has gotten in
-    /// sync once and only needs to process blocks in the ValidationInterface
-    /// queue. If the index is catching up from far behind, this method does
-    /// not block and immediately returns false.
-    bool BlockUntilSyncedToCurrentChain();
-
-    void Interrupt();
-
-    /// Start initializes the sync state and registers the instance as a
-    /// ValidationInterface so that it stays in sync with blockchain updates.
-    void Start();
-
-    /// Stops the instance from staying in sync with blockchain updates.
-    void Stop();
-};
 
 /**
  * TxIndex is used to look up transactions included in the blockchain by hash.