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// Copyright (c) 2017-2019 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 <shutdown.h>
#include <tinyformat.h>
#include <ui_interface.h>
#include <util/system.h>
#include <validation.h>
#include <warnings.h>
constexpr char DB_BEST_BLOCK = 'B';
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::DB::DB(const fs::path& path, size_t n_cache_size, bool f_memory, bool f_wipe, bool f_obfuscate) :
CDBWrapper(path, n_cache_size, f_memory, f_wipe, f_obfuscate)
{}
bool BaseIndex::DB::ReadBestBlock(CBlockLocator& locator) const
{
bool success = Read(DB_BEST_BLOCK, locator);
if (!success) {
locator.SetNull();
}
return success;
}
void BaseIndex::DB::WriteBestBlock(CDBBatch& batch, const CBlockLocator& locator)
{
batch.Write(DB_BEST_BLOCK, locator);
}
BaseIndex::~BaseIndex()
{
Interrupt();
Stop();
}
bool BaseIndex::Init()
{
CBlockLocator locator;
if (!GetDB().ReadBestBlock(locator)) {
locator.SetNull();
}
LOCK(cs_main);
if (locator.IsNull()) {
m_best_block_index = nullptr;
} else {
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) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
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) {
m_best_block_index = pindex;
// No need to handle errors in Commit. If it fails, the error will be already be
// logged. The best way to recover is to continue, as index cannot be corrupted by
// a missed commit to disk for an advanced index state.
Commit();
return;
}
{
LOCK(cs_main);
const CBlockIndex* pindex_next = NextSyncBlock(pindex);
if (!pindex_next) {
m_best_block_index = pindex;
m_synced = true;
// No need to handle errors in Commit. See rationale above.
Commit();
break;
}
if (pindex_next->pprev != pindex && !Rewind(pindex, pindex_next->pprev)) {
FatalError("%s: Failed to rewind index %s to a previous chain tip",
__func__, GetName());
return;
}
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) {
m_best_block_index = pindex;
last_locator_write_time = current_time;
// No need to handle errors in Commit. See rationale above.
Commit();
}
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::Commit()
{
CDBBatch batch(GetDB());
if (!CommitInternal(batch) || !GetDB().WriteBatch(batch)) {
return error("%s: Failed to commit latest %s state", __func__, GetName());
}
return true;
}
bool BaseIndex::CommitInternal(CDBBatch& batch)
{
LOCK(cs_main);
GetDB().WriteBestBlock(batch, ::ChainActive().GetLocator(m_best_block_index));
return true;
}
bool BaseIndex::Rewind(const CBlockIndex* current_tip, const CBlockIndex* new_tip)
{
assert(current_tip == m_best_block_index);
assert(current_tip->GetAncestor(new_tip->nHeight) == new_tip);
// In the case of a reorg, ensure persisted block locator is not stale.
m_best_block_index = new_tip;
if (!Commit()) {
// If commit fails, revert the best block index to avoid corruption.
m_best_block_index = current_tip;
return false;
}
return true;
}
void BaseIndex::BlockConnected(const std::shared_ptr<const CBlock>& block, const CBlockIndex* pindex)
{
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 (best_block_index != pindex->pprev && !Rewind(best_block_index, pindex->pprev)) {
FatalError("%s: Failed to rewind index %s to a previous chain tip",
__func__, GetName());
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;
}
// No need to handle errors in Commit. If it fails, the error will be already be logged. The
// best way to recover is to continue, as index cannot be corrupted by a missed commit to disk
// for an advanced index state.
Commit();
}
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();
}
}
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