Merge pull request #4468

e11b2ce Fix large reorgs (Pieter Wuille)
afc32c5 Fix rebuild-chainstate feature and improve its performance (Pieter Wuille)
16d5194 Skip reindexed blocks individually (Pieter Wuille)
ad96e7c Make -reindex cope with out-of-order blocks (Wladimir J. van der Laan)
e17bd58 Rename setBlockIndexValid to setBlockIndexCandidates (Pieter Wuille)
1af838b Add height to "Requesting block" debug (R E Broadley)
1bcee67 Better logging of stalling (R E Broadley)
4c93322 Improve getheaders (sending) logging (R E Broadley)
f244c99 Remove CheckMinWork, as we always know all parent headers (Pieter Wuille)
ad6e601 RPC additions after headers-first (Pieter Wuille)
341735e Headers-first synchronization (Pieter Wuille)

1 files changed, 17 insertions, 9 deletions

diff --git a/src/main.h b/src/main.h
index cad7eebfb7..7939b087ec 100644
--- a/src/main.h
+++ b/src/main.h
@@ -72,9 +72,17 @@ static const int MAX_SCRIPTCHECK_THREADS = 16;
 /** -par default (number of script-checking threads, 0 = auto) */
 static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
 /** Number of blocks that can be requested at any given time from a single peer. */
-static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 128;
-/** Timeout in seconds before considering a block download peer unresponsive. */
-static const unsigned int BLOCK_DOWNLOAD_TIMEOUT = 60;
+static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 16;
+/** Timeout in seconds during which a peer must stall block download progress before being disconnected. */
+static const unsigned int BLOCK_STALLING_TIMEOUT = 2;
+/** Number of headers sent in one getheaders result. We rely on the assumption that if a peer sends
+ *  less than this number, we reached their tip. Changing this value is a protocol upgrade. */
+static const unsigned int MAX_HEADERS_RESULTS = 2000;
+/** Size of the "block download window": how far ahead of our current height do we fetch?
+ *  Larger windows tolerate larger download speed differences between peer, but increase the potential
+ *  degree of disordering of blocks on disk (which make reindexing and in the future perhaps pruning
+ *  harder). We'll probably want to make this a per-peer adaptive value at some point. */
+static const unsigned int BLOCK_DOWNLOAD_WINDOW = 1024;
 
 /** "reject" message codes **/
 static const unsigned char REJECT_MALFORMED = 0x01;
@@ -110,6 +118,9 @@ extern bool fIsBareMultisigStd;
 extern unsigned int nCoinCacheSize;
 extern CFeeRate minRelayTxFee;
 
+// Best header we've seen so far (used for getheaders queries' starting points).
+extern CBlockIndex *pindexBestHeader;
+
 // Minimum disk space required - used in CheckDiskSpace()
 static const uint64_t nMinDiskSpace = 52428800;
 
@@ -137,8 +148,6 @@ void RegisterNodeSignals(CNodeSignals& nodeSignals);
 /** Unregister a network node */
 void UnregisterNodeSignals(CNodeSignals& nodeSignals);
 
-void PushGetBlocks(CNode* pnode, CBlockIndex* pindexBegin, uint256 hashEnd);
-
 /** Process an incoming block */
 bool ProcessBlock(CValidationState &state, CNode* pfrom, CBlock* pblock, CDiskBlockPos *dbp = NULL);
 /** Check whether enough disk space is available for an incoming block */
@@ -193,6 +202,8 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
 struct CNodeStateStats {
     int nMisbehavior;
     int nSyncHeight;
+    int nCommonHeight;
+    std::vector<int> vHeightInFlight;
 };
 
 struct CDiskTxPos : public CDiskBlockPos
@@ -439,9 +450,6 @@ bool DisconnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex
 // Apply the effects of this block (with given index) on the UTXO set represented by coins
 bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins, bool fJustCheck = false);
 
-// Add this block to the block index, and if necessary, switch the active block chain to this
-bool AddToBlockIndex(CBlock& block, CValidationState& state, const CDiskBlockPos& pos);
-
 // Context-independent validity checks
 bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, bool fCheckPOW = true);
 bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW = true, bool fCheckMerkleRoot = true);
@@ -449,7 +457,7 @@ bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW = t
 // Store block on disk
 // if dbp is provided, the file is known to already reside on disk
 bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex **pindex, CDiskBlockPos* dbp = NULL);
-bool AcceptBlockHeader(CBlockHeader& block, CValidationState& state, CBlockIndex **ppindex= NULL);
+bool AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, CBlockIndex **ppindex= NULL);