comment

src/validation.h

@@ -81,9 +81,17 @@ static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
 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. */
-// IBD: make it same as MAX_HEADERS_RESULTS to match buffersize
-static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 2000; // (was 16) // FIXME.SUGAR
+// FIXME.SUGAR
+// GetPoWHash_cached
+/** IBD: which sets MAX_BLOCKS_IN_TRANSIT_PER_PEER to be same as MAX_HEADERS_RESULTS.
+ *  Without this change, at least in Resistance the block headers download would get unnecessarily
+ *  far ahead of the full blocks download, resulting in more work lost and redone in case the
+ *  initial blocks download is interrupted and continued.
+ *  The work loss is because we do not yet store cached PoWs on disk. */
+static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 2000; // (was 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