net: Serve blocks directly from disk when possible

In `ProcessGetBlockData`, send the block data directly from disk if
type MSG_WITNESS_BLOCK is requested. This is a valid shortcut as the
on-disk format matches the network format.

This is expected to increase performance because a deserialization and
subsequent serialization roundtrip is avoided.
This commit is contained in:
Wladimir J. van der Laan
2018-05-02 14:10:27 +02:00
parent 598db389c3
commit 0bf431870e
3 changed files with 107 additions and 47 deletions

View File

@@ -1125,6 +1125,52 @@ bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex, const Consensus
return true;
}
bool ReadRawBlockFromDisk(std::vector<uint8_t>& block, const CDiskBlockPos& pos, const CMessageHeader::MessageStartChars& message_start)
{
CDiskBlockPos hpos = pos;
hpos.nPos -= 8; // Seek back 8 bytes for meta header
CAutoFile filein(OpenBlockFile(hpos, true), SER_DISK, CLIENT_VERSION);
if (filein.IsNull()) {
return error("%s: OpenBlockFile failed for %s", __func__, pos.ToString());
}
try {
CMessageHeader::MessageStartChars blk_start;
unsigned int blk_size;
filein >> blk_start >> blk_size;
if (memcmp(blk_start, message_start, CMessageHeader::MESSAGE_START_SIZE)) {
return error("%s: Block magic mismatch for %s: %s versus expected %s", __func__, pos.ToString(),
HexStr(blk_start, blk_start + CMessageHeader::MESSAGE_START_SIZE),
HexStr(message_start, message_start + CMessageHeader::MESSAGE_START_SIZE));
}
if (blk_size > MAX_SIZE) {
return error("%s: Block data is larger than maximum deserialization size for %s: %s versus %s", __func__, pos.ToString(),
blk_size, MAX_SIZE);
}
block.resize(blk_size); // Zeroing of memory is intentional here
filein.read((char*)block.data(), blk_size);
} catch(const std::exception& e) {
return error("%s: Read from block file failed: %s for %s", __func__, e.what(), pos.ToString());
}
return true;
}
bool ReadRawBlockFromDisk(std::vector<uint8_t>& block, const CBlockIndex* pindex, const CMessageHeader::MessageStartChars& message_start)
{
CDiskBlockPos block_pos;
{
LOCK(cs_main);
block_pos = pindex->GetBlockPos();
}
return ReadRawBlockFromDisk(block, block_pos, message_start);
}
CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams)
{
int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;