From 0187d4c118ab4c0f5c2d4fb180c2a8dea8ac53cf Mon Sep 17 00:00:00 2001 From: John Newbery Date: Sun, 10 May 2020 22:28:21 -0400 Subject: [indexes] Add compact block filter headers cache Cache block filter headers at heights of multiples of 1000 in memory. Block filter headers at height 1000x are checkpointed, and will be the most frequently requested. Cache them in memory to avoid costly disk reads. --- src/index/blockfilterindex.cpp | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) (limited to 'src/index/blockfilterindex.cpp') diff --git a/src/index/blockfilterindex.cpp b/src/index/blockfilterindex.cpp index c3ce8d7af0..7dba115593 100644 --- a/src/index/blockfilterindex.cpp +++ b/src/index/blockfilterindex.cpp @@ -31,6 +31,12 @@ constexpr char DB_FILTER_POS = 'P'; constexpr unsigned int MAX_FLTR_FILE_SIZE = 0x1000000; // 16 MiB /** The pre-allocation chunk size for fltr?????.dat files */ constexpr unsigned int FLTR_FILE_CHUNK_SIZE = 0x100000; // 1 MiB +/** Maximum size of the cfheaders cache + * We have a limit to prevent a bug in filling this cache + * potentially turning into an OOM. At 2000 entries, this cache + * is big enough for a 2,000,000 length block chain, which + * we should be enough until ~2047. */ +constexpr size_t CF_HEADERS_CACHE_MAX_SZ{2000}; namespace { @@ -387,13 +393,32 @@ bool BlockFilterIndex::LookupFilter(const CBlockIndex* block_index, BlockFilter& return ReadFilterFromDisk(entry.pos, filter_out); } -bool BlockFilterIndex::LookupFilterHeader(const CBlockIndex* block_index, uint256& header_out) const +bool BlockFilterIndex::LookupFilterHeader(const CBlockIndex* block_index, uint256& header_out) { + LOCK(m_cs_headers_cache); + + bool is_checkpoint{block_index->nHeight % CFCHECKPT_INTERVAL == 0}; + + if (is_checkpoint) { + // Try to find the block in the headers cache if this is a checkpoint height. + auto header = m_headers_cache.find(block_index->GetBlockHash()); + if (header != m_headers_cache.end()) { + header_out = header->second; + return true; + } + } + DBVal entry; if (!LookupOne(*m_db, block_index, entry)) { return false; } + if (is_checkpoint && + m_headers_cache.size() < CF_HEADERS_CACHE_MAX_SZ) { + // Add to the headers cache if this is a checkpoint height. + m_headers_cache.emplace(block_index->GetBlockHash(), entry.header); + } + header_out = entry.header; return true; } -- cgit v1.2.3