Merge #14121: Index for BIP 157 block filters

c7efb652f3 blockfilter: Update BIP 158 test vectors. (Jim Posen)
19308c9e21 rpc: Add getblockfilter RPC method. (Jim Posen)
ff35105096 init: Add CLI option to enable block filter index. (Jim Posen)
accc8b8b18 index: Access functions for global block filter indexes. (Jim Posen)
2bc90e4e7b test: Unit test for block filter index reorg handling. (Jim Posen)
6bcf0998c0 test: Unit tests for block index filter. (Jim Posen)
b5e8200db7 index: Implement lookup methods on block filter index. (Jim Posen)
75a76e3619 index: Implement block filter index with write operations. (Jim Posen)
2ad2338ef9 serialize: Serialization support for big-endian 32-bit ints. (Jim Posen)
ba6ff9a6f7 blockfilter: Functions to translate filter types to/from names. (Jim Posen)
62b7a4f094 index: Ensure block locator is not stale after chain reorg. (Jim Posen)
4368384f1d index: Allow atomic commits of index state to be extended. (Jim Posen)

Pull request description:

  This introduces a new BlockFilterIndex class, which is required for BIP 157 support.

  The index is uses the asynchronous BaseIndex infrastructure driven by the ValidationInterface callbacks. Filters are stored sequentially in flat files and the disk location of each filter is indexed in LevelDB along with the filter hash and header. The index is designed to ensure persistence of filters reorganized out of the main chain to simplify the BIP 157 net implementation.

  Stats (block height = 565500):
  - Syncing the index from scratch takes 45m
  - Total index size is 3.8 GiB

ACKs for commit c7efb6:
  MarcoFalke:
    utACK c7efb652f3543b001b4dd22186a354605b14f47e
  ryanofsky:
    Slightly tested ACK c7efb652f3543b001b4dd22186a354605b14f47e (I just rebuilt the index with the updated PR and tested the RPC). Changes since last review: rebase, fixed compile errors in internal commits, new comments, updated error messages, tweaked cache size logic, renamed commit method, renamed constants and globals, fixed whitespace, extra BlockFilterIndex::Init error check.

Tree-SHA512: f8ed7a9b6f76df45933aa5eba92b27b3af83f6df2ccb3728a5c89eec80f654344dc14f055f6f63eb9b3a7649dd8af6553fe14969889e7e2fd2f8461574d18f28

1 files changed, 1 insertions, 0 deletions

diff --git a/src/validation.h b/src/validation.h
index 9f00cab49e..041d8860b0 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -116,6 +116,7 @@ static const int64_t MAX_FEE_ESTIMATION_TIP_AGE = 3 * 60 * 60;
 
 static const bool DEFAULT_CHECKPOINTS_ENABLED = true;
 static const bool DEFAULT_TXINDEX = false;
+static const char* const DEFAULT_BLOCKFILTERINDEX = "0";
 static const unsigned int DEFAULT_BANSCORE_THRESHOLD = 100;
 /** Default for -persistmempool */
 static const bool DEFAULT_PERSIST_MEMPOOL = true;