txospenderindex: disable bloom filters to optimize disk usage

LevelDB bloom filters are only consulted on Get point reads.
They are not consulted for iterator seeks.
txospenderindex only reads via iterator seeks, so building
them is wasted effort and space.

src/dbwrapper.cpp

@@ -136,12 +136,12 @@ static void SetMaxOpenFiles(leveldb::Options *options) {
              options->max_open_files, default_open_files);
 }
 
-static leveldb::Options GetOptions(size_t nCacheSize)
+static leveldb::Options GetOptions(size_t nCacheSize, bool bloom_filter)
 {
     leveldb::Options options;
     options.block_cache = leveldb::NewLRUCache(nCacheSize / 2);
     options.write_buffer_size = nCacheSize / 4; // up to two write buffers may be held in memory simultaneously
-    options.filter_policy = leveldb::NewBloomFilterPolicy(10);
+    options.filter_policy = bloom_filter ? leveldb::NewBloomFilterPolicy(10) : nullptr;
     options.compression = leveldb::kNoCompression;
     options.info_log = new CBitcoinLevelDBLogger();
     if (leveldb::kMajorVersion > 1 || (leveldb::kMajorVersion == 1 && leveldb::kMinorVersion >= 16)) {
@@ -225,7 +225,7 @@ CDBWrapper::CDBWrapper(const DBParams& params)
     DBContext().iteroptions.verify_checksums = true;
     DBContext().iteroptions.fill_cache = false;
     DBContext().syncoptions.sync = true;
-    DBContext().options = GetOptions(params.cache_bytes);
+    DBContext().options = GetOptions(params.cache_bytes, params.bloom_filter);
     DBContext().options.create_if_missing = true;
     DBContext().options.max_file_size = params.max_file_size;
     assert(!(params.testing_env && params.memory_only));

src/dbwrapper.h

@@ -47,6 +47,8 @@ struct DBParams {
     //! If true, store data obfuscated via simple XOR. If false, XOR with a
     //! zero'd byte array.
     bool obfuscate = false;
+    //! If true, build a LevelDB bloom filter to accelerate point lookups.
+    bool bloom_filter = true;
     //! Passed-through options.
     DBOptions options{};
     //! If non-null, use this as the leveldb::Env instead of the default.

src/index/base.cpp

@@ -65,13 +65,14 @@ CBlockLocator GetLocator(interfaces::Chain& chain, const uint256& block_hash)
     return locator;
 }
 
-BaseIndex::DB::DB(const fs::path& path, size_t n_cache_size, bool f_memory, bool f_wipe, bool f_obfuscate) :
+BaseIndex::DB::DB(const fs::path& path, size_t n_cache_size, bool f_memory, bool f_wipe, bool f_obfuscate, bool f_bloom) :
     CDBWrapper{DBParams{
         .path = path,
         .cache_bytes = n_cache_size,
         .memory_only = f_memory,
         .wipe_data = f_wipe,
         .obfuscate = f_obfuscate,
+        .bloom_filter = f_bloom,
         .options = [] { DBOptions options; node::ReadDatabaseArgs(gArgs, options); return options; }()}}
 {}
 

src/index/base.h

@@ -65,7 +65,7 @@ protected:
     {
     public:
         DB(const fs::path& path, size_t n_cache_size,
-           bool f_memory = false, bool f_wipe = false, bool f_obfuscate = false);
+           bool f_memory = false, bool f_wipe = false, bool f_obfuscate = false, bool f_bloom = true);
 
         /// Read block locator of the chain that the index is in sync with.
         /// Note, the returned locator will be empty if no record exists.

src/index/txospenderindex.cpp

@@ -62,7 +62,7 @@ struct DBKey {
 };
 
 TxoSpenderIndex::TxoSpenderIndex(std::unique_ptr<interfaces::Chain> chain, size_t n_cache_size, bool f_memory, bool f_wipe)
-    : BaseIndex(std::move(chain), "txospenderindex", "txospenderidx"), m_db{std::make_unique<DB>(gArgs.GetDataDirNet() / "indexes" / "txospenderindex" / "db", n_cache_size, f_memory, f_wipe)}
+    : BaseIndex(std::move(chain), "txospenderindex", "txospenderidx"), m_db{std::make_unique<DB>(gArgs.GetDataDirNet() / "indexes" / "txospenderindex" / "db", n_cache_size, f_memory, f_wipe, /*f_obfuscate=*/false, /*f_bloom=*/false)}
 {
     if (!m_db->Read("siphash_key", m_siphash_key)) {
         FastRandomContext rng(false);

src/test/fuzz/dbwrapper.cpp

@@ -188,6 +188,7 @@ DBParams ConsumeDBParams(FuzzedDataProvider& provider, leveldb::Env* testing_env
         .path = "dbwrapper_fuzz",
         .cache_bytes = provider.ConsumeIntegralInRange<size_t>(64 << 10, 1_MiB),
         .obfuscate = obfuscate,
+        .bloom_filter = provider.ConsumeBool(),
         .options = options,
         .testing_env = testing_env,
         .max_file_size = provider.ConsumeBool()