Add store prune method.

include/bitcoin/database/error.hpp

@@ -91,6 +91,7 @@ enum error_t : uint8_t
     /// tables
     create_table,
     close_table,
+    prune_table,
     backup_table,
     restore_table,
     verify_table,

include/bitcoin/database/impl/store.ipp

@@ -19,6 +19,7 @@
 #ifndef LIBBITCOIN_DATABASE_STORE_IPP
 #define LIBBITCOIN_DATABASE_STORE_IPP
 
+#include <chrono>
 #include <unordered_map>
 #include <bitcoin/system.hpp>
 #include <bitcoin/database/boost.hpp>
@@ -49,6 +50,7 @@ const std::unordered_map<event_t, std::string> CLASS::events
 
     { event_t::wait_lock, "wait_lock" },
     { event_t::flush_body, "flush_body" },
+    { event_t::prune_table, "prune_table" },
     { event_t::backup_table, "backup_table" },
     { event_t::copy_header, "copy_header" },
     { event_t::archive_snapshot, "archive_snapshot" },
@@ -416,6 +418,61 @@ code CLASS::open(const event_handler& handler) NOEXCEPT
     return ec;
 }
 
+TEMPLATE
+code CLASS::prune(const event_handler& handler) NOEXCEPT
+{
+    while (!transactor_mutex_.try_lock_for(std::chrono::seconds(1)))
+    {
+        handler(event_t::wait_lock, table_t::store);
+    }
+
+    code ec{ error::success };
+    const auto prune = [&handler](code& ec, auto& storage, table_t table) NOEXCEPT
+    {
+        if (!ec)
+        {
+            handler(event_t::prune_table, table);
+            if (!storage.reset())
+                ec = error::prune_table;
+        }
+    };
+
+    const auto unload = [&handler](code& ec, auto& storage, table_t table) NOEXCEPT
+    {
+        if (!ec)
+        {
+            handler(event_t::unload_file, table);
+            ec = storage.unload();
+        }
+    };
+
+    const auto load = [&handler](code& ec, auto& storage, table_t table) NOEXCEPT
+    {
+        if (!ec)
+        {
+            handler(event_t::load_file, table);
+            ec = storage.load();
+        }
+    };
+
+    // Prevouts resettable if all candidates confirmed (fork is candidate top).
+    const query<CLASS> query_{ *this };
+    if (query_.get_fork() == query_.get_top_candidate())
+    {
+        // zeroize table head, set body logical size to zero.
+        prune(ec, prevout, table_t::prevout_table);
+
+        // unmap body, setting mapped size to logical size (zero).
+        unload(ec, prevout_body_, table_t::prevout_body);
+
+        // map body, making table usable again.
+        load(ec, prevout_body_, table_t::prevout_body);
+    }
+
+    transactor_mutex_.unlock();
+    return ec;
+}
+
 TEMPLATE
 code CLASS::snapshot(const event_handler& handler) NOEXCEPT
 {

include/bitcoin/database/primitives/arraymap.hpp

@@ -76,7 +76,7 @@ class arraymap
     /// Capacity of body in bytes.
     size_t capacity() const NOEXCEPT;
 
-    /// Increase count as neccesary to specified.
+    /// Increase count as necessary to specified.
     bool expand(const Link& count) NOEXCEPT;
 
     /// Errors.

include/bitcoin/database/primitives/hashmap.hpp

@@ -79,7 +79,7 @@ class hashmap
     /// Capacity of body in bytes.
     size_t capacity() const NOEXCEPT;
 
-    /// Increase count as neccesary to specified.
+    /// Increase count as necessary to specified.
     bool expand(const Link& count) NOEXCEPT;
 
     /// Diagnostic counters.

include/bitcoin/database/primitives/nomap.hpp

@@ -71,7 +71,7 @@ class nomap
     /// Reduce count as specified.
     bool truncate(const Link& count) NOEXCEPT;
 
-    /// Increase count as neccesary to specified.
+    /// Increase count as necessary to specified.
     bool expand(const Link& count) NOEXCEPT;
 
     /// Errors.

include/bitcoin/database/store.hpp

@@ -63,6 +63,9 @@ class store
     /// Open and load the set of tables, set locks.
     code open(const event_handler& handler) NOEXCEPT;
 
+    /// Prune prunable tables (from loaded, leaves loaded).
+    code prune(const event_handler& handler) NOEXCEPT;
+
     /// Snapshot the set of tables (from loaded, leaves loaded).
     code snapshot(const event_handler& handler) NOEXCEPT;
 

include/bitcoin/database/tables/event.hpp

@@ -36,6 +36,7 @@ enum class event_t
 
     wait_lock,
     flush_body,
+    prune_table,
     backup_table,
     copy_header,
     archive_snapshot,

src/error.cpp

@@ -83,6 +83,7 @@ DEFINE_ERROR_T_MESSAGE_MAP(error)
     // tables
     { create_table, "failed to create table" },
     { close_table, "failed to close table" },
+    { prune_table, "failed to prune table" },
     { backup_table, "failed to backup table" },
     { restore_table, "failed to restore table" },
     { verify_table, "failed to verify table" },

test/error.cpp

@@ -329,6 +329,15 @@ BOOST_AUTO_TEST_CASE(error_t__code__close_table__true_exected_message)
     BOOST_REQUIRE_EQUAL(ec.message(), "failed to close table");
 }
 
+BOOST_AUTO_TEST_CASE(error_t__code__prune_table__true_exected_message)
+{
+    constexpr auto value = error::prune_table;
+    const auto ec = code(value);
+    BOOST_REQUIRE(ec);
+    BOOST_REQUIRE(ec == value);
+    BOOST_REQUIRE_EQUAL(ec.message(), "failed to prune table");
+}
+
 BOOST_AUTO_TEST_CASE(error_t__code__backup_table__true_exected_message)
 {
     constexpr auto value = error::backup_table;

test/query/archive_read.cpp

@@ -40,8 +40,7 @@ struct query_archive_read_setup_fixture
 
 BOOST_FIXTURE_TEST_SUITE(query_archive_read_tests, query_archive_read_setup_fixture)
 
-const auto events_handler = [](auto, auto) {};
-
+////const auto events_handler = [](auto, auto) {};
 
 BOOST_AUTO_TEST_CASE(query_archive_read_test)
 {

test/query/consensus.cpp

@@ -40,8 +40,7 @@ struct query_consensus_setup_fixture
 
 BOOST_FIXTURE_TEST_SUITE(query_consensus_tests, query_consensus_setup_fixture)
 
-const auto events_handler = [](auto, auto) {};
-
+////const auto events_handler = [](auto, auto) {};
 
 BOOST_AUTO_TEST_CASE(query_consensus_test)
 {

test/query/height.cpp

@@ -40,8 +40,7 @@ struct query_height_setup_fixture
 
 BOOST_FIXTURE_TEST_SUITE(query_height_tests, query_height_setup_fixture)
 
-const auto events_handler = [](auto, auto) {};
-
+////const auto events_handler = [](auto, auto) {};
 
 BOOST_AUTO_TEST_CASE(query_height_test)
 {

test/query/network.cpp

@@ -40,8 +40,7 @@ struct query_network_setup_fixture
 
 BOOST_FIXTURE_TEST_SUITE(query_network_tests, query_network_setup_fixture)
 
-const auto events_handler = [](auto, auto) {};
-
+////const auto events_handler = [](auto, auto) {};
 
 BOOST_AUTO_TEST_CASE(query_network_test)
 {

test/query/objects.cpp

@@ -40,8 +40,7 @@ struct query_objects_setup_fixture
 
 BOOST_FIXTURE_TEST_SUITE(query_objects_tests, query_objects_setup_fixture)
 
-const auto events_handler = [](auto, auto) {};
-
+////const auto events_handler = [](auto, auto) {};
 
 BOOST_AUTO_TEST_CASE(query_objects_test)
 {

test/store.cpp

@@ -17,6 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "test.hpp"
+#include "mocks/blocks.hpp"
 #include "mocks/map_store.hpp"
 
  // these are the slow tests (mmap)
@@ -274,6 +275,22 @@ BOOST_AUTO_TEST_CASE(store__open__created__success)
     BOOST_REQUIRE(!instance.close(events));
 }
 
+// prune
+// ----------------------------------------------------------------------------
+// Empty store asserts so create and initialize.
+
+BOOST_AUTO_TEST_CASE(store__prune__initialized__success)
+{
+    settings configuration{};
+    configuration.path = TEST_DIRECTORY;
+    store<map> instance{ configuration };
+    query<store<map>> query_{ instance };
+    BOOST_REQUIRE(!instance.create(events));
+    BOOST_REQUIRE(query_.initialize(test::genesis));
+    BOOST_REQUIRE(!instance.prune(events));
+    BOOST_REQUIRE(!instance.close(events));
+}
+
 // snapshot
 // ----------------------------------------------------------------------------
 

test/tables/caches/prevout.cpp

@@ -25,7 +25,6 @@ BOOST_AUTO_TEST_SUITE(prevout_tests)
 using namespace system;
 using namespace system::chain;
 using tx = schema::transaction::link;
-constexpr auto terminal = schema::transaction::link::terminal;
 const std::vector<tx::integer> conflicts1{ 0x01020304 };
 const std::vector<tx::integer> conflicts2{ 0xbaadf00d, 0x01020304 };
 

test/tables/caches/validated_bk.cpp

@@ -64,11 +64,8 @@ BOOST_AUTO_TEST_CASE(validated_bk__put__two__expected)
     table::validated_bk instance{ head_store, body_store, 8 };
     BOOST_REQUIRE(instance.create());
 
-    table::validated_bk::link link1{};
     BOOST_REQUIRE(instance.put(0, slab1));
     BOOST_REQUIRE_EQUAL(instance.at(0), 0u);
-
-    table::validated_bk::link link2{};
     BOOST_REQUIRE(instance.put(1, slab2));
     BOOST_REQUIRE_EQUAL(instance.at(1), 10u);