Add/test get_position_tx().

Author: evoskuil

include/bitcoin/database/impl/query/archive_read.ipp

@@ -189,6 +189,17 @@ bool CLASS::get_tx_position(size_t& out, const tx_link& link) const NOEXCEPT
     return true;
 }
 
+TEMPLATE
+tx_link CLASS::get_position_tx(const header_link& link,
+    size_t position) const NOEXCEPT
+{
+    table::txs::get_at_position txs{ {}, position };
+    if (!store_.txs.at(to_txs(link), txs))
+        return {};
+
+    return txs.tx_fk;
+}
+
 // Sizes.
 // ----------------------------------------------------------------------------
 

include/bitcoin/database/query.hpp

@@ -344,8 +344,10 @@ class query
     inline hash_digest get_point_hash(const point_link& link) const NOEXCEPT;
 
     /// False position implies not confirmed (or fault).
-    bool get_tx_position(size_t& out, const tx_link& link) const NOEXCEPT;
     bool get_tx_height(size_t& out, const tx_link& link) const NOEXCEPT;
+    bool get_tx_position(size_t& out, const tx_link& link) const NOEXCEPT;
+    tx_link get_position_tx(const header_link& link,
+        size_t position) const NOEXCEPT;
 
     /// Sizes.
     bool get_tx_size(size_t& out, const tx_link& link,

include/bitcoin/database/tables/archives/txs.hpp

@@ -288,6 +288,37 @@ struct txs
         size_t position{};
     };
 
+    struct get_at_position
+      : public schema::txs
+    {
+        inline link count() const NOEXCEPT
+        {
+            BC_ASSERT(false);
+            return {};
+        }
+
+        inline bool from_data(reader& source) NOEXCEPT
+        {
+            // tx sizes
+            source.skip_bytes(skip_sizes);
+
+            // tx fks
+            const auto number = source.read_little_endian<ct::integer, ct::size>();
+            if (position < number)
+            {
+                source.skip_bytes(position * tx::size);
+                tx_fk = source.read_little_endian<tx::integer, tx::size>();
+                return source;
+            }
+
+            source.invalidate();
+            return source;
+        }
+
+        const size_t position{};
+        tx::integer tx_fk{};
+    };
+
     struct get_coinbase
       : public schema::txs
     {

test/query/archive_read.cpp

@@ -428,6 +428,12 @@ BOOST_AUTO_TEST_CASE(query_archive_read__get_tx_position__confirmed__expected)
     BOOST_REQUIRE(query.get_tx_position(out, 4));
     BOOST_REQUIRE_EQUAL(out, 0u);
     BOOST_REQUIRE(!query.get_tx_position(out, 5));
+
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(0, 0), 0u);
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(1, 0), 1u);
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(2, 0), 2u);
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(2, 1), 3u);
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(3, 0), 4u);
 }
 
 BOOST_AUTO_TEST_CASE(query_archive_read__get_tx_position__always__expected)
@@ -474,6 +480,27 @@ BOOST_AUTO_TEST_CASE(query_archive_read__get_tx_position__always__expected)
     BOOST_REQUIRE(!query.get_tx_position(out, 5));
 }
 
+
+BOOST_AUTO_TEST_CASE(query_archive_read__get_position_tx__always__expected)
+{
+    settings settings{};
+    settings.path = TEST_DIRECTORY;
+    test::chunk_store store{ settings };
+    test::query_accessor query{ store };
+    BOOST_REQUIRE(!store.create(events_handler));
+    BOOST_REQUIRE(query.initialize(test::genesis));
+    BOOST_REQUIRE(query.set(test::block1a, context{ 0, 1, 0 }, false, false));
+    BOOST_REQUIRE(query.set(test::block2a, context{ 0, 2, 0 }, false, false));
+    BOOST_REQUIRE(query.set(test::block3a, context{ 0, 3, 0 }, false, false));
+
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(0, 0), 0u);
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(1, 0), 1u);
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(2, 0), 2u);
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(2, 1), 3u);
+    BOOST_REQUIRE_EQUAL(query.get_position_tx(3, 0), 4u);
+    BOOST_REQUIRE(query.get_position_tx(3, 1).is_terminal());
+}
+
 BOOST_AUTO_TEST_CASE(query_archive_read__get_tx_sizes__coinbase__204)
 {
     settings settings{};