Add relative locktime helpers.

Author: evoskuil

include/bitcoin/system/chain/input.hpp

@@ -43,6 +43,7 @@ class BC_API input
 
     typedef std::shared_ptr<const input> cptr;
 
+    static bool is_relative_locktime_applied(uint32_t sequence) NOEXCEPT;
     static bool is_locked(uint32_t sequence, size_t height,
         uint32_t median_time_past, size_t prevout_height,
         uint32_t prevout_median_time_past) NOEXCEPT;

include/bitcoin/system/chain/transaction.hpp

@@ -45,6 +45,10 @@ class BC_API transaction
     typedef std::shared_ptr<const transaction> cptr;
     typedef input_cptrs::const_iterator input_iterator;
 
+    // BIP68: if bit 31 is set then no consensus meaning is applied.
+    static bool is_relative_locktime_applied(bool coinbase, uint32_t version,
+        uint32_t sequence) NOEXCEPT;
+
     /// Not genesis and at least 100 blocks deep.
     static bool is_coinbase_mature(size_t coinbase_height,
         size_t height) NOEXCEPT;

src/chain/input.cpp

@@ -388,13 +388,19 @@ bool input::is_roller() const NOEXCEPT
     return script_->is_roller() || (prevout && prevout->script().is_roller());
 }
 
+// static
+bool input::is_relative_locktime_applied(uint32_t sequence) NOEXCEPT
+{
+    // BIP68: if bit 31 is set then no consensus meaning is applied.
+    return !get_right(sequence, relative_locktime_disabled_bit);
+}
+
 // static
 bool input::is_locked(uint32_t sequence, size_t height,
     uint32_t median_time_past, size_t prevout_height,
     uint32_t prevout_median_time_past) NOEXCEPT
 {
-    // BIP68: if bit 31 is set then no consensus meaning is applied.
-    if (get_right(sequence, relative_locktime_disabled_bit))
+    if (!is_relative_locktime_applied(sequence))
         return false;
 
     // BIP68: the low 16 bits of the sequence apply to relative lock-time.

src/chain/transaction.cpp

@@ -1115,6 +1115,7 @@ constexpr bool is_non_coinbase_mature(size_t tx_height, size_t height) NOEXCEPT
     return tx_height <= height;
 }
 
+// static
 //*****************************************************************************
 // CONSENSUS: Coinbase output matures at 100 blocks depth.
 // CONSENSUS: Genesis coinbase is forever immature (exception).
@@ -1141,6 +1142,17 @@ bool transaction::is_immature(size_t height) const NOEXCEPT
     return !std::all_of(inputs_->begin(), inputs_->end(), mature);
 }
 
+// static
+bool transaction::is_relative_locktime_applied(bool coinbase, uint32_t version,
+    uint32_t sequence) NOEXCEPT
+{
+    // BIP68: not applied to the sequence of the input of a coinbase.
+    // BIP68: if bit 31 is set then no consensus meaning is applied.
+    // BIP68: applied to txs with a version greater than or equal to two.
+    return !coinbase && input::is_relative_locktime_applied(sequence) &&
+        (version >= relative_locktime_min_version);
+}
+
 bool transaction::is_internal_lock(const input& in) const NOEXCEPT
 {
     // BIP68: not applied to the sequence of the input of a coinbase.