wallet2_api: implement estimateTransactionFee

src/wallet/api/wallet.cpp

@@ -1671,6 +1671,26 @@ void WalletImpl::disposeTransaction(PendingTransaction *t)
     delete t;
 }
 
+uint64_t WalletImpl::estimateTransactionFee(const std::vector<std::pair<std::string, uint64_t>> &destinations,
+                                            PendingTransaction::Priority priority) const
+{
+    const size_t pubkey_size = 33;
+    const size_t encrypted_paymentid_size = 11;
+    const size_t extra_size = pubkey_size + encrypted_paymentid_size;
+
+    return m_wallet->estimate_fee(
+        m_wallet->use_fork_rules(HF_VERSION_PER_BYTE_FEE, 0),
+        m_wallet->use_fork_rules(4, 0),
+        1,
+        m_wallet->get_min_ring_size() - 1,
+        destinations.size() + 1,
+        extra_size,
+        m_wallet->use_fork_rules(8, 0),
+        m_wallet->get_base_fee(),
+        m_wallet->get_fee_multiplier(m_wallet->adjust_priority(static_cast<uint32_t>(priority))),
+        m_wallet->get_fee_quantization_mask());
+}
+
 TransactionHistory *WalletImpl::history()
 {
     return m_history.get();

src/wallet/api/wallet.h

@@ -166,6 +166,8 @@ public:
     bool importKeyImages(const std::string &filename) override;
 
     virtual void disposeTransaction(PendingTransaction * t) override;
+    virtual uint64_t estimateTransactionFee(const std::vector<std::pair<std::string, uint64_t>> &destinations,
+                                            PendingTransaction::Priority priority) const override;
     virtual TransactionHistory * history() override;
     virtual AddressBook * addressBook() override;
     virtual Subaddress * subaddress() override;

src/wallet/api/wallet2_api.h

@@ -879,6 +879,14 @@ struct Wallet
      */
     virtual void disposeTransaction(PendingTransaction * t) = 0;
 
+    /*!
+     * \brief Estimates transaction fee.
+     * \param destinations Vector consisting of <address, amount> pairs.
+     * \return Estimated fee.
+     */
+    virtual uint64_t estimateTransactionFee(const std::vector<std::pair<std::string, uint64_t>> &destinations,
+                                            PendingTransaction::Priority priority) const = 0;
+
    /*!
     * \brief exportKeyImages - exports key images to file
     * \param filename

src/wallet/wallet2.cpp

@@ -879,20 +879,6 @@ uint8_t get_bulletproof_fork()
   return 8;
 }
 
-uint64_t estimate_fee(bool use_per_byte_fee, bool use_rct, int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof, uint64_t base_fee, uint64_t fee_multiplier, uint64_t fee_quantization_mask)
-{
-  if (use_per_byte_fee)
-  {
-    const size_t estimated_tx_weight = estimate_tx_weight(use_rct, n_inputs, mixin, n_outputs, extra_size, bulletproof);
-    return calculate_fee_from_weight(base_fee, estimated_tx_weight, fee_multiplier, fee_quantization_mask);
-  }
-  else
-  {
-    const size_t estimated_tx_size = estimate_tx_size(use_rct, n_inputs, mixin, n_outputs, extra_size, bulletproof);
-    return calculate_fee(base_fee, estimated_tx_size, fee_multiplier);
-  }
-}
-
 uint64_t calculate_fee(bool use_per_byte_fee, const cryptonote::transaction &tx, size_t blob_size, uint64_t base_fee, uint64_t fee_multiplier, uint64_t fee_quantization_mask)
 {
   if (use_per_byte_fee)
@@ -7098,6 +7084,20 @@ bool wallet2::sign_multisig_tx_from_file(const std::string &filename, std::vecto
   return sign_multisig_tx_to_file(exported_txs, filename, txids);
 }
 //----------------------------------------------------------------------------------------------------
+uint64_t wallet2::estimate_fee(bool use_per_byte_fee, bool use_rct, int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof, uint64_t base_fee, uint64_t fee_multiplier, uint64_t fee_quantization_mask) const
+{
+  if (use_per_byte_fee)
+  {
+    const size_t estimated_tx_weight = estimate_tx_weight(use_rct, n_inputs, mixin, n_outputs, extra_size, bulletproof);
+    return calculate_fee_from_weight(base_fee, estimated_tx_weight, fee_multiplier, fee_quantization_mask);
+  }
+  else
+  {
+    const size_t estimated_tx_size = estimate_tx_size(use_rct, n_inputs, mixin, n_outputs, extra_size, bulletproof);
+    return calculate_fee(base_fee, estimated_tx_size, fee_multiplier);
+  }
+}
+
 uint64_t wallet2::get_fee_multiplier(uint32_t priority, int fee_algorithm)
 {
   static const struct

src/wallet/wallet2.h

@@ -1243,6 +1243,7 @@ private:
     std::vector<std::pair<uint64_t, uint64_t>> estimate_backlog(const std::vector<std::pair<double, double>> &fee_levels);
     std::vector<std::pair<uint64_t, uint64_t>> estimate_backlog(uint64_t min_tx_weight, uint64_t max_tx_weight, const std::vector<uint64_t> &fees);
 
+    uint64_t estimate_fee(bool use_per_byte_fee, bool use_rct, int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof, uint64_t base_fee, uint64_t fee_multiplier, uint64_t fee_quantization_mask) const;
     uint64_t get_fee_multiplier(uint32_t priority, int fee_algorithm = -1);
     uint64_t get_base_fee();
     uint64_t get_fee_quantization_mask();