feat(wallet): improvements to UTXO selection

base_layer/wallet/src/output_manager_service/input_selection.rs

@@ -0,0 +1,126 @@
+//  Copyright 2022. The Tari Project
+//
+//  Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
+//  following conditions are met:
+//
+//  1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
+//  disclaimer.
+//
+//  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
+//  following disclaimer in the documentation and/or other materials provided with the distribution.
+//
+//  3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
+//  products derived from this software without specific prior written permission.
+//
+//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+//  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+//  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+//  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+//  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+//  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+//  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+use std::{
+    fmt,
+    fmt::{Display, Formatter},
+};
+
+use tari_common_types::types::PublicKey;
+
+use crate::output_manager_service::storage::models::DbUnblindedOutput;
+
+#[derive(Debug, Clone, Default)]
+pub struct UtxoSelectionCriteria {
+    pub filter: UtxoSelectionFilter,
+    pub ordering: UtxoSelectionOrdering,
+}
+
+impl UtxoSelectionCriteria {
+    pub fn largest_first() -> Self {
+        Self {
+            filter: UtxoSelectionFilter::Standard,
+            ordering: UtxoSelectionOrdering::LargestFirst,
+        }
+    }
+
+    pub fn for_token(unique_id: Vec<u8>, parent_public_key: Option<PublicKey>) -> Self {
+        Self {
+            filter: UtxoSelectionFilter::TokenOutput {
+                unique_id,
+                parent_public_key,
+            },
+            ordering: UtxoSelectionOrdering::Default,
+        }
+    }
+}
+
+impl Display for UtxoSelectionCriteria {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        write!(f, "filter: {}, ordering: {}", self.filter, self.ordering)
+    }
+}
+
+/// UTXO selection ordering
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum UtxoSelectionOrdering {
+    /// The Default ordering is heuristic and depends on the requested value and the value of the available UTXOs.
+    /// If the requested value is larger than the largest available UTXO, we select LargerFirst as inputs, otherwise
+    /// SmallestFirst.
+    Default,
+    /// Start from the smallest UTXOs and work your way up until the amount is covered. Main benefit
+    /// is removing small UTXOs from the blockchain, con is that it costs more in fees
+    SmallestFirst,
+    /// A strategy that selects the largest UTXOs first. Preferred when the amount is large
+    LargestFirst,
+}
+
+impl Default for UtxoSelectionOrdering {
+    fn default() -> Self {
+        UtxoSelectionOrdering::Default
+    }
+}
+
+impl Display for UtxoSelectionOrdering {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            UtxoSelectionOrdering::SmallestFirst => write!(f, "Smallest"),
+            UtxoSelectionOrdering::LargestFirst => write!(f, "Largest"),
+            UtxoSelectionOrdering::Default => write!(f, "Default"),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum UtxoSelectionFilter {
+    /// Select OutputType::Standard or OutputType::Coinbase outputs only
+    Standard,
+    /// Select matching token outputs. This will be deprecated in future.
+    TokenOutput {
+        unique_id: Vec<u8>,
+        parent_public_key: Option<PublicKey>,
+    },
+    /// Selects specific outputs. All outputs must be exist and be spendable.
+    SpecificOutputs { outputs: Vec<DbUnblindedOutput> },
+}
+
+impl Default for UtxoSelectionFilter {
+    fn default() -> Self {
+        UtxoSelectionFilter::Standard
+    }
+}
+
+impl Display for UtxoSelectionFilter {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        match self {
+            UtxoSelectionFilter::Standard => {
+                write!(f, "Standard")
+            },
+            UtxoSelectionFilter::TokenOutput { .. } => {
+                write!(f, "TokenOutput{{..}}")
+            },
+            UtxoSelectionFilter::SpecificOutputs { outputs } => {
+                write!(f, "Specific({} output(s))", outputs.len())
+            },
+        }
+    }
+}

base_layer/wallet/src/output_manager_service/mod.rs

@@ -20,7 +20,20 @@
 // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 // USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-use std::sync::Arc;
+pub mod config;
+pub mod error;
+pub mod handle;
+
+mod input_selection;
+pub use input_selection::{UtxoSelectionCriteria, UtxoSelectionFilter, UtxoSelectionOrdering};
+
+mod recovery;
+pub mod resources;
+pub mod service;
+pub mod storage;
+mod tasks;
+
+use std::{marker::PhantomData, sync::Arc};
 
 use futures::future;
 use log::*;
@@ -47,16 +60,6 @@ use crate::{
     },
 };
 
-pub mod config;
-pub mod error;
-pub mod handle;
-mod recovery;
-pub mod resources;
-pub mod service;
-pub mod storage;
-mod tasks;
-use std::marker::PhantomData;
-
 const LOG_TARGET: &str = "wallet::output_manager_service::initializer";
 
 pub struct OutputManagerServiceInitializer<T, TKeyManagerInterface>