feat: add KeyRing changeset

Author: thunderbiscuit

wallet/src/keyring/changeset.rs

@@ -0,0 +1,47 @@
+use crate::keyring::BTreeMap;
+
+use bitcoin::Network;
+use chain::Merge;
+use miniscript::{Descriptor, DescriptorPublicKey};
+use serde::{Deserialize, Serialize};
+
+/// Represents changes to the `KeyRing`.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct ChangeSet<K: Ord> {
+    /// Network.
+    pub network: Option<Network>,
+    /// Added descriptors.
+    pub descriptors: BTreeMap<K, Descriptor<DescriptorPublicKey>>,
+    /// Default keychain
+    pub default_keychain: Option<K>,
+}
+
+impl<K: Ord> Default for ChangeSet<K> {
+    fn default() -> Self {
+        Self {
+            network: None,
+            descriptors: Default::default(),
+            default_keychain: None,
+        }
+    }
+}
+
+impl<K: Ord> Merge for ChangeSet<K> {
+    fn merge(&mut self, other: Self) {
+        // merge network
+        if other.network.is_some() && self.network.is_none() {
+            self.network = other.network;
+        }
+        // merge descriptors
+        self.descriptors.extend(other.descriptors);
+
+        // Note: if a new default keychain has been set, it will take precedence over the old one.
+        if other.default_keychain.is_some() {
+            self.default_keychain = other.default_keychain;
+        }
+    }
+
+    fn is_empty(&self) -> bool {
+        self.network.is_none() && self.descriptors.is_empty()
+    }
+}

wallet/src/keyring/mod.rs

@@ -93,4 +93,23 @@ where
     pub fn list_keychains(&self) -> &BTreeMap<K, Descriptor<DescriptorPublicKey>> {
         &self.descriptors
     }
+
+    /// Initial changeset.
+    pub fn initial_changeset(&self) -> ChangeSet<K> {
+        ChangeSet {
+            network: Some(self.network),
+            descriptors: self.descriptors.clone(),
+            default_keychain: Some(self.default_keychain.clone()),
+        }
+    }
+
+    /// Construct from changeset.
+    pub fn from_changeset(changeset: ChangeSet<K>) -> Option<Self> {
+        Some(Self {
+            secp: Secp256k1::new(),
+            network: changeset.network?,
+            descriptors: changeset.descriptors,
+            default_keychain: changeset.default_keychain?,
+        })
+    }
 }

wallet/src/lib.rs

@@ -27,6 +27,7 @@ pub extern crate serde;
 pub extern crate serde_json;
 
 pub mod descriptor;
+pub mod keyring;
 pub mod keys;
 pub mod psbt;
 #[cfg(feature = "test-utils")]