Add a generalized "Blockchain" interface

src/blockchain/mod.rs

@@ -0,0 +1,86 @@
+use std::collections::HashSet;
+use std::sync::mpsc::{channel, Receiver, Sender};
+
+use bitcoin::{Transaction, Txid};
+
+use crate::database::{BatchDatabase, DatabaseUtils};
+use crate::error::Error;
+
+#[cfg(feature = "electrum")]
+pub mod electrum;
+#[cfg(feature = "electrum")]
+pub use self::electrum::ElectrumBlockchain;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum Capability {
+    FullHistory,
+    GetAnyTx,
+}
+
+pub trait Blockchain {
+    fn offline() -> Self;
+}
+
+pub struct OfflineBlockchain;
+impl Blockchain for OfflineBlockchain {
+    fn offline() -> Self {
+        OfflineBlockchain
+    }
+}
+
+pub trait OnlineBlockchain: Blockchain {
+    fn get_capabilities(&self) -> HashSet<Capability>;
+
+    fn setup<D: BatchDatabase + DatabaseUtils, P: Progress>(
+        &mut self,
+        stop_gap: Option<usize>,
+        database: &mut D,
+        progress_update: P,
+    ) -> Result<(), Error>;
+    fn sync<D: BatchDatabase + DatabaseUtils, P: Progress>(
+        &mut self,
+        stop_gap: Option<usize>,
+        database: &mut D,
+        progress_update: P,
+    ) -> Result<(), Error> {
+        self.setup(stop_gap, database, progress_update)
+    }
+
+    fn get_tx(&mut self, txid: &Txid) -> Result<Option<Transaction>, Error>;
+    fn broadcast(&mut self, tx: &Transaction) -> Result<(), Error>;
+
+    fn get_height(&mut self) -> Result<usize, Error>;
+}
+
+pub type ProgressData = (f32, Option<String>);
+
+pub trait Progress {
+    fn update(&self, progress: f32, message: Option<String>) -> Result<(), Error>;
+}
+
+pub fn progress() -> (Sender<ProgressData>, Receiver<ProgressData>) {
+    channel()
+}
+
+impl Progress for Sender<ProgressData> {
+    fn update(&self, progress: f32, message: Option<String>) -> Result<(), Error> {
+        if progress < 0.0 || progress > 100.0 {
+            return Err(Error::InvalidProgressValue(progress));
+        }
+
+        self.send((progress, message))
+            .map_err(|_| Error::ProgressUpdateError)
+    }
+}
+
+pub struct NoopProgress;
+
+pub fn noop_progress() -> NoopProgress {
+    NoopProgress
+}
+
+impl Progress for NoopProgress {
+    fn update(&self, _progress: f32, _message: Option<String>) -> Result<(), Error> {
+        Ok(())
+    }
+}