fedimint_bitcoind/
lib.rs

1#![deny(clippy::pedantic)]
2#![allow(clippy::cast_possible_truncation)]
3#![allow(clippy::cast_sign_loss)]
4#![allow(clippy::missing_errors_doc)]
5#![allow(clippy::missing_panics_doc)]
6#![allow(clippy::module_name_repetitions)]
7#![allow(clippy::similar_names)]
8
9use std::env;
10use std::fmt::Debug;
11use std::sync::Arc;
12
13use anyhow::{Result, format_err};
14use bitcoin::{ScriptBuf, Transaction, Txid};
15use esplora_client::{AsyncClient, Builder};
16use fedimint_core::envs::FM_FORCE_BITCOIN_RPC_URL_ENV;
17use fedimint_core::txoproof::TxOutProof;
18use fedimint_core::util::SafeUrl;
19use fedimint_core::{apply, async_trait_maybe_send};
20
21#[cfg(feature = "bitcoincore")]
22pub mod bitcoincore;
23
24pub fn create_esplora_rpc(url: &SafeUrl) -> Result<DynBitcoindRpc> {
25    let url = env::var(FM_FORCE_BITCOIN_RPC_URL_ENV)
26        .ok()
27        .map(|s| SafeUrl::parse(&s))
28        .transpose()?
29        .unwrap_or_else(|| url.clone());
30
31    Ok(EsploraClient::new(&url)?.into_dyn())
32}
33
34pub type DynBitcoindRpc = Arc<dyn IBitcoindRpc + Send + Sync>;
35
36/// Trait that allows interacting with the Bitcoin blockchain
37///
38/// Functions may panic if the bitcoind node is not reachable.
39#[apply(async_trait_maybe_send!)]
40pub trait IBitcoindRpc: Debug + Send + Sync + 'static {
41    /// If a transaction is included in a block, returns the block height.
42    async fn get_tx_block_height(&self, txid: &Txid) -> Result<Option<u64>>;
43
44    /// Watches for a script and returns any transaction associated with it
45    async fn watch_script_history(&self, script: &ScriptBuf) -> Result<()>;
46
47    /// Get script transaction history
48    async fn get_script_history(&self, script: &ScriptBuf) -> Result<Vec<Transaction>>;
49
50    /// Returns a proof that a tx is included in the bitcoin blockchain
51    async fn get_txout_proof(&self, txid: Txid) -> Result<TxOutProof>;
52
53    fn into_dyn(self) -> DynBitcoindRpc
54    where
55        Self: Sized,
56    {
57        Arc::new(self)
58    }
59}
60
61#[derive(Debug)]
62pub struct EsploraClient {
63    client: AsyncClient,
64}
65
66impl EsploraClient {
67    pub fn new(url: &SafeUrl) -> anyhow::Result<Self> {
68        Ok(Self {
69            // URL needs to have any trailing path including '/' removed
70            client: Builder::new(url.as_str().trim_end_matches('/')).build_async()?,
71        })
72    }
73}
74
75#[apply(async_trait_maybe_send!)]
76impl IBitcoindRpc for EsploraClient {
77    async fn get_tx_block_height(&self, txid: &Txid) -> anyhow::Result<Option<u64>> {
78        Ok(self
79            .client
80            .get_tx_status(txid)
81            .await?
82            .block_height
83            .map(u64::from))
84    }
85
86    async fn watch_script_history(&self, _: &ScriptBuf) -> anyhow::Result<()> {
87        // no watching needed, has all the history already
88        Ok(())
89    }
90
91    async fn get_script_history(
92        &self,
93        script: &ScriptBuf,
94    ) -> anyhow::Result<Vec<bitcoin::Transaction>> {
95        const MAX_TX_HISTORY: usize = 1000;
96
97        let mut transactions = Vec::new();
98        let mut last_seen: Option<Txid> = None;
99
100        loop {
101            let page = self.client.scripthash_txs(script, last_seen).await?;
102
103            if page.is_empty() {
104                break;
105            }
106
107            for tx in &page {
108                transactions.push(tx.to_tx());
109            }
110
111            if transactions.len() >= MAX_TX_HISTORY {
112                return Err(format_err!(
113                    "Script history exceeds maximum limit of {}",
114                    MAX_TX_HISTORY
115                ));
116            }
117
118            last_seen = Some(page.last().expect("page not empty").txid);
119        }
120
121        Ok(transactions)
122    }
123
124    async fn get_txout_proof(&self, txid: Txid) -> anyhow::Result<TxOutProof> {
125        let proof = self
126            .client
127            .get_merkle_block(&txid)
128            .await?
129            .ok_or(format_err!("No merkle proof found"))?;
130
131        Ok(TxOutProof {
132            block_header: proof.header,
133            merkle_proof: proof.txn,
134        })
135    }
136}
fedimint_bitcoind/lib.rs

fedimint_bitcoind/
lib.rs
