Add blockchain.block.tweaks RPC method

Author: jlest01

src/db.rs

@@ -273,6 +273,16 @@ impl DBStore {
         self.iter_cf(self.headers_cf(), opts, None)
     }
 
+    pub(crate) fn read_tweaks(&self, height: u64) -> Vec<(Box<[u8]>, Box<[u8]>)> {
+        let mut opts = rocksdb::ReadOptions::default();
+        opts.set_iterate_lower_bound(height.to_be_bytes());
+        opts.fill_cache(false);
+        self.db
+            .iterator_cf_opt(self.tweak_cf(), opts, rocksdb::IteratorMode::Start)
+            .map(|row| row.expect("tweak iterator failed"))
+            .collect()
+    }
+
     pub(crate) fn get_tip(&self) -> Option<Vec<u8>> {
         self.db
             .get_cf(self.headers_cf(), TIP_KEY)

src/electrum.rs

@@ -235,6 +235,10 @@ impl Rpc {
         Ok(json!({"count": count, "hex": String::from_iter(hex_headers), "max": max_count}))
     }
 
+    fn sp_tweaks(&self, (start_height,): (usize,)) -> Result<Value> {
+        Ok(json!(self.tracker.get_tweaks(start_height)?))
+    }
+
     fn estimate_fee(&self, (nblocks,): (u16,)) -> Result<Value> {
         Ok(self
             .daemon
@@ -554,6 +558,7 @@ impl Rpc {
                 Params::Banner => Ok(json!(self.banner)),
                 Params::BlockHeader(args) => self.block_header(*args),
                 Params::BlockHeaders(args) => self.block_headers(*args),
+                Params::SpTweaks(args) => self.sp_tweaks(*args),
                 Params::Donation => Ok(Value::Null),
                 Params::EstimateFee(args) => self.estimate_fee(*args),
                 Params::Features => self.features(),
@@ -583,6 +588,7 @@ enum Params {
     Banner,
     BlockHeader((usize,)),
     BlockHeaders((usize, usize)),
+    SpTweaks((usize,)),
     TransactionBroadcast((String,)),
     Donation,
     EstimateFee((u16,)),
@@ -608,6 +614,7 @@ impl Params {
         Ok(match method {
             "blockchain.block.header" => Params::BlockHeader(convert(params)?),
             "blockchain.block.headers" => Params::BlockHeaders(convert(params)?),
+            "blockchain.block.tweaks" => Params::SpTweaks(convert(params)?),
             "blockchain.estimatefee" => Params::EstimateFee(convert(params)?),
             "blockchain.headers.subscribe" => Params::HeadersSubscribe,
             "blockchain.relayfee" => Params::RelayFee,

src/index.rs

@@ -1,5 +1,6 @@
 use anyhow::{Context, Result};
 use bitcoin::consensus::{deserialize, Decodable, Encodable};
+use bitcoin::hex::DisplayHex;
 use bitcoin::secp256k1::PublicKey;
 use bitcoin::hashes::Hash;
 use bitcoin::{BlockHash, OutPoint, Txid, XOnlyPublicKey};
@@ -167,6 +168,26 @@ impl Index {
             .map(|row| HashPrefixRow::from_db_row(row).height())
             .filter_map(move |height| self.chain.get_block_hash(height))
     }
+
+    pub(crate) fn get_tweaks(&self, height: u64) -> impl Iterator<Item = (u64, Vec<String>)> + '_ {
+        self.store
+            .read_tweaks(height)
+            .into_iter()
+            .filter_map(move |(block_height, tweaks)| {
+                assert!(tweaks.len() % 33 == 0 && tweaks.len() > 0);
+                assert!(block_height.len() == 8);
+
+                let tweak_row_block_height =
+                    u64::from_be_bytes(block_height[..].try_into().unwrap());
+                let pks = tweaks
+                    .chunks(33)
+                    .map(|x| format!("{}", x.as_hex()))
+                    .collect();
+
+                Some((tweak_row_block_height, pks))
+            })
+    }
+
     pub(crate) fn silent_payments_sync(
         &mut self,
         daemon: &Daemon,

src/tracker.rs

@@ -5,6 +5,7 @@ use bitcoin_slices::{
     Error::VisitBreak,
     Visit,
 };
+use std::collections::HashMap;
 
 use crate::{
     cache::Cache,
@@ -134,4 +135,13 @@ impl Tracker {
         })?;
         Ok(result)
     }
+
+    pub(crate) fn get_tweaks(&self, height: usize) -> Result<HashMap<u64, Vec<String>>> {
+        let tweaks: Vec<(u64, Vec<String>)> = self.index.get_tweaks(height as u64).collect();
+        let mut res: HashMap<u64, Vec<String>> = HashMap::new();
+        for (height, tweaks) in tweaks {
+            res.entry(height).or_insert_with(Vec::new).extend(tweaks)
+        }
+        Ok(res)
+    }
 }