Create and store block filters (#89)

* Create a simple filter builder

* Index txid

This is useful for fetching utxos for their txid

* Implement query logic

* query script hashes, not scripts

* Move block filters to a dedicated module

* Document methods

* actually create block filters

* Expose final things to cli

Cargo.toml

@@ -5,6 +5,7 @@ members = [
     "crates/floresta-chain",
     "crates/floresta-cli",
     "crates/floresta-common",
+    "crates/floresta-compact-filters",
     "crates/floresta-electrum",
     "crates/floresta-watch-only",
     "crates/floresta-wire",

crates/floresta-cli/src/main.rs

@@ -56,6 +56,7 @@ fn get_req(cmd: &Cli) -> (Vec<Box<RawValue>>, String) {
         Methods::ListTransactions => "gettransactions",
         Methods::Stop => "stop",
         Methods::AddNode { .. } => "addnode",
+        Methods::GetFilters { .. } => "getblockfilter",
     };
     let params = match &cmd.methods {
         Methods::GetBlockchainInfo => Vec::new(),
@@ -92,6 +93,9 @@ fn get_req(cmd: &Cli) -> (Vec<Box<RawValue>>, String) {
         Methods::AddNode { node } => {
             vec![arg(node)]
         }
+        Methods::GetFilters { height } => {
+            vec![arg(height)]
+        }
     };
 
     (params, method.to_string())
@@ -182,4 +186,7 @@ pub enum Methods {
     /// Usage: addnode <ip:[port]>
     #[command(name = "addnode")]
     AddNode { node: String },
+    /// Returns the filters for a given block
+    #[command(name = "getfilter")]
+    GetFilters { height: u32 },
 }

crates/floresta-compact-filters/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "floresta-compact-filters"
+version = "0.1.0"
+authors = ["Davidson Sousa <[email protected]>"]
+edition = "2018"
+homepage = "https://github.com/davidson-souza/floresta"
+repository = "https://github.com/davidson-souza/floresta"
+description = """
+                BIP158 compact filters for easy rescan of the blockchain in 
+                light clients.
+            """
+
+[dependencies]
+bitcoin_hashes = "0.11.0"
+bitcoin = "0.29"
+floresta-common = { path = "../floresta-common" }
+floresta-chain = { path = "../floresta-chain", default-features = false }
+kv = "0.24.0"
+log = "0.4.20"
+