Kernel lookup api method (#3000)

* Kernel lookup api * Min and max height parameters, scan backwards * Return null instead of 404 if kernel not found * Return TxKernel instead of TxKernelPrintable * Update description of KernelHandler
2019-08-30 11:03:12 +02:00
parent d36a0b29ef
commit 30156cdcf9
5 changed files with 173 additions and 3 deletions
@@ -26,6 +26,7 @@ use self::blocks_api::HeaderHandler;
 use self::chain_api::ChainCompactHandler;
 use self::chain_api::ChainHandler;
 use self::chain_api::ChainValidationHandler;
+use self::chain_api::KernelHandler;
 use self::chain_api::OutputHandler;
 use self::peers_api::PeerHandler;
 use self::peers_api::PeersAllHandler;
@@ -119,7 +120,9 @@ pub fn build_router(
 	let output_handler = OutputHandler {
 		chain: Arc::downgrade(&chain),
 	};
-
+	let kernel_handler = KernelHandler {
+		chain: Arc::downgrade(&chain),
+	};
 	let block_handler = BlockHandler {
 		chain: Arc::downgrade(&chain),
 	};
@@ -171,6 +174,7 @@ pub fn build_router(
 	router.add_route("/v1/headers/*", Arc::new(header_handler))?;
 	router.add_route("/v1/chain", Arc::new(chain_tip_handler))?;
 	router.add_route("/v1/chain/outputs/*", Arc::new(output_handler))?;
+	router.add_route("/v1/chain/kernels/*", Arc::new(kernel_handler))?;
 	router.add_route("/v1/chain/compact", Arc::new(chain_compact_handler))?;
 	router.add_route("/v1/chain/validate", Arc::new(chain_validation_handler))?;
 	router.add_route("/v1/txhashset/*", Arc::new(txhashset_handler))?;
@@ -197,3 +197,72 @@ impl Handler for OutputHandler {
 		}
 	}
 }
+
+/// Kernel handler, search for a kernel by excess commitment
+/// GET /v1/chain/kernels/XXX?min_height=YYY&max_height=ZZZ
+/// The `min_height` and `max_height` parameters are optional
+pub struct KernelHandler {
+	pub chain: Weak<chain::Chain>,
+}
+
+impl KernelHandler {
+	fn get_kernel(&self, req: Request<Body>) -> Result<Option<LocatedTxKernel>, Error> {
+		let excess = req
+			.uri()
+			.path()
+			.trim_end_matches('/')
+			.rsplit('/')
+			.next()
+			.ok_or(ErrorKind::RequestError("missing excess".into()))?;
+		let excess = util::from_hex(excess.to_owned())
+			.map_err(|_| ErrorKind::RequestError("invalid excess hex".into()))?;
+		if excess.len() != 33 {
+			return Err(ErrorKind::RequestError("invalid excess length".into()).into());
+		}
+		let excess = Commitment::from_vec(excess);
+
+		let chain = w(&self.chain)?;
+
+		let mut min_height: Option<u64> = None;
+		let mut max_height: Option<u64> = None;
+
+		// Check query parameters for minimum and maximum search height
+		if let Some(q) = req.uri().query() {
+			let params = QueryParams::from(q);
+			if let Some(h) = params.get("min_height") {
+				let h = h
+					.parse()
+					.map_err(|_| ErrorKind::RequestError("invalid minimum height".into()))?;
+				// Default is genesis
+				min_height = if h == 0 { None } else { Some(h) };
+			}
+			if let Some(h) = params.get("max_height") {
+				let h = h
+					.parse()
+					.map_err(|_| ErrorKind::RequestError("invalid maximum height".into()))?;
+				// Default is current head
+				let head_height = chain
+					.head()
+					.map_err(|e| ErrorKind::Internal(format!("{}", e)))?
+					.height;
+				max_height = if h >= head_height { None } else { Some(h) };
+			}
+		}
+
+		let kernel = chain
+			.get_kernel_height(&excess, min_height, max_height)
+			.map_err(|e| ErrorKind::Internal(format!("{}", e)))?
+			.map(|(tx_kernel, height, mmr_index)| LocatedTxKernel {
+				tx_kernel,
+				height,
+				mmr_index,
+			});
+		Ok(kernel)
+	}
+}
+
+impl Handler for KernelHandler {
+	fn get(&self, req: Request<Body>) -> ResponseFuture {
+		result_to_response(self.get_kernel(req))
+	}
+}
@@ -17,7 +17,7 @@ use std::sync::Arc;
 use crate::chain;
 use crate::core::core::hash::Hashed;
 use crate::core::core::merkle_proof::MerkleProof;
-use crate::core::core::KernelFeatures;
+use crate::core::core::{KernelFeatures, TxKernel};
 use crate::core::{core, ser};
 use crate::p2p;
 use crate::util;
@@ -699,6 +699,13 @@ pub struct OutputListing {
 	pub outputs: Vec<OutputPrintable>,
 }

+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct LocatedTxKernel {
+	pub tx_kernel: TxKernel,
+	pub height: u64,
+	pub mmr_index: u64,
+}
+
 #[derive(Serialize, Deserialize)]
 pub struct PoolInfo {
 	/// Size of the pool