Merge pull request #960 from dfinity/Add_example_for_block_headers

chore: Add example of using bitcoin_get_block_headers to basic_bitcoin

Author: dragoljub-duric

rust/basic_bitcoin/README.md

@@ -42,7 +42,7 @@ To clone and build the smart contract in **Rust**:
 ```bash
 git clone https://github.com/dfinity/examples
 cd examples/rust/basic_bitcoin
-cargo build --release --target wasm32-unknown unknown
+cargo build --release --target wasm32-unknown-unknown
 ```
 
 ### Acquire cycles to deploy
@@ -214,6 +214,21 @@ it sent to the network. You can track the status of this transaction using a
 transaction has at least one confirmation, you should be able to see it
 reflected in your current balance.
 
+## Step 6: Retrieving block headers
+
+You can also get a range of Bitcoin block headers by using the `get_block_headers` 
+endpoint on your canister.
+
+Make the call using the command line. Be sure to replace `10` with your desired start height:
+
+```bash
+dfx canister --network=ic call basic_bitcoin get_block_headers "(10: nat32)"
+```
+or replace `0` and `11` with your desired start and end height respectively:
+```bash
+dfx canister --network=ic call basic_bitcoin get_block_headers "(0: nat32, 11: nat32)"
+```
+
 ## Conclusion
 
 In this tutorial, you were able to:

rust/basic_bitcoin/src/basic_bitcoin/basic_bitcoin.did

@@ -32,6 +32,14 @@ type get_utxos_response = record {
   next_page : opt blob;
 };
 
+type block_header = blob;
+type block_height = nat32;
+
+type get_block_headers_response = record {
+  tip_height : block_height;
+  block_headers : vec block_header;
+};
+
 service : (network) -> {
   "get_p2pkh_address" : () -> (bitcoin_address);
 
@@ -43,6 +51,8 @@ service : (network) -> {
 
   "get_utxos" : (bitcoin_address) -> (get_utxos_response);
 
+  "get_block_headers" : (start_height : block_height, end_height : opt block_height) -> (get_block_headers_response);
+
   "get_current_fee_percentiles" : () -> (vec millisatoshi_per_vbyte);
 
   "send_from_p2pkh" : (

rust/basic_bitcoin/src/basic_bitcoin/src/bitcoin_api.rs

@@ -1,8 +1,10 @@
+use candid::Principal;
 use ic_cdk::api::management_canister::bitcoin::{
     bitcoin_get_balance, bitcoin_get_current_fee_percentiles, bitcoin_get_utxos,
     bitcoin_send_transaction, BitcoinNetwork, GetBalanceRequest, GetCurrentFeePercentilesRequest,
     GetUtxosRequest, GetUtxosResponse, MillisatoshiPerByte, SendTransactionRequest,
 };
+use crate::{GetBlockHeadersRequest, GetBlockHeadersResponse};
 
 /// Returns the balance of the given bitcoin address.
 ///
@@ -36,6 +38,31 @@ pub async fn get_utxos(network: BitcoinNetwork, address: String) -> GetUtxosResp
     utxos_res.unwrap().0
 }
 
+/// Returns the block headers in the given height range.
+pub(crate) async fn get_block_headers(network: BitcoinNetwork, start_height: u32, end_height: Option<u32>) -> GetBlockHeadersResponse{
+    let cycles = match network {
+        BitcoinNetwork::Mainnet => 10_000_000_000,
+        BitcoinNetwork::Testnet => 10_000_000_000,
+        BitcoinNetwork::Regtest => 0,
+    };
+
+    let request = GetBlockHeadersRequest{
+        start_height,
+        end_height,
+        network
+    };
+
+    let res = ic_cdk::api::call::call_with_payment128::<(GetBlockHeadersRequest,), (GetBlockHeadersResponse,)>(
+        Principal::management_canister(),
+        "bitcoin_get_block_headers",
+        (request,),
+        cycles,
+    )
+    .await;
+
+    res.unwrap().0
+}
+
 /// Returns the 100 fee percentiles measured in millisatoshi/byte.
 /// Percentiles are computed from the last 10,000 transactions (if available).
 ///
@@ -61,3 +88,4 @@ pub async fn send_transaction(network: BitcoinNetwork, transaction: Vec<u8>) {
 
     res.unwrap();
 }
+

rust/basic_bitcoin/src/basic_bitcoin/src/lib.rs

@@ -3,6 +3,7 @@ mod bitcoin_wallet;
 mod ecdsa_api;
 mod schnorr_api;
 
+use candid::{CandidType, Deserialize};
 use ic_cdk::api::management_canister::bitcoin::{
     BitcoinNetwork, GetUtxosResponse, MillisatoshiPerByte,
 };
@@ -52,6 +53,31 @@ pub async fn get_utxos(address: String) -> GetUtxosResponse {
     bitcoin_api::get_utxos(network, address).await
 }
 
+pub type Height = u32;
+pub type BlockHeader = Vec<u8>;
+
+/// A request for getting the block headers for a given height range.
+#[derive(CandidType, Debug, Deserialize, PartialEq, Eq)]
+pub struct GetBlockHeadersRequest {
+    pub start_height: Height,
+    pub end_height: Option<Height>,
+    pub network: BitcoinNetwork,
+}
+
+/// The response returned for a request for getting the block headers from a given height.
+#[derive(CandidType, Debug, Deserialize, PartialEq, Eq, Clone)]
+pub struct GetBlockHeadersResponse {
+    pub tip_height: Height,
+    pub block_headers: Vec<BlockHeader>,
+}
+
+/// Returns the block headers in the given height range.
+#[update]
+pub async fn get_block_headers(start_height: u32, end_height: Option<u32>) -> GetBlockHeadersResponse{
+    let network = NETWORK.with(|n| n.get());
+    bitcoin_api::get_block_headers(network, start_height, end_height).await
+}
+
 /// Returns the 100 fee percentiles measured in millisatoshi/byte.
 /// Percentiles are computed from the last 10,000 transactions (if available).
 #[update]