subxt: update to version 0.33 (#25)

adapt to subxt's API changes

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "blockstats"
-version = "0.2.0"
+version = "0.3.0"
 edition = "2021"
 rust-version = "1.56.1"
 authors = ["Parity Technologies <admin@parity.io>"]
@@ -14,7 +14,7 @@ include = ["src/**/*", "LICENSE", "README.md"]
 [dependencies]
 codec = { package = "parity-scale-codec", version = "3"  }
 futures = "0.3"
-subxt = "0.28"
+subxt = { version = "0.33", features = ["substrate-compat"] }
 
 [dev-dependencies]
 clap = { version = "4", features = ["derive"] }

src/lib.rs

@@ -5,8 +5,10 @@
 
 use core::ops::Add;
 use futures::{TryStream, TryStreamExt};
-use std::{boxed::Box, fmt, sync::Arc};
+use std::{boxed::Box, fmt};
 use subxt::{
+    backend::{legacy::LegacyRpcMethods, rpc::RpcClient},
+    error::MetadataError,
     ext::{scale_decode, sp_core::H256},
     storage::{address::StaticStorageMapKey, address::Yes, Address},
     Error, OnlineClient, PolkadotConfig as DefaultConfig,
@@ -75,28 +77,31 @@ impl fmt::Display for BlockStats {
 pub async fn subscribe_stats(
     url: &str,
 ) -> Result<impl TryStream<Ok = BlockStats, Error = Error> + Unpin, Error> {
-    let client = OnlineClient::<DefaultConfig>::from_url(url).await?;
-    subscribe_stats_with_client(client).await
+    let rpc_client = RpcClient::from_url(url).await?;
+    subscribe_stats_with_client(rpc_client).await
 }
 
 /// Connect to the specified node and listen for new blocks using OnlineClient.
 pub async fn subscribe_stats_with_client(
-    client: OnlineClient<DefaultConfig>,
+    rpc_client: RpcClient,
 ) -> Result<impl TryStream<Ok = BlockStats, Error = Error> + Unpin, Error> {
-    let client = Arc::new(client);
-
+    let client = OnlineClient::<DefaultConfig>::from_rpc_client(rpc_client.clone()).await?;
     let blocks = client.blocks().subscribe_best().await?;
 
     let max_block_weights: BlockWeights = {
         let metadata = client.metadata();
-        let pallet = metadata.pallet("System")?;
-        let constant = pallet.constant("BlockWeights")?;
-        codec::Decode::decode(&mut &constant.value[..])?
+        let pallet = metadata.pallet_by_name_err("System")?;
+        let constant_name = "BlockWeights";
+        let constant = pallet
+            .constant_by_name(constant_name)
+            .ok_or_else(|| MetadataError::ConstantNameNotFound(constant_name.to_owned()))?;
+        codec::Decode::decode(&mut &constant.value()[..])?
     };
 
     Ok(Box::pin(blocks.map_err(Into::into).and_then(
         move |block| {
             let client = client.clone();
+            let rpc_methods = LegacyRpcMethods::<DefaultConfig>::new(rpc_client.clone());
 
             let block_weight_address =
                 Address::<StaticStorageMapKey, PerDispatchClass<Weight>, Yes, Yes, ()>::new_static(
@@ -107,9 +112,8 @@ pub async fn subscribe_stats_with_client(
                 )
                 .unvalidated();
             async move {
-                let stats = client
-                    .rpc()
-                    .block_stats(block.hash())
+                let stats = rpc_methods
+                    .dev_get_block_stats(block.hash())
                     .await?
                     .ok_or_else(|| Error::Other("Block not available.".to_string()))?;
                 let weight = client