feat(http-stats): added /miners endpoint to http server (#43)

Description
---
Added new `/miners` endpoint to http server to show how many shares
particular miners have.

Motivation and Context
---

How Has This Been Tested?
---
- Start P2Pool
- Query http://127.0.0.1:19000/miners

Example response:
```json
{
  "sha3": {
    "327atsnkv9bFARzE6fayMGWmjj13mArRHNAb2U2nNZXUc4vPnkfHkAjiYaBD7x49HeNTzw46Zjrkrqt4sB4M9PMTjBf": 35,
    "322SDoFr5ZqC4mpLtxoEow2zH4zdkZGpWgsVFzYQSgvZoSfgcGmrg3zmyyBAkGPDcoqe7pimicfz3wdhNDHrdaoJ7VD": 60,
    "324wcQjgDRE6Uz647Kjh6Zp1dNX8scYbLE3nXk2x65X5qyvoU8NjbLCSmzxSfUuNvhBbTiauJFRLhP4pepkLst7Q4Dt": 60
  },
  "randomx": {
    "322SDoFr5ZqC4mpLtxoEow2zH4zdkZGpWgsVFzYQSgvZoSfgcGmrg3zmyyBAkGPDcoqe7pimicfz3wdhNDHrdaoJ7VD": 1,
    "324wcQjgDRE6Uz647Kjh6Zp1dNX8scYbLE3nXk2x65X5qyvoU8NjbLCSmzxSfUuNvhBbTiauJFRLhP4pepkLst7Q4Dt": 3
  }
}
```

What process can a PR reviewer use to test or verify this change?
---

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Breaking Changes
---

- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

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<!-- BREAKING CHANGE: Description what the user should do, e.g. delete a
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Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sha_p2pool"
-version = "0.1.5-pre.6"
+version = "0.1.5-pre.7"
 edition = "2021"
 
 [dependencies]

src/server/http/server.rs

@@ -93,6 +93,7 @@ where
     pub fn routes(&self) -> Router {
         Router::new()
             .route("/stats", get(handlers::handle_get_stats))
+            .route("/miners", get(handlers::handle_miners_with_shares))
             .route("/health", get(health::handle_health))
             .route("/version", get(version::handle_version))
             .with_state(AppState {

src/server/http/stats/handlers.rs

@@ -26,6 +26,28 @@ use crate::sharechain::SHARE_COUNT;
 
 const LOG_TARGET: &str = "p2pool::server::stats::get";
 
+pub async fn handle_miners_with_shares(
+    State(state): State<AppState>,
+) -> Result<Json<HashMap<String, HashMap<String, u64>>>, StatusCode> {
+    let mut result = HashMap::with_capacity(2);
+    result.insert(
+        PowAlgorithm::Sha3x.to_string().to_lowercase(),
+        state.share_chain_sha3x.miners_with_shares().await.map_err(|error| {
+            error!(target: LOG_TARGET, "Failed to get Sha3x miners with shares: {error:?}");
+            StatusCode::INTERNAL_SERVER_ERROR
+        })?,
+    );
+    result.insert(
+        PowAlgorithm::RandomX.to_string().to_lowercase(),
+        state.share_chain_random_x.miners_with_shares().await.map_err(|error| {
+            error!(target: LOG_TARGET, "Failed to get RandomX miners with shares: {error:?}");
+            StatusCode::INTERNAL_SERVER_ERROR
+        })?,
+    );
+
+    Ok(Json(result))
+}
+
 pub async fn handle_get_stats(State(state): State<AppState>) -> Result<Json<HashMap<String, Stats>>, StatusCode> {
     let mut result = HashMap::with_capacity(2);
     result.insert(

src/sharechain/in_memory.rs

@@ -521,6 +521,13 @@ impl ShareChain for InMemoryShareChain {
 
         Ok(hash_rates_sum.div(hash_rates_count))
     }
+
+    async fn miners_with_shares(&self) -> ShareChainResult<HashMap<String, u64>> {
+        let levels_lock = self.block_levels.read().await;
+        let chain = self.chain(levels_lock.iter());
+        let chain = chain.iter().tail(BLOCKS_WINDOW).collect_vec();
+        Ok(self.miners_with_shares(chain))
+    }
 }
 
 #[cfg(test)]

src/sharechain/mod.rs

@@ -5,6 +5,7 @@ use crate::sharechain::{block::Block, error::Error};
 use async_trait::async_trait;
 use minotari_app_grpc::tari_rpc::{NewBlockCoinbase, SubmitBlockRequest};
 use num::BigUint;
+use std::collections::HashMap;
 use tari_common_types::types::FixedHash;
 use tari_core::consensus::ConsensusManager;
 use tari_core::proof_of_work::randomx_factory::RandomXFactory;
@@ -107,4 +108,7 @@ pub trait ShareChain: Send + Sync + 'static {
     /// (including all blocks and not just strongest chain).
     /// Returning number is the result in hash/second.
     async fn hash_rate(&self) -> ShareChainResult<BigUint>;
+
+    /// Returns the current miners with all the current shares in the current blocks window.
+    async fn miners_with_shares(&self) -> ShareChainResult<HashMap<String, u64>>;
 }