module cleanup

binaries/cuprated/src/constants.rs

@@ -18,9 +18,6 @@ pub const VERSION_BUILD: &str = if cfg!(debug_assertions) {
 pub const PANIC_CRITICAL_SERVICE_ERROR: &str =
     "A service critical to Cuprate's function returned an unexpected error.";
 
-/// The error message returned when an unsupported RPC call is requested.
-pub const UNSUPPORTED_RPC_CALL: &str = "This RPC call is not supported by Cuprate.";
-
 pub const EXAMPLE_CONFIG: &str = include_str!("../Cuprated.toml");
 
 #[cfg(test)]

binaries/cuprated/src/rpc.rs

@@ -2,13 +2,9 @@
 //!
 //! Will contain the code to initiate the RPC and a request handler.
 
-mod bin;
 mod constants;
-mod handler;
-mod helper;
-mod json;
-mod other;
-mod request;
-mod shared;
+mod handlers;
+mod rpc_handler;
+mod service;
 
-pub use handler::CupratedRpcHandler;
+pub use rpc_handler::CupratedRpcHandler;

binaries/cuprated/src/rpc/constants.rs

@@ -3,3 +3,6 @@
 /// The string message used in RPC response fields for when
 /// `cuprated` does not support a field that `monerod` has.
 pub(super) const FIELD_NOT_SUPPORTED: &str = "`cuprated` does not support this field.";
+
+/// The error message returned when an unsupported RPC call is requested.
+pub(super) const UNSUPPORTED_RPC_CALL: &str = "This RPC call is not supported by Cuprate.";

binaries/cuprated/src/rpc/handlers.rs

@@ -0,0 +1,18 @@
+//! RPC handler functions.
+//!
+//! These are the glue (async) functions that connect all the
+//! internal `cuprated` functions and fulfill the request.
+//!
+//! - JSON-RPC handlers are in [`json_rpc`]
+//! - Other JSON endpoint handlers are in [`other_json`]
+//! - Other binary endpoint handlers are in [`bin`]
+//!
+//! - [`helper`] contains helper functions used by many handlers
+//! - [`shared`] contains shared functions used by multiple handlers
+
+pub(super) mod bin;
+pub(super) mod json_rpc;
+pub(super) mod other_json;
+
+mod helper;
+mod shared;

binaries/cuprated/src/rpc/handlers/bin.rs

@@ -26,13 +26,13 @@ use cuprate_types::{
 };
 
 use crate::rpc::{
-    helper,
-    request::{blockchain, txpool},
-    shared, CupratedRpcHandler,
+    handlers::{helper, shared},
+    service::{blockchain, txpool},
+    CupratedRpcHandler,
 };
 
 /// Map a [`BinRequest`] to the function that will lead to a [`BinResponse`].
-pub(super) async fn map_request(
+pub async fn map_request(
     state: CupratedRpcHandler,
     request: BinRequest,
 ) -> Result<BinResponse, Error> {

binaries/cuprated/src/rpc/handlers/helper.rs

@@ -3,7 +3,7 @@
 //! Many of the handlers have bodies with only small differences,
 //! the identical code is extracted and reused here in these functions.
 //!
-//! These build on-top of [`crate::rpc::request`] functions.
+//! These build on-top of [`crate::rpc::service`] functions.
 
 use anyhow::{anyhow, Error};
 
@@ -17,9 +17,9 @@ use cuprate_rpc_types::{
 };
 use cuprate_types::HardFork;
 
-use crate::{
-    rpc::request::{blockchain, blockchain_context},
-    rpc::CupratedRpcHandler,
+use crate::rpc::{
+    service::{blockchain, blockchain_context},
+    CupratedRpcHandler,
 };
 
 /// Map some data into a [`BlockHeader`].

binaries/cuprated/src/rpc/handlers/json_rpc.rs

@@ -58,19 +58,18 @@ use cuprate_types::{
 };
 
 use crate::{
-    constants::{UNSUPPORTED_RPC_CALL, VERSION_BUILD},
+    constants::VERSION_BUILD,
     rpc::{
-        helper,
-        request::{address_book, blockchain, blockchain_context, blockchain_manager, txpool},
-        shared, CupratedRpcHandler,
+        constants::{FIELD_NOT_SUPPORTED, UNSUPPORTED_RPC_CALL},
+        handlers::{helper, shared},
+        service::{address_book, blockchain, blockchain_context, blockchain_manager, txpool},
+        CupratedRpcHandler,
     },
     statics::START_INSTANT_UNIX,
 };
 
-use super::constants::FIELD_NOT_SUPPORTED;
-
 /// Map a [`JsonRpcRequest`] to the function that will lead to a [`JsonRpcResponse`].
-pub(super) async fn map_request(
+pub async fn map_request(
     state: CupratedRpcHandler,
     request: JsonRpcRequest,
 ) -> Result<JsonRpcResponse, Error> {

binaries/cuprated/src/rpc/handlers/other_json.rs

@@ -43,19 +43,17 @@ use cuprate_types::{
 use monero_serai::transaction::{Input, Timelock, Transaction};
 
 use crate::{
-    constants::UNSUPPORTED_RPC_CALL,
     rpc::{
-        helper,
-        request::{blockchain, blockchain_context, blockchain_manager, txpool},
-        shared, CupratedRpcHandler,
+        constants::UNSUPPORTED_RPC_CALL,
+        handlers::{helper, shared},
+        service::{address_book, blockchain, blockchain_context, blockchain_manager, txpool},
+        CupratedRpcHandler,
     },
     statics::START_INSTANT_UNIX,
 };
 
-use super::request::address_book;
-
 /// Map a [`OtherRequest`] to the function that will lead to a [`OtherResponse`].
-pub(super) async fn map_request(
+pub async fn map_request(
     state: CupratedRpcHandler,
     request: OtherRequest,
 ) -> Result<OtherResponse, Error> {

binaries/cuprated/src/rpc/handlers/shared.rs

@@ -1,8 +1,12 @@
 //! RPC handler functions that are shared between different endpoint/methods.
 
-use std::collections::{HashMap, HashSet};
+use std::{
+    collections::{HashMap, HashSet},
+    num::NonZero,
+};
 
 use anyhow::{anyhow, Error};
+use cuprate_types::OutputDistributionInput;
 use monero_serai::transaction::Timelock;
 
 use cuprate_constants::rpc::MAX_RESTRICTED_GLOBAL_FAKE_OUTS_COUNT;
@@ -19,8 +23,8 @@ use cuprate_rpc_types::{
 };
 
 use crate::rpc::{
-    helper,
-    request::{blockchain, txpool},
+    handlers::helper,
+    service::{blockchain, txpool},
     CupratedRpcHandler,
 };
 
@@ -97,36 +101,35 @@ pub(super) async fn get_transaction_pool_hashes(
 /// <https://github.com/monero-project/monero/blob/cc73fe71162d564ffda8e549b79a350bca53c454/src/rpc/core_rpc_server.cpp#L3352-L3398>
 ///
 /// Shared between:
-/// - JSON-RPC's `get_output_distribution`
+/// - Other JSON's `/get_output_distribution`
 /// - Binary's `/get_output_distribution.bin`
+///
+/// Returns transaction hashes.
 pub(super) async fn get_output_distribution(
     mut state: CupratedRpcHandler,
     request: GetOutputDistributionRequest,
 ) -> Result<GetOutputDistributionResponse, Error> {
-    if state.is_restricted() && request.amounts != [1, 0] {
+    if state.is_restricted() && request.amounts != [0] {
         return Err(anyhow!(
             "Restricted RPC can only get output distribution for RCT outputs. Use your own node."
         ));
     }
 
-    // 0 is placeholder for the whole chain
-    let req_to_height = if request.to_height == 0 {
-        helper::top_height(&mut state).await?.0.saturating_sub(1)
-    } else {
-        request.to_height
+    let input = OutputDistributionInput {
+        amounts: request.amounts,
+        cumulative: request.cumulative,
+        from_height: request.from_height,
+
+        // 0 / `None` is placeholder for the whole chain
+        to_height: NonZero::new(request.to_height),
     };
 
-    let distributions = request.amounts.into_iter().map(|amount| {
-        fn get_output_distribution() -> Result<Distribution, Error> {
-            todo!("https://github.com/monero-project/monero/blob/893916ad091a92e765ce3241b94e706ad012b62a/src/rpc/rpc_handler.cpp#L29");
-            Err(anyhow!("Failed to get output distribution"))
-        }
-
-        get_output_distribution()
-    }).collect::<Result<Vec<Distribution>, _>>()?;
+    let distributions = blockchain::output_distribution(&mut state.blockchain_read, input).await?;
 
     Ok(GetOutputDistributionResponse {
         base: helper::access_response_base(false),
-        distributions,
+        distributions: todo!(
+            "This type contains binary strings: <https://github.com/monero-project/monero/issues/9422>"
+        ),
     })
 }

binaries/cuprated/src/rpc/rpc_handler.rs

@@ -19,7 +19,7 @@ use cuprate_rpc_types::{
 };
 use cuprate_txpool::service::TxpoolReadHandle;
 
-use crate::rpc::{bin, json, other};
+use crate::rpc::handlers;
 
 /// TODO: use real type when public.
 #[derive(Clone)]
@@ -217,7 +217,7 @@ impl Service<JsonRpcRequest> for CupratedRpcHandler {
 
     fn call(&mut self, request: JsonRpcRequest) -> Self::Future {
         let state = self.clone();
-        Box::pin(json::map_request(state, request))
+        Box::pin(handlers::json_rpc::map_request(state, request))
     }
 }
 
@@ -232,7 +232,7 @@ impl Service<BinRequest> for CupratedRpcHandler {
 
     fn call(&mut self, request: BinRequest) -> Self::Future {
         let state = self.clone();
-        Box::pin(bin::map_request(state, request))
+        Box::pin(handlers::bin::map_request(state, request))
     }
 }
 
@@ -247,6 +247,6 @@ impl Service<OtherRequest> for CupratedRpcHandler {
 
     fn call(&mut self, request: OtherRequest) -> Self::Future {
         let state = self.clone();
-        Box::pin(other::map_request(state, request))
+        Box::pin(handlers::other_json::map_request(state, request))
     }
 }

binaries/cuprated/src/rpc/service.rs

@@ -1,4 +1,4 @@
-//! Convenience functions for requests/responses.
+//! Convenience functions for Cuprate's various [`tower::Service`] requests/responses.
 //!
 //! This module implements many methods for
 //! [`CupratedRpcHandler`](crate::rpc::CupratedRpcHandler)

binaries/cuprated/src/rpc/service/address_book.rs

@@ -17,7 +17,7 @@ use cuprate_rpc_types::misc::ConnectionInfo;
 // FIXME: use `anyhow::Error` over `tower::BoxError` in address book.
 
 /// [`AddressBookRequest::PeerlistSize`]
-pub(crate) async fn peerlist_size<Z: NetworkZone>(
+pub async fn peerlist_size<Z: NetworkZone>(
     address_book: &mut impl AddressBook<Z>,
 ) -> Result<(u64, u64), Error> {
     let AddressBookResponse::PeerlistSize { white, grey } = address_book
@@ -35,7 +35,7 @@ pub(crate) async fn peerlist_size<Z: NetworkZone>(
 }
 
 /// [`AddressBookRequest::ConnectionInfo`]
-pub(crate) async fn connection_info<Z: NetworkZone>(
+pub async fn connection_info<Z: NetworkZone>(
     address_book: &mut impl AddressBook<Z>,
 ) -> Result<Vec<ConnectionInfo>, Error> {
     let AddressBookResponse::ConnectionInfo(vec) = address_book
@@ -92,7 +92,7 @@ pub(crate) async fn connection_info<Z: NetworkZone>(
 }
 
 /// [`AddressBookRequest::ConnectionCount`]
-pub(crate) async fn connection_count<Z: NetworkZone>(
+pub async fn connection_count<Z: NetworkZone>(
     address_book: &mut impl AddressBook<Z>,
 ) -> Result<(u64, u64), Error> {
     let AddressBookResponse::ConnectionCount { incoming, outgoing } = address_book
@@ -110,7 +110,7 @@ pub(crate) async fn connection_count<Z: NetworkZone>(
 }
 
 /// [`AddressBookRequest::SetBan`]
-pub(crate) async fn set_ban<Z: NetworkZone>(
+pub async fn set_ban<Z: NetworkZone>(
     address_book: &mut impl AddressBook<Z>,
     set_ban: cuprate_p2p_core::types::SetBan<Z::Addr>,
 ) -> Result<(), Error> {
@@ -129,7 +129,7 @@ pub(crate) async fn set_ban<Z: NetworkZone>(
 }
 
 /// [`AddressBookRequest::GetBan`]
-pub(crate) async fn get_ban<Z: NetworkZone>(
+pub async fn get_ban<Z: NetworkZone>(
     address_book: &mut impl AddressBook<Z>,
     peer: Z::Addr,
 ) -> Result<Option<std::time::Instant>, Error> {
@@ -148,7 +148,7 @@ pub(crate) async fn get_ban<Z: NetworkZone>(
 }
 
 /// [`AddressBookRequest::GetBans`]
-pub(crate) async fn get_bans<Z: NetworkZone>(
+pub async fn get_bans<Z: NetworkZone>(
     address_book: &mut impl AddressBook<Z>,
 ) -> Result<Vec<BanState<Z::Addr>>, Error> {
     let AddressBookResponse::GetBans(bans) = address_book
@@ -166,7 +166,7 @@ pub(crate) async fn get_bans<Z: NetworkZone>(
 }
 
 /// [`AddressBookRequest::Peerlist`]
-pub(crate) async fn peerlist<Z: NetworkZone>(
+pub async fn peerlist<Z: NetworkZone>(
     address_book: &mut impl AddressBook<Z>,
 ) -> Result<(Vec<Peer>, Vec<Peer>), Error> {
     let AddressBookResponse::Peerlist(peerlist) = address_book

binaries/cuprated/src/rpc/service/blockchain.rs

@@ -14,13 +14,15 @@ use cuprate_helper::cast::{u64_to_usize, usize_to_u64};
 use cuprate_types::{
     blockchain::{BlockchainReadRequest, BlockchainResponse},
     rpc::{
-        ChainInfo, CoinbaseTxSum, KeyImageSpentStatus, OutputHistogramEntry, OutputHistogramInput,
+        ChainInfo, CoinbaseTxSum, KeyImageSpentStatus, OutputDistributionData,
+        OutputHistogramEntry, OutputHistogramInput,
     },
-    BlockCompleteEntry, Chain, ExtendedBlockHeader, OutputOnChain, TxInBlockchain,
+    BlockCompleteEntry, Chain, ExtendedBlockHeader, OutputDistributionInput, OutputOnChain,
+    TxInBlockchain,
 };
 
 /// [`BlockchainReadRequest::Block`].
-pub(crate) async fn block(
+pub async fn block(
     blockchain_read: &mut BlockchainReadHandle,
     height: u64,
 ) -> Result<Block, Error> {
@@ -39,7 +41,7 @@ pub(crate) async fn block(
 }
 
 /// [`BlockchainReadRequest::BlockByHash`].
-pub(crate) async fn block_by_hash(
+pub async fn block_by_hash(
     blockchain_read: &mut BlockchainReadHandle,
     hash: [u8; 32],
 ) -> Result<Block, Error> {
@@ -56,7 +58,7 @@ pub(crate) async fn block_by_hash(
 }
 
 /// [`BlockchainReadRequest::BlockExtendedHeader`].
-pub(crate) async fn block_extended_header(
+pub async fn block_extended_header(
     blockchain_read: &mut BlockchainReadHandle,
     height: u64,
 ) -> Result<ExtendedBlockHeader, Error> {
@@ -75,7 +77,7 @@ pub(crate) async fn block_extended_header(
 }
 
 /// [`BlockchainReadRequest::BlockHash`].
-pub(crate) async fn block_hash(
+pub async fn block_hash(
     blockchain_read: &mut BlockchainReadHandle,
     height: u64,
     chain: Chain,
@@ -96,7 +98,7 @@ pub(crate) async fn block_hash(
 }
 
 /// [`BlockchainReadRequest::FindBlock`].
-pub(crate) async fn find_block(
+pub async fn find_block(
     blockchain_read: &mut BlockchainReadHandle,
     block_hash: [u8; 32],
 ) -> Result<Option<(Chain, usize)>, Error> {
@@ -113,7 +115,7 @@ pub(crate) async fn find_block(
 }
 
 /// [`BlockchainReadRequest::FilterUnknownHashes`].
-pub(crate) async fn filter_unknown_hashes(
+pub async fn filter_unknown_hashes(
     blockchain_read: &mut BlockchainReadHandle,
     block_hashes: HashSet<[u8; 32]>,
 ) -> Result<HashSet<[u8; 32]>, Error> {
@@ -130,7 +132,7 @@ pub(crate) async fn filter_unknown_hashes(
 }
 
 /// [`BlockchainReadRequest::BlockExtendedHeaderInRange`]
-pub(crate) async fn block_extended_header_in_range(
+pub async fn block_extended_header_in_range(
     blockchain_read: &mut BlockchainReadHandle,
     range: Range<usize>,
     chain: Chain,
@@ -150,7 +152,7 @@ pub(crate) async fn block_extended_header_in_range(
 }
 
 /// [`BlockchainReadRequest::ChainHeight`].
-pub(crate) async fn chain_height(
+pub async fn chain_height(
     blockchain_read: &mut BlockchainReadHandle,
 ) -> Result<(u64, [u8; 32]), Error> {
     let BlockchainResponse::ChainHeight(height, hash) = blockchain_read
@@ -166,7 +168,7 @@ pub(crate) async fn chain_height(
 }
 
 /// [`BlockchainReadRequest::GeneratedCoins`].
-pub(crate) async fn generated_coins(
+pub async fn generated_coins(
     blockchain_read: &mut BlockchainReadHandle,
     block_height: u64,
 ) -> Result<u64, Error> {
@@ -185,7 +187,7 @@ pub(crate) async fn generated_coins(
 }
 
 /// [`BlockchainReadRequest::Outputs`]
-pub(crate) async fn outputs(
+pub async fn outputs(
     blockchain_read: &mut BlockchainReadHandle,
     outputs: HashMap<u64, HashSet<u64>>,
 ) -> Result<HashMap<u64, HashMap<u64, OutputOnChain>>, Error> {
@@ -202,7 +204,7 @@ pub(crate) async fn outputs(
 }
 
 /// [`BlockchainReadRequest::NumberOutputsWithAmount`]
-pub(crate) async fn number_outputs_with_amount(
+pub async fn number_outputs_with_amount(
     blockchain_read: &mut BlockchainReadHandle,
     output_amounts: Vec<u64>,
 ) -> Result<HashMap<u64, usize>, Error> {
@@ -221,7 +223,7 @@ pub(crate) async fn number_outputs_with_amount(
 }
 
 /// [`BlockchainReadRequest::KeyImagesSpent`]
-pub(crate) async fn key_images_spent(
+pub async fn key_images_spent(
     blockchain_read: &mut BlockchainReadHandle,
     key_images: Vec<[u8; 32]>,
 ) -> Result<Vec<bool>, Error> {
@@ -238,7 +240,7 @@ pub(crate) async fn key_images_spent(
 }
 
 /// [`BlockchainReadRequest::CompactChainHistory`]
-pub(crate) async fn compact_chain_history(
+pub async fn compact_chain_history(
     blockchain_read: &mut BlockchainReadHandle,
 ) -> Result<(Vec<[u8; 32]>, u128), Error> {
     let BlockchainResponse::CompactChainHistory {
@@ -257,7 +259,7 @@ pub(crate) async fn compact_chain_history(
 }
 
 /// [`BlockchainReadRequest::FindFirstUnknown`]
-pub(crate) async fn find_first_unknown(
+pub async fn find_first_unknown(
     blockchain_read: &mut BlockchainReadHandle,
     hashes: Vec<[u8; 32]>,
 ) -> Result<Option<(usize, u64)>, Error> {
@@ -274,9 +276,7 @@ pub(crate) async fn find_first_unknown(
 }
 
 /// [`BlockchainReadRequest::TotalTxCount`]
-pub(crate) async fn total_tx_count(
-    blockchain_read: &mut BlockchainReadHandle,
-) -> Result<u64, Error> {
+pub async fn total_tx_count(blockchain_read: &mut BlockchainReadHandle) -> Result<u64, Error> {
     let BlockchainResponse::TotalTxCount(tx_count) = blockchain_read
         .ready()
         .await?
@@ -290,7 +290,7 @@ pub(crate) async fn total_tx_count(
 }
 
 /// [`BlockchainReadRequest::DatabaseSize`]
-pub(crate) async fn database_size(
+pub async fn database_size(
     blockchain_read: &mut BlockchainReadHandle,
 ) -> Result<(u64, u64), Error> {
     let BlockchainResponse::DatabaseSize {
@@ -308,8 +308,25 @@ pub(crate) async fn database_size(
     Ok((database_size, free_space))
 }
 
+/// [`BlockchainReadRequest::OutputDistribution`]
+pub async fn output_distribution(
+    blockchain_read: &mut BlockchainReadHandle,
+    input: OutputDistributionInput,
+) -> Result<Vec<OutputDistributionData>, Error> {
+    let BlockchainResponse::OutputDistribution(data) = blockchain_read
+        .ready()
+        .await?
+        .call(BlockchainReadRequest::OutputDistribution(input))
+        .await?
+    else {
+        unreachable!();
+    };
+
+    Ok(data)
+}
+
 /// [`BlockchainReadRequest::OutputHistogram`]
-pub(crate) async fn output_histogram(
+pub async fn output_histogram(
     blockchain_read: &mut BlockchainReadHandle,
     input: OutputHistogramInput,
 ) -> Result<Vec<OutputHistogramEntry>, Error> {
@@ -326,7 +343,7 @@ pub(crate) async fn output_histogram(
 }
 
 /// [`BlockchainReadRequest::CoinbaseTxSum`]
-pub(crate) async fn coinbase_tx_sum(
+pub async fn coinbase_tx_sum(
     blockchain_read: &mut BlockchainReadHandle,
     height: u64,
     count: u64,
@@ -347,7 +364,7 @@ pub(crate) async fn coinbase_tx_sum(
 }
 
 /// [`BlockchainReadRequest::AltChains`]
-pub(crate) async fn alt_chains(
+pub async fn alt_chains(
     blockchain_read: &mut BlockchainReadHandle,
 ) -> Result<Vec<ChainInfo>, Error> {
     let BlockchainResponse::AltChains(vec) = blockchain_read
@@ -363,9 +380,7 @@ pub(crate) async fn alt_chains(
 }
 
 /// [`BlockchainReadRequest::AltChainCount`]
-pub(crate) async fn alt_chain_count(
-    blockchain_read: &mut BlockchainReadHandle,
-) -> Result<u64, Error> {
+pub async fn alt_chain_count(blockchain_read: &mut BlockchainReadHandle) -> Result<u64, Error> {
     let BlockchainResponse::AltChainCount(count) = blockchain_read
         .ready()
         .await?
@@ -379,7 +394,7 @@ pub(crate) async fn alt_chain_count(
 }
 
 /// [`BlockchainReadRequest::Transactions`].
-pub(crate) async fn transactions(
+pub async fn transactions(
     blockchain_read: &mut BlockchainReadHandle,
     tx_hashes: HashSet<[u8; 32]>,
 ) -> Result<(Vec<TxInBlockchain>, Vec<[u8; 32]>), Error> {
@@ -396,9 +411,7 @@ pub(crate) async fn transactions(
 }
 
 /// [`BlockchainReadRequest::TotalRctOutputs`].
-pub(crate) async fn total_rct_outputs(
-    blockchain_read: &mut BlockchainReadHandle,
-) -> Result<u64, Error> {
+pub async fn total_rct_outputs(blockchain_read: &mut BlockchainReadHandle) -> Result<u64, Error> {
     let BlockchainResponse::TotalRctOutputs(n) = blockchain_read
         .ready()
         .await?
@@ -412,7 +425,7 @@ pub(crate) async fn total_rct_outputs(
 }
 
 /// [`BlockchainReadRequest::BlockCompleteEntries`].
-pub(crate) async fn block_complete_entries(
+pub async fn block_complete_entries(
     blockchain_read: &mut BlockchainReadHandle,
     block_hashes: Vec<[u8; 32]>,
 ) -> Result<(Vec<BlockCompleteEntry>, Vec<[u8; 32]>, usize), Error> {
@@ -433,7 +446,7 @@ pub(crate) async fn block_complete_entries(
 }
 
 /// [`BlockchainReadRequest::BlockCompleteEntriesByHeight`].
-pub(crate) async fn block_complete_entries_by_height(
+pub async fn block_complete_entries_by_height(
     blockchain_read: &mut BlockchainReadHandle,
     block_heights: Vec<u64>,
 ) -> Result<Vec<BlockCompleteEntry>, Error> {
@@ -452,7 +465,7 @@ pub(crate) async fn block_complete_entries_by_height(
 }
 
 /// [`BlockchainReadRequest::TxOutputIndexes`].
-pub(crate) async fn tx_output_indexes(
+pub async fn tx_output_indexes(
     blockchain_read: &mut BlockchainReadHandle,
     tx_hash: [u8; 32],
 ) -> Result<Vec<u64>, Error> {

binaries/cuprated/src/rpc/service/blockchain_context.rs

@@ -16,7 +16,7 @@ use cuprate_types::{
 // FIXME: use `anyhow::Error` over `tower::BoxError` in blockchain context.
 
 /// [`BlockChainContextRequest::Context`].
-pub(crate) async fn context(
+pub async fn context(
     blockchain_context: &mut BlockChainContextService,
 ) -> Result<BlockChainContext, Error> {
     let BlockChainContextResponse::Context(context) = blockchain_context
@@ -34,7 +34,7 @@ pub(crate) async fn context(
 }
 
 /// [`BlockChainContextRequest::HardForkInfo`].
-pub(crate) async fn hard_fork_info(
+pub async fn hard_fork_info(
     blockchain_context: &mut BlockChainContextService,
     hard_fork: HardFork,
 ) -> Result<HardForkInfo, Error> {
@@ -53,7 +53,7 @@ pub(crate) async fn hard_fork_info(
 }
 
 /// [`BlockChainContextRequest::FeeEstimate`].
-pub(crate) async fn fee_estimate(
+pub async fn fee_estimate(
     blockchain_context: &mut BlockChainContextService,
     grace_blocks: u64,
 ) -> Result<FeeEstimate, Error> {
@@ -72,7 +72,7 @@ pub(crate) async fn fee_estimate(
 }
 
 /// [`BlockChainContextRequest::CalculatePow`]
-pub(crate) async fn calculate_pow(
+pub async fn calculate_pow(
     blockchain_context: &mut BlockChainContextService,
     hardfork: HardFork,
     block: Block,
@@ -104,7 +104,7 @@ pub(crate) async fn calculate_pow(
 }
 
 /// [`BlockChainContextRequest::BatchGetDifficulties`]
-pub(crate) async fn batch_get_difficulties(
+pub async fn batch_get_difficulties(
     blockchain_context: &mut BlockChainContextService,
     difficulties: Vec<(u64, HardFork)>,
 ) -> Result<Vec<u128>, Error> {

binaries/cuprated/src/rpc/service/blockchain_manager.rs

@@ -10,12 +10,12 @@ use cuprate_p2p_core::{types::ConnectionId, NetworkZone};
 use cuprate_pruning::PruningSeed;
 use cuprate_rpc_types::misc::Span;
 
-use crate::rpc::handler::{
+use crate::rpc::rpc_handler::{
     BlockchainManagerHandle, BlockchainManagerRequest, BlockchainManagerResponse,
 };
 
 /// [`BlockchainManagerRequest::PopBlocks`]
-pub(crate) async fn pop_blocks(
+pub async fn pop_blocks(
     blockchain_manager: &mut BlockchainManagerHandle,
     amount: u64,
 ) -> Result<u64, Error> {
@@ -34,9 +34,7 @@ pub(crate) async fn pop_blocks(
 }
 
 /// [`BlockchainManagerRequest::Prune`]
-pub(crate) async fn prune(
-    blockchain_manager: &mut BlockchainManagerHandle,
-) -> Result<PruningSeed, Error> {
+pub async fn prune(blockchain_manager: &mut BlockchainManagerHandle) -> Result<PruningSeed, Error> {
     let BlockchainManagerResponse::Prune(seed) = blockchain_manager
         .ready()
         .await?
@@ -50,9 +48,7 @@ pub(crate) async fn prune(
 }
 
 /// [`BlockchainManagerRequest::Pruned`]
-pub(crate) async fn pruned(
-    blockchain_manager: &mut BlockchainManagerHandle,
-) -> Result<bool, Error> {
+pub async fn pruned(blockchain_manager: &mut BlockchainManagerHandle) -> Result<bool, Error> {
     let BlockchainManagerResponse::Pruned(pruned) = blockchain_manager
         .ready()
         .await?
@@ -66,7 +62,7 @@ pub(crate) async fn pruned(
 }
 
 /// [`BlockchainManagerRequest::RelayBlock`]
-pub(crate) async fn relay_block(
+pub async fn relay_block(
     blockchain_manager: &mut BlockchainManagerHandle,
     block: Box<Block>,
 ) -> Result<(), Error> {
@@ -83,9 +79,7 @@ pub(crate) async fn relay_block(
 }
 
 /// [`BlockchainManagerRequest::Syncing`]
-pub(crate) async fn syncing(
-    blockchain_manager: &mut BlockchainManagerHandle,
-) -> Result<bool, Error> {
+pub async fn syncing(blockchain_manager: &mut BlockchainManagerHandle) -> Result<bool, Error> {
     let BlockchainManagerResponse::Syncing(syncing) = blockchain_manager
         .ready()
         .await?
@@ -99,9 +93,7 @@ pub(crate) async fn syncing(
 }
 
 /// [`BlockchainManagerRequest::Synced`]
-pub(crate) async fn synced(
-    blockchain_manager: &mut BlockchainManagerHandle,
-) -> Result<bool, Error> {
+pub async fn synced(blockchain_manager: &mut BlockchainManagerHandle) -> Result<bool, Error> {
     let BlockchainManagerResponse::Synced(syncing) = blockchain_manager
         .ready()
         .await?
@@ -115,7 +107,7 @@ pub(crate) async fn synced(
 }
 
 /// [`BlockchainManagerRequest::Target`]
-pub(crate) async fn target(
+pub async fn target(
     blockchain_manager: &mut BlockchainManagerHandle,
 ) -> Result<std::time::Duration, Error> {
     let BlockchainManagerResponse::Target(target) = blockchain_manager
@@ -131,9 +123,7 @@ pub(crate) async fn target(
 }
 
 /// [`BlockchainManagerRequest::TargetHeight`]
-pub(crate) async fn target_height(
-    blockchain_manager: &mut BlockchainManagerHandle,
-) -> Result<u64, Error> {
+pub async fn target_height(blockchain_manager: &mut BlockchainManagerHandle) -> Result<u64, Error> {
     let BlockchainManagerResponse::TargetHeight { height } = blockchain_manager
         .ready()
         .await?
@@ -147,7 +137,7 @@ pub(crate) async fn target_height(
 }
 
 /// [`BlockchainManagerRequest::GenerateBlocks`]
-pub(crate) async fn generate_blocks(
+pub async fn generate_blocks(
     blockchain_manager: &mut BlockchainManagerHandle,
     amount_of_blocks: u64,
     prev_block: Option<[u8; 32]>,
@@ -172,7 +162,7 @@ pub(crate) async fn generate_blocks(
 }
 
 // [`BlockchainManagerRequest::Spans`]
-pub(crate) async fn spans<Z: NetworkZone>(
+pub async fn spans<Z: NetworkZone>(
     blockchain_manager: &mut BlockchainManagerHandle,
 ) -> Result<Vec<Span>, Error> {
     // let BlockchainManagerResponse::Spans(vec) = blockchain_manager
@@ -205,7 +195,7 @@ pub(crate) async fn spans<Z: NetworkZone>(
 }
 
 /// [`BlockchainManagerRequest::NextNeededPruningSeed`]
-pub(crate) async fn next_needed_pruning_seed(
+pub async fn next_needed_pruning_seed(
     blockchain_manager: &mut BlockchainManagerHandle,
 ) -> Result<PruningSeed, Error> {
     let BlockchainManagerResponse::NextNeededPruningSeed(seed) = blockchain_manager
@@ -221,7 +211,7 @@ pub(crate) async fn next_needed_pruning_seed(
 }
 
 /// [`BlockchainManagerRequest::CreateBlockTemplate`]
-pub(crate) async fn create_block_template(
+pub async fn create_block_template(
     blockchain_manager: &mut BlockchainManagerHandle,
     prev_block: [u8; 32],
     account_public_address: String,
@@ -244,7 +234,7 @@ pub(crate) async fn create_block_template(
 }
 
 /// [`BlockchainManagerRequest::Sync`]
-pub(crate) async fn sync(blockchain_manager: &mut BlockchainManagerHandle) -> Result<(), Error> {
+pub async fn sync(blockchain_manager: &mut BlockchainManagerHandle) -> Result<(), Error> {
     let BlockchainManagerResponse::Ok = blockchain_manager
         .ready()
         .await?
@@ -258,7 +248,7 @@ pub(crate) async fn sync(blockchain_manager: &mut BlockchainManagerHandle) -> Re
 }
 
 /// [`BlockchainManagerRequest::Stop`]
-pub(crate) async fn stop(blockchain_manager: &mut BlockchainManagerHandle) -> Result<(), Error> {
+pub async fn stop(blockchain_manager: &mut BlockchainManagerHandle) -> Result<(), Error> {
     let BlockchainManagerResponse::Ok = blockchain_manager
         .ready()
         .await?

binaries/cuprated/src/rpc/service/txpool.rs

@@ -23,7 +23,7 @@ use cuprate_types::{
 // FIXME: use `anyhow::Error` over `tower::BoxError` in txpool.
 
 /// [`TxpoolReadRequest::Backlog`]
-pub(crate) async fn backlog(txpool_read: &mut TxpoolReadHandle) -> Result<Vec<TxEntry>, Error> {
+pub async fn backlog(txpool_read: &mut TxpoolReadHandle) -> Result<Vec<TxEntry>, Error> {
     let TxpoolReadResponse::Backlog(tx_entries) = txpool_read
         .ready()
         .await
@@ -39,7 +39,7 @@ pub(crate) async fn backlog(txpool_read: &mut TxpoolReadHandle) -> Result<Vec<Tx
 }
 
 /// [`TxpoolReadRequest::Size`]
-pub(crate) async fn size(
+pub async fn size(
     txpool_read: &mut TxpoolReadHandle,
     include_sensitive_txs: bool,
 ) -> Result<u64, Error> {
@@ -60,7 +60,7 @@ pub(crate) async fn size(
 }
 
 /// TODO
-pub(crate) async fn pool_info(
+pub async fn pool_info(
     txpool_read: &mut TxpoolReadHandle,
     include_sensitive_txs: bool,
     max_tx_count: usize,
@@ -85,7 +85,7 @@ pub(crate) async fn pool_info(
 }
 
 /// TODO
-pub(crate) async fn txs_by_hash(
+pub async fn txs_by_hash(
     txpool_read: &mut TxpoolReadHandle,
     tx_hashes: Vec<[u8; 32]>,
     include_sensitive_txs: bool,
@@ -108,7 +108,7 @@ pub(crate) async fn txs_by_hash(
 }
 
 /// TODO
-pub(crate) async fn key_images_spent(
+pub async fn key_images_spent(
     txpool_read: &mut TxpoolReadHandle,
     key_images: Vec<[u8; 32]>,
     include_sensitive_txs: bool,
@@ -131,7 +131,7 @@ pub(crate) async fn key_images_spent(
 }
 
 /// TODO
-pub(crate) async fn pool(
+pub async fn pool(
     txpool_read: &mut TxpoolReadHandle,
     include_sensitive_txs: bool,
 ) -> Result<(Vec<TxInfo>, Vec<SpentKeyImageInfo>), Error> {
@@ -158,7 +158,7 @@ pub(crate) async fn pool(
 }
 
 /// TODO
-pub(crate) async fn pool_stats(
+pub async fn pool_stats(
     txpool_read: &mut TxpoolReadHandle,
     include_sensitive_txs: bool,
 ) -> Result<TxpoolStats, Error> {
@@ -179,25 +179,19 @@ pub(crate) async fn pool_stats(
 }
 
 /// TODO
-pub(crate) async fn flush(
-    txpool_manager: &mut Infallible,
-    tx_hashes: Vec<[u8; 32]>,
-) -> Result<(), Error> {
+pub async fn flush(txpool_manager: &mut Infallible, tx_hashes: Vec<[u8; 32]>) -> Result<(), Error> {
     todo!();
     Ok(())
 }
 
 /// TODO
-pub(crate) async fn relay(
-    txpool_manager: &mut Infallible,
-    tx_hashes: Vec<[u8; 32]>,
-) -> Result<(), Error> {
+pub async fn relay(txpool_manager: &mut Infallible, tx_hashes: Vec<[u8; 32]>) -> Result<(), Error> {
     todo!();
     Ok(())
 }
 
 /// TODO
-pub(crate) async fn check_maybe_relay_local(
+pub async fn check_maybe_relay_local(
     txpool_manager: &mut Infallible,
     tx: Transaction,
     relay: bool,

rpc/interface/src/route/json_rpc.rs

@@ -1,15 +1,10 @@
 //! JSON-RPC 2.0 endpoint route functions.
 
 //---------------------------------------------------------------------------------------------------- Import
-use std::borrow::Cow;
-
 use axum::{extract::State, http::StatusCode, Json};
 use tower::ServiceExt;
 
-use cuprate_json_rpc::{
-    error::{ErrorCode, ErrorObject},
-    Id, Response,
-};
+use cuprate_json_rpc::{Id, Response};
 use cuprate_rpc_types::{
     json::{JsonRpcRequest, JsonRpcResponse},
     RpcCallValue,

rpc/interface/src/route/mod.rs

@@ -6,4 +6,4 @@
 pub(crate) mod bin;
 pub(crate) mod fallback;
 pub(crate) mod json_rpc;
-pub(crate) mod other;
+pub(crate) mod other_json;

rpc/interface/src/router_builder.rs

@@ -4,7 +4,7 @@
 use axum::Router;
 
 use crate::{
-    route::{bin, fallback, json_rpc, other},
+    route::{bin, fallback, json_rpc, other_json},
     rpc_handler::RpcHandler,
 };
 
@@ -140,36 +140,36 @@ generate_router_builder! {
     json_rpc => "/json_rpc" => json_rpc::json_rpc => (get, post),
 
     // Other JSON routes.
-    other_get_height                  => "/get_height"                  => other::get_height                  => (get, post),
-    other_getheight                   => "/getheight"                   => other::get_height                  => (get, post),
-    other_get_transactions            => "/get_transactions"            => other::get_transactions            => (get, post),
-    other_gettransactions             => "/gettransactions"             => other::get_transactions            => (get, post),
-    other_get_alt_blocks_hashes       => "/get_alt_blocks_hashes"       => other::get_alt_blocks_hashes       => (get, post),
-    other_is_key_image_spent          => "/is_key_image_spent"          => other::is_key_image_spent          => (get, post),
-    other_send_raw_transaction        => "/send_raw_transaction"        => other::send_raw_transaction        => (get, post),
-    other_sendrawtransaction          => "/sendrawtransaction"          => other::send_raw_transaction        => (get, post),
-    other_start_mining                => "/start_mining"                => other::start_mining                => (get, post),
-    other_stop_mining                 => "/stop_mining"                 => other::stop_mining                 => (get, post),
-    other_mining_status               => "/mining_status"               => other::mining_status               => (get, post),
-    other_save_bc                     => "/save_bc"                     => other::save_bc                     => (get, post),
-    other_get_peer_list               => "/get_peer_list"               => other::get_peer_list               => (get, post),
-    other_get_public_nodes            => "/get_public_nodes"            => other::get_public_nodes            => (get, post),
-    other_set_log_hash_rate           => "/set_log_hash_rate"           => other::set_log_hash_rate           => (get, post),
-    other_set_log_level               => "/set_log_level"               => other::set_log_level               => (get, post),
-    other_set_log_categories          => "/set_log_categories"          => other::set_log_categories          => (get, post),
-    other_get_transaction_pool        => "/get_transaction_pool"        => other::get_transaction_pool        => (get, post),
-    other_get_transaction_pool_hashes => "/get_transaction_pool_hashes" => other::get_transaction_pool_hashes => (get, post),
-    other_get_transaction_pool_stats  => "/get_transaction_pool_stats"  => other::get_transaction_pool_stats  => (get, post),
-    other_set_bootstrap_daemon        => "/set_bootstrap_daemon"        => other::set_bootstrap_daemon        => (get, post),
-    other_stop_daemon                 => "/stop_daemon"                 => other::stop_daemon                 => (get, post),
-    other_get_net_stats               => "/get_net_stats"               => other::get_net_stats               => (get, post),
-    other_get_limit                   => "/get_limit"                   => other::get_limit                   => (get, post),
-    other_set_limit                   => "/set_limit"                   => other::set_limit                   => (get, post),
-    other_out_peers                   => "/out_peers"                   => other::out_peers                   => (get, post),
-    other_in_peers                    => "/in_peers"                    => other::in_peers                    => (get, post),
-    other_get_outs                    => "/get_outs"                    => other::get_outs                    => (get, post),
-    other_update                      => "/update"                      => other::update                      => (get, post),
-    other_pop_blocks                  => "/pop_blocks"                  => other::pop_blocks                  => (get, post),
+    other_get_height                  => "/get_height"                  => other_json::get_height                  => (get, post),
+    other_getheight                   => "/getheight"                   => other_json::get_height                  => (get, post),
+    other_get_transactions            => "/get_transactions"            => other_json::get_transactions            => (get, post),
+    other_gettransactions             => "/gettransactions"             => other_json::get_transactions            => (get, post),
+    other_get_alt_blocks_hashes       => "/get_alt_blocks_hashes"       => other_json::get_alt_blocks_hashes       => (get, post),
+    other_is_key_image_spent          => "/is_key_image_spent"          => other_json::is_key_image_spent          => (get, post),
+    other_send_raw_transaction        => "/send_raw_transaction"        => other_json::send_raw_transaction        => (get, post),
+    other_sendrawtransaction          => "/sendrawtransaction"          => other_json::send_raw_transaction        => (get, post),
+    other_start_mining                => "/start_mining"                => other_json::start_mining                => (get, post),
+    other_stop_mining                 => "/stop_mining"                 => other_json::stop_mining                 => (get, post),
+    other_mining_status               => "/mining_status"               => other_json::mining_status               => (get, post),
+    other_save_bc                     => "/save_bc"                     => other_json::save_bc                     => (get, post),
+    other_get_peer_list               => "/get_peer_list"               => other_json::get_peer_list               => (get, post),
+    other_get_public_nodes            => "/get_public_nodes"            => other_json::get_public_nodes            => (get, post),
+    other_set_log_hash_rate           => "/set_log_hash_rate"           => other_json::set_log_hash_rate           => (get, post),
+    other_set_log_level               => "/set_log_level"               => other_json::set_log_level               => (get, post),
+    other_set_log_categories          => "/set_log_categories"          => other_json::set_log_categories          => (get, post),
+    other_get_transaction_pool        => "/get_transaction_pool"        => other_json::get_transaction_pool        => (get, post),
+    other_get_transaction_pool_hashes => "/get_transaction_pool_hashes" => other_json::get_transaction_pool_hashes => (get, post),
+    other_get_transaction_pool_stats  => "/get_transaction_pool_stats"  => other_json::get_transaction_pool_stats  => (get, post),
+    other_set_bootstrap_daemon        => "/set_bootstrap_daemon"        => other_json::set_bootstrap_daemon        => (get, post),
+    other_stop_daemon                 => "/stop_daemon"                 => other_json::stop_daemon                 => (get, post),
+    other_get_net_stats               => "/get_net_stats"               => other_json::get_net_stats               => (get, post),
+    other_get_limit                   => "/get_limit"                   => other_json::get_limit                   => (get, post),
+    other_set_limit                   => "/set_limit"                   => other_json::set_limit                   => (get, post),
+    other_out_peers                   => "/out_peers"                   => other_json::out_peers                   => (get, post),
+    other_in_peers                    => "/in_peers"                    => other_json::in_peers                    => (get, post),
+    other_get_outs                    => "/get_outs"                    => other_json::get_outs                    => (get, post),
+    other_update                      => "/update"                      => other_json::update                      => (get, post),
+    other_pop_blocks                  => "/pop_blocks"                  => other_json::pop_blocks                  => (get, post),
 
     // Binary routes.
     bin_get_blocks                  => "/get_blocks.bin"                  => bin::get_blocks                  => (get, post),

storage/blockchain/src/service/read.rs

@@ -30,7 +30,7 @@ use cuprate_helper::map::combine_low_high_bits_to_u128;
 use cuprate_types::{
     blockchain::{BlockchainReadRequest, BlockchainResponse},
     rpc::OutputHistogramInput,
-    Chain, ChainId, ExtendedBlockHeader, OutputOnChain, TxsInBlock,
+    Chain, ChainId, ExtendedBlockHeader, OutputDistributionInput, OutputOnChain, TxsInBlock,
 };
 
 use crate::{
@@ -142,6 +142,7 @@ fn map_request(
         R::Transactions { tx_hashes } => transactions(env, tx_hashes),
         R::TotalRctOutputs => total_rct_outputs(env),
         R::TxOutputIndexes { tx_hash } => tx_output_indexes(env, &tx_hash),
+        R::OutputDistribution(input) => output_distribution(env, input),
     }
 
     /* SOMEDAY: post-request handling, run some code for each request? */
@@ -832,3 +833,8 @@ fn tx_output_indexes(env: &ConcreteEnv, tx_hash: &[u8; 32]) -> ResponseResult {
 
     Ok(BlockchainResponse::TxOutputIndexes(o_indexes.0))
 }
+
+/// [`BlockchainReadRequest::OutputDistribution`]
+fn output_distribution(env: &ConcreteEnv, input: OutputDistributionInput) -> ResponseResult {
+    Ok(BlockchainResponse::OutputDistribution(todo!()))
+}

types/types/src/blockchain.rs

@@ -11,9 +11,12 @@ use std::{
 use monero_serai::block::Block;
 
 use crate::{
-    rpc::{ChainInfo, CoinbaseTxSum, OutputHistogramEntry, OutputHistogramInput},
+    rpc::{
+        ChainInfo, CoinbaseTxSum, OutputDistributionData, OutputHistogramEntry,
+        OutputHistogramInput,
+    },
     types::{Chain, ExtendedBlockHeader, OutputOnChain, TxsInBlock, VerifiedBlockInformation},
-    AltBlockInformation, BlockCompleteEntry, ChainId, TxInBlockchain,
+    AltBlockInformation, BlockCompleteEntry, ChainId, OutputDistributionInput, TxInBlockchain,
 };
 
 //---------------------------------------------------------------------------------------------------- ReadRequest
@@ -154,6 +157,12 @@ pub enum BlockchainReadRequest {
     /// TODO: document fields after impl.
     OutputHistogram(OutputHistogramInput),
 
+    /// Get the distribution for an output amount.
+    ///
+    /// - TODO: document fields after impl.
+    /// - TODO: <https://github.com/monero-project/monero/blob/893916ad091a92e765ce3241b94e706ad012b62a/src/rpc/rpc_handler.cpp#L29>
+    OutputDistribution(OutputDistributionInput),
+
     /// Get the coinbase amount and the fees amount for
     /// `N` last blocks starting at particular height.
     ///
@@ -352,6 +361,9 @@ pub enum BlockchainResponse {
         free_space: u64,
     },
 
+    /// Response to [`BlockchainReadRequest::OutputDistribution`].
+    OutputDistribution(Vec<OutputDistributionData>),
+
     /// Response to [`BlockchainReadRequest::OutputHistogram`].
     OutputHistogram(Vec<OutputHistogramEntry>),
 

types/types/src/lib.rs

@@ -24,9 +24,9 @@ pub use transaction_verification_data::{
     CachedVerificationState, TransactionVerificationData, TxVersion,
 };
 pub use types::{
-    AltBlockInformation, BlockTemplate, Chain, ChainId, ExtendedBlockHeader, OutputOnChain,
-    TxInBlockchain, TxInPool, TxRelayChecks, TxsInBlock, VerifiedBlockInformation,
-    VerifiedTransactionInformation,
+    AltBlockInformation, BlockTemplate, Chain, ChainId, ExtendedBlockHeader,
+    OutputDistributionInput, OutputOnChain, TxInBlockchain, TxInPool, TxRelayChecks, TxsInBlock,
+    VerifiedBlockInformation, VerifiedTransactionInformation,
 };
 
 //---------------------------------------------------------------------------------------------------- Feature-gated

types/types/src/rpc/types.rs

@@ -253,6 +253,7 @@ define_struct_and_impl_epee! {
         45..=50
     )]
     OutputDistributionData {
+        amount: u64,
         distribution: Vec<u64>,
         start_height: u64,
         base: u64,

types/types/src/types.rs

@@ -208,6 +208,17 @@ bitflags::bitflags! {
     }
 }
 
+/// Used in RPC's `get_output_distribution`.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct OutputDistributionInput {
+    pub amounts: Vec<u64>,
+    pub cumulative: bool,
+    pub from_height: u64,
+
+    /// [`None`] means the entire blockchain.
+    pub to_height: Option<NonZero<u64>>,
+}
+
 //---------------------------------------------------------------------------------------------------- Tests
 #[cfg(test)]
 mod test {