Put snapshot download & snapshot message compute behind a 'fs' feature

- This feature is disabled by default
- A `full` feature is also added to enable it and any other features that we
  would add in the future

Author: Alenar

mithril-client/Cargo.toml

@@ -13,25 +13,35 @@ include = ["**/*.rs", "Cargo.toml", "README.md", ".gitignore"]
 [lib]
 crate-type = ["lib", "cdylib", "staticlib"]
 
+[[example]]
+name = "snapshot_list_get_show_download_verify"
+path = "examples/snapshot_list_get_show_download_verify.rs"
+required-features = ["fs"]
+
+[[test]]
+name = "snapshot_list_get_show_download_verify"
+path = "tests/snapshot_list_get_show_download_verify.rs"
+required-features = ["fs"]
+
 [dependencies]
 anyhow = "1.0.75"
 async-recursion = "1.0.5"
 async-trait = "0.1.73"
 chrono = { version = "0.4.31", features = ["serde"] }
-flate2 = "1.0.27"
-flume = "0.11.0"
+flate2 = { version = "1.0.27", optional = true }
+flume = { version = "0.11.0", optional = true }
 futures = "0.3.28"
 mithril-common = { path = "../mithril-common", version = "0.2" }
 reqwest = { version = "0.11.22", features = ["json", "stream"] }
 semver = "1.0.19"
 serde = { version = "1.0.188", features = ["derive"] }
 serde_json = "1.0.107"
 slog = "2.7.0"
-tar = "0.4.40"
+tar = { version = "0.4.40", optional = true }
 thiserror = "1.0.49"
 tokio = { version = "1.32.0", features = ["sync"] }
 uuid = { version = "1.5.0", features = ["v4"] }
-zstd = "0.13.0"
+zstd = { version = "0.13.0", optional = true }
 
 [dev-dependencies]
 httpmock = "0.6.8"
@@ -47,4 +57,14 @@ tokio = { version = "1.32.0", features = ["macros", "rt"] }
 warp = "0.3"
 
 [features]
+# Include nothing by default
+default = []
+full = ["fs"]
+# Enable file system releated functionnality, right now that mean ony snapshot download
+fs = ["flate2", "flume", "tar", "tokio/rt", "zstd"]
 portable = ["mithril-common/portable"]
+
+[package.metadata.docs.rs]
+all-features = true
+# enable unstable features in the documentation
+rustdoc-args = ["--cfg", "docsrs"]

mithril-client/src/client.rs

@@ -5,6 +5,7 @@ use crate::certificate_client::{
 use crate::feedback::{FeedbackReceiver, FeedbackSender};
 use crate::mithril_stake_distribution_client::MithrilStakeDistributionClient;
 use crate::snapshot_client::SnapshotClient;
+#[cfg(feature = "fs")]
 use crate::snapshot_downloader::{HttpSnapshotDownloader, SnapshotDownloader};
 use crate::MithrilResult;
 use anyhow::{anyhow, Context};
@@ -45,6 +46,7 @@ pub struct ClientBuilder {
     genesis_verification_key: String,
     aggregator_client: Option<Arc<dyn AggregatorClient>>,
     certificate_verifier: Option<Arc<dyn CertificateVerifier>>,
+    #[cfg(feature = "fs")]
     snapshot_downloader: Option<Arc<dyn SnapshotDownloader>>,
     logger: Option<Logger>,
     feedback_receivers: Vec<Arc<dyn FeedbackReceiver>>,
@@ -59,6 +61,7 @@ impl ClientBuilder {
             genesis_verification_key: genesis_verification_key.to_string(),
             aggregator_client: None,
             certificate_verifier: None,
+            #[cfg(feature = "fs")]
             snapshot_downloader: None,
             logger: None,
             feedback_receivers: vec![],
@@ -75,6 +78,7 @@ impl ClientBuilder {
             genesis_verification_key: genesis_verification_key.to_string(),
             aggregator_client: None,
             certificate_verifier: None,
+            #[cfg(feature = "fs")]
             snapshot_downloader: None,
             logger: None,
             feedback_receivers: vec![],
@@ -115,6 +119,7 @@ impl ClientBuilder {
             Some(client) => client,
         };
 
+        #[cfg(feature = "fs")]
         let snapshot_downloader = match self.snapshot_downloader {
             None => Arc::new(
                 HttpSnapshotDownloader::new(feedback_sender.clone(), logger.clone())
@@ -146,6 +151,7 @@ impl ClientBuilder {
         ));
         let snapshot_client = Arc::new(SnapshotClient::new(
             aggregator_client,
+            #[cfg(feature = "fs")]
             snapshot_downloader,
             feedback_sender,
             logger,
@@ -176,6 +182,7 @@ impl ClientBuilder {
         self
     }
 
+    cfg_fs! {
     /// Set the [SnapshotDownloader] that will be used to download snapshots.
     pub fn with_snapshot_downloader(
         mut self,
@@ -184,6 +191,7 @@ impl ClientBuilder {
         self.snapshot_downloader = Some(snapshot_downloader);
         self
     }
+    }
 
     /// Set the [Logger] to use.
     pub fn with_logger(mut self, logger: Logger) -> Self {

mithril-client/src/lib.rs

@@ -1,4 +1,5 @@
 #![warn(missing_docs)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 //! Define all the tooling necessary to manipulate Mithril certified types from a
 //! [Mithril Aggregator](https://mithril.network/rust-doc/mithril_aggregator/index.html).
@@ -19,6 +20,8 @@
 //!
 //! Below is an example describing the usage of most of the library's functions together:
 //!
+//! **Note:** _Snapshot download and the compute snapshot message functions are available using crate feature_ **fs**.
+//!
 //! ```no_run
 //! # async fn run() -> mithril_client::MithrilResult<()> {
 //! use mithril_client::{ClientBuilder, MessageBuilder};
@@ -52,14 +55,26 @@
 //! # }
 //! ```
 
+macro_rules! cfg_fs {
+    ($($item:item)*) => {
+        $(
+            #[cfg(feature = "fs")]
+            #[cfg_attr(docsrs, doc(cfg(feature = "fs")))]
+            $item
+        )*
+    }
+}
+
 pub mod aggregator_client;
 pub mod certificate_client;
 mod client;
 pub mod feedback;
 mod message;
 pub mod mithril_stake_distribution_client;
 pub mod snapshot_client;
-pub mod snapshot_downloader;
+cfg_fs! {
+    pub mod snapshot_downloader;
+}
 mod type_alias;
 mod utils;
 

mithril-client/src/message.rs

@@ -25,30 +25,31 @@ impl MessageBuilder {
         }
     }
 
-    /// Set the [ImmutableDigester] to be used for the message computation for snapshot.
-    ///
-    /// If not set a default implementation will be used.
-    pub fn with_immutable_digester(
-        mut self,
-        immutable_digester: Arc<dyn ImmutableDigester>,
-    ) -> Self {
-        self.immutable_digester = Some(immutable_digester);
-        self
-    }
-
     /// Set the [Logger] to use.
     pub fn with_logger(mut self, logger: Logger) -> Self {
         self.logger = logger;
         self
     }
 
+    cfg_fs! {
     fn get_immutable_digester(&self) -> Arc<dyn ImmutableDigester> {
         match self.immutable_digester.as_ref() {
             None => Arc::new(CardanoImmutableDigester::new(None, self.logger.clone())),
             Some(digester) => digester.clone(),
         }
     }
 
+    /// Set the [ImmutableDigester] to be used for the message computation for snapshot.
+    ///
+    /// If not set a default implementation will be used.
+    pub fn with_immutable_digester(
+        mut self,
+        immutable_digester: Arc<dyn ImmutableDigester>,
+    ) -> Self {
+        self.immutable_digester = Some(immutable_digester);
+        self
+    }
+
     /// Compute message for a snapshot (based on the directory where it was unpacked).
     ///
     /// Warning: this operation can be quite long depending on the snapshot size.
@@ -74,6 +75,7 @@ impl MessageBuilder {
 
         Ok(message)
     }
+    }
 
     /// Compute message for a Mithril stake distribution.
     pub fn compute_mithril_stake_distribution_message(

mithril-client/src/snapshot_client.rs

@@ -40,6 +40,7 @@
 //! ```
 //!
 //! # Download a snapshot
+//! **Note:** _Available on crate feature_ **fs** _only._
 //!
 //! To download and simultaneously unpack the tarball of a snapshots using the [ClientBuilder][crate::client::ClientBuilder].
 //!
@@ -63,12 +64,13 @@
 //! ```
 
 use anyhow::Context;
-use slog::{warn, Logger};
-use std::{path::Path, sync::Arc};
+use slog::Logger;
+use std::sync::Arc;
 use thiserror::Error;
 
 use crate::aggregator_client::{AggregatorClient, AggregatorClientError, AggregatorRequest};
-use crate::feedback::{FeedbackSender, MithrilEvent};
+use crate::feedback::FeedbackSender;
+#[cfg(feature = "fs")]
 use crate::snapshot_downloader::SnapshotDownloader;
 use crate::{MithrilResult, Snapshot, SnapshotListItem};
 
@@ -89,6 +91,7 @@ pub enum SnapshotClientError {
 /// Aggregator client for the snapshot artifact
 pub struct SnapshotClient {
     aggregator_client: Arc<dyn AggregatorClient>,
+    #[cfg(feature = "fs")]
     snapshot_downloader: Arc<dyn SnapshotDownloader>,
     feedback_sender: FeedbackSender,
     logger: Logger,
@@ -98,12 +101,13 @@ impl SnapshotClient {
     /// Constructs a new `SnapshotClient`.
     pub fn new(
         aggregator_client: Arc<dyn AggregatorClient>,
-        snapshot_downloader: Arc<dyn SnapshotDownloader>,
+        #[cfg(feature = "fs")] snapshot_downloader: Arc<dyn SnapshotDownloader>,
         feedback_sender: FeedbackSender,
         logger: Logger,
     ) -> Self {
         Self {
             aggregator_client,
+            #[cfg(feature = "fs")]
             snapshot_downloader,
             feedback_sender,
             logger,
@@ -143,15 +147,18 @@ impl SnapshotClient {
         }
     }
 
+    cfg_fs! {
     /// Download and unpack the given snapshot to the given directory
     ///
     /// **NOTE**: The directory should already exist, and the user running the binary
     /// must have read/write access to it.
     pub async fn download_unpack(
         &self,
         snapshot: &Snapshot,
-        target_dir: &Path,
+        target_dir: &std::path::Path,
     ) -> MithrilResult<()> {
+        use crate::feedback::MithrilEvent;
+
         for location in snapshot.locations.as_slice() {
             if self.snapshot_downloader.probe(location).await.is_ok() {
                 let download_id = MithrilEvent::new_snapshot_download_id();
@@ -182,7 +189,7 @@ impl SnapshotClient {
                         Ok(())
                     }
                     Err(e) => {
-                        warn!(
+                        slog::warn!(
                             self.logger,
                             "Failed downloading snapshot from '{location}' Error: {e}."
                         );
@@ -200,14 +207,18 @@ impl SnapshotClient {
         }
         .into())
     }
+    }
 }
 
-#[cfg(test)]
-mod tests {
+#[cfg(all(test, feature = "fs"))]
+mod tests_download {
     use crate::{
-        aggregator_client::MockAggregatorHTTPClient, feedback::StackFeedbackReceiver,
-        snapshot_downloader::MockHttpSnapshotDownloader, test_utils,
+        aggregator_client::MockAggregatorHTTPClient,
+        feedback::{MithrilEvent, StackFeedbackReceiver},
+        snapshot_downloader::MockHttpSnapshotDownloader,
+        test_utils,
     };
+    use std::path::Path;
 
     use super::*;
 

mithril-client/src/utils/mod.rs

@@ -1,8 +1,10 @@
 //! Utilities module
 //! This module contains tools needed mostly for the snapshot download and unpack.
 
-mod stream_reader;
-mod unpacker;
+cfg_fs! {
+    mod stream_reader;
+    mod unpacker;
 
-pub use stream_reader::*;
-pub use unpacker::*;
+    pub use stream_reader::*;
+    pub use unpacker::*;
+}