fix: tenderdash-proto rebuilt with every run due to changed *.proto

proto-compiler/src/functions.rs

@@ -325,3 +325,37 @@ pub(crate) fn tenderdash_commitish() -> String {
         Err(_) => DEFAULT_TENDERDASH_COMMITISH.to_string(),
     }
 }
+
+/// Save the commitish of last successful download to a file in a state file,
+/// located in the `dir` directory and named `download.state`.
+pub(crate) fn save_state(dir: &Path, commitish: &str) {
+    let state_file = PathBuf::from(&dir).join("download.state");
+
+    std::fs::write(&state_file, commitish)
+        .map_err(|e| {
+            println!(
+                "[warn] => Failed to write download.state file {}: {}",
+                state_file.display(),
+                e
+            );
+        })
+        .ok();
+}
+
+/// Check if the state file contains the same commitish as the one we are trying
+/// to download. State file should be located in the `dir` and named
+/// `download.state`
+pub(crate) fn check_state(dir: &Path, commitish: &str) -> bool {
+    let state_file = PathBuf::from(&dir).join("download.state");
+
+    match read_to_string(state_file) {
+        Ok(content) => {
+            println!(
+                "[info] => Found previously downloaded Tenderdash {}.",
+                content.trim()
+            );
+            content.eq(commitish)
+        },
+        Err(_) => false,
+    }
+}

proto-compiler/src/lib.rs

@@ -11,6 +11,8 @@ use functions::{
 mod constants;
 use constants::{CUSTOM_FIELD_ATTRIBUTES, CUSTOM_TYPE_ATTRIBUTES, TENDERDASH_REPO};
 
+use crate::functions::{check_state, save_state};
+
 /// Import and compile protobuf definitions for Tenderdash.
 ///
 /// Checkouts tenderdash repository to ../target/tenderdash and generates
@@ -25,7 +27,7 @@ pub fn proto_compile() {
         .join("src")
         .join("tenderdash.rs");
 
-    let target_dir = root.join("..").join("proto").join("src").join("prost");
+    let prost_out_dir = root.join("..").join("proto").join("src").join("prost");
 
     let out_dir = var("OUT_DIR")
         .map(PathBuf::from)
@@ -47,13 +49,21 @@ pub fn proto_compile() {
     let thirdparty_dir = root.join("third_party");
 
     let commitish = tenderdash_commitish();
-    println!("[info] => Fetching {TENDERDASH_REPO} at {commitish} into {tenderdash_dir:?}");
-    fetch_commitish(
-        &PathBuf::from(&tenderdash_dir),
-        &cargo_target_dir,
-        TENDERDASH_REPO,
-        &commitish,
-    ); // This panics if it fails.
+
+    // check if this commitish is already downloaded
+    let download = !check_state(&prost_out_dir, &commitish);
+
+    if download {
+        println!("[info] => Fetching {TENDERDASH_REPO} at {commitish} into {tenderdash_dir:?}.");
+        fetch_commitish(
+            &PathBuf::from(&tenderdash_dir),
+            &cargo_target_dir,
+            TENDERDASH_REPO,
+            &commitish,
+        ); // This panics if it fails.
+    } else {
+        println!("[info] => Skipping download.");
+    }
 
     // We need all files in proto/tendermint/abci, plus .../types/canonical.proto
     // for signature verification
@@ -100,9 +110,10 @@ pub fn proto_compile() {
     pb.compile_protos(&protos, &proto_includes_paths).unwrap();
 
     println!("[info] => Removing old structs and copying new structs.");
-    copy_files(&out_dir, &target_dir); // This panics if it fails.
+    copy_files(&out_dir, &prost_out_dir); // This panics if it fails.
 
     generate_tenderdash_lib(&out_dir, &tenderdash_lib_target, &abci_ver, &tenderdash_ver);
 
+    save_state(&prost_out_dir, &commitish);
     println!("[info] => Done!");
 }

proto/src/error.rs

@@ -1,7 +1,7 @@
 //! This module defines the various errors that be raised during Protobuf
 //! conversions.
 
-use core::{convert::TryFrom, fmt::Display, num::TryFromIntError};
+use core::{fmt::Display, num::TryFromIntError};
 
 use flex_error::{define_error, DisplayOnly};
 use prost::{DecodeError, EncodeError};

proto/src/lib.rs

@@ -23,10 +23,7 @@ mod error;
 #[allow(warnings)]
 mod tenderdash;
 
-use core::{
-    convert::{TryFrom, TryInto},
-    fmt::Display,
-};
+use core::fmt::Display;
 
 use bytes::{Buf, BufMut};
 pub use error::Error;

proto/src/serializers/part_set_header_total.rs

@@ -5,7 +5,7 @@
 //! from a string-quoted integer value into an integer value without quotes in
 //! Tendermint Core v0.34.0. This deserializer allows backwards-compatibility by
 //! deserializing both ways. See also: <https://github.com/informalsystems/tendermint-rs/issues/679>
-use core::{convert::TryFrom, fmt::Formatter};
+use core::fmt::Formatter;
 
 use serde::{
     de::{Error, Visitor},