chore(solc): always use sync sources reading (#1667)

ethers-solc/Cargo.toml

@@ -69,6 +69,7 @@ harness = false
 
 [[bench]]
 name = "read_all"
+required-features = ["project-util"]
 harness = false
 
 [[test]]

ethers-solc/benches/read_all.rs

@@ -4,7 +4,7 @@ extern crate criterion;
 
 use criterion::Criterion;
 use ethers_core::rand;
-use ethers_solc::artifacts::Source;
+use ethers_solc::{artifacts::Source, project_util::TempProject};
 use rand::{distributions::Alphanumeric, Rng};
 use std::{
     fs::File,
@@ -14,10 +14,26 @@ use std::{
 
 fn read_all_benchmark(c: &mut Criterion) {
     let root = tempfile::tempdir().unwrap();
-    let inputs = prepare_contracts(root.path(), 8);
+    let inputs = prepare_contracts(root.path(), 35);
 
     let mut group = c.benchmark_group("read many");
-    group.sample_size(10);
+    group.bench_function("sequential", |b| {
+        b.iter(|| {
+            Source::read_all(&inputs).unwrap();
+        });
+    });
+    group.bench_function("parallel", |b| {
+        b.iter(|| {
+            Source::par_read_all(&inputs).unwrap();
+        });
+    });
+}
+
+fn read_solmate(c: &mut Criterion) {
+    let prj = TempProject::checkout("transmissions11/solmate").unwrap();
+    let inputs = ethers_solc::utils::source_files(prj.sources_path());
+
+    let mut group = c.benchmark_group("read solmate");
     group.bench_function("sequential", |b| {
         b.iter(|| {
             Source::read_all(&inputs).unwrap();
@@ -40,7 +56,7 @@ fn prepare_contracts(root: &Path, num: usize) -> Vec<PathBuf> {
         let mut rng = rand::thread_rng();
 
         // let's assume a solidity file is between 2kb and 16kb
-        let n: usize = rng.gen_range(2..17);
+        let n: usize = rng.gen_range(4..17);
         let s: String = rng.sample_iter(&Alphanumeric).take(n * 1024).map(char::from).collect();
         writer.write_all(s.as_bytes()).unwrap();
         writer.flush().unwrap();
@@ -49,5 +65,5 @@ fn prepare_contracts(root: &Path, num: usize) -> Vec<PathBuf> {
     files
 }
 
-criterion_group!(benches, read_all_benchmark);
+criterion_group!(benches, read_all_benchmark, read_solmate);
 criterion_main!(benches);

ethers-solc/src/artifacts/mod.rs

@@ -1187,10 +1187,6 @@ pub struct Source {
 }
 
 impl Source {
-    /// this is a heuristically measured threshold at which we can generally expect a speedup by
-    /// using rayon's `par_iter`, See `Self::read_all_files`
-    pub const NUM_READ_PAR: usize = 8;
-
     /// Reads the file content
     pub fn read(file: impl AsRef<Path>) -> Result<Self, SolcIoError> {
         let file = file.as_ref();
@@ -1206,17 +1202,7 @@ impl Source {
     ///
     /// Depending on the len of the vec it will try to read the files in parallel
     pub fn read_all_files(files: Vec<PathBuf>) -> Result<Sources, SolcIoError> {
-        use rayon::prelude::*;
-
-        if files.len() < Self::NUM_READ_PAR {
         Self::read_all(files)
-        } else {
-            files
-                .par_iter()
-                .map(Into::into)
-                .map(|file| Self::read(&file).map(|source| (file, source)))
-                .collect()
-        }
     }
 
     /// Reads all files
@@ -1235,7 +1221,7 @@ impl Source {
     /// Parallelized version of `Self::read_all` that reads all files using a parallel iterator
     ///
     /// NOTE: this is only expected to be faster than `Self::read_all` if the given iterator
-    /// contains at least several paths. see also `Self::read_all_files`.
+    /// contains at least several paths or the files are rather large.
     pub fn par_read_all<T, I>(files: I) -> Result<Sources, SolcIoError>
     where
         I: IntoIterator<Item = T>,