From 0ec7d4489d4827ff6f3f4c776e85a4f7e12443c7 Mon Sep 17 00:00:00 2001
From: nalabrie <ku9ca7cmlk@gmail.com>
Date: Sun, 14 Jul 2024 02:54:12 -0400
Subject: [PATCH] Added multithreading by default to zstd compression. Bumped
 zstd package version. Added num_cpus package to get core count.

---
 CHANGELOG.md             | 2 ++
 Cargo.lock               | 5 +++--
 Cargo.toml               | 3 ++-
 src/commands/compress.rs | 8 +++++---
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c69577..7598567 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,8 @@ Categories Used:
 
 ### New Features
 
+- Add multithreading support for `zstd` compression [\#688](https://github.com/ouch-org/ouch/pull/688) ([nalabrie](https://github.com/nalabrie))
+
 ### Bug Fixes
 
 - Fix output corrupted on parallel decompression [\#642](https://github.com/ouch-org/ouch/pull/642) ([AntoniosBarotsis](https://github.com/AntoniosBarotsis))
diff --git a/Cargo.lock b/Cargo.lock
index e535ffc..3b6fa56 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -848,6 +848,7 @@ dependencies = [
  "libc",
  "linked-hash-map",
  "lz4_flex",
+ "num_cpus",
  "once_cell",
  "parse-display",
  "proptest",
@@ -1796,9 +1797,9 @@ dependencies = [
 
 [[package]]
 name = "zstd"
-version = "0.13.1"
+version = "0.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2d789b1514203a1120ad2429eae43a7bd32b90976a7bb8a05f7ec02fa88cc23a"
+checksum = "fcf2b778a664581e31e389454a7072dab1647606d44f7feea22cd5abb9c9f3f9"
 dependencies = [
  "zstd-safe",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 15a9fba..991f2a6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,6 +23,7 @@ ignore = "0.4.22"
 libc = "0.2.155"
 linked-hash-map = "0.5.6"
 lz4_flex = "0.11.3"
+num_cpus = "1.16.0"
 once_cell = "1.19.0"
 rayon = "1.10.0"
 same-file = "1.0.6"
@@ -34,7 +35,7 @@ time = { version = "0.3.36", default-features = false }
 unrar = { version = "0.5.3", optional = true }
 xz2 = "0.1.7"
 zip = { version = "0.6.6", default-features = false, features = ["time"] }
-zstd = { version = "0.13.1", default-features = false }
+zstd = { version = "0.13.2", default-features = false, features = ["zstdmt"]}
 
 [target.'cfg(not(unix))'.dependencies]
 is_executable = "1.0.1"
diff --git a/src/commands/compress.rs b/src/commands/compress.rs
index 10fa660..55625ca 100644
--- a/src/commands/compress.rs
+++ b/src/commands/compress.rs
@@ -69,16 +69,18 @@ pub fn compress_files(
                     .from_writer(encoder),
             ),
             Zstd => {
-                let zstd_encoder = zstd::stream::write::Encoder::new(
+                let mut zstd_encoder = zstd::stream::write::Encoder::new(
                     encoder,
                     level.map_or(zstd::DEFAULT_COMPRESSION_LEVEL, |l| {
                         (l as i32).clamp(zstd::zstd_safe::min_c_level(), zstd::zstd_safe::max_c_level())
                     }),
-                );
+                )?;
+                // Use all available PHYSICAL cores for compression
+                zstd_encoder.multithread(num_cpus::get_physical() as u32)?;
                 // Safety:
                 //     Encoder::new() can only fail if `level` is invalid, but the level
                 //     is `clamp`ed and therefore guaranteed to be valid
-                Box::new(zstd_encoder.unwrap().auto_finish())
+                Box::new(zstd_encoder.auto_finish())
             }
             Tar | Zip | Rar | SevenZip => unreachable!(),
         };