perf: use mimalloc

CHANGELOG.md

@@ -17,6 +17,33 @@ Types of changes
 - Security in case of vulnerabilities.
 -->
 
+### Changed
+
+- Linux binaries now use [mimalloc](https://github.com/microsoft/mimalloc)
+  to provide much better performance when formatting Nixpkgs:
+
+  - x86_64-unknown-linux-gnu, 1.3x faster,
+    from 0m10.639s to 0m8.381s
+
+  - x86_64-unknown-linux-musl, 15.8x faster,
+    from 2m32.686s to 0m9.642s
+
+  - [On QEMU](https://www.qemu.org/) aarch64-unknown-linux-musl,
+    4.6x faster,
+    from 5m26s to 1m10s
+
+  - [On QEMU](https://www.qemu.org/) armv6l-unknown-linux-musleabihf,
+    1.05x faster,
+    from 8m7s to 7m41s
+
+  - [On QEMU](https://www.qemu.org/) armv7l-unknown-linux-musleabihf,
+    1.15x faster,
+    from 5m54s to 5m7s
+
+  - [On QEMU](https://www.qemu.org/) i686-unknown-linux-musl,
+    1.07x faster,
+    from 2m44s to 2m33s
+
 ## [0.6.0] - 2022-02-25
 
 ### Added

Cargo.lock

@@ -20,6 +20,7 @@ dependencies = [
 name = "alejandra_engine"
 version = "0.6.0"
 dependencies = [
+ "mimalloc",
  "rnix",
  "rowan",
 ]
@@ -62,6 +63,12 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "cc"
+version = "1.0.73"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2fff2a6927b3bb87f9595d67196a70493f627687a71d87a0d692242c33f58c11"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -191,6 +198,15 @@ version = "0.2.119"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1bf2e165bb3457c8e098ea76f3e3bc9db55f87aa90d52d0e6be741470916aaa4"
 
+[[package]]
+name = "libmimalloc-sys"
+version = "0.1.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7705fc40f6ed493f73584abbb324e74f96b358ff60dfe5659a0f8fc12c590a69"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "memchr"
 version = "2.4.1"
@@ -206,6 +222,15 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "mimalloc"
+version = "0.1.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0dfa131390c2f6bdb3242f65ff271fcdaca5ff7b6c08f28398be7f2280e3926"
+dependencies = [
+ "libmimalloc-sys",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.14"

src/alejandra_engine/Cargo.toml

@@ -2,6 +2,24 @@
 rnix = "*"
 rowan = "0.12.6" # follows rnix
 
+[target.aarch64-unknown-linux-musl.dependencies]
+mimalloc = { version = "*", default-features = false }
+
+[target.armv6l-unknown-linux-musleabihf.dependencies]
+mimalloc = { version = "*", default-features = false }
+
+[target.armv7l-unknown-linux-musleabihf.dependencies]
+mimalloc = { version = "*", default-features = false }
+
+[target.i686-unknown-linux-musl.dependencies]
+mimalloc = { version = "*", default-features = false }
+
+[target.x86_64-unknown-linux-gnu.dependencies]
+mimalloc = { version = "*", default-features = false }
+
+[target.x86_64-unknown-linux-musl.dependencies]
+mimalloc = { version = "*", default-features = false }
+
 [package]
 authors = ["Kevin Amado <kamadorueda@gmail.com>"]
 description = "The Uncompromising Nix Code Formatter"

src/alejandra_engine/src/lib.rs

@@ -1,3 +1,32 @@
+#[cfg(any(
+    all(
+        target_arch = "aarch64",
+        target_vendor = "unknown",
+        target_os = "linux",
+        target_env = "musl"
+    ),
+    all(
+        any(target_arch = "armv6l", target_arch = "armv7l",),
+        target_vendor = "unknown",
+        target_os = "linux",
+        target_env = "musleabihf"
+    ),
+    all(
+        target_arch = "i686",
+        target_vendor = "unknown",
+        target_os = "linux",
+        target_env = "musl"
+    ),
+    all(
+        target_arch = "x86_64",
+        target_vendor = "unknown",
+        target_os = "linux",
+        any(target_env = "gnu", target_env = "musl")
+    ),
+))]
+#[global_allocator]
+static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
 pub(crate) mod builder;
 pub(crate) mod children;
 pub mod format;