From fab2257317c3d2d7faf2697ec223964bd92afa4a Mon Sep 17 00:00:00 2001
From: Amos Wenger <amos@bearcove.net>
Date: Tue, 29 Oct 2024 18:36:56 +0100
Subject: [PATCH] Allow overriding compression levels with environment
 variables
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This introduces three environment variables, with the following defaults:

  * `AXOASSET_GZ_LEVEL=6`
  * `AXOASSET_XZ_LEVEL=9`
  * `AXOASSET_ZSTD_LEVEL=3`

(The defaults are unchanged, but when we iterate on dist builds using
dist itself, exporting `AXOASSET_XZ_LEVEL=1` will make it go faster —
it is _genuinely_ the blocker on warm builds lol)
---
 Cargo.lock         |  5 +++--
 Cargo.toml         |  1 +
 src/compression.rs | 38 ++++++++++++++++++++++++++++++--------
 3 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index f7a4b07..d6f9e5a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -136,6 +136,7 @@ dependencies = [
  "clap",
  "flate2",
  "image",
+ "lazy_static",
  "miette",
  "mime",
  "reqwest",
@@ -908,9 +909,9 @@ dependencies = [
 
 [[package]]
 name = "lazy_static"
-version = "1.4.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "libc"
diff --git a/Cargo.toml b/Cargo.toml
index 5e21c38..920a244 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -45,6 +45,7 @@ xz2 = { version = "0.1.7", optional = true, features = ["static"] }
 zstd = { version = "0.13.0", optional = true }
 toml_edit = { version = "0.22.5", optional = true }
 walkdir = "2.5.0"
+lazy_static = "1.5.0"
 
 [dev-dependencies]
 assert_fs = "1"
diff --git a/src/compression.rs b/src/compression.rs
index cf917c5..3883967 100644
--- a/src/compression.rs
+++ b/src/compression.rs
@@ -18,6 +18,27 @@ pub(crate) enum CompressionImpl {
     Zstd,
 }
 
+lazy_static::lazy_static! {
+    static ref DEFAULT_GZ_LEVEL: u32 = {
+        std::env::var("AXOASSET_GZ_LEVEL")
+            .ok()
+            .and_then(|val| val.parse().ok())
+            .unwrap_or(6)
+    };
+    static ref DEFAULT_XZ_LEVEL: u32 = {
+        std::env::var("AXOASSET_XZ_LEVEL")
+            .ok()
+            .and_then(|val| val.parse().ok())
+            .unwrap_or(9)
+    };
+    static ref DEFAULT_ZSTD_LEVEL: i32 = {
+        std::env::var("AXOASSET_ZSTD_LEVEL")
+            .ok()
+            .and_then(|val| val.parse().ok())
+            .unwrap_or(3)
+    };
+}
+
 #[cfg(feature = "compression-tar")]
 pub(crate) fn tar_dir(
     src_path: &Utf8Path,
@@ -52,7 +73,7 @@ pub(crate) fn tar_dir(
             // Wrap our file in compression
             let zip_output = GzBuilder::new()
                 .filename(zip_contents_name)
-                .write(final_zip_file, Compression::default());
+                .write(final_zip_file, Compression::new(*DEFAULT_GZ_LEVEL));
 
             // Write the tar to the compression stream
             let mut tar = tar::Builder::new(zip_output);
@@ -87,7 +108,7 @@ pub(crate) fn tar_dir(
             // Drop the file to close it
         }
         CompressionImpl::Xzip => {
-            let zip_output = XzEncoder::new(final_zip_file, 9);
+            let zip_output = XzEncoder::new(final_zip_file, *DEFAULT_XZ_LEVEL);
             // Write the tar to the compression stream
             let mut tar = tar::Builder::new(zip_output);
 
@@ -122,12 +143,13 @@ pub(crate) fn tar_dir(
         }
         CompressionImpl::Zstd => {
             // Wrap our file in compression
-            let zip_output = ZstdEncoder::new(final_zip_file, 0).map_err(|details| {
-                AxoassetError::Compression {
-                    reason: "failed to create zstd encoder".to_string(),
-                    details,
-                }
-            })?;
+            let zip_output =
+                ZstdEncoder::new(final_zip_file, *DEFAULT_ZSTD_LEVEL).map_err(|details| {
+                    AxoassetError::Compression {
+                        reason: "failed to create zstd encoder".to_string(),
+                        details,
+                    }
+                })?;
 
             // Write the tar to the compression stream
             let mut tar = tar::Builder::new(zip_output);