From 8aefe88104e097b79c5b5553627c1a762555435b Mon Sep 17 00:00:00 2001
From: Nick Winans <nick@winans.io>
Date: Sat, 6 Jul 2024 13:38:35 -0700
Subject: [PATCH] Add compression level option to serde.compress (#224)

---
 crates/lune-std-serde/src/compress_decompress.rs | 12 +++++++++---
 crates/lune-std-serde/src/lib.rs                 |  4 ++--
 types/serde.luau                                 |  3 ++-
 3 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/crates/lune-std-serde/src/compress_decompress.rs b/crates/lune-std-serde/src/compress_decompress.rs
index 3e5aaa0..86b5c87 100644
--- a/crates/lune-std-serde/src/compress_decompress.rs
+++ b/crates/lune-std-serde/src/compress_decompress.rs
@@ -13,6 +13,7 @@ use async_compression::{
         BrotliDecoder, BrotliEncoder, GzipDecoder, GzipEncoder, ZlibDecoder, ZlibEncoder,
     },
     Level::Best as CompressionQuality,
+    Level::Precise as PreciseCompressionQuality,
 };
 
 /**
@@ -119,6 +120,7 @@ impl<'lua> FromLua<'lua> for CompressDecompressFormat {
 pub async fn compress<'lua>(
     source: impl AsRef<[u8]>,
     format: CompressDecompressFormat,
+    level: Option<i32>,
 ) -> LuaResult<Vec<u8>> {
     if let CompressDecompressFormat::LZ4 = format {
         let source = source.as_ref().to_vec();
@@ -130,18 +132,22 @@ pub async fn compress<'lua>(
 
     let mut bytes = Vec::new();
     let reader = BufReader::new(source.as_ref());
+    let compression_quality = match level {
+        Some(l) => PreciseCompressionQuality(l),
+        None => CompressionQuality,
+    };
 
     match format {
         CompressDecompressFormat::Brotli => {
-            let mut encoder = BrotliEncoder::with_quality(reader, CompressionQuality);
+            let mut encoder = BrotliEncoder::with_quality(reader, compression_quality);
             copy(&mut encoder, &mut bytes).await?;
         }
         CompressDecompressFormat::GZip => {
-            let mut encoder = GzipEncoder::with_quality(reader, CompressionQuality);
+            let mut encoder = GzipEncoder::with_quality(reader, compression_quality);
             copy(&mut encoder, &mut bytes).await?;
         }
         CompressDecompressFormat::ZLib => {
-            let mut encoder = ZlibEncoder::with_quality(reader, CompressionQuality);
+            let mut encoder = ZlibEncoder::with_quality(reader, compression_quality);
             copy(&mut encoder, &mut bytes).await?;
         }
         CompressDecompressFormat::LZ4 => unreachable!(),
diff --git a/crates/lune-std-serde/src/lib.rs b/crates/lune-std-serde/src/lib.rs
index 4a66adf..26ee26a 100644
--- a/crates/lune-std-serde/src/lib.rs
+++ b/crates/lune-std-serde/src/lib.rs
@@ -46,9 +46,9 @@ fn serde_decode(lua: &Lua, (format, bs): (EncodeDecodeFormat, BString)) -> LuaRe
 
 async fn serde_compress(
     lua: &Lua,
-    (format, bs): (CompressDecompressFormat, BString),
+    (format, bs, level): (CompressDecompressFormat, BString, Option<i32>),
 ) -> LuaResult<LuaString> {
-    let bytes = compress(bs, format).await?;
+    let bytes = compress(bs, format, level).await?;
     lua.create_string(bytes)
 }
 
diff --git a/types/serde.luau b/types/serde.luau
index aa17edc..cd2658d 100644
--- a/types/serde.luau
+++ b/types/serde.luau
@@ -136,9 +136,10 @@ end
 
 	@param format The format to use
 	@param s The string to compress
+	@param level The compression level to use, clamped to the format's limits. The best compression level is used by default
 	@return The compressed string
 ]=]
-function serde.compress(format: CompressDecompressFormat, s: buffer | string): string
+function serde.compress(format: CompressDecompressFormat, s: buffer | string, level: number?): string
 	return nil :: any
 end