use mimalloc

.gitignore

@@ -2,6 +2,6 @@
 /Cargo.lock
 .vscode
 
-/flamegraph.svg
-/perf.data
-/perf.data.old
+flamegraph.svg
+perf.data
+perf.data.old

README.md

@@ -51,21 +51,27 @@ let mut buffer = Vec::new();
 nbt.write(&mut buffer);
 ```
 
+## Performance guide
+
+Use the borrow variant of `Nbt` if possible, and avoid allocating unnecessarily (for example, keep strings as `Cow<str>` if you can).
+
+The most significant and simple optimization you can do is switching to an allocator like [mimalloc](https://docs.rs/mimalloc/latest/mimalloc/) (it's ~20% faster on my machine). Setting `RUSTFLAGS='-C target-cpu=native'` when running your code may also help a little bit.
+
 ## Implementation details
 
 Simdnbt currently makes use of SIMD instructions for two things:
 - swapping the endianness of int arrays
 - checking if a string is plain ascii for faster mutf8 to utf8 conversion
 
-Simdnbt takes some shortcuts to be this fast, some people call it cheating but I think it's fair game:
+Simdnbt ~~cheats~~ takes some shortcuts to be this fast:
 1. it requires a reference to the original data (to avoid cloning)
 2. it doesn't validate/decode the mutf-8 strings at decode-time
 
 ## Benchmarks
 
-Simdnbt is likely the fastest NBT decoder in existence.
+Simdnbt is likely the fastest NBT decoder currently in existence.
 
-Here's a benchmark comparing Simdnbt against a few of the other fastest nbt crates (though without actually accessing the data):
+Here's a benchmark comparing Simdnbt against a few of the other fastest NBT crates (though without actually accessing the data):
 
 ![simdnbt is ~3x faster than the second fastest nbt crate](https://github.com/azalea-rs/simdnbt/assets/27899617/03a4f916-d162-4a23-aa1a-12f1b11dc903)
 

simdnbt/Cargo.toml

@@ -23,7 +23,7 @@ fastnbt = "2.4.4"
 azalea-nbt = { git = "https://github.com/azalea-rs/azalea", rev = "84e036ce3752ecf57904b0f5aff1f33d43e95a32" }
 hematite-nbt = { version = "0.5.2", default-features = false }
 
-tikv-jemallocator = "0.5"
+mimalloc = "0.1.39"
 
 [features]
 default = ["derive"]
@@ -35,7 +35,7 @@ debug = false
 
 [profile.bench]
 lto = true
-debug = false
+debug = true
 
 [[bench]]
 harness = false

simdnbt/benches/nbt.rs

@@ -47,10 +47,10 @@ fn bench_file(filename: &str, c: &mut Criterion) {
 }
 
 #[global_allocator]
-static GLOBAL: tikv_jemallocator::Jemalloc = tikv_jemallocator::Jemalloc;
+static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
 
 fn bench(c: &mut Criterion) {
-    bench_file("bigtest.nbt", c);
+    // bench_file("bigtest.nbt", c);
     // bench_file("simple_player.dat", c);
     bench_file("complex_player.dat", c);
     // bench_file("level.dat", c);