chore: add benchmarks to avoid parsing performance regressions

Author: Byron

Cargo.lock

@@ -12,6 +12,12 @@ rust-version = "1.65"
 [lib]
 doctest = false
 
+[[bench]]
+name = "decode-objects"
+harness = false
+path = "./benches/decode_objects.rs"
+
+
 [features]
 ## Data structures implement `serde::Serialize` and `serde::Deserialize`.
 serde = ["dep:serde", "bstr/serde", "smallvec/serde", "gix-hash/serde", "gix-actor/serde"]
@@ -39,6 +45,7 @@ serde = { version = "1.0.114", optional = true, default-features = false, featur
 document-features = { version = "0.2.0", optional = true }
 
 [dev-dependencies]
+criterion = "0.5.1"
 pretty_assertions = "1.0.0"
 gix-testtools = { path = "../tests/tools"}
 

gix-object/Cargo.toml

@@ -0,0 +1,35 @@
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+
+fn parse_commit(c: &mut Criterion) {
+    c.bench_function("CommitRef(sig)", |b| {
+        b.iter(|| black_box(gix_object::CommitRef::from_bytes(COMMIT_WITH_MULTI_LINE_HEADERS)).unwrap())
+    });
+    c.bench_function("CommitRefIter(sig)", |b| {
+        b.iter(|| black_box(gix_object::CommitRefIter::from_bytes(COMMIT_WITH_MULTI_LINE_HEADERS).count()))
+    });
+}
+
+fn parse_tag(c: &mut Criterion) {
+    c.bench_function("TagRef(sig)", |b| {
+        b.iter(|| black_box(gix_object::TagRef::from_bytes(TAG_WITH_SIGNATURE)).unwrap())
+    });
+    c.bench_function("TagRefIter(sig)", |b| {
+        b.iter(|| black_box(gix_object::TagRefIter::from_bytes(TAG_WITH_SIGNATURE).count()))
+    });
+}
+
+fn parse_tree(c: &mut Criterion) {
+    c.bench_function("TreeRef(sig)", |b| {
+        b.iter(|| black_box(gix_object::TreeRef::from_bytes(TREE)).unwrap())
+    });
+    c.bench_function("TreeRefIter(sig)", |b| {
+        b.iter(|| black_box(gix_object::TreeRefIter::from_bytes(TREE).count()))
+    });
+}
+
+criterion_group!(benches, parse_commit, parse_tag, parse_tree);
+criterion_main!(benches);
+
+const COMMIT_WITH_MULTI_LINE_HEADERS: &[u8] = include_bytes!("../tests/fixtures/commit/two-multiline-headers.txt");
+const TAG_WITH_SIGNATURE: &[u8] = include_bytes!("../tests/fixtures/tag/signed.txt");
+const TREE: &[u8] = include_bytes!("../tests/fixtures/tree/everything.tree");

gix-object/benches/decode_objects.rs

@@ -19,7 +19,7 @@ clear-target:
 
 # Run cargo clippy on all crates
 clippy *clippy-args:
-    cargo clippy --all --tests --examples -- {{ clippy-args }}
+    cargo clippy --all --tests --examples --benches -- {{ clippy-args }}
     cargo clippy --all --no-default-features --features small -- {{ clippy-args }}
     cargo clippy --all --no-default-features --features max-pure -- {{ clippy-args }}
     cargo clippy --all --no-default-features --features lean-async --tests -- {{ clippy-args }}