Use mimalloc (#961)

<!-- The PR description should answer 2 important questions: -->

### What

We started using `mimalloc` allocator in MBS a while ago with good
results, let's use it here too.

Once `v3-engine-multitenant` is merged we should use it there too.

### How

Import crate, switch it on in engine binary and in benchmarks.

<img width="845" alt="Screenshot 2024-08-13 at 10 10 49"
src="https://github.com/user-attachments/assets/dc872668-1633-468a-86d3-51fca5be68bf">
V3_GIT_ORIGIN_REV_ID: ebad91bb57964477d0f227e341c7bd12d54f0f68

Author: danieljharvey

v3/Cargo.lock

@@ -89,6 +89,7 @@ jsonptr = "0.4"
 jsonwebkey = "0.3"
 jsonwebtoken = "8"
 lexical-core = "0.8"
+mimalloc = "0.1"
 mockito = { version = "~1.4", default-features = false } # v1.5+ depends on http v1
 nonempty = "0.10"
 openssl = "0.10"

v3/Cargo.toml

@@ -40,6 +40,7 @@ axum = { workspace = true }
 base64 = { workspace = true }
 clap = { workspace = true, features = ["derive", "env"] }
 json_value_merge = { workspace = true }
+mimalloc = { workspace = true }
 nonempty = { workspace = true }
 reqwest = { workspace = true, features = ["json", "multipart"] }
 schemars = { workspace = true, features = ["smol_str"] }

v3/crates/engine/Cargo.toml

@@ -19,6 +19,10 @@ use std::path::Path;
 
 use lang_graphql as gql;
 
+// match allocator used by engine binary
+#[global_allocator]
+static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
 pub fn merge_with_common_metadata(
     common_metadata_path: &Path,
     metadata_path_string: &Path,

v3/crates/engine/benches/execute.rs

@@ -43,6 +43,9 @@ use tracing_util::{
 
 mod cors;
 
+#[global_allocator]
+static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
 const DEFAULT_PORT: u16 = 3000;
 
 const MB: usize = 1_048_576;