fix: replacing DefaultHasher (#1926)

Co-authored-by: Tushar Mathur <tusharmath@gmail.com>

Cargo.toml

@@ -153,6 +153,7 @@ tonic-types = "0.11.0"
 datatest-stable = "0.2.9"
 tokio-test = "0.4.4"
 base64 = "0.22.1"
+tailcall-hasher = { path = "tailcall-hasher" }
 
 [dev-dependencies]
 tailcall-prettier = { path = "tailcall-prettier" }
@@ -211,7 +212,8 @@ members = [
     "tailcall-query-plan",
     "tailcall-fixtures",
     "tailcall-upstream-grpc",
-    "tailcall-tracker"]
+    "tailcall-tracker",
+    "tailcall-hasher"]
 
 # Boost execution_spec snapshot diffing performance
 [profile.dev.package]

src/core/graphql/request_template.rs

@@ -1,11 +1,11 @@
 #![allow(clippy::too_many_arguments)]
 
-use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};
 
 use derive_setters::Setters;
 use hyper::HeaderMap;
 use reqwest::header::HeaderValue;
+use tailcall_hasher::TailcallHasher;
 
 use crate::core::config::{GraphQLOperationType, KeyValue};
 use crate::core::has_headers::HasHeaders;
@@ -128,7 +128,7 @@ impl RequestTemplate {
 
 impl<Ctx: PathGraphql + HasHeaders + GraphQLOperationContext> CacheKey<Ctx> for RequestTemplate {
     fn cache_key(&self, ctx: &Ctx) -> u64 {
-        let mut hasher = DefaultHasher::new();
+        let mut hasher = TailcallHasher::default();
         let graphql_query = self.render_graphql_query(ctx);
         graphql_query.hash(&mut hasher);
         hasher.finish()

src/core/grpc/data_loader_request.rs

@@ -1,8 +1,8 @@
-use std::collections::hash_map::DefaultHasher;
 use std::collections::BTreeSet;
 use std::hash::{Hash, Hasher};
 
 use anyhow::Result;
+use tailcall_hasher::TailcallHasher;
 
 use super::request_template::RenderedRequestTemplate;
 
@@ -28,11 +28,11 @@ impl Hash for DataLoaderRequest {
 
 impl PartialEq for DataLoaderRequest {
     fn eq(&self, other: &Self) -> bool {
-        let mut hasher_self = DefaultHasher::new();
+        let mut hasher_self = TailcallHasher::default();
         self.hash(&mut hasher_self);
         let hash_self = hasher_self.finish();
 
-        let mut hasher_other = DefaultHasher::new();
+        let mut hasher_other = TailcallHasher::default();
         other.hash(&mut hasher_other);
         let hash_other = hasher_other.finish();
 

src/core/grpc/request_template.rs

@@ -1,11 +1,11 @@
-use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};
 
 use anyhow::Result;
 use derive_setters::Setters;
 use hyper::header::CONTENT_TYPE;
 use hyper::{HeaderMap, Method};
 use reqwest::header::HeaderValue;
+use tailcall_hasher::TailcallHasher;
 use url::Url;
 
 use super::request::create_grpc_request;
@@ -108,7 +108,7 @@ impl RenderedRequestTemplate {
 
 impl<Ctx: PathString + HasHeaders> CacheKey<Ctx> for RequestTemplate {
     fn cache_key(&self, ctx: &Ctx) -> u64 {
-        let mut hasher = DefaultHasher::new();
+        let mut hasher = TailcallHasher::default();
         let rendered_req = self.render(ctx).unwrap();
         rendered_req.hash(&mut hasher);
         hasher.finish()

src/core/http/data_loader_request.rs

@@ -1,8 +1,9 @@
-use std::collections::hash_map::DefaultHasher;
 use std::collections::BTreeSet;
 use std::hash::{Hash, Hasher};
 use std::ops::Deref;
 
+use tailcall_hasher::TailcallHasher;
+
 #[derive(Debug)]
 pub struct DataLoaderRequest(reqwest::Request, BTreeSet<String>);
 
@@ -41,11 +42,11 @@ impl Hash for DataLoaderRequest {
 
 impl PartialEq for DataLoaderRequest {
     fn eq(&self, other: &Self) -> bool {
-        let mut hasher_self = DefaultHasher::new();
+        let mut hasher_self = TailcallHasher::default();
         self.hash(&mut hasher_self);
         let hash_self = hasher_self.finish();
 
-        let mut hasher_other = DefaultHasher::new();
+        let mut hasher_other = TailcallHasher::default();
         other.hash(&mut hasher_other);
         let hash_other = hasher_other.finish();
 

src/core/http/request_template.rs

@@ -1,10 +1,10 @@
 use std::borrow::Cow;
-use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};
 
 use derive_setters::Setters;
 use hyper::HeaderMap;
 use reqwest::header::HeaderValue;
+use tailcall_hasher::TailcallHasher;
 use url::Url;
 
 use crate::core::config::Encoding;
@@ -226,7 +226,7 @@ impl TryFrom<Endpoint> for RequestTemplate {
 
 impl<Ctx: PathString + HasHeaders> CacheKey<Ctx> for RequestTemplate {
     fn cache_key(&self, ctx: &Ctx) -> u64 {
-        let mut hasher = DefaultHasher::new();
+        let mut hasher = TailcallHasher::default();
         let state = &mut hasher;
 
         self.method.hash(state);

tailcall-hasher/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "tailcall-hasher"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+fxhash = "0.2.1"

tailcall-hasher/src/lib.rs

@@ -0,0 +1,21 @@
+use std::hash::Hasher;
+
+use fxhash::FxHasher;
+
+/// A hasher that uses the FxHash algorithm. Currently it's a dumb wrapper
+/// around `fxhash::FxHasher`. We could potentially add some custom logic here
+/// in the future.
+#[derive(Default)]
+pub struct TailcallHasher {
+    hasher: FxHasher,
+}
+
+impl Hasher for TailcallHasher {
+    fn finish(&self) -> u64 {
+        self.hasher.finish()
+    }
+
+    fn write(&mut self, bytes: &[u8]) {
+        self.hasher.write(bytes)
+    }
+}