From 58de0772998bfd510ed3054cd9f1e8d294592f2f Mon Sep 17 00:00:00 2001
From: uzlopak <aras.abbasi@googlemail.com>
Date: Mon, 19 Feb 2024 16:51:29 +0100
Subject: [PATCH 1/3] perf: improve TernarySearchTree

---
 benchmarks/TernarySearchTree.mjs | 20 ++++++++++++++++++++
 lib/core/tree.js                 |  8 ++++++--
 test/node-test/tree.js           |  7 +++++++
 3 files changed, 33 insertions(+), 2 deletions(-)
 create mode 100644 benchmarks/TernarySearchTree.mjs

diff --git a/benchmarks/TernarySearchTree.mjs b/benchmarks/TernarySearchTree.mjs
new file mode 100644
index 00000000000..413288a6af3
--- /dev/null
+++ b/benchmarks/TernarySearchTree.mjs
@@ -0,0 +1,20 @@
+import { bench, group, run } from 'mitata'
+import { tree } from '../lib/core/tree.js'
+
+const contentLength = Buffer.from('Content-Length')
+const contentLengthUpperCase = Buffer.from('Content-Length'.toUpperCase())
+const contentLengthLowerCase = Buffer.from('Content-Length'.toLowerCase())
+
+group('tree.search', () => {
+  bench('content-length', () => {
+    tree.lookup(contentLengthLowerCase)
+  })
+  bench('CONTENT-LENGTH', () => {
+    tree.lookup(contentLengthUpperCase)
+  })
+  bench('Content-Length', () => {
+    tree.lookup(contentLength)
+  })
+})
+
+await run()
diff --git a/lib/core/tree.js b/lib/core/tree.js
index 366fc7d3207..889b935b608 100644
--- a/lib/core/tree.js
+++ b/lib/core/tree.js
@@ -83,7 +83,10 @@ class TstNode {
     while (node !== null && index < keylength) {
       let code = key[index]
       // A-Z
-      if (code >= 0x41 && code <= 0x5a) {
+      // First check if it is bigger than 0x5a.
+      // Lowercase letters have higher char codes than uppercase ones.
+      // Also we assume that headers will mostly contain lowercase characters.
+      if (code <= 0x5a && code >= 0x41) {
         // Lowercase for uppercase.
         code |= 32
       }
@@ -109,7 +112,7 @@ class TernarySearchTree {
 
   /**
    * @param {Uint8Array} key
-   * @param {any} value
+   * @param {void}
    * */
   insert (key, value) {
     if (this.node === null) {
@@ -121,6 +124,7 @@ class TernarySearchTree {
 
   /**
    * @param {Uint8Array} key
+   * @return {TstNode | null}
    */
   lookup (key) {
     return this.node?.search(key)?.value ?? null
diff --git a/test/node-test/tree.js b/test/node-test/tree.js
index eee3fa85eac..44a7d7960ac 100644
--- a/test/node-test/tree.js
+++ b/test/node-test/tree.js
@@ -13,6 +13,13 @@ describe('Ternary Search Tree', () => {
     assert.throws(() => tst.insert(Buffer.from(''), ''))
   })
 
+  test('looking up not inserted key returns null', () => {
+    assert.throws(() => new TernarySearchTree().insert(Buffer.from(''), ''))
+    const tst = new TernarySearchTree()
+    tst.insert(Buffer.from('a'), 'a')
+    assert.strictEqual(tst.lookup(Buffer.from('non-existant')), null)
+  })
+
   test('duplicate key', () => {
     const tst = new TernarySearchTree()
     const key = Buffer.from('a')

From 0cd1a00f0151dfeb97004dc371fd32e347ecf451 Mon Sep 17 00:00:00 2001
From: Aras Abbasi <aras.abbasi@googlemail.com>
Date: Mon, 19 Feb 2024 22:39:34 +0100
Subject: [PATCH 2/3] Apply suggestions from code review

---
 lib/core/tree.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/core/tree.js b/lib/core/tree.js
index 889b935b608..5ed179f304b 100644
--- a/lib/core/tree.js
+++ b/lib/core/tree.js
@@ -112,7 +112,7 @@ class TernarySearchTree {
 
   /**
    * @param {Uint8Array} key
-   * @param {void}
+   * @param {any} value
    * */
   insert (key, value) {
     if (this.node === null) {

From 5ca863c1d27a5570ff47f0e47ab5ddab0c789514 Mon Sep 17 00:00:00 2001
From: Aras Abbasi <aras.abbasi@googlemail.com>
Date: Tue, 20 Feb 2024 00:13:27 +0100
Subject: [PATCH 3/3] Apply suggestions from code review

Co-authored-by: tsctx <91457664+tsctx@users.noreply.github.com>
---
 lib/core/tree.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/core/tree.js b/lib/core/tree.js
index 5ed179f304b..9b50767c6d3 100644
--- a/lib/core/tree.js
+++ b/lib/core/tree.js
@@ -124,7 +124,7 @@ class TernarySearchTree {
 
   /**
    * @param {Uint8Array} key
-   * @return {TstNode | null}
+   * @return {any}
    */
   lookup (key) {
     return this.node?.search(key)?.value ?? null