From f3b770bb3846a74ef8adec432ff62ec4ef8a9ecd Mon Sep 17 00:00:00 2001
From: Sean Reece <reece.sean@gmail.com>
Date: Tue, 6 Aug 2024 14:34:41 -0400
Subject: [PATCH 1/8] Initial commit

---
 src/objectid.ts              | 7 +++++++
 src/utils/node_byte_utils.ts | 2 +-
 test/node/object_id.test.ts  | 8 +++++++-
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/objectid.ts b/src/objectid.ts
index c3b8c615e..3b8413a9e 100644
--- a/src/objectid.ts
+++ b/src/objectid.ts
@@ -212,6 +212,11 @@ export class ObjectId extends BSONValue {
     return this.id;
   }
 
+  /** ObjectId bytes @internal */
+  get buffer(): Uint8Array {
+    return this.id;
+  }
+
   /**
    * The ObjectId bytes
    * @readonly
@@ -283,6 +288,8 @@ export class ObjectId extends BSONValue {
    * Generate a 12 byte id buffer used in ObjectId's
    *
    * @param time - pass in a second based timestamp.
+   * @param buffer - Optionally pass in a buffer instance.
+   * @param offset - Optionally pass in a buffer offset.
    */
   static generate(time?: number): Uint8Array;
   /**
diff --git a/src/utils/node_byte_utils.ts b/src/utils/node_byte_utils.ts
index ba9ffd5db..90d612c7c 100644
--- a/src/utils/node_byte_utils.ts
+++ b/src/utils/node_byte_utils.ts
@@ -6,7 +6,7 @@ type NodeJsEncoding = 'base64' | 'hex' | 'utf8' | 'binary';
 type NodeJsBuffer = ArrayBufferView &
   Uint8Array & {
     write(string: string, offset: number, length: undefined, encoding: 'utf8'): number;
-    copy(target: Uint8Array, targetStart: number, sourceStart: number, sourceEnd: number): number;
+    copy(target: Uint8Array, targetStart: number, sourceStart?: number, sourceEnd?: number): number;
     toString: (this: Uint8Array, encoding: NodeJsEncoding, start?: number, end?: number) => string;
     equals: (this: Uint8Array, other: Uint8Array) => boolean;
     swap32: (this: NodeJsBuffer) => NodeJsBuffer;
diff --git a/test/node/object_id.test.ts b/test/node/object_id.test.ts
index f9f1b5290..bd6f8f370 100644
--- a/test/node/object_id.test.ts
+++ b/test/node/object_id.test.ts
@@ -4,6 +4,9 @@ import * as util from 'util';
 import { expect } from 'chai';
 import { bufferFromHexArray } from './tools/utils';
 import { isBufferOrUint8Array } from './tools/utils';
+import { _pool, _offset } from '../../src/objectid';
+
+ObjectId.poolSize = 100;
 
 describe('ObjectId', function () {
   describe('static createFromTime()', () => {
@@ -539,9 +542,12 @@ describe('ObjectId', function () {
       let equalId = { _bsontype: 'ObjectId', [oidKId]: oid.id };
 
       const propAccessRecord: string[] = [];
+
       equalId = new Proxy(equalId, {
         get(target, prop: string, recv) {
-          if (prop !== '_bsontype') {
+          if (typeof prop === 'symbol') {
+            propAccessRecord.push((prop as symbol).toString());
+          } else if (prop !== '_bsontype') {
             propAccessRecord.push(prop);
           }
           return Reflect.get(target, prop, recv);

From 2f3ece489d06e1816fd2d3fe3fe3177812dddf7f Mon Sep 17 00:00:00 2001
From: Sean Reece <reece.sean@gmail.com>
Date: Wed, 14 Aug 2024 23:42:53 -0400
Subject: [PATCH 2/8] Improvements

---
 src/utils/node_byte_utils.ts |  2 +-
 test/node/object_id.test.ts  | 12 ++++++++----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/utils/node_byte_utils.ts b/src/utils/node_byte_utils.ts
index 90d612c7c..ba9ffd5db 100644
--- a/src/utils/node_byte_utils.ts
+++ b/src/utils/node_byte_utils.ts
@@ -6,7 +6,7 @@ type NodeJsEncoding = 'base64' | 'hex' | 'utf8' | 'binary';
 type NodeJsBuffer = ArrayBufferView &
   Uint8Array & {
     write(string: string, offset: number, length: undefined, encoding: 'utf8'): number;
-    copy(target: Uint8Array, targetStart: number, sourceStart?: number, sourceEnd?: number): number;
+    copy(target: Uint8Array, targetStart: number, sourceStart: number, sourceEnd: number): number;
     toString: (this: Uint8Array, encoding: NodeJsEncoding, start?: number, end?: number) => string;
     equals: (this: Uint8Array, other: Uint8Array) => boolean;
     swap32: (this: NodeJsBuffer) => NodeJsBuffer;
diff --git a/test/node/object_id.test.ts b/test/node/object_id.test.ts
index bd6f8f370..7d72a236b 100644
--- a/test/node/object_id.test.ts
+++ b/test/node/object_id.test.ts
@@ -4,10 +4,16 @@ import * as util from 'util';
 import { expect } from 'chai';
 import { bufferFromHexArray } from './tools/utils';
 import { isBufferOrUint8Array } from './tools/utils';
-import { _pool, _offset } from '../../src/objectid';
 
 ObjectId.poolSize = 100;
 
+declare module '../register-bson' {
+  interface ObjectId {
+    pool: Uint8Array;
+    offset: number;
+  }
+}
+
 describe('ObjectId', function () {
   describe('static createFromTime()', () => {
     it('creates an objectId with user defined value in the timestamp field', function () {
@@ -545,9 +551,7 @@ describe('ObjectId', function () {
 
       equalId = new Proxy(equalId, {
         get(target, prop: string, recv) {
-          if (typeof prop === 'symbol') {
-            propAccessRecord.push((prop as symbol).toString());
-          } else if (prop !== '_bsontype') {
+          if (prop !== '_bsontype') {
             propAccessRecord.push(prop);
           }
           return Reflect.get(target, prop, recv);

From 4b773e6035dddc068f25e1eb3f41aea5276c4ba8 Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Thu, 12 Dec 2024 10:30:57 -0500
Subject: [PATCH 3/8] Disable pool and improve perf for poolSize=1

---
 src/objectid.ts             | 2 +-
 test/node/object_id.test.ts | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/objectid.ts b/src/objectid.ts
index 3b8413a9e..a6ef274dd 100644
--- a/src/objectid.ts
+++ b/src/objectid.ts
@@ -35,7 +35,7 @@ function incrementPool(): void {
 let PROCESS_UNIQUE: Uint8Array | null = null;
 
 /** ObjectId hexString cache @internal */
-const __idCache = new WeakMap(); // TODO(NODE-6549): convert this to #__id private field when target updated to ES2022
+const __idCache = new WeakMap<ObjectId, string>(); // TODO(NODE-6549): convert this to #__id private field when target updated to ES2022
 
 /** @public */
 export interface ObjectIdLike {
diff --git a/test/node/object_id.test.ts b/test/node/object_id.test.ts
index 7d72a236b..9ea4c19d3 100644
--- a/test/node/object_id.test.ts
+++ b/test/node/object_id.test.ts
@@ -548,7 +548,6 @@ describe('ObjectId', function () {
       let equalId = { _bsontype: 'ObjectId', [oidKId]: oid.id };
 
       const propAccessRecord: string[] = [];
-
       equalId = new Proxy(equalId, {
         get(target, prop: string, recv) {
           if (prop !== '_bsontype') {

From 30beb4427e7a78631b99ce1b4767b713a0699f11 Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Thu, 12 Dec 2024 11:24:15 -0500
Subject: [PATCH 4/8] fix: use weakmap private

---
 src/objectid.ts | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/objectid.ts b/src/objectid.ts
index a6ef274dd..e8a475d7c 100644
--- a/src/objectid.ts
+++ b/src/objectid.ts
@@ -36,6 +36,8 @@ let PROCESS_UNIQUE: Uint8Array | null = null;
 
 /** ObjectId hexString cache @internal */
 const __idCache = new WeakMap<ObjectId, string>(); // TODO(NODE-6549): convert this to #__id private field when target updated to ES2022
+const __pool = new WeakMap<ObjectId, Uint8Array>(); // TODO(NODE-6549): convert this to #pool private field when target updated to ES2022
+const __offset = new WeakMap<ObjectId, number>(); // TODO(NODE-6549): convert this to #offset private field when target updated to ES2022
 
 /** @public */
 export interface ObjectIdLike {
@@ -76,12 +78,20 @@ export class ObjectId extends BSONValue {
   }
 
   /** ObjectId buffer pool pointer @internal */
-  private pool: Uint8Array;
-  /** Buffer pool offset @internal */
-  private offset?: number;
+  private get pool(): Uint8Array {
+    return __pool.get(this) as Uint8Array;
+  }
+  private set pool(value: Uint8Array) {
+    __pool.set(this, value);
+  }
 
-  /** ObjectId hexString cache @internal */
-  private __id?: string;
+  /** Buffer pool offset @internal */
+  private get offset(): number | undefined {
+    return __offset.get(this);
+  }
+  private set offset(value: number) {
+    __offset.set(this, value);
+  }
 
   /**
    * Create ObjectId from a number.

From 951207c935adedcd169dd16150eafc8c4825bbf6 Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Thu, 12 Dec 2024 11:45:37 -0500
Subject: [PATCH 5/8] test: use before and after to set poolSize

---
 test/node/object_id.test.ts | 226 +++++++++++++++++-------------------
 1 file changed, 107 insertions(+), 119 deletions(-)

diff --git a/test/node/object_id.test.ts b/test/node/object_id.test.ts
index 9ea4c19d3..9e2b33fac 100644
--- a/test/node/object_id.test.ts
+++ b/test/node/object_id.test.ts
@@ -267,91 +267,121 @@ describe('ObjectId', function () {
     ).to.be.true;
   });
 
-  it('should correctly use buffer pool for ObjectId creation', function () {
-    const oldPoolSize = ObjectId.poolSize;
-    ObjectId.poolSize = 2;
-    const obj = new ObjectId();
-    const obj2 = new ObjectId();
-
-    expect(obj.offset).to.equal(0);
-    expect(obj2.offset).to.equal(12);
-    expect(obj.offset).to.not.equal(obj2.offset);
-    expect(obj.pool).to.equal(obj2.pool);
-
-    expect(obj.id).to.not.equal(obj2.id);
-    ObjectId.poolSize = oldPoolSize;
-  });
-
-  it('should respect buffer pool size for ObjectId creation', function () {
-    const oldPoolSize = ObjectId.poolSize;
-    ObjectId.poolSize = 2;
-    const test = new ObjectId();
-    // Must fill current (large) pool first
-    const num = (test.pool.byteLength - test.offset) / 12;
-    for (let i = 0; i < num + 1; i++) {
-      new ObjectId();
-    }
+  it('ObjectId.poolSize should be 1 by default', function () {
+    expect(ObjectId.poolSize).to.equal(1);
+  });
 
-    const obj = new ObjectId();
-    const obj2 = new ObjectId();
-    const obj3 = new ObjectId();
-
-    expect(obj.offset).to.equal(0);
-    expect(obj2.offset).to.equal(12);
-    expect(obj3.offset).to.equal(0);
-    expect(obj.pool).to.equal(obj2.pool);
-    expect(obj2.pool).to.not.equal(obj3.pool);
-
-    expect(obj.id).to.not.equal(obj2.id);
-    expect(obj2.id).to.not.equal(obj3.id);
-    ObjectId.poolSize = oldPoolSize;
-  });
-
-  it('should allow poolSize of 1', function () {
-    const oldPoolSize = ObjectId.poolSize;
-    ObjectId.poolSize = 1;
-    const test = new ObjectId();
-    // Must fill current (large) pool first
-    const num = (test.pool.byteLength - test.offset) / 12;
-    for (let i = 0; i < num + 1; i++) {
-      new ObjectId();
-    }
+  describe('when poolSize is greater than 1', function () {
+    let oldPoolSize;
+    before(function () {
+      oldPoolSize = ObjectId.poolSize;
+      ObjectId.poolSize = 2;
+    });
+
+    after(function () {
+      ObjectId.poolSize = oldPoolSize;
+    });
+
+    it('should correctly use buffer pool for ObjectId creation', function () {
+      const obj = new ObjectId();
+      const obj2 = new ObjectId();
+
+      expect(obj.offset).to.equal(0);
+      expect(obj2.offset).to.equal(12);
+      expect(obj.offset).to.not.equal(obj2.offset);
+      expect(obj.pool).to.equal(obj2.pool);
+
+      expect(obj.id).to.not.equal(obj2.id);
+    });
+
+    it('should respect buffer pool size for ObjectId creation', function () {
+      const oldPoolSize = ObjectId.poolSize;
+      ObjectId.poolSize = 2;
+      const test = new ObjectId();
+      // Must fill current (large) pool first
+      const num = (test.pool.byteLength - test.offset) / 12;
+      for (let i = 0; i < num + 1; i++) {
+        new ObjectId();
+      }
 
-    const obj = new ObjectId();
-    const obj2 = new ObjectId();
-    const obj3 = new ObjectId();
+      const obj = new ObjectId();
+      const obj2 = new ObjectId();
+      const obj3 = new ObjectId();
 
-    expect(obj.offset).to.equal(undefined);
-    expect(obj2.offset).to.equal(undefined);
-    expect(obj3.offset).to.equal(undefined);
-    expect(obj.pool).to.not.equal(obj2.pool);
-    expect(obj2.pool).to.not.equal(obj3.pool);
+      expect(obj.offset).to.equal(0);
+      expect(obj2.offset).to.equal(12);
+      expect(obj3.offset).to.equal(0);
+      expect(obj.pool).to.equal(obj2.pool);
+      expect(obj2.pool).to.not.equal(obj3.pool);
 
-    expect(obj.id).to.not.equal(obj2.id);
-    expect(obj2.id).to.not.equal(obj3.id);
-    ObjectId.poolSize = oldPoolSize;
+      expect(obj.id).to.not.equal(obj2.id);
+      expect(obj2.id).to.not.equal(obj3.id);
+      ObjectId.poolSize = oldPoolSize;
+    });
   });
 
-  it('should default to poolSize = 1 when invalid poolSize set', function () {
-    const oldPoolSize = ObjectId.poolSize;
+  describe('when poolSize is 1', function () {
+    let oldPoolSize;
+    before(function () {
+      oldPoolSize = ObjectId.poolSize;
+      ObjectId.poolSize = 1;
+    });
 
-    ObjectId.poolSize = 0;
-    expect(ObjectId.poolSize).to.equal(1);
-    ObjectId.poolSize = -1;
-    expect(ObjectId.poolSize).to.equal(1);
-    ObjectId.poolSize = 0n;
-    expect(ObjectId.poolSize).to.equal(1);
-    ObjectId.poolSize = '';
-    expect(ObjectId.poolSize).to.equal(1);
-    ObjectId.poolSize = NaN;
-    expect(ObjectId.poolSize).to.equal(1);
-    ObjectId.poolSize = {};
-    expect(ObjectId.poolSize).to.equal(1);
-    ObjectId.poolSize = false;
-    expect(ObjectId.poolSize).to.equal(1);
-    ObjectId.poolSize = '1';
+    after(function () {
+      ObjectId.poolSize = oldPoolSize;
+    });
+
+    it('should allow poolSize of 1', function () {
+      const test = new ObjectId();
+      // Must fill current (large) pool first
+      const num = (test.pool.byteLength - test.offset) / 12;
+      for (let i = 0; i < num + 1; i++) {
+        new ObjectId();
+      }
+
+      const obj = new ObjectId();
+      const obj2 = new ObjectId();
+      const obj3 = new ObjectId();
+
+      expect(obj.offset).to.equal(undefined);
+      expect(obj2.offset).to.equal(undefined);
+      expect(obj3.offset).to.equal(undefined);
+      expect(obj.pool).to.not.equal(obj2.pool);
+      expect(obj2.pool).to.not.equal(obj3.pool);
+
+      expect(obj.id).to.not.equal(obj2.id);
+      expect(obj2.id).to.not.equal(obj3.id);
+    });
+  });
+
+  describe('when poolSize is modified', function () {
+    let oldPoolSize;
+    beforeEach(function () {
+      oldPoolSize = ObjectId.poolSize;
+      ObjectId.poolSize = 1;
+    });
 
-    ObjectId.poolSize = oldPoolSize;
+    afterEach(function () {
+      ObjectId.poolSize = oldPoolSize;
+    });
+
+    it('should default to poolSize = 1 when invalid poolSize set', function () {
+      ObjectId.poolSize = 0;
+      expect(ObjectId.poolSize).to.equal(1);
+      ObjectId.poolSize = -1;
+      expect(ObjectId.poolSize).to.equal(1);
+      ObjectId.poolSize = 0n;
+      expect(ObjectId.poolSize).to.equal(1);
+      ObjectId.poolSize = '';
+      expect(ObjectId.poolSize).to.equal(1);
+      ObjectId.poolSize = NaN;
+      expect(ObjectId.poolSize).to.equal(1);
+      ObjectId.poolSize = {};
+      expect(ObjectId.poolSize).to.equal(1);
+      ObjectId.poolSize = false;
+      expect(ObjectId.poolSize).to.equal(1);
+      ObjectId.poolSize = '1';
+    });
   });
 
   it('should throw error if non-12 byte non-24 hex string passed in', function () {
@@ -543,48 +573,6 @@ describe('ObjectId', function () {
       expect(oid.toString()).to.not.equal(equalId.toString());
       expect(oid.equals(equalId)).to.be.true;
     });
-
-    it('should use otherId[kId] Buffer for equality when otherId has _bsontype === ObjectId', () => {
-      let equalId = { _bsontype: 'ObjectId', [oidKId]: oid.id };
-
-      const propAccessRecord: string[] = [];
-      equalId = new Proxy(equalId, {
-        get(target, prop: string, recv) {
-          if (prop !== '_bsontype') {
-            propAccessRecord.push(prop);
-          }
-          return Reflect.get(target, prop, recv);
-        }
-      });
-
-      expect(oid.equals(equalId)).to.be.true;
-      // once for the 11th byte shortcut
-      // once for the total equality
-      expect(propAccessRecord).to.deep.equal(['pool', oidKId, oidKId]);
-    });
-
-    it('should use otherId[kId] Pool for equality when otherId has _bsontype === ObjectId when using pool', () => {
-      const oldPoolSize = ObjectId.poolSize;
-      ObjectId.poolSize = 2;
-      const oid = new ObjectId(oidString);
-      let equalId = new ObjectId(oidString);
-
-      const propAccessRecord: string[] = [];
-      equalId = new Proxy(equalId, {
-        get(target, prop: string, recv) {
-          if (prop !== '_bsontype') {
-            propAccessRecord.push(prop);
-          }
-          return Reflect.get(target, prop, recv);
-        }
-      });
-
-      expect(oid.equals(equalId)).to.be.true;
-      // once for the 11th byte shortcut
-      // once for the total equality
-      expect(propAccessRecord).to.contain('pool').contain('offset');
-      ObjectId.poolSize = oldPoolSize;
-    });
   });
 
   context('createFromHexString()', () => {

From be3b64606ff754a4d73cadb744396dde1d796a62 Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Thu, 12 Dec 2024 16:01:01 -0500
Subject: [PATCH 6/8] refactor: encapsulate pooling helpers

---
 src/objectid.ts             | 74 +++++++++++++++++++------------------
 test/node/object_id.test.ts |  9 -----
 2 files changed, 39 insertions(+), 44 deletions(-)

diff --git a/src/objectid.ts b/src/objectid.ts
index e8a475d7c..1aaa41c88 100644
--- a/src/objectid.ts
+++ b/src/objectid.ts
@@ -4,32 +4,39 @@ import { type InspectFn, defaultInspect } from './parser/utils';
 import { ByteUtils } from './utils/byte_utils';
 import { NumberUtils } from './utils/number_utils';
 
-// Settings for ObjectId Buffer pool
-// Disable pool by default in order to ensure compatibility
-// Specify larger poolSize to enable pool
-let currentPool: Uint8Array | null = null;
-let poolSize = 1; // Disable pool by default.
-let currentPoolOffset = 0;
+const ObjectIdPooling: {
+  currentPool: Uint8Array | null;
+  poolSize: number;
+  currentPoolOffset: number;
+  getPool(): { readonly currentPool: Uint8Array; readonly currentPoolOffset: number };
+  incrementPool(): void;
+} = {
+  // Settings for ObjectId Buffer pool
+  // Disable pool by default in order to ensure compatibility
+  // Specify larger poolSize to enable pool
+  currentPool: null,
+  poolSize: 1, // Disable pool by default.
+  currentPoolOffset: 0,
+  /**
+   * Retrieves a ObjectId pool and offset. This function may create a new ObjectId buffer pool and reset the pool offset
+   * @internal
+   */
+  getPool() {
+    if (!this.currentPool || this.currentPoolOffset + 12 > this.currentPool.length) {
+      this.currentPool = ByteUtils.allocateUnsafe(this.poolSize * 12);
+      this.currentPoolOffset = 0;
+    }
+    return { currentPool: this.currentPool, currentPoolOffset: this.currentPoolOffset } as const;
+  },
 
-/**
- * Retrieves a ObjectId pool and offset. This function may create a new ObjectId buffer pool and reset the pool offset
- * @internal
- */
-function getPool(): [Uint8Array, number] {
-  if (!currentPool || currentPoolOffset + 12 > currentPool.length) {
-    currentPool = ByteUtils.allocateUnsafe(poolSize * 12);
-    currentPoolOffset = 0;
+  /**
+   * Increments the pool offset by 12 bytes
+   * @internal
+   */
+  incrementPool(): void {
+    this.currentPoolOffset += 12;
   }
-  return [currentPool, currentPoolOffset];
-}
-
-/**
- * Increments the pool offset by 12 bytes
- * @internal
- */
-function incrementPool(): void {
-  currentPoolOffset += 12;
-}
+};
 
 // Unique sequence for the current process (initialized on first use)
 let PROCESS_UNIQUE: Uint8Array | null = null;
@@ -70,11 +77,11 @@ export class ObjectId extends BSONValue {
    * The size of the current ObjectId buffer pool.
    */
   static get poolSize(): number {
-    return poolSize;
+    return ObjectIdPooling.poolSize;
   }
 
   static set poolSize(size: number) {
-    poolSize = Math.max(Math.abs(Number(size)) >>> 0, 1);
+    ObjectIdPooling.poolSize = Math.max(Math.abs(Number(size)) >>> 0, 1);
   }
 
   /** ObjectId buffer pool pointer @internal */
@@ -168,11 +175,13 @@ export class ObjectId extends BSONValue {
     let offset: number;
 
     // Special case when poolSize === 1 and a 12 byte buffer is passed in - just persist buffer
-    if (poolSize === 1 && ArrayBuffer.isView(workingId) && workingId.length === 12) {
+    if (ObjectId.poolSize === 1 && ArrayBuffer.isView(workingId) && workingId.length === 12) {
       pool = ByteUtils.toLocalBufferType(workingId);
       offset = 0;
     } else {
-      [pool, offset] = getPool();
+      const currentPool = ObjectIdPooling.getPool();
+      pool = currentPool.currentPool;
+      offset = currentPool.currentPoolOffset;
 
       // The following cases use workingId to construct an ObjectId
       if (workingId == null || typeof workingId === 'number') {
@@ -211,15 +220,10 @@ export class ObjectId extends BSONValue {
     // Increment pool offset once we have completed initialization
     this.pool = pool;
     // Only set offset if pool is used
-    if (poolSize > 1) {
+    if (ObjectId.poolSize > 1) {
       this.offset = offset;
     }
-    incrementPool();
-  }
-
-  /** ObjectId bytes @internal */
-  get buffer(): Uint8Array {
-    return this.id;
+    ObjectIdPooling.incrementPool();
   }
 
   /** ObjectId bytes @internal */
diff --git a/test/node/object_id.test.ts b/test/node/object_id.test.ts
index 9e2b33fac..09f545b6a 100644
--- a/test/node/object_id.test.ts
+++ b/test/node/object_id.test.ts
@@ -5,15 +5,6 @@ import { expect } from 'chai';
 import { bufferFromHexArray } from './tools/utils';
 import { isBufferOrUint8Array } from './tools/utils';
 
-ObjectId.poolSize = 100;
-
-declare module '../register-bson' {
-  interface ObjectId {
-    pool: Uint8Array;
-    offset: number;
-  }
-}
-
 describe('ObjectId', function () {
   describe('static createFromTime()', () => {
     it('creates an objectId with user defined value in the timestamp field', function () {

From 129038f679cc5fcb0462f6a19b19c0d9e119f83b Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Fri, 13 Dec 2024 13:34:36 -0500
Subject: [PATCH 7/8] refactor: remove WeakMap private pool and offset
 properties

---
 src/objectid.ts             | 19 ++-----------------
 test/node/object_id.test.ts | 12 ++++++++++++
 2 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/src/objectid.ts b/src/objectid.ts
index 1aaa41c88..15ec130fd 100644
--- a/src/objectid.ts
+++ b/src/objectid.ts
@@ -43,8 +43,6 @@ let PROCESS_UNIQUE: Uint8Array | null = null;
 
 /** ObjectId hexString cache @internal */
 const __idCache = new WeakMap<ObjectId, string>(); // TODO(NODE-6549): convert this to #__id private field when target updated to ES2022
-const __pool = new WeakMap<ObjectId, Uint8Array>(); // TODO(NODE-6549): convert this to #pool private field when target updated to ES2022
-const __offset = new WeakMap<ObjectId, number>(); // TODO(NODE-6549): convert this to #offset private field when target updated to ES2022
 
 /** @public */
 export interface ObjectIdLike {
@@ -84,21 +82,8 @@ export class ObjectId extends BSONValue {
     ObjectIdPooling.poolSize = Math.max(Math.abs(Number(size)) >>> 0, 1);
   }
 
-  /** ObjectId buffer pool pointer @internal */
-  private get pool(): Uint8Array {
-    return __pool.get(this) as Uint8Array;
-  }
-  private set pool(value: Uint8Array) {
-    __pool.set(this, value);
-  }
-
-  /** Buffer pool offset @internal */
-  private get offset(): number | undefined {
-    return __offset.get(this);
-  }
-  private set offset(value: number) {
-    __offset.set(this, value);
-  }
+  private pool: Uint8Array;
+  private offset: number | undefined;
 
   /**
    * Create ObjectId from a number.
diff --git a/test/node/object_id.test.ts b/test/node/object_id.test.ts
index 09f545b6a..6a8da7e13 100644
--- a/test/node/object_id.test.ts
+++ b/test/node/object_id.test.ts
@@ -309,6 +309,12 @@ describe('ObjectId', function () {
       expect(obj2.id).to.not.equal(obj3.id);
       ObjectId.poolSize = oldPoolSize;
     });
+
+    it('two identical ObjectId values are not deep equal', function () {
+      const oid0 = new ObjectId('00'.repeat(12));
+      const oid1 = new ObjectId('00'.repeat(12));
+      expect(oid0).to.not.deep.equal(oid1);
+    });
   });
 
   describe('when poolSize is 1', function () {
@@ -343,6 +349,12 @@ describe('ObjectId', function () {
       expect(obj.id).to.not.equal(obj2.id);
       expect(obj2.id).to.not.equal(obj3.id);
     });
+
+    it('two identical ObjectId values are deep equal', function () {
+      const oid0 = new ObjectId('00'.repeat(12));
+      const oid1 = new ObjectId('00'.repeat(12));
+      expect(oid0).to.deep.equal(oid1);
+    });
   });
 
   describe('when poolSize is modified', function () {

From 04317bd1abc1f88d9f588932d356853209083d95 Mon Sep 17 00:00:00 2001
From: Neal Beeken <neal.beeken@mongodb.com>
Date: Tue, 7 Jan 2025 15:13:05 -0500
Subject: [PATCH 8/8] chore: don't change src

---
 src/objectid.ts | 80 +++++++++++++++++++++++--------------------------
 1 file changed, 37 insertions(+), 43 deletions(-)

diff --git a/src/objectid.ts b/src/objectid.ts
index 15ec130fd..c3b8c615e 100644
--- a/src/objectid.ts
+++ b/src/objectid.ts
@@ -4,45 +4,38 @@ import { type InspectFn, defaultInspect } from './parser/utils';
 import { ByteUtils } from './utils/byte_utils';
 import { NumberUtils } from './utils/number_utils';
 
-const ObjectIdPooling: {
-  currentPool: Uint8Array | null;
-  poolSize: number;
-  currentPoolOffset: number;
-  getPool(): { readonly currentPool: Uint8Array; readonly currentPoolOffset: number };
-  incrementPool(): void;
-} = {
-  // Settings for ObjectId Buffer pool
-  // Disable pool by default in order to ensure compatibility
-  // Specify larger poolSize to enable pool
-  currentPool: null,
-  poolSize: 1, // Disable pool by default.
-  currentPoolOffset: 0,
-  /**
-   * Retrieves a ObjectId pool and offset. This function may create a new ObjectId buffer pool and reset the pool offset
-   * @internal
-   */
-  getPool() {
-    if (!this.currentPool || this.currentPoolOffset + 12 > this.currentPool.length) {
-      this.currentPool = ByteUtils.allocateUnsafe(this.poolSize * 12);
-      this.currentPoolOffset = 0;
-    }
-    return { currentPool: this.currentPool, currentPoolOffset: this.currentPoolOffset } as const;
-  },
+// Settings for ObjectId Buffer pool
+// Disable pool by default in order to ensure compatibility
+// Specify larger poolSize to enable pool
+let currentPool: Uint8Array | null = null;
+let poolSize = 1; // Disable pool by default.
+let currentPoolOffset = 0;
 
-  /**
-   * Increments the pool offset by 12 bytes
-   * @internal
-   */
-  incrementPool(): void {
-    this.currentPoolOffset += 12;
+/**
+ * Retrieves a ObjectId pool and offset. This function may create a new ObjectId buffer pool and reset the pool offset
+ * @internal
+ */
+function getPool(): [Uint8Array, number] {
+  if (!currentPool || currentPoolOffset + 12 > currentPool.length) {
+    currentPool = ByteUtils.allocateUnsafe(poolSize * 12);
+    currentPoolOffset = 0;
   }
-};
+  return [currentPool, currentPoolOffset];
+}
+
+/**
+ * Increments the pool offset by 12 bytes
+ * @internal
+ */
+function incrementPool(): void {
+  currentPoolOffset += 12;
+}
 
 // Unique sequence for the current process (initialized on first use)
 let PROCESS_UNIQUE: Uint8Array | null = null;
 
 /** ObjectId hexString cache @internal */
-const __idCache = new WeakMap<ObjectId, string>(); // TODO(NODE-6549): convert this to #__id private field when target updated to ES2022
+const __idCache = new WeakMap(); // TODO(NODE-6549): convert this to #__id private field when target updated to ES2022
 
 /** @public */
 export interface ObjectIdLike {
@@ -75,15 +68,20 @@ export class ObjectId extends BSONValue {
    * The size of the current ObjectId buffer pool.
    */
   static get poolSize(): number {
-    return ObjectIdPooling.poolSize;
+    return poolSize;
   }
 
   static set poolSize(size: number) {
-    ObjectIdPooling.poolSize = Math.max(Math.abs(Number(size)) >>> 0, 1);
+    poolSize = Math.max(Math.abs(Number(size)) >>> 0, 1);
   }
 
+  /** ObjectId buffer pool pointer @internal */
   private pool: Uint8Array;
-  private offset: number | undefined;
+  /** Buffer pool offset @internal */
+  private offset?: number;
+
+  /** ObjectId hexString cache @internal */
+  private __id?: string;
 
   /**
    * Create ObjectId from a number.
@@ -160,13 +158,11 @@ export class ObjectId extends BSONValue {
     let offset: number;
 
     // Special case when poolSize === 1 and a 12 byte buffer is passed in - just persist buffer
-    if (ObjectId.poolSize === 1 && ArrayBuffer.isView(workingId) && workingId.length === 12) {
+    if (poolSize === 1 && ArrayBuffer.isView(workingId) && workingId.length === 12) {
       pool = ByteUtils.toLocalBufferType(workingId);
       offset = 0;
     } else {
-      const currentPool = ObjectIdPooling.getPool();
-      pool = currentPool.currentPool;
-      offset = currentPool.currentPoolOffset;
+      [pool, offset] = getPool();
 
       // The following cases use workingId to construct an ObjectId
       if (workingId == null || typeof workingId === 'number') {
@@ -205,10 +201,10 @@ export class ObjectId extends BSONValue {
     // Increment pool offset once we have completed initialization
     this.pool = pool;
     // Only set offset if pool is used
-    if (ObjectId.poolSize > 1) {
+    if (poolSize > 1) {
       this.offset = offset;
     }
-    ObjectIdPooling.incrementPool();
+    incrementPool();
   }
 
   /** ObjectId bytes @internal */
@@ -287,8 +283,6 @@ export class ObjectId extends BSONValue {
    * Generate a 12 byte id buffer used in ObjectId's
    *
    * @param time - pass in a second based timestamp.
-   * @param buffer - Optionally pass in a buffer instance.
-   * @param offset - Optionally pass in a buffer offset.
    */
   static generate(time?: number): Uint8Array;
   /**