perf optimizations, buffer index and deserialization fix

Author: aditi-khare-mongoDB

etc/benchmarks/main.mjs

@@ -9,7 +9,7 @@ console.log();
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 await runner({
-  skip: false,
+  skip: true,
   name: 'deserialize({ oid, string }, { validation: { utf8: false } })',
   iterations,
   setup(libs) {
@@ -58,6 +58,15 @@ await runner({
   }
 });
 
+await runner({
+  skip: false,
+  name: 'Double Serialization',
+  iterations,
+  run(i, bson) {
+    bson.lib.serialize({ d: 2.3 });
+  }
+});
+
 // End
 console.log(
   'Total time taken to benchmark:',

src/parser/deserializer.ts

@@ -263,10 +263,12 @@ function deserializeObject(
         (buffer[index++] << 16) |
         (buffer[index++] << 24);
     } else if (elementType === constants.BSON_DATA_NUMBER && promoteValues === false) {
-      value = new Double(buffer.readDoubleLE(index));
+      const dv = new DataView(buffer.buffer, buffer.byteOffset, buffer.byteLength);
+      value = new Double(dv.getFloat64(index, true));
       index = index + 8;
     } else if (elementType === constants.BSON_DATA_NUMBER) {
-      value = buffer.readDoubleLE(index);
+      const dv = new DataView(buffer.buffer, buffer.byteOffset, buffer.byteLength);
+      value = dv.getFloat64(index, true);
       index = index + 8;
     } else if (elementType === constants.BSON_DATA_DATE) {
       const lowBits =

src/parser/serializer.ts

@@ -78,6 +78,12 @@ function serializeString(
   return index;
 }
 
+const SPACE_FOR_FLOAT64 = new Uint8Array(8);
+const DV_FOR_FLOAT64 = new DataView(
+  SPACE_FOR_FLOAT64.buffer,
+  SPACE_FOR_FLOAT64.byteOffset,
+  SPACE_FOR_FLOAT64.byteLength
+);
 function serializeNumber(
   buffer: Buffer,
   key: string,
@@ -118,7 +124,8 @@ function serializeNumber(
     index = index + numberOfWrittenBytes;
     buffer[index++] = 0;
     // Write float
-    buffer.writeDoubleLE(value, index);
+    DV_FOR_FLOAT64.setFloat64(0, value, true);
+    buffer.set(SPACE_FOR_FLOAT64, index);
     // Adjust index
     index = index + 8;
   }
@@ -486,7 +493,8 @@ function serializeDouble(
   buffer[index++] = 0;
 
   // Write float
-  buffer.writeDoubleLE(value.value, index);
+  DV_FOR_FLOAT64.setFloat64(0, value.value, true);
+  buffer.set(SPACE_FOR_FLOAT64, index);
 
   // Adjust index
   index = index + 8;

test/node/bson_corpus.spec.test.js

@@ -3,7 +3,7 @@
 
 const Buffer = require('buffer').Buffer;
 const BSON = require('../register-bson');
-const { getNodeMajor } = require('./tools/utils');
+const { getNodeMajor, isBrowser } = require('./tools/utils');
 const BSONError = BSON.BSONError;
 const EJSON = BSON.EJSON;
 
@@ -122,7 +122,7 @@ describe('BSON Corpus', function () {
         describe('valid-bson', function () {
           for (const v of valid) {
             it(v.description, function () {
-              if (v.description === 'NaN with payload' && getNodeMajor() < 10) {
+              if (v.description === 'NaN with payload' && !isBrowser() && getNodeMajor() < 10) {
                 this.skip();
               }
 

test/node/double_tests.js

@@ -1,7 +1,7 @@
 'use strict';
 
 const BSON = require('../register-bson');
-const { getNodeMajor } = require('./tools/utils');
+const { getNodeMajor, isBrowser } = require('./tools/utils');
 const Double = BSON.Double;
 
 describe('Double', function () {
@@ -64,11 +64,14 @@ describe('Double', function () {
     });
 
     it('NaN with payload', function () {
-      if (getNodeMajor() < 10) {
+      if (!isBrowser() && getNodeMajor() < 10) {
         this.skip();
       }
       let buffer = Buffer.from('120000000000F87F', 'hex');
-      let value = buffer.readDoubleLE(0);
+
+      const dv = new DataView(buffer.buffer, buffer.byteOffset, buffer.byteLength);
+      let value = dv.getFloat64(0, true);
+
       let serializedDouble = BSON.serialize({ d: value });
       expect(serializedDouble.subarray(7, 15)).to.deep.equal(buffer);
       let { d: newVal } = BSON.deserialize(serializedDouble, { promoteValues: true });