Field Value migration (#2784)

Author: schmidt-sebastian

packages/firestore/CHANGELOG.md

@@ -1,4 +1,10 @@
 # Unreleased
+- [changed] Changed the in-memory representation of Firestore documents to
+  reduce memory allocations and improve performance. Calls to 
+  `DocumentSnapshot.getData()` and `DocumentSnapshot.toObject()` will see
+  the biggest improvement.
+
+# 1.10.1
 - [fixed] Fixed an issue where the number value `-0.0` would lose its sign when
   stored in Firestore.
 

packages/firestore/src/api/blob.ts

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2017 Google Inc.
+ * Copyright 2017 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,11 +23,7 @@ import {
   validateArgType,
   validateExactNumberOfArgs
 } from '../util/input_validation';
-import { primitiveComparator } from '../util/misc';
-import {
-  binaryStringFromUint8Array,
-  uint8ArrayFromBinaryString
-} from '../util/byte_string';
+import { ByteString } from '../util/byte_string';
 
 /** Helper function to assert Uint8Array is available at runtime. */
 function assertUint8ArrayAvailable(): void {
@@ -57,24 +53,21 @@ function assertBase64Available(): void {
  * using the hack above to make sure no-one outside this module can call it.
  */
 export class Blob {
-  // Prefix with underscore to signal this is a private variable in JS and
-  // prevent it showing up for autocompletion.
-  // A binary string is a string with each char as Unicode code point in the
-  // range of [0, 255], essentially simulating a byte array.
-  private _binaryString: string;
+  // Prefix with underscore to signal that we consider this not part of the
+  // public API and to prevent it from showing up for autocompletion.
+  _byteString: ByteString;
 
-  private constructor(binaryString: string) {
+  constructor(byteString: ByteString) {
     assertBase64Available();
-    this._binaryString = binaryString;
+    this._byteString = byteString;
   }
 
   static fromBase64String(base64: string): Blob {
     validateExactNumberOfArgs('Blob.fromBase64String', arguments, 1);
     validateArgType('Blob.fromBase64String', 'string', 1, base64);
     assertBase64Available();
     try {
-      const binaryString = PlatformSupport.getPlatform().atob(base64);
-      return new Blob(binaryString);
+      return new Blob(ByteString.fromBase64String(base64));
     } catch (e) {
       throw new FirestoreError(
         Code.INVALID_ARGUMENT,
@@ -89,42 +82,27 @@ export class Blob {
     if (!(array instanceof Uint8Array)) {
       throw invalidClassError('Blob.fromUint8Array', 'Uint8Array', 1, array);
     }
-    const binaryString = binaryStringFromUint8Array(array);
-    return new Blob(binaryString);
+    return new Blob(ByteString.fromUint8Array(array));
   }
 
   toBase64(): string {
     validateExactNumberOfArgs('Blob.toBase64', arguments, 0);
     assertBase64Available();
-    return PlatformSupport.getPlatform().btoa(this._binaryString);
+    return this._byteString.toBase64();
   }
 
   toUint8Array(): Uint8Array {
     validateExactNumberOfArgs('Blob.toUint8Array', arguments, 0);
     assertUint8ArrayAvailable();
-    const buffer = uint8ArrayFromBinaryString(this._binaryString);
-    return buffer;
+    return this._byteString.toUint8Array();
   }
 
   toString(): string {
     return 'Blob(base64: ' + this.toBase64() + ')';
   }
 
   isEqual(other: Blob): boolean {
-    return this._binaryString === other._binaryString;
-  }
-
-  _approximateByteSize(): number {
-    // Assume UTF-16 encoding in memory (see StringValue.approximateByteSize())
-    return this._binaryString.length * 2;
-  }
-
-  /**
-   * Actually private to JS consumers of our API, so this function is prefixed
-   * with an underscore.
-   */
-  _compareTo(other: Blob): number {
-    return primitiveComparator(this._binaryString, other._binaryString);
+    return this._byteString.isEqual(other._byteString);
   }
 }