Rework FieldMask to use a SortedSet of FieldPaths

Rather than an array.

Port of firebase/firebase-android-sdk#137

Author: rsgowman

packages/firestore/src/api/user_data_converter.ts

@@ -336,7 +336,7 @@ export class UserDataConverter {
     let fieldTransforms: FieldTransform[];
 
     if (!fieldPaths) {
-      fieldMask = new FieldMask(context.fieldMask);
+      fieldMask = FieldMask.fromArray(context.fieldMask);
       fieldTransforms = context.fieldTransforms;
     } else {
       const validatedFieldPaths: FieldPath[] = [];
@@ -367,7 +367,7 @@ export class UserDataConverter {
         validatedFieldPaths.push(fieldPath);
       }
 
-      fieldMask = new FieldMask(validatedFieldPaths);
+      fieldMask = FieldMask.fromArray(validatedFieldPaths);
       fieldTransforms = context.fieldTransforms.filter(transform =>
         fieldMask.covers(transform.field)
       );
@@ -407,7 +407,7 @@ export class UserDataConverter {
       }
     });
 
-    const mask = new FieldMask(fieldMaskPaths);
+    const mask = FieldMask.fromArray(fieldMaskPaths);
     return new ParsedUpdateData(updateData, mask, context.fieldTransforms);
   }
 
@@ -462,7 +462,7 @@ export class UserDataConverter {
       }
     }
 
-    const mask = new FieldMask(fieldMaskPaths);
+    const mask = FieldMask.fromArray(fieldMaskPaths);
     return new ParsedUpdateData(updateData, mask, context.fieldTransforms);
   }
 

packages/firestore/src/model/mutation.ts

@@ -18,6 +18,7 @@ import { Timestamp } from '../api/timestamp';
 import { SnapshotVersion } from '../core/snapshot_version';
 import { assert } from '../util/assert';
 import * as misc from '../util/misc';
+import { SortedSet } from '../util/sorted_set';
 
 import {
   Document,
@@ -41,28 +42,34 @@ import { TransformOperation } from './transform_operation';
  *             containing foo
  */
 export class FieldMask {
-  constructor(readonly fields: FieldPath[]) {
+  private constructor(readonly fields: SortedSet<FieldPath>) {
     // TODO(dimond): validation of FieldMask
   }
 
+  static fromArray(fields: FieldPath[]): FieldMask {
+    let fieldsAsSet = new SortedSet<FieldPath>(FieldPath.comparator);
+    fields.forEach(fieldPath => (fieldsAsSet = fieldsAsSet.add(fieldPath)));
+    return new FieldMask(fieldsAsSet);
+  }
+
   /**
    * Verifies that `fieldPath` is included by at least one field in this field
    * mask.
    *
    * This is an O(n) operation, where `n` is the size of the field mask.
    */
   covers(fieldPath: FieldPath): boolean {
-    for (const fieldMaskPath of this.fields) {
+    let found = false;
+    this.fields.forEach(fieldMaskPath => {
       if (fieldMaskPath.isPrefixOf(fieldPath)) {
-        return true;
+        found = true;
       }
-    }
-
-    return false;
+    });
+    return found;
   }
 
   isEqual(other: FieldMask): boolean {
-    return misc.arrayEquals(this.fields, other.fields);
+    return this.fields.isEqual(other.fields);
   }
 }
 
@@ -448,7 +455,7 @@ export class PatchMutation extends Mutation {
   }
 
   private patchObject(data: ObjectValue): ObjectValue {
-    for (const fieldPath of this.fieldMask.fields) {
+    this.fieldMask.fields.forEach(fieldPath => {
       if (!fieldPath.isEmpty()) {
         const newValue = this.data.field(fieldPath);
         if (newValue !== undefined) {
@@ -457,7 +464,7 @@ export class PatchMutation extends Mutation {
           data = data.delete(fieldPath);
         }
       }
-    }
+    });
     return data;
   }
 }

packages/firestore/src/remote/serializer.ts

@@ -1304,15 +1304,19 @@ export class JsonProtoSerializer {
   }
 
   toDocumentMask(fieldMask: FieldMask): api.DocumentMask {
+    const canonicalFields: string[] = [];
+    fieldMask.fields.forEach(field =>
+      canonicalFields.push(field.canonicalString())
+    );
     return {
-      fieldPaths: fieldMask.fields.map(field => field.canonicalString())
+      fieldPaths: canonicalFields
     };
   }
 
   fromDocumentMask(proto: api.DocumentMask): FieldMask {
     const paths = proto.fieldPaths || [];
     const fields = paths.map(path => FieldPath.fromServerFormat(path));
-    return new FieldMask(fields);
+    return FieldMask.fromArray(fields);
   }
 }
 

packages/firestore/test/unit/remote/node/serializer.test.ts

@@ -605,7 +605,7 @@ describe('Serializer', () => {
     // tslint:disable-next-line:ban TODO(b/34988481): Implement correct escaping
     it.skip('converts a weird path', () => {
       const expected: api.DocumentMask = { fieldPaths: ['foo.`bar.baz\\qux`'] };
-      const mask = new FieldMask([
+      const mask = FieldMask.fromArray([
         FieldPath.fromServerFormat('foo.bar\\.baz\\\\qux')
       ]);
       const actual = s.toDocumentMask(mask);
@@ -618,7 +618,7 @@ describe('Serializer', () => {
 
     // tslint:disable-next-line:ban TODO(b/34988481): Implement correct escaping
     it.skip('converts a weird path', () => {
-      const expected = new FieldMask([
+      const expected = FieldMask.fromArray([
         FieldPath.fromServerFormat('foo.bar\\.baz\\\\qux')
       ]);
       const proto: api.DocumentMask = { fieldPaths: ['foo.`bar.baz\\qux`'] };