feat(json-type): 🎸 implement "map" type capacity estimator codegen

Author: streamich

src/json-type/codegen/capacity/__tests__/CapacityEstimatorCodegenContext.spec.ts

@@ -155,6 +155,38 @@ describe('object', () => {
   });
 });
 
+describe('map', () => {
+  test('empty', () => {
+    const system = new TypeSystem();
+    const type = system.t.map;
+    const estimator = type.compileCapacityEstimator({});
+    expect(estimator(123)).toBe(maxEncodingCapacity({}));
+  });
+
+  test('with one field', () => {
+    const system = new TypeSystem();
+    const type = system.t.Map(system.t.bool);
+    const estimator = type.compileCapacityEstimator({});
+    expect(estimator({foo: true})).toBe(maxEncodingCapacity({foo: true}));
+  });
+
+  test('three number fields', () => {
+    const system = new TypeSystem();
+    const type = system.t.Map(system.t.num);
+    const estimator = type.compileCapacityEstimator({});
+    const data = {foo: 1, bar: 2, baz: 3};
+    expect(estimator(data)).toBe(maxEncodingCapacity(data));
+  });
+
+  test('nested maps', () => {
+    const system = new TypeSystem();
+    const type = system.t.Map(system.t.Map(system.t.str));
+    const estimator = type.compileCapacityEstimator({});
+    const data = {foo: {bar: 'baz'}, baz: {bar: 'foo'}};
+    expect(estimator(data)).toBe(maxEncodingCapacity(data));
+  });
+});
+
 describe('ref', () => {
   test('two hops', () => {
     const system = new TypeSystem();

src/json-type/type/classes.ts

@@ -1142,11 +1142,7 @@ export class ArrayType<T extends Type> extends AbstractType<schema.ArraySchema<S
     ctx.inc(MaxEncodingOverhead.Array);
     const rLen = codegen.var(`${value.use()}.length`);
     const type = this.type;
-    codegen.js(
-      `size += ${
-        MaxEncodingOverhead.ArrayElement === 1 ? `${rLen}` : `${MaxEncodingOverhead.ArrayElement} * ${rLen}`
-      };`,
-    );
+    codegen.js(`size += ${MaxEncodingOverhead.ArrayElement} * ${rLen}`);
     // TODO: Use ".capacityEstimator()" here.
     const fn = type.compileCapacityEstimator({
       system: ctx.options.system,
@@ -2005,31 +2001,19 @@ export class MapType<T extends Type> extends AbstractType<schema.MapSchema<Schem
   }
 
   public codegenCapacityEstimator(ctx: CapacityEstimatorCodegenContext, value: JsExpression): void {
-    ctx.codegen.js(`size += maxEncodingCapacity(${value.use()});`);
-    // throw new Error('TODO CAP');
-  //   const codegen = ctx.codegen;
-  //   ctx.inc(MaxEncodingOverhead.Array);
-  //   const rLen = codegen.var(`${value.use()}.length`);
-  //   const type = this.type;
-  //   codegen.js(
-  //     `size += ${
-  //       MaxEncodingOverhead.ArrayElement === 1 ? `${rLen}` : `${MaxEncodingOverhead.ArrayElement} * ${rLen}`
-  //     };`,
-  //   );
-  //   // TODO: Use ".capacityEstimator()" here.
-  //   const fn = type.compileCapacityEstimator({
-  //     system: ctx.options.system,
-  //     name: ctx.options.name,
-  //   });
-  //   const isConstantSizeType = type instanceof ConstType || type instanceof BooleanType || type instanceof NumberType;
-  //   if (isConstantSizeType) {
-  //     codegen.js(`size += ${rLen} * ${fn(null)};`);
-  //   } else {
-  //     const r = codegen.var(value.use());
-  //     const rFn = codegen.linkDependency(fn);
-  //     const ri = codegen.getRegister();
-  //     codegen.js(`for(var ${ri} = ${rLen}; ${ri}-- !== 0;) size += ${rFn}(${r}[${ri}]);`);
-  //   }
+    const codegen = ctx.codegen;
+    ctx.inc(MaxEncodingOverhead.Object);
+    const r = codegen.var(value.use());
+    const rKeys = codegen.var(`Object.keys(${r})`);
+    const rKey = codegen.var();
+    const rLen = codegen.var(`${rKeys}.length`);
+    codegen.js(`size += ${MaxEncodingOverhead.ObjectElement} * ${rLen}`);
+    const ri = codegen.var('0');
+    codegen.js(`for (; ${ri} < ${rLen}; ${ri}++) {`);
+    codegen.js(`${rKey} = ${rKeys}[${ri}];`);
+    codegen.js(`size += ${MaxEncodingOverhead.String} + ${MaxEncodingOverhead.StringLengthMultiplier} * ${rKey}.length;`);
+    this.type.codegenCapacityEstimator(ctx, new JsExpression(() => `${r}[${rKey}]`));
+    codegen.js(`}`);
   }
 
   public random(): Record<string, unknown> {