EncodeBase64 and DecodeBase64 ops

tfjs-converter/docs/supported_ops.md

@@ -268,6 +268,13 @@
 |Not mapped|ifft|
 |Not mapped|rfft|
 
+## Operations - Strings
+
+|Tensorflow Op Name|Tensorflow.js Op Name|
+|---|---|
+|DecodeBase64|decodeBase64|
+|EncodeBase64|encodeBase64|
+
 ## Tensors - Transformations
 
 |Tensorflow Op Name|Tensorflow.js Op Name|

tfjs-converter/python/tensorflowjs/op_list/string.json

@@ -0,0 +1,31 @@
+[
+  {
+    "tfOpName": "DecodeBase64",
+    "category": "string",
+    "inputs": [
+      {
+        "start": 0,
+        "name": "input",
+        "type": "tensor"
+      }
+    ]
+  },
+  {
+    "tfOpName": "EncodeBase64",
+    "category": "string",
+    "inputs": [
+      {
+        "start": 0,
+        "name": "input",
+        "type": "tensor"
+      }
+    ],
+    "attrs": [
+      {
+        "tfName": "pad",
+        "name": "pad",
+        "type": "bool"
+      }
+    ]
+  }
+]

tfjs-converter/src/operations/executors/string_executor.ts

@@ -0,0 +1,46 @@
+/**
+ * @license
+ * Copyright 2019 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
+
+import * as tfc from '@tensorflow/tfjs-core';
+
+import {NamedTensorsMap} from '../../data/types';
+import {ExecutionContext} from '../../executor/execution_context';
+import {InternalOpExecutor, Node} from '../types';
+
+import {getParamValue} from './utils';
+
+export let executeOp: InternalOpExecutor =
+    (node: Node, tensorMap: NamedTensorsMap,
+     context: ExecutionContext): tfc.Tensor[] => {
+      switch (node.op) {
+        case 'DecodeBase64': {
+          const input =
+              getParamValue('str', node, tensorMap, context) as tfc.Tensor;
+          return [tfc.decodeBase64(input)];
+        }
+        case 'EncodeBase64': {
+          const input =
+              getParamValue('str', node, tensorMap, context) as tfc.Tensor;
+          const pad = getParamValue('pad', node, tensorMap, context) as boolean;
+          return [tfc.encodeBase64(input, pad)];
+        }
+        default:
+          throw TypeError(`Node type ${node.op} is not implemented`);
+      }
+    };
+
+export const CATEGORY = 'string';

tfjs-converter/src/operations/executors/string_executor_test.ts

@@ -0,0 +1,62 @@
+/**
+ * @license
+ * Copyright 2019 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
+import * as tfc from '@tensorflow/tfjs-core';
+
+import {ExecutionContext} from '../../executor/execution_context';
+import {Node} from '../types';
+
+import {executeOp} from './string_executor';
+import {createBoolAttr, createTensorAttr} from './test_helper';
+
+describe('string', () => {
+  let node: Node;
+  const input1 = [tfc.tensor(['a'], [1], 'string')];
+  const context = new ExecutionContext({}, {});
+
+  beforeEach(() => {
+    node = {
+      name: 'test',
+      op: '',
+      category: 'string',
+      inputNames: ['input1'],
+      inputs: [],
+      inputParams: {str: createTensorAttr(0)},
+      attrParams: {},
+      children: []
+    };
+  });
+
+  describe('executeOp', () => {
+    describe('DecodeBase64', () => {
+      it('should call tfc.decodeBase64', () => {
+        spyOn(tfc, 'decodeBase64');
+        node.op = 'DecodeBase64';
+        executeOp(node, {input1}, context);
+        expect(tfc.decodeBase64).toHaveBeenCalledWith(input1[0]);
+      });
+    });
+    describe('EncodeBase64', () => {
+      it('should call tfc.encodeBase64', () => {
+        spyOn(tfc, 'encodeBase64');
+        node.op = 'EncodeBase64';
+        node.attrParams.pad = createBoolAttr(true);
+        executeOp(node, {input1}, context);
+        expect(tfc.encodeBase64).toHaveBeenCalledWith(input1[0], true);
+      });
+    });
+  });
+});

tfjs-converter/src/operations/op_list/string.ts

@@ -0,0 +1,32 @@
+import {OpMapper} from '../types';
+
+/**
+ * @license
+ * Copyright 2019 Google LLC. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
+
+export const json: OpMapper[] = [
+  {
+    'tfOpName': 'DecodeBase64',
+    'category': 'string',
+    'inputs': [{'start': 0, 'name': 'input', 'type': 'tensor'}]
+  },
+  {
+    'tfOpName': 'EncodeBase64',
+    'category': 'string',
+    'inputs': [{'start': 0, 'name': 'input', 'type': 'tensor'}],
+    'attrs': [{'tfName': 'pad', 'name': 'pad', 'type': 'bool'}]
+  }
+];

tfjs-converter/src/operations/types.ts

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2018 Google LLC. All Rights Reserved.
+ * Copyright 2019 Google LLC. All Rights Reserved.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
@@ -25,7 +25,7 @@ export type ParamType = 'number'|'string'|'string[]'|'number[]'|'bool'|'bool[]'|
 export type Category =
     'arithmetic'|'basic_math'|'control'|'convolution'|'custom'|'dynamic'|
     'evaluation'|'image'|'creation'|'graph'|'logical'|'matrices'|
-    'normalization'|'reduction'|'slice_join'|'spectral'|'transformation';
+    'normalization'|'reduction'|'slice_join'|'spectral'|'string'|'transformation';
 
 // For mapping input or attributes of NodeDef into TensorFlow.js op param.
 export declare interface ParamMapper {

tfjs-core/src/backends/backend.ts

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2018 Google Inc. All Rights Reserved.
+ * Copyright 2019 Google Inc. All Rights Reserved.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
@@ -17,7 +17,7 @@
 
 import {Conv2DInfo, Conv3DInfo} from '../ops/conv_util';
 import {FusedBatchMatMulConfig, FusedConv2DConfig} from '../ops/fused_util';
-import {Backend, DataId, Scalar, Tensor, Tensor1D, Tensor2D, Tensor3D, Tensor4D, Tensor5D} from '../tensor';
+import {Backend, DataId, Scalar, StringTensor, Tensor, Tensor1D, Tensor2D, Tensor3D, Tensor4D, Tensor5D} from '../tensor';
 import {BackendValues, DataType, Rank, ShapeMap} from '../types';
 
 export const EPSILON_FLOAT32 = 1e-7;
@@ -659,6 +659,15 @@ export class KernelBackend implements TensorStorage, Backend, BackendTimer {
   dispose(): void {
     return notYetImplemented('dispose');
   }
+
+  encodeBase64<T extends StringTensor>(str: StringTensor|Tensor, pad = false):
+      T {
+    throw new Error('Not yet implemented');
+  }
+
+  decodeBase64<T extends StringTensor>(str: StringTensor|Tensor): T {
+    throw new Error('Not yet implemented');
+  }
 }
 
 function notYetImplemented(kernelName: string): never {

tfjs-core/src/backends/cpu/backend_cpu.ts

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2017 Google Inc. All Rights Reserved.
+ * Copyright 2019 Google Inc. All Rights Reserved.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
@@ -35,7 +35,7 @@ import {buffer, scalar, tensor, tensor4d} from '../../ops/ops';
 import * as scatter_nd_util from '../../ops/scatter_nd_util';
 import * as selu_util from '../../ops/selu_util';
 import {computeFlatOffset, computeOutShape, isSliceContinous} from '../../ops/slice_util';
-import {DataId, Scalar, Tensor, Tensor1D, Tensor2D, Tensor3D, Tensor4D, Tensor5D, TensorBuffer} from '../../tensor';
+import {DataId, Scalar, StringTensor, Tensor, Tensor1D, Tensor2D, Tensor3D, Tensor4D, Tensor5D, TensorBuffer} from '../../tensor';
 import {BackendValues, DataType, DataValues, NumericDataType, Rank, ShapeMap, TypedArray, upcastType} from '../../types';
 import * as util from '../../util';
 import {getArrayFromDType, inferDtype, now, sizeFromShape} from '../../util';
@@ -44,6 +44,7 @@ import * as backend_util from '../backend_util';
 import * as complex_util from '../complex_util';
 import {nonMaxSuppressionV3} from '../non_max_suppression_impl';
 import {split} from '../split_shared';
+import {decodeBase64Impl, encodeBase64Impl} from '../string_shared';
 import {tile} from '../tile_impl';
 import {topkImpl} from '../topk_impl';
 import {whereImpl} from '../where_impl';
@@ -3552,6 +3553,17 @@ export class MathBackendCPU extends KernelBackend {
 
   dispose() {}
 
+  encodeBase64<T extends StringTensor>(str: StringTensor|Tensor, pad = false):
+      T {
+    const sVals = this.readSync(str.dataId) as Uint8Array[];
+    return encodeBase64Impl(sVals, str.shape, pad);
+  }
+
+  decodeBase64<T extends StringTensor>(str: StringTensor|Tensor): T {
+    const sVals = this.readSync(str.dataId) as Uint8Array[];
+    return decodeBase64Impl(sVals, str.shape);
+  }
+
   floatPrecision(): 16|32 {
     return 32;
   }

tfjs-core/src/backends/string_shared.ts

@@ -0,0 +1,58 @@
+/**
+ * @license
+ * Copyright 2019 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
+
+import {arrayBufferToBase64String, base64StringToArrayBuffer, urlSafeBase64, urlUnsafeBase64} from '../io/io_utils';
+import {StringTensor} from '../tensor';
+import {decodeString} from '../util';
+import {ENGINE} from '../engine';
+
+/** Shared implementation of the encodeBase64 kernel across WebGL and CPU. */
+export function encodeBase64Impl<T extends StringTensor>(
+    values: Uint8Array[], shape: number[], pad = false): T {
+  const resultValues = new Array(values.length);
+
+  for (let i = 0; i < values.length; ++i) {
+    const bStr = arrayBufferToBase64String(values[i].buffer);
+    const bStrUrl = urlSafeBase64(bStr);
+
+    if (pad) {
+      resultValues[i] = bStrUrl;
+    } else {
+      // Remove padding
+      resultValues[i] = bStrUrl.replace(/=/g, '');
+    }
+  }
+
+  return ENGINE.makeTensor(resultValues, shape, 'string') as T;
+}
+
+/** Shared implementation of the decodeBase64 kernel across WebGL and CPU. */
+export function decodeBase64Impl<T extends StringTensor>(
+    values: Uint8Array[], shape: number[]): T {
+  const resultValues = new Array(values.length);
+
+  for (let i = 0; i < values.length; ++i) {
+    // Undo URL safe and decode from Base64 to ArrayBuffer
+    const bStrUrl = decodeString(values[i]);
+    const bStr = urlUnsafeBase64(bStrUrl);
+    const aBuff = base64StringToArrayBuffer(bStr);
+
+    resultValues[i] = decodeString(new Uint8Array(aBuff));
+  }
+
+  return ENGINE.makeTensor(resultValues, shape, 'string') as T;
+}

tfjs-core/src/backends/webgl/backend_webgl.ts

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2017 Google Inc. All Rights Reserved.
+ * Copyright 2019 Google Inc. All Rights Reserved.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
@@ -38,7 +38,7 @@ import * as segment_util from '../../ops/segment_util';
 import * as slice_util from '../../ops/slice_util';
 import {softmax} from '../../ops/softmax';
 import {range, scalar, tensor} from '../../ops/tensor_ops';
-import {DataId, Scalar, Tensor, Tensor1D, Tensor2D, Tensor3D, Tensor4D, Tensor5D} from '../../tensor';
+import {DataId, Scalar, StringTensor, Tensor, Tensor1D, Tensor2D, Tensor3D, Tensor4D, Tensor5D} from '../../tensor';
 import {BackendValues, DataType, DataTypeMap, NumericDataType, Rank, RecursiveArray, ShapeMap, sumOutType, TypedArray, upcastType} from '../../types';
 import * as util from '../../util';
 import {getArrayFromDType, getTypedArrayFromDType, inferDtype, sizeFromShape} from '../../util';
@@ -47,6 +47,7 @@ import * as backend_util from '../backend_util';
 import {mergeRealAndImagArrays} from '../complex_util';
 import {nonMaxSuppressionV3} from '../non_max_suppression_impl';
 import {split} from '../split_shared';
+import {decodeBase64Impl, encodeBase64Impl} from '../string_shared';
 import {tile} from '../tile_impl';
 import {topkImpl} from '../topk_impl';
 import {whereImpl} from '../where_impl';
@@ -2311,6 +2312,17 @@ export class MathBackendWebGL extends KernelBackend {
     return split(x, sizeSplits, axis);
   }
 
+  encodeBase64<T extends StringTensor>(str: StringTensor|Tensor, pad = false):
+      T {
+    const sVals = this.readSync(str.dataId) as Uint8Array[];
+    return encodeBase64Impl(sVals, str.shape, pad);
+  }
+
+  decodeBase64<T extends StringTensor>(str: StringTensor|Tensor): T {
+    const sVals = this.readSync(str.dataId) as Uint8Array[];
+    return decodeBase64Impl(sVals, str.shape);
+  }
+
   scatterND<R extends Rank>(
       indices: Tensor, updates: Tensor, shape: ShapeMap[R]): Tensor<R> {
     const {sliceRank, numUpdates, sliceSize, strides, outputSize} =