Extract IndexedShapeWrapper into a separate file

I am going to use IndexedShapeWrapper in my implementation of MAXIMUM.

Bug: 113560501
Test: mma
Change-Id: I8a740167f128819ca3005c19da5b607537ad07eb
Merged-In: I8a740167f128819ca3005c19da5b607537ad07eb
(cherry picked from commit 8b165e64bce2eed15d34a2a7d319916ccebbf88a)

4 files changed, 170 insertions, 105 deletions

diff --git a/nn/common/Android.bp b/nn/common/Android.bp
index 517ac73b2..877a2ebb2 100644
--- a/nn/common/Android.bp
+++ b/nn/common/Android.bp
@@ -55,6 +55,7 @@ cc_library_static {
     srcs: [
         "CpuExecutor.cpp",
         "GraphDump.cpp",
+        "IndexedShapeWrapper.cpp",
         "OperationsUtils.cpp",
         "Utils.cpp",
         "ValidateHal.cpp",
diff --git a/nn/common/IndexedShapeWrapper.cpp b/nn/common/IndexedShapeWrapper.cpp
new file mode 100644
index 000000000..e90665986
--- /dev/null
+++ b/nn/common/IndexedShapeWrapper.cpp
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#define LOG_TAG "IndexedShapeWrapper"
+
+#include "IndexedShapeWrapper.h"
+
+namespace android {
+namespace nn {
+
+IndexedShapeWrapper::IndexedShapeWrapper(const Shape& wrapped_shape) : shape(&wrapped_shape) {
+    strides.resize(shape->dimensions.size());
+    strides.back() = 1;
+    for (int i = strides.size() - 2; i >= 0; --i) {
+        strides[i] = shape->dimensions[i + 1] * strides[i + 1];
+    }
+}
+
+bool IndexedShapeWrapper::nextIndexInplace(std::vector<uint32_t>* index, bool* lastIndex) const {
+    NN_CHECK(isValid(*index));
+
+    bool anyIndicesLeft = false;
+    for (int i = 0; i < index->size(); ++i) {
+        if (index->at(i) < shape->dimensions[i] - 1) {
+            anyIndicesLeft = true;
+            break;
+        }
+    }
+    if (!anyIndicesLeft) {
+        *lastIndex = true;
+        return true;
+    }
+    for (int i = index->size() - 1; i >= 0; --i) {
+        ++index->at(i);
+        if (index->at(i) == shape->dimensions[i]) {
+            index->at(i) = 0;
+        } else {
+            break;
+        }
+    }
+    return true;
+}
+
+bool IndexedShapeWrapper::indexToFlatIndex(const std::vector<uint32_t>& index,
+                                           uint32_t* flatIndex) const {
+    NN_CHECK(isValid(index));
+
+    *flatIndex = 0;
+    for (int i = 0; i < index.size(); ++i) {
+        *flatIndex += strides[i] * index[i];
+    }
+    return true;
+}
+
+bool IndexedShapeWrapper::broadcastedIndexToFlatIndex(const std::vector<uint32_t>& index,
+                                                      uint32_t* flatIndex) const {
+    NN_CHECK(index.size() >= strides.size());
+
+    *flatIndex = 0;
+    for (int i = 1; i <= strides.size(); ++i) {
+        uint32_t currentIndex = index[index.size() - i];
+        uint32_t currentDimSize = shape->dimensions[shape->dimensions.size() - i];
+        NN_CHECK(currentIndex < currentDimSize || currentDimSize == 1);
+        if (currentDimSize != 1) {
+            *flatIndex += strides[strides.size() - i] * index[index.size() - i];
+        }
+    }
+    return true;
+}
+
+bool IndexedShapeWrapper::isValid(const std::vector<uint32_t>& index) const {
+    if (index.size() != shape->dimensions.size()) {
+        LOG(ERROR) << "Index: " << toString(index)
+                   << " has a different number of dimensions from shape: "
+                   << toString(shape->dimensions);
+        return false;
+    }
+    for (int i = 0; i < index.size(); ++i) {
+        if (index[i] >= shape->dimensions[i]) {
+            LOG(ERROR) << "Invalid index: " << toString(index)
+                       << " is out of range for shape: " << toString(shape->dimensions);
+            return false;
+        }
+    }
+    return true;
+}
+
+}  // namespace nn
+}  // namespace android
diff --git a/nn/common/include/IndexedShapeWrapper.h b/nn/common/include/IndexedShapeWrapper.h
new file mode 100644
index 000000000..8ae53ccbf
--- /dev/null
+++ b/nn/common/include/IndexedShapeWrapper.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#ifndef FRAMEWORKS_ML_NN_INDEXED_SHAPE_WRAPPER_H
+#define FRAMEWORKS_ML_NN_INDEXED_SHAPE_WRAPPER_H
+
+#include "OperationsUtils.h"
+
+namespace android {
+namespace nn {
+
+// A wrapper over a Shape class implementing some indexing logic for a wrapped
+// shape.
+// To get an offset for an element in a tensor from vector index, one needs to
+// calculate strides first. This class removes the need to recalculate strides
+// for every indexing and also provides some utility functions.
+class IndexedShapeWrapper {
+   public:
+    IndexedShapeWrapper(const Shape& wrapped_shape);
+
+    // Calculates the next index in a lexicograpical order for a wrapped shape
+    // inplace. Only accepts valid index for a given shape as an input.
+    // Sets lastIndex to true if the received index was the last in a
+    // lexicographical order for a given shape. In this case, index stays the
+    // same.
+    bool nextIndexInplace(std::vector<uint32_t>* index, bool* lastIndex) const;
+
+    // Given an index as a vector with per-dimension indices, calculates an
+    // offset of the element in a flattened tensor.
+    bool indexToFlatIndex(const std::vector<uint32_t>& index, uint32_t* flatIndex) const;
+
+    // Same as indexToFlatIndex, only ignores first dimensions of an index if
+    // they are not present in the shape. Also ignores dimensions of a shape of
+    // size 1.
+    // For example:
+    //    for shape:    [3, 1, 2]
+    //    and index: [4, 2, 5, 1]
+    // the function will ignore dimensions with indices 4 and 5 and set
+    // flatIndex to 5 as a result.
+    bool broadcastedIndexToFlatIndex(const std::vector<uint32_t>& index, uint32_t* flatIndex) const;
+
+   private:
+    const Shape* const shape;
+    std::vector<uint32_t> strides;
+
+    bool isValid(const std::vector<uint32_t>& index) const;
+};
+
+}  // namespace nn
+}  // namespace android
+
+#endif  // FRAMEWORKS_ML_NN_INDEXED_SHAPE_WRAPPER_H
diff --git a/nn/common/operations/Pow.cpp b/nn/common/operations/Pow.cpp
index db59d94df..f944b9881 100644
--- a/nn/common/operations/Pow.cpp
+++ b/nn/common/operations/Pow.cpp
@@ -17,120 +17,17 @@
 #define LOG_TAG "Operations"
 
 #include "Pow.h"
+#include "IndexedShapeWrapper.h"
+#include "OperationsUtils.h"
 
 #include <cmath>
 
-#include "OperationsUtils.h"
-
 namespace android {
 namespace nn {
 namespace pow {
 
 namespace {
 
-// A wrapper over a Shape class implementing some indexing logic for a wrapped
-// shape.
-// To get an offset for an element in a tensor from vector index, one needs to
-// calculate strides first. This class removes the need to recalculate strides
-// for every indexing and also provides some utility functions.
-class IndexedShapeWrapper {
-   public:
-    IndexedShapeWrapper(const Shape& wrapped_shape) : shape(&wrapped_shape) {
-        strides.resize(shape->dimensions.size());
-        strides.back() = 1;
-        for (int i = strides.size() - 2; i >= 0; --i) {
-            strides[i] = shape->dimensions[i + 1] * strides[i + 1];
-        }
-    }
-
-    // Calculates the next index in a lexicograpical order for a wrapped shape
-    // inplace. Only accepts valid index for a given shape as an input.
-    // Sets lastIndex to true if the received index was the last in a
-    // lexicographical order for a given shape. In this case, index stays the
-    // same.
-    bool nextIndexInplace(std::vector<uint32_t>* index, bool* lastIndex) const {
-        NN_CHECK(isValid(*index));
-
-        bool anyIndicesLeft = false;
-        for (int i = 0; i < index->size(); ++i) {
-            if (index->at(i) < shape->dimensions[i] - 1) {
-                anyIndicesLeft = true;
-                break;
-            }
-        }
-        if (!anyIndicesLeft) {
-            *lastIndex = true;
-            return true;
-        }
-        for (int i = index->size() - 1; i >= 0; --i) {
-            ++index->at(i);
-            if (index->at(i) == shape->dimensions[i]) {
-                index->at(i) = 0;
-            } else {
-                break;
-            }
-        }
-        return true;
-    }
-
-    // Given an index as a vector with per-dimension indices, calculates an
-    // offset of the element in a flattened tensor.
-    bool indexToFlatIndex(const std::vector<uint32_t>& index, uint32_t* flatIndex) const {
-        NN_CHECK(isValid(index));
-
-        *flatIndex = 0;
-        for (int i = 0; i < index.size(); ++i) {
-            *flatIndex += strides[i] * index[i];
-        }
-        return true;
-    }
-
-    // Same as indexToFlatIndex, only ignores first dimensions of an index if
-    // they are not present in the shape. Also ignores dimensions of a shape of
-    // size 1.
-    // For example:
-    //    for shape:    [3, 1, 2]
-    //    and index: [4, 2, 5, 1]
-    // the function will ignore dimensions with indices 4 and 5 and set
-    // flatIndex to 5 as a result.
-    bool broadcastedIndexToFlatIndex(const std::vector<uint32_t>& index,
-                                     uint32_t* flatIndex) const {
-        NN_CHECK(index.size() >= strides.size());
-
-        *flatIndex = 0;
-        for (int i = 1; i <= strides.size(); ++i) {
-            uint32_t currentIndex = index[index.size() - i];
-            uint32_t currentDimSize = shape->dimensions[shape->dimensions.size() - i];
-            NN_CHECK(currentIndex < currentDimSize || currentDimSize == 1);
-            if (currentDimSize != 1) {
-                *flatIndex += strides[strides.size() - i] * index[index.size() - i];
-            }
-        }
-        return true;
-    }
-
-   private:
-    const Shape* const shape;
-    std::vector<uint32_t> strides;
-
-    bool isValid(const std::vector<uint32_t>& index) const {
-        if (index.size() != shape->dimensions.size()) {
-            LOG(ERROR) << "Index: " << toString(index)
-                       << " has a different number of dimensions from shape: "
-                       << toString(shape->dimensions);
-            return false;
-        }
-        for (int i = 0; i < index.size(); ++i) {
-            if (index[i] >= shape->dimensions[i]) {
-                LOG(ERROR) << "Invalid index: " << toString(index)
-                           << " is out of range for shape: " << toString(shape->dimensions);
-                return false;
-            }
-        }
-        return true;
-    }
-};
-
 template <typename T>
 bool evalGeneric(const T* baseData, const Shape& baseShape, const T* exponentData,
                  const Shape& exponentShape, T* outputData, const Shape& outputShape) {