| /* |
| * Copyright 2023, 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 MEDIA_HISTOGRAM_H_ |
| #define MEDIA_HISTOGRAM_H_ |
| |
| #include <limits> |
| #include <sstream> |
| #include <string> |
| #include <vector> |
| |
| namespace android { |
| |
| template<typename T> |
| class MediaHistogram { |
| public: |
| MediaHistogram(); |
| void clear(); |
| bool setup(size_t bucketCount, T width, T floor = 0); |
| bool setup(const std::vector<T> &bucketLimits); |
| void insert(T sample); |
| size_t size() const; |
| int64_t operator[](int) const; |
| T getMin() const { return mMin; } |
| T getMax() const { return mMax; } |
| T getCount() const { return mCount; } |
| T getSum() const { return mSum; } |
| T getAvg() const { return mSum / (mCount == 0 ? 1 : mCount); } |
| T getPercentile(int) const; |
| std::string emit() const; |
| std::string emitBuckets() const; |
| private: |
| MediaHistogram(const MediaHistogram &); // disallow |
| |
| void allocate(size_t bucketCount, bool withBucketLimits); |
| |
| T mFloor, mCeiling, mWidth; |
| T mMin, mMax, mSum; |
| int64_t mBelow, mAbove, mCount; |
| std::vector<T> mBuckets; |
| std::vector<T> mBucketLimits; |
| }; |
| |
| template<typename T> |
| MediaHistogram<T>::MediaHistogram() { |
| mWidth = mCeiling = mFloor = -1; |
| clear(); |
| } |
| |
| template<typename T> |
| void MediaHistogram<T>::clear() { |
| for (int i = 0; i < mBuckets.size(); ++i) { |
| mBuckets[i] = 0; |
| } |
| mMin = std::numeric_limits<T>::max(); |
| mMax = std::numeric_limits<T>::min(); |
| mSum = 0; |
| mCount = 0; |
| mBelow = mAbove = 0; |
| } |
| |
| template<typename T> |
| bool MediaHistogram<T>::setup(size_t bucketCount, T width, T floor) { |
| if (bucketCount <= 0 || width <= 0) { |
| return false; |
| } |
| allocate(bucketCount, false); |
| |
| mWidth = width; |
| mFloor = floor; |
| mCeiling = floor + bucketCount * width; |
| clear(); |
| return true; |
| } |
| |
| template<typename T> |
| bool MediaHistogram<T>::setup(const std::vector<T> &bucketLimits) { |
| if (bucketLimits.size() <= 1) { |
| return false; |
| } |
| // The floor is the first bucket limit value, so offset by 1 |
| size_t bucketCount = bucketLimits.size() - 1; |
| allocate(bucketCount, true); |
| |
| mWidth = -1; |
| mFloor = bucketLimits[0]; |
| for (size_t i = 0; i < bucketCount; ++i) { |
| // The floor is the first bucket, so offset by 1 |
| mBucketLimits[i] = bucketLimits[i + 1]; |
| } |
| mCeiling = bucketLimits[bucketCount]; |
| clear(); |
| return true; |
| } |
| |
| template<typename T> |
| void MediaHistogram<T>::allocate(size_t bucketCount, bool withBucketLimits) { |
| assert(bucketCount > 0); |
| if (bucketCount != mBuckets.size()) { |
| mBuckets = std::vector<T>(bucketCount, 0); |
| } |
| if (withBucketLimits && mBucketLimits.size() != bucketCount) { |
| mBucketLimits = std::vector<T>(bucketCount, 0); |
| } |
| } |
| |
| template<typename T> |
| void MediaHistogram<T>::insert(T sample) { |
| // histogram is not set up |
| if (mBuckets.size() == 0) { |
| return; |
| } |
| |
| mCount++; |
| mSum += sample; |
| mMin = std::min(mMin, sample); |
| mMax = std::max(mMax, sample); |
| |
| if (sample < mFloor) { |
| mBelow++; |
| } else if (sample >= mCeiling) { |
| mAbove++; |
| } else if (mWidth == -1) { |
| // A binary search might be more efficient for large number of buckets, but it is expected |
| // that there will never be a large amount of buckets, so keep the code simple. |
| for (size_t slot = 0; slot < mBucketLimits.size(); ++slot) { |
| if (sample < mBucketLimits[slot]) { |
| mBuckets[slot]++; |
| break; |
| } |
| } |
| } else { |
| int64_t slot = (sample - mFloor) / mWidth; |
| assert(slot < mBuckets.size()); |
| mBuckets[slot]++; |
| } |
| return; |
| } |
| |
| template<typename T> |
| size_t MediaHistogram<T>::size() const { |
| return mBuckets.size() + 1; |
| } |
| |
| template<typename T> |
| int64_t MediaHistogram<T>::operator[](int i) const { |
| assert(i >= 0); |
| assert(i <= mBuckets.size()); |
| if (i == mBuckets.size()) { |
| return mAbove; |
| } |
| return mBuckets[i]; |
| } |
| |
| template<typename T> |
| std::string MediaHistogram<T>::emit() const { |
| // emits: floor,width,below{bucket0,bucket1,...., bucketN}above |
| // or.. emits: below{bucket0,bucket1,...., bucketN}above |
| // unconfigured will emit: 0{}0 |
| // XXX: is this best representation? |
| std::stringstream ss(""); |
| if (mWidth == -1) { |
| ss << mBelow << "{"; |
| } else { |
| ss << mFloor << "," << mWidth << "," << mBelow << "{"; |
| } |
| for (size_t i = 0; i < mBuckets.size(); i++) { |
| if (i != 0) { |
| ss << ","; |
| } |
| ss << mBuckets[i]; |
| } |
| ss << "}" << mAbove; |
| return ss.str(); |
| } |
| |
| template<typename T> |
| std::string MediaHistogram<T>::emitBuckets() const { |
| std::stringstream ss(""); |
| if (mWidth == -1) { |
| ss << mFloor; |
| for (size_t i = 0; i < mBucketLimits.size(); ++i) { |
| ss << ',' << mBucketLimits[i]; |
| } |
| } else { |
| ss << mFloor; |
| for (size_t i = 1; i <= mBuckets.size(); ++i) { |
| ss << ',' << (mFloor + i * mWidth); |
| } |
| } |
| return ss.str(); |
| } |
| |
| } // android |
| |
| #endif // MEDIA_HISTOGRAM_H_ |