[TeX] Introduced Telemetry Express Histogram Logging APIs

/*

 * Copyright (C) 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.

 */

package com.android.internal.expresslog;

import android.annotation.NonNull;

import com.android.internal.util.FrameworkStatsLog;

/** CounterHistogram encapsulates StatsD write API calls */

public final class Histogram {

    private final long mMetricIdHash;

    private final BinOptions mBinOptions;

    public Histogram(@NonNull String metricId, @NonNull BinOptions binOptions) {

        mMetricIdHash = Utils.hashString(metricId);

        mBinOptions = binOptions;

    }

    /**

     * Logs increment sample count for automatically calculated bin

     *

     * @hide

     */

    public void logSample(float sample) {

        final int binIndex = mBinOptions.getBinForSample(sample);

        FrameworkStatsLog.write(FrameworkStatsLog.EXPRESS_HISTOGRAM_SAMPLE_REPORTED, mMetricIdHash,

                /*count*/ 1, binIndex);

    }

    /** Used by CounterHistogram to map data sample to corresponding bin */

    public interface BinOptions {

        /**

         * Returns bins count to be used by counter histogram

         *

         * @return bins count used to initialize Options, including overflow & underflow bins

         * @hide

         */

        int getBinsCount();

        /**

         * @return zero based index

         * Calculates bin index for the input sample value

         * index == 0 stands for underflow

         * index == getBinsCount() - 1 stands for overflow

         * @hide

         */

        int getBinForSample(float sample);

    }

    /** Used by CounterHistogram to map data sample to corresponding bin for on uniform bins */

    public static final class UniformOptions implements BinOptions {

        private final int mBinCount;

        private final float mMinValue;

        private final float mExclusiveMaxValue;

        private final float mBinSize;

        public UniformOptions(int binCount, float minValue, float exclusiveMaxValue) {

            if (binCount < 1) {

                throw new IllegalArgumentException("Bin count should be positive number");

            }

            if (exclusiveMaxValue <= minValue) {

                throw new IllegalArgumentException("Bins range invalid (maxValue < minValue)");

            }

            mMinValue = minValue;

            mExclusiveMaxValue = exclusiveMaxValue;

            mBinSize = (mExclusiveMaxValue - minValue) / binCount;

            // Implicitly add 2 for the extra undeflow & overflow bins

            mBinCount = binCount + 2;

        }

        @Override

        public int getBinsCount() {

            return mBinCount;

        }

        @Override

        public int getBinForSample(float sample) {

            if (sample < mMinValue) {

                // goes to underflow

                return 0;

            } else if (sample >= mExclusiveMaxValue) {

                // goes to overflow

                return mBinCount - 1;

            }

            return (int) ((sample - mMinValue) / mBinSize + 1);

        }

    }

}

{

  "presubmit": [

    {

      "name": "ExpressLogTests",

      "options": [

        {

          "exclude-annotation": "org.junit.Ignore"

        }

      ]

    }

  ]

}

 No newline at end of file

// Copyright (C) 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.

package {

    // See: http://go/android-license-faq

    // A large-scale-change added 'default_applicable_licenses' to import

    // all of the 'license_kinds' from "frameworks_base_license"

    // to get the below license kinds:

    //   SPDX-license-identifier-Apache-2.0

    default_applicable_licenses: ["frameworks_base_license"],

}

android_test {

    name: "ExpressLogTests",

    srcs: [

        "src/**/*.java",

    ],

    static_libs: [

        "androidx.test.rules",

        "modules-utils-build",

    ],

    libs: [

        "android.test.base",

        "android.test.runner",

    ],

    platform_apis: true,

    test_suites: [

        "general-tests",

    ],

    certificate: "platform",

}

<?xml version="1.0" encoding="utf-8"?>

<!-- Copyright (C) 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.

-->

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

          android:installLocation="internalOnly"

          package="com.android.internal.expresslog" >

    <application >

        <uses-library android:name="android.test.runner" />

    </application>

    <instrumentation android:name="androidx.test.runner.AndroidJUnitRunner"

            android:targetPackage="com.android.internal.expresslog"

            android:label="Telemetry Express Logging Helper Tests" />

</manifest>

# Bug component: 719316

# Stats/expresslog

file:/services/core/java/com/android/server/stats/OWNERS