| /* |
| * Copyright (C) 2017 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 android.os; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.nio.charset.StandardCharsets; |
| |
| /** |
| * Wrapper class for sending data from Android OS to StatsD. |
| * |
| * @hide |
| */ |
| public final class StatsLogEventWrapper implements Parcelable { |
| private ByteArrayOutputStream mStorage = new ByteArrayOutputStream(); |
| |
| // Below are constants copied from log/log.h |
| private static final int EVENT_TYPE_INT = 0; /* int32_t */ |
| private static final int EVENT_TYPE_LONG = 1; /* int64_t */ |
| private static final int EVENT_TYPE_STRING = 2; |
| private static final int EVENT_TYPE_LIST = 3; |
| private static final int EVENT_TYPE_FLOAT = 4; |
| |
| // Keep this in sync with system/core/logcat/event.logtags |
| private static final int STATS_BUFFER_TAG_ID = 1937006964; |
| /** |
| * Creates a log_event that is binary-encoded as implemented in |
| * system/core/liblog/log_event_list.c; this allows us to use the same parsing logic in statsd |
| * for pushed and pulled data. The write* methods must be called in the same order as their |
| * field number. There is no checking that the correct number of write* methods is called. |
| * We also write an END_LIST character before beginning to write to parcel, but this END_LIST |
| * may be unnecessary. |
| * |
| * @param tag The integer representing the tag for this event. |
| * @param fields The number of fields specified in this event. |
| */ |
| public StatsLogEventWrapper(long elapsedNanos, int tag, int fields) { |
| // Write four bytes from tag, starting with least-significant bit. |
| // For pulled data, this tag number is not really used. We use the same tag number as |
| // pushed ones to be consistent. |
| write4Bytes(STATS_BUFFER_TAG_ID); |
| mStorage.write(EVENT_TYPE_LIST); // This is required to start the log entry. |
| mStorage.write(fields + 2); // Indicate number of elements in this list. +1 for the tag |
| // The first element is the elapsed realtime. |
| writeLong(elapsedNanos); |
| // The second element is the real atom tag number |
| writeInt(tag); |
| } |
| |
| /** |
| * Boilerplate for Parcel. |
| */ |
| public static final Parcelable.Creator<StatsLogEventWrapper> CREATOR = new |
| Parcelable.Creator<StatsLogEventWrapper>() { |
| public StatsLogEventWrapper createFromParcel(Parcel in) { |
| android.util.EventLog.writeEvent(0x534e4554, "112550251", |
| android.os.Binder.getCallingUid(), ""); |
| // Purposefully leaving this method not implemented. |
| throw new RuntimeException("Not implemented"); |
| } |
| |
| public StatsLogEventWrapper[] newArray(int size) { |
| android.util.EventLog.writeEvent(0x534e4554, "112550251", |
| android.os.Binder.getCallingUid(), ""); |
| // Purposefully leaving this method not implemented. |
| throw new RuntimeException("Not implemented"); |
| } |
| }; |
| |
| private void write4Bytes(int val) { |
| mStorage.write(val); |
| mStorage.write(val >>> 8); |
| mStorage.write(val >>> 16); |
| mStorage.write(val >>> 24); |
| } |
| |
| private void write8Bytes(long val) { |
| write4Bytes((int) (val & 0xFFFFFFFF)); // keep the lowe 32-bits |
| write4Bytes((int) (val >>> 32)); // Write the high 32-bits. |
| } |
| |
| /** |
| * Adds 32-bit integer to output. |
| */ |
| public void writeInt(int val) { |
| mStorage.write(EVENT_TYPE_INT); |
| write4Bytes(val); |
| } |
| |
| /** |
| * Adds 64-bit long to output. |
| */ |
| public void writeLong(long val) { |
| mStorage.write(EVENT_TYPE_LONG); |
| write8Bytes(val); |
| } |
| |
| /** |
| * Adds a 4-byte floating point value to output. |
| */ |
| public void writeFloat(float val) { |
| int v = Float.floatToIntBits(val); |
| mStorage.write(EVENT_TYPE_FLOAT); |
| write4Bytes(v); |
| } |
| |
| /** |
| * Adds a string to the output. |
| */ |
| public void writeString(String val) { |
| mStorage.write(EVENT_TYPE_STRING); |
| write4Bytes(val.length()); |
| byte[] bytes = val.getBytes(StandardCharsets.UTF_8); |
| mStorage.write(bytes, 0, bytes.length); |
| } |
| |
| /** |
| * Writes the stored fields to a byte array. Will first write a new-line character to denote |
| * END_LIST before writing contents to byte array. |
| */ |
| public void writeToParcel(Parcel out, int flags) { |
| mStorage.write(10); // new-line character is same as END_LIST |
| out.writeByteArray(mStorage.toByteArray()); |
| } |
| |
| /** |
| * Boilerplate for Parcel. |
| */ |
| public int describeContents() { |
| return 0; |
| } |
| } |