| /* |
| * Copyright (C) 2019 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.util; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.os.SystemClock; |
| |
| import com.android.internal.annotations.GuardedBy; |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| /** |
| * StatsEvent builds and stores the buffer sent over the statsd socket. |
| * This class defines and encapsulates the socket protocol. |
| * |
| * <p>Usage:</p> |
| * <pre> |
| * // Pushed event |
| * StatsEvent statsEvent = StatsEvent.newBuilder() |
| * .setAtomId(atomId) |
| * .writeBoolean(false) |
| * .writeString("annotated String field") |
| * .addBooleanAnnotation(annotationId, true) |
| * .usePooledBuffer() |
| * .build(); |
| * StatsLog.write(statsEvent); |
| * |
| * // Pulled event |
| * StatsEvent statsEvent = StatsEvent.newBuilder() |
| * .setAtomId(atomId) |
| * .writeBoolean(false) |
| * .writeString("annotated String field") |
| * .addBooleanAnnotation(annotationId, true) |
| * .build(); |
| * </pre> |
| * @hide |
| **/ |
| public final class StatsEvent { |
| // Type Ids. |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_INT = 0x00; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_LONG = 0x01; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_STRING = 0x02; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_LIST = 0x03; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_FLOAT = 0x04; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_BOOLEAN = 0x05; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_BYTE_ARRAY = 0x06; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_OBJECT = 0x07; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_KEY_VALUE_PAIRS = 0x08; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_ATTRIBUTION_CHAIN = 0x09; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final byte TYPE_ERRORS = 0x0F; |
| |
| // Error flags. |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_NO_TIMESTAMP = 0x1; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_NO_ATOM_ID = 0x2; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_OVERFLOW = 0x4; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_ATTRIBUTION_CHAIN_TOO_LONG = 0x8; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_TOO_MANY_KEY_VALUE_PAIRS = 0x10; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_ANNOTATION_DOES_NOT_FOLLOW_FIELD = 0x20; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_INVALID_ANNOTATION_ID = 0x40; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_ANNOTATION_ID_TOO_LARGE = 0x80; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_TOO_MANY_ANNOTATIONS = 0x100; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_TOO_MANY_FIELDS = 0x200; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int ERROR_ATTRIBUTION_UIDS_TAGS_SIZES_NOT_EQUAL = 0x1000; |
| |
| // Size limits. |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int MAX_ANNOTATION_COUNT = 15; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int MAX_ATTRIBUTION_NODES = 127; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int MAX_NUM_ELEMENTS = 127; |
| |
| /** |
| * @hide |
| **/ |
| @VisibleForTesting |
| public static final int MAX_KEY_VALUE_PAIRS = 127; |
| |
| private static final int LOGGER_ENTRY_MAX_PAYLOAD = 4068; |
| |
| // Max payload size is 4 bytes less as 4 bytes are reserved for statsEventTag. |
| // See android_util_StatsLog.cpp. |
| private static final int MAX_PAYLOAD_SIZE = LOGGER_ENTRY_MAX_PAYLOAD - 4; |
| |
| private final int mAtomId; |
| private final byte[] mPayload; |
| private Buffer mBuffer; |
| private final int mNumBytes; |
| |
| private StatsEvent(final int atomId, @Nullable final Buffer buffer, |
| @NonNull final byte[] payload, final int numBytes) { |
| mAtomId = atomId; |
| mBuffer = buffer; |
| mPayload = payload; |
| mNumBytes = numBytes; |
| } |
| |
| /** |
| * Returns a new StatsEvent.Builder for building StatsEvent object. |
| **/ |
| @NonNull |
| public static StatsEvent.Builder newBuilder() { |
| return new StatsEvent.Builder(Buffer.obtain()); |
| } |
| |
| /** |
| * Get the atom Id of the atom encoded in this StatsEvent object. |
| * |
| * @hide |
| **/ |
| public int getAtomId() { |
| return mAtomId; |
| } |
| |
| /** |
| * Get the byte array that contains the encoded payload that can be sent to statsd. |
| * |
| * @hide |
| **/ |
| @NonNull |
| public byte[] getBytes() { |
| return mPayload; |
| } |
| |
| /** |
| * Get the number of bytes used to encode the StatsEvent payload. |
| * |
| * @hide |
| **/ |
| public int getNumBytes() { |
| return mNumBytes; |
| } |
| |
| /** |
| * Recycle resources used by this StatsEvent object. |
| * No actions should be taken on this StatsEvent after release() is called. |
| **/ |
| public void release() { |
| if (mBuffer != null) { |
| mBuffer.release(); |
| mBuffer = null; |
| } |
| } |
| |
| /** |
| * Builder for constructing a StatsEvent object. |
| * |
| * <p>This class defines and encapsulates the socket encoding for the buffer. |
| * The write methods must be called in the same order as the order of fields in the |
| * atom definition.</p> |
| * |
| * <p>setAtomId() can be called anytime before build().</p> |
| * |
| * <p>Example:</p> |
| * <pre> |
| * // Atom definition. |
| * message MyAtom { |
| * optional int32 field1 = 1; |
| * optional int64 field2 = 2; |
| * optional string field3 = 3 [(annotation1) = true]; |
| * } |
| * |
| * // StatsEvent construction for pushed event. |
| * StatsEvent.newBuilder() |
| * StatsEvent statsEvent = StatsEvent.newBuilder() |
| * .setAtomId(atomId) |
| * .writeInt(3) // field1 |
| * .writeLong(8L) // field2 |
| * .writeString("foo") // field 3 |
| * .addBooleanAnnotation(annotation1Id, true) |
| * .usePooledBuffer() |
| * .build(); |
| * |
| * // StatsEvent construction for pulled event. |
| * StatsEvent.newBuilder() |
| * StatsEvent statsEvent = StatsEvent.newBuilder() |
| * .setAtomId(atomId) |
| * .writeInt(3) // field1 |
| * .writeLong(8L) // field2 |
| * .writeString("foo") // field 3 |
| * .addBooleanAnnotation(annotation1Id, true) |
| * .build(); |
| * </pre> |
| **/ |
| public static final class Builder { |
| // Fixed positions. |
| private static final int POS_NUM_ELEMENTS = 1; |
| private static final int POS_TIMESTAMP_NS = POS_NUM_ELEMENTS + Byte.BYTES; |
| private static final int POS_ATOM_ID = POS_TIMESTAMP_NS + Byte.BYTES + Long.BYTES; |
| |
| private final Buffer mBuffer; |
| private long mTimestampNs; |
| private int mAtomId; |
| private byte mCurrentAnnotationCount; |
| private int mPos; |
| private int mPosLastField; |
| private byte mLastType; |
| private int mNumElements; |
| private int mErrorMask; |
| private boolean mUsePooledBuffer = false; |
| |
| private Builder(final Buffer buffer) { |
| mBuffer = buffer; |
| mCurrentAnnotationCount = 0; |
| mAtomId = 0; |
| mTimestampNs = SystemClock.elapsedRealtimeNanos(); |
| mNumElements = 0; |
| |
| // Set mPos to 0 for writing TYPE_OBJECT at 0th position. |
| mPos = 0; |
| writeTypeId(TYPE_OBJECT); |
| |
| // Set mPos to after atom id's location in the buffer. |
| // First 2 elements in the buffer are event timestamp followed by the atom id. |
| mPos = POS_ATOM_ID + Byte.BYTES + Integer.BYTES; |
| mPosLastField = 0; |
| mLastType = 0; |
| } |
| |
| /** |
| * Sets the atom id for this StatsEvent. |
| **/ |
| @NonNull |
| public Builder setAtomId(final int atomId) { |
| mAtomId = atomId; |
| return this; |
| } |
| |
| /** |
| * Sets the timestamp in nanos for this StatsEvent. |
| **/ |
| @VisibleForTesting |
| @NonNull |
| public Builder setTimestampNs(final long timestampNs) { |
| mTimestampNs = timestampNs; |
| return this; |
| } |
| |
| /** |
| * Write a boolean field to this StatsEvent. |
| **/ |
| @NonNull |
| public Builder writeBoolean(final boolean value) { |
| // Write boolean typeId byte followed by boolean byte representation. |
| writeTypeId(TYPE_BOOLEAN); |
| mPos += mBuffer.putBoolean(mPos, value); |
| mNumElements++; |
| return this; |
| } |
| |
| /** |
| * Write an integer field to this StatsEvent. |
| **/ |
| @NonNull |
| public Builder writeInt(final int value) { |
| // Write integer typeId byte followed by 4-byte representation of value. |
| writeTypeId(TYPE_INT); |
| mPos += mBuffer.putInt(mPos, value); |
| mNumElements++; |
| return this; |
| } |
| |
| /** |
| * Write a long field to this StatsEvent. |
| **/ |
| @NonNull |
| public Builder writeLong(final long value) { |
| // Write long typeId byte followed by 8-byte representation of value. |
| writeTypeId(TYPE_LONG); |
| mPos += mBuffer.putLong(mPos, value); |
| mNumElements++; |
| return this; |
| } |
| |
| /** |
| * Write a float field to this StatsEvent. |
| **/ |
| @NonNull |
| public Builder writeFloat(final float value) { |
| // Write float typeId byte followed by 4-byte representation of value. |
| writeTypeId(TYPE_FLOAT); |
| mPos += mBuffer.putFloat(mPos, value); |
| mNumElements++; |
| return this; |
| } |
| |
| /** |
| * Write a String field to this StatsEvent. |
| **/ |
| @NonNull |
| public Builder writeString(@NonNull final String value) { |
| // Write String typeId byte, followed by 4-byte representation of number of bytes |
| // in the UTF-8 encoding, followed by the actual UTF-8 byte encoding of value. |
| final byte[] valueBytes = stringToBytes(value); |
| writeByteArray(valueBytes, TYPE_STRING); |
| return this; |
| } |
| |
| /** |
| * Write a byte array field to this StatsEvent. |
| **/ |
| @NonNull |
| public Builder writeByteArray(@NonNull final byte[] value) { |
| // Write byte array typeId byte, followed by 4-byte representation of number of bytes |
| // in value, followed by the actual byte array. |
| writeByteArray(value, TYPE_BYTE_ARRAY); |
| return this; |
| } |
| |
| private void writeByteArray(@NonNull final byte[] value, final byte typeId) { |
| writeTypeId(typeId); |
| final int numBytes = value.length; |
| mPos += mBuffer.putInt(mPos, numBytes); |
| mPos += mBuffer.putByteArray(mPos, value); |
| mNumElements++; |
| } |
| |
| /** |
| * Write an attribution chain field to this StatsEvent. |
| * |
| * The sizes of uids and tags must be equal. The AttributionNode at position i is |
| * made up of uids[i] and tags[i]. |
| * |
| * @param uids array of uids in the attribution nodes. |
| * @param tags array of tags in the attribution nodes. |
| **/ |
| @NonNull |
| public Builder writeAttributionChain( |
| @NonNull final int[] uids, @NonNull final String[] tags) { |
| final byte numUids = (byte) uids.length; |
| final byte numTags = (byte) tags.length; |
| |
| if (numUids != numTags) { |
| mErrorMask |= ERROR_ATTRIBUTION_UIDS_TAGS_SIZES_NOT_EQUAL; |
| } else if (numUids > MAX_ATTRIBUTION_NODES) { |
| mErrorMask |= ERROR_ATTRIBUTION_CHAIN_TOO_LONG; |
| } else { |
| // Write attribution chain typeId byte, followed by 1-byte representation of |
| // number of attribution nodes, followed by encoding of each attribution node. |
| writeTypeId(TYPE_ATTRIBUTION_CHAIN); |
| mPos += mBuffer.putByte(mPos, numUids); |
| for (int i = 0; i < numUids; i++) { |
| // Each uid is encoded as 4-byte representation of its int value. |
| mPos += mBuffer.putInt(mPos, uids[i]); |
| |
| // Each tag is encoded as 4-byte representation of number of bytes in its |
| // UTF-8 encoding, followed by the actual UTF-8 bytes. |
| final byte[] tagBytes = stringToBytes(tags[i]); |
| mPos += mBuffer.putInt(mPos, tagBytes.length); |
| mPos += mBuffer.putByteArray(mPos, tagBytes); |
| } |
| mNumElements++; |
| } |
| return this; |
| } |
| |
| /** |
| * Write KeyValuePairsAtom entries to this StatsEvent. |
| * |
| * @param intMap Integer key-value pairs. |
| * @param longMap Long key-value pairs. |
| * @param stringMap String key-value pairs. |
| * @param floatMap Float key-value pairs. |
| **/ |
| @NonNull |
| public Builder writeKeyValuePairs( |
| @NonNull final SparseIntArray intMap, |
| @NonNull final SparseLongArray longMap, |
| @NonNull final SparseArray<String> stringMap, |
| @NonNull final SparseArray<Float> floatMap) { |
| final int intMapSize = intMap.size(); |
| final int longMapSize = longMap.size(); |
| final int stringMapSize = stringMap.size(); |
| final int floatMapSize = floatMap.size(); |
| final int totalCount = intMapSize + longMapSize + stringMapSize + floatMapSize; |
| |
| if (totalCount > MAX_KEY_VALUE_PAIRS) { |
| mErrorMask |= ERROR_TOO_MANY_KEY_VALUE_PAIRS; |
| } else { |
| writeTypeId(TYPE_KEY_VALUE_PAIRS); |
| mPos += mBuffer.putByte(mPos, (byte) totalCount); |
| |
| for (int i = 0; i < intMapSize; i++) { |
| final int key = intMap.keyAt(i); |
| final int value = intMap.valueAt(i); |
| mPos += mBuffer.putInt(mPos, key); |
| writeTypeId(TYPE_INT); |
| mPos += mBuffer.putInt(mPos, value); |
| } |
| |
| for (int i = 0; i < longMapSize; i++) { |
| final int key = longMap.keyAt(i); |
| final long value = longMap.valueAt(i); |
| mPos += mBuffer.putInt(mPos, key); |
| writeTypeId(TYPE_LONG); |
| mPos += mBuffer.putLong(mPos, value); |
| } |
| |
| for (int i = 0; i < stringMapSize; i++) { |
| final int key = stringMap.keyAt(i); |
| final String value = stringMap.valueAt(i); |
| mPos += mBuffer.putInt(mPos, key); |
| writeTypeId(TYPE_STRING); |
| final byte[] valueBytes = stringToBytes(value); |
| mPos += mBuffer.putInt(mPos, valueBytes.length); |
| mPos += mBuffer.putByteArray(mPos, valueBytes); |
| } |
| |
| for (int i = 0; i < floatMapSize; i++) { |
| final int key = floatMap.keyAt(i); |
| final float value = floatMap.valueAt(i); |
| mPos += mBuffer.putInt(mPos, key); |
| writeTypeId(TYPE_FLOAT); |
| mPos += mBuffer.putFloat(mPos, value); |
| } |
| |
| mNumElements++; |
| } |
| |
| return this; |
| } |
| |
| /** |
| * Write a boolean annotation for the last field written. |
| **/ |
| @NonNull |
| public Builder addBooleanAnnotation( |
| final byte annotationId, final boolean value) { |
| // Ensure there's a field written to annotate. |
| if (0 == mPosLastField) { |
| mErrorMask |= ERROR_ANNOTATION_DOES_NOT_FOLLOW_FIELD; |
| } else if (mCurrentAnnotationCount >= MAX_ANNOTATION_COUNT) { |
| mErrorMask |= ERROR_TOO_MANY_ANNOTATIONS; |
| } else { |
| mPos += mBuffer.putByte(mPos, annotationId); |
| mPos += mBuffer.putByte(mPos, TYPE_BOOLEAN); |
| mPos += mBuffer.putBoolean(mPos, value); |
| mCurrentAnnotationCount++; |
| writeAnnotationCount(); |
| } |
| return this; |
| } |
| |
| /** |
| * Write an integer annotation for the last field written. |
| **/ |
| @NonNull |
| public Builder addIntAnnotation(final byte annotationId, final int value) { |
| if (0 == mPosLastField) { |
| mErrorMask |= ERROR_ANNOTATION_DOES_NOT_FOLLOW_FIELD; |
| } else if (mCurrentAnnotationCount >= MAX_ANNOTATION_COUNT) { |
| mErrorMask |= ERROR_TOO_MANY_ANNOTATIONS; |
| } else { |
| mPos += mBuffer.putByte(mPos, annotationId); |
| mPos += mBuffer.putByte(mPos, TYPE_INT); |
| mPos += mBuffer.putInt(mPos, value); |
| mCurrentAnnotationCount++; |
| writeAnnotationCount(); |
| } |
| return this; |
| } |
| |
| /** |
| * Indicates to reuse Buffer's byte array as the underlying payload in StatsEvent. |
| * This should be called for pushed events to reduce memory allocations and garbage |
| * collections. |
| **/ |
| @NonNull |
| public Builder usePooledBuffer() { |
| mUsePooledBuffer = true; |
| return this; |
| } |
| |
| /** |
| * Builds a StatsEvent object with values entered in this Builder. |
| **/ |
| @NonNull |
| public StatsEvent build() { |
| if (0L == mTimestampNs) { |
| mErrorMask |= ERROR_NO_TIMESTAMP; |
| } |
| if (0 == mAtomId) { |
| mErrorMask |= ERROR_NO_ATOM_ID; |
| } |
| if (mBuffer.hasOverflowed()) { |
| mErrorMask |= ERROR_OVERFLOW; |
| } |
| if (mNumElements > MAX_NUM_ELEMENTS) { |
| mErrorMask |= ERROR_TOO_MANY_FIELDS; |
| } |
| |
| int size = mPos; |
| mPos = POS_TIMESTAMP_NS; |
| writeLong(mTimestampNs); |
| writeInt(mAtomId); |
| if (0 == mErrorMask) { |
| mBuffer.putByte(POS_NUM_ELEMENTS, (byte) mNumElements); |
| } else { |
| mPos += mBuffer.putByte(mPos, TYPE_ERRORS); |
| mPos += mBuffer.putInt(mPos, mErrorMask); |
| mBuffer.putByte(POS_NUM_ELEMENTS, (byte) 3); |
| size = mPos; |
| } |
| |
| if (mUsePooledBuffer) { |
| return new StatsEvent(mAtomId, mBuffer, mBuffer.getBytes(), size); |
| } else { |
| // Create a copy of the buffer with the required number of bytes. |
| final byte[] payload = new byte[size]; |
| System.arraycopy(mBuffer.getBytes(), 0, payload, 0, size); |
| |
| // Return Buffer instance to the pool. |
| mBuffer.release(); |
| |
| return new StatsEvent(mAtomId, null, payload, size); |
| } |
| } |
| |
| private void writeTypeId(final byte typeId) { |
| mPosLastField = mPos; |
| mLastType = typeId; |
| mCurrentAnnotationCount = 0; |
| final byte encodedId = (byte) (typeId & 0x0F); |
| mPos += mBuffer.putByte(mPos, encodedId); |
| } |
| |
| private void writeAnnotationCount() { |
| // Use first 4 bits for annotation count and last 4 bits for typeId. |
| final byte encodedId = (byte) ((mCurrentAnnotationCount << 4) | (mLastType & 0x0F)); |
| mBuffer.putByte(mPosLastField, encodedId); |
| } |
| |
| @NonNull |
| private static byte[] stringToBytes(@Nullable final String value) { |
| return (null == value ? "" : value).getBytes(UTF_8); |
| } |
| } |
| |
| private static final class Buffer { |
| private static Object sLock = new Object(); |
| |
| @GuardedBy("sLock") |
| private static Buffer sPool; |
| |
| private final byte[] mBytes = new byte[MAX_PAYLOAD_SIZE]; |
| private boolean mOverflow = false; |
| |
| @NonNull |
| private static Buffer obtain() { |
| final Buffer buffer; |
| synchronized (sLock) { |
| buffer = null == sPool ? new Buffer() : sPool; |
| sPool = null; |
| } |
| buffer.reset(); |
| return buffer; |
| } |
| |
| private Buffer() { |
| } |
| |
| @NonNull |
| private byte[] getBytes() { |
| return mBytes; |
| } |
| |
| private void release() { |
| synchronized (sLock) { |
| if (null == sPool) { |
| sPool = this; |
| } |
| } |
| } |
| |
| private void reset() { |
| mOverflow = false; |
| } |
| |
| private boolean hasOverflowed() { |
| return mOverflow; |
| } |
| |
| /** |
| * Checks for available space in the byte array. |
| * |
| * @param index starting position in the buffer to start the check. |
| * @param numBytes number of bytes to check from index. |
| * @return true if space is available, false otherwise. |
| **/ |
| private boolean hasEnoughSpace(final int index, final int numBytes) { |
| final boolean result = index + numBytes < MAX_PAYLOAD_SIZE; |
| if (!result) { |
| mOverflow = true; |
| } |
| return result; |
| } |
| |
| /** |
| * Writes a byte into the buffer. |
| * |
| * @param index position in the buffer where the byte is written. |
| * @param value the byte to write. |
| * @return number of bytes written to buffer from this write operation. |
| **/ |
| private int putByte(final int index, final byte value) { |
| if (hasEnoughSpace(index, Byte.BYTES)) { |
| mBytes[index] = (byte) (value); |
| return Byte.BYTES; |
| } |
| return 0; |
| } |
| |
| /** |
| * Writes a boolean into the buffer. |
| * |
| * @param index position in the buffer where the boolean is written. |
| * @param value the boolean to write. |
| * @return number of bytes written to buffer from this write operation. |
| **/ |
| private int putBoolean(final int index, final boolean value) { |
| return putByte(index, (byte) (value ? 1 : 0)); |
| } |
| |
| /** |
| * Writes an integer into the buffer. |
| * |
| * @param index position in the buffer where the integer is written. |
| * @param value the integer to write. |
| * @return number of bytes written to buffer from this write operation. |
| **/ |
| private int putInt(final int index, final int value) { |
| if (hasEnoughSpace(index, Integer.BYTES)) { |
| // Use little endian byte order. |
| mBytes[index] = (byte) (value); |
| mBytes[index + 1] = (byte) (value >> 8); |
| mBytes[index + 2] = (byte) (value >> 16); |
| mBytes[index + 3] = (byte) (value >> 24); |
| return Integer.BYTES; |
| } |
| return 0; |
| } |
| |
| /** |
| * Writes a long into the buffer. |
| * |
| * @param index position in the buffer where the long is written. |
| * @param value the long to write. |
| * @return number of bytes written to buffer from this write operation. |
| **/ |
| private int putLong(final int index, final long value) { |
| if (hasEnoughSpace(index, Long.BYTES)) { |
| // Use little endian byte order. |
| mBytes[index] = (byte) (value); |
| mBytes[index + 1] = (byte) (value >> 8); |
| mBytes[index + 2] = (byte) (value >> 16); |
| mBytes[index + 3] = (byte) (value >> 24); |
| mBytes[index + 4] = (byte) (value >> 32); |
| mBytes[index + 5] = (byte) (value >> 40); |
| mBytes[index + 6] = (byte) (value >> 48); |
| mBytes[index + 7] = (byte) (value >> 56); |
| return Long.BYTES; |
| } |
| return 0; |
| } |
| |
| /** |
| * Writes a float into the buffer. |
| * |
| * @param index position in the buffer where the float is written. |
| * @param value the float to write. |
| * @return number of bytes written to buffer from this write operation. |
| **/ |
| private int putFloat(final int index, final float value) { |
| return putInt(index, Float.floatToIntBits(value)); |
| } |
| |
| /** |
| * Copies a byte array into the buffer. |
| * |
| * @param index position in the buffer where the byte array is copied. |
| * @param value the byte array to copy. |
| * @return number of bytes written to buffer from this write operation. |
| **/ |
| private int putByteArray(final int index, @NonNull final byte[] value) { |
| final int numBytes = value.length; |
| if (hasEnoughSpace(index, numBytes)) { |
| System.arraycopy(value, 0, mBytes, index, numBytes); |
| return numBytes; |
| } |
| return 0; |
| } |
| } |
| } |