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API for Google App Engine standard environment with some of the dependencies shaded (repackaged)
/*
* Copyright 2016-17, OpenCensus Authors
*
* 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 io.opencensus.trace;
import io.opencensus.common.Internal;
import io.opencensus.internal.Utils;
import java.util.Random;
import javax.annotation.Nullable;
import javax.annotation.concurrent.Immutable;
/**
* A class that represents a trace identifier. A valid trace identifier is a 16-byte array with at
* least one non-zero byte.
*
* @since 0.5
*/
@Immutable
public final class TraceId implements Comparable {
/**
* The size in bytes of the {@code TraceId}.
*
* @since 0.5
*/
public static final int SIZE = 16;
private static final int BASE16_SIZE = 2 * BigendianEncoding.LONG_BASE16;
private static final long INVALID_ID = 0;
/**
* The invalid {@code TraceId}. All bytes are '\0'.
*
* @since 0.5
*/
public static final TraceId INVALID = new TraceId(INVALID_ID, INVALID_ID);
// The internal representation of the TraceId.
private final long idHi;
private final long idLo;
private TraceId(long idHi, long idLo) {
this.idHi = idHi;
this.idLo = idLo;
}
/**
* Returns a {@code TraceId} built from a byte representation.
*
* @param src the representation of the {@code TraceId}.
* @return a {@code TraceId} whose representation is given by the {@code src} parameter.
* @throws NullPointerException if {@code src} is null.
* @throws IllegalArgumentException if {@code src.length} is not {@link TraceId#SIZE}.
* @since 0.5
*/
public static TraceId fromBytes(byte[] src) {
Utils.checkNotNull(src, "src");
Utils.checkArgument(src.length == SIZE, "Invalid size: expected %s, got %s", SIZE, src.length);
return fromBytes(src, 0);
}
/**
* Returns a {@code TraceId} whose representation is copied from the {@code src} beginning at the
* {@code srcOffset} offset.
*
* @param src the buffer where the representation of the {@code TraceId} is copied.
* @param srcOffset the offset in the buffer where the representation of the {@code TraceId}
* begins.
* @return a {@code TraceId} whose representation is copied from the buffer.
* @throws NullPointerException if {@code src} is null.
* @throws IndexOutOfBoundsException if {@code srcOffset+TraceId.SIZE} is greater than {@code
* src.length}.
* @since 0.5
*/
public static TraceId fromBytes(byte[] src, int srcOffset) {
Utils.checkNotNull(src, "src");
return new TraceId(
BigendianEncoding.longFromByteArray(src, srcOffset),
BigendianEncoding.longFromByteArray(src, srcOffset + BigendianEncoding.LONG_BYTES));
}
/**
* Returns a {@code TraceId} built from a lowercase base16 representation.
*
* @param src the lowercase base16 representation.
* @return a {@code TraceId} built from a lowercase base16 representation.
* @throws NullPointerException if {@code src} is null.
* @throws IllegalArgumentException if {@code src.length} is not {@code 2 * TraceId.SIZE} OR if
* the {@code str} has invalid characters.
* @since 0.11
*/
public static TraceId fromLowerBase16(CharSequence src) {
Utils.checkNotNull(src, "src");
Utils.checkArgument(
src.length() == BASE16_SIZE,
"Invalid size: expected %s, got %s",
BASE16_SIZE,
src.length());
return fromLowerBase16(src, 0);
}
/**
* Returns a {@code TraceId} built from a lowercase base16 representation.
*
* @param src the lowercase base16 representation.
* @param srcOffset the offset in the buffer where the representation of the {@code TraceId}
* begins.
* @return a {@code TraceId} built from a lowercase base16 representation.
* @throws NullPointerException if {@code src} is null.
* @throws IllegalArgumentException if not enough characters in the {@code src} from the {@code
* srcOffset}.
* @since 0.11
*/
public static TraceId fromLowerBase16(CharSequence src, int srcOffset) {
Utils.checkNotNull(src, "src");
return new TraceId(
BigendianEncoding.longFromBase16String(src, srcOffset),
BigendianEncoding.longFromBase16String(src, srcOffset + BigendianEncoding.LONG_BASE16));
}
/**
* Generates a new random {@code TraceId}.
*
* @param random the random number generator.
* @return a new valid {@code TraceId}.
* @since 0.5
*/
public static TraceId generateRandomId(Random random) {
long idHi;
long idLo;
do {
idHi = random.nextLong();
idLo = random.nextLong();
} while (idHi == INVALID_ID && idLo == INVALID_ID);
return new TraceId(idHi, idLo);
}
/**
* Returns the 16-bytes array representation of the {@code TraceId}.
*
* @return the 16-bytes array representation of the {@code TraceId}.
* @since 0.5
*/
public byte[] getBytes() {
byte[] bytes = new byte[SIZE];
BigendianEncoding.longToByteArray(idHi, bytes, 0);
BigendianEncoding.longToByteArray(idLo, bytes, BigendianEncoding.LONG_BYTES);
return bytes;
}
/**
* Copies the byte array representations of the {@code TraceId} into the {@code dest} beginning at
* the {@code destOffset} offset.
*
* @param dest the destination buffer.
* @param destOffset the starting offset in the destination buffer.
* @throws NullPointerException if {@code dest} is null.
* @throws IndexOutOfBoundsException if {@code destOffset+TraceId.SIZE} is greater than {@code
* dest.length}.
* @since 0.5
*/
public void copyBytesTo(byte[] dest, int destOffset) {
BigendianEncoding.longToByteArray(idHi, dest, destOffset);
BigendianEncoding.longToByteArray(idLo, dest, destOffset + BigendianEncoding.LONG_BYTES);
}
/**
* Copies the lowercase base16 representations of the {@code TraceId} into the {@code dest}
* beginning at the {@code destOffset} offset.
*
* @param dest the destination buffer.
* @param destOffset the starting offset in the destination buffer.
* @throws IndexOutOfBoundsException if {@code destOffset + 2 * TraceId.SIZE} is greater than
* {@code dest.length}.
* @since 0.18
*/
public void copyLowerBase16To(char[] dest, int destOffset) {
BigendianEncoding.longToBase16String(idHi, dest, destOffset);
BigendianEncoding.longToBase16String(idLo, dest, destOffset + BASE16_SIZE / 2);
}
/**
* Returns whether the {@code TraceId} is valid. A valid trace identifier is a 16-byte array with
* at least one non-zero byte.
*
* @return {@code true} if the {@code TraceId} is valid.
* @since 0.5
*/
public boolean isValid() {
return idHi != INVALID_ID || idLo != INVALID_ID;
}
/**
* Returns the lowercase base16 encoding of this {@code TraceId}.
*
* @return the lowercase base16 encoding of this {@code TraceId}.
* @since 0.11
*/
public String toLowerBase16() {
char[] chars = new char[BASE16_SIZE];
copyLowerBase16To(chars, 0);
return new String(chars);
}
/**
* Returns the lower 8 bytes of the trace-id as a long value, assuming little-endian order. This
* is used in ProbabilitySampler.
*
* This method is marked as internal and subject to change.
*
* @return the lower 8 bytes of the trace-id as a long value, assuming little-endian order.
*/
@Internal
public long getLowerLong() {
return (idHi < 0) ? -idHi : idHi;
}
@Override
public boolean equals(@Nullable Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof TraceId)) {
return false;
}
TraceId that = (TraceId) obj;
return idHi == that.idHi && idLo == that.idLo;
}
@Override
public int hashCode() {
// Copied from Arrays.hashCode(long[])
int result = 1;
result = 31 * result + ((int) (idHi ^ (idHi >>> 32)));
result = 31 * result + ((int) (idLo ^ (idLo >>> 32)));
return result;
}
@Override
public String toString() {
return "TraceId{traceId=" + toLowerBase16() + "}";
}
@Override
public int compareTo(TraceId that) {
if (idHi == that.idHi) {
if (idLo == that.idLo) {
return 0;
}
return idLo < that.idLo ? -1 : 1;
}
return idHi < that.idHi ? -1 : 1;
}
}