nl.topicus.jdbc.shaded.io.opencensus.trace.TraceOptions Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of spanner-jdbc Show documentation
Show all versions of spanner-jdbc Show documentation
JDBC Driver for Google Cloud Spanner
/*
* Copyright 2017, 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 nl.topicus.jdbc.shaded.io.opencensus.trace;
import static nl.topicus.jdbc.shaded.com.google.common.base.Preconditions.checkArgument;
import static nl.topicus.jdbc.shaded.com.google.common.base.Preconditions.checkElementIndex;
import static nl.topicus.jdbc.shaded.com.google.common.base.Preconditions.checkNotNull;
import nl.topicus.jdbc.shaded.com.google.common.annotations.VisibleForTesting;
import nl.topicus.jdbc.shaded.com.google.common.base.MoreObjects;
import nl.topicus.jdbc.shaded.com.google.common.base.Objects;
import nl.topicus.jdbc.shaded.javax.annotation.concurrent.Immutable;
/**
* A class that represents global trace options. These options are propagated to all child {@link
* nl.topicus.jdbc.shaded.io.opencensus.trace.Span spans}. These determine features such as whether a {@code Span} should
* be traced. It is implemented as a bitmask.
*/
@Immutable
public final class TraceOptions {
// Default options. Nothing set.
private static final byte DEFAULT_OPTIONS = 0;
// Bit to represent whether trace is sampled or not.
private static final byte IS_SAMPLED = 0x1;
/** The size in bytes of the {@code TraceOptions}. */
public static final int SIZE = 1;
/** The default {@code TraceOptions}. */
public static final TraceOptions DEFAULT = new TraceOptions(DEFAULT_OPTIONS);
// The set of enabled features is determined by all the enabled bits.
private final byte options;
// Creates a new {@code TraceOptions} with the given options.
private TraceOptions(byte options) {
this.options = options;
}
/**
* Returns a {@code TraceOptions} built from a byte representation.
*
* Equivalent with:
*
*
{@code
* TraceOptions.fromBytes(buffer, 0);
* }
*
* @param buffer the representation of the {@code TraceOptions}.
* @return a {@code TraceOptions} whose representation is given by the {@code buffer} parameter.
* @throws NullPointerException if {@code buffer} is null.
* @throws IllegalArgumentException if {@code buffer.length} is not {@link TraceOptions#SIZE}.
*/
public static TraceOptions fromBytes(byte[] buffer) {
checkNotNull(buffer, "buffer");
checkArgument(buffer.length == SIZE, "Invalid size: expected %s, got %s", SIZE, buffer.length);
return new TraceOptions(buffer[0]);
}
/**
* Returns a {@code TraceOptions} whose representation is copied from the {@code src} beginning at
* the {@code srcOffset} offset.
*
* @param src the buffer where the representation of the {@code TraceOptions} is copied.
* @param srcOffset the offset in the buffer where the representation of the {@code TraceOptions}
* begins.
* @return a {@code TraceOptions} whose representation is copied from the buffer.
* @throws NullPointerException if {@code src} is null.
* @throws IndexOutOfBoundsException if {@code srcOffset+TraceOptions.SIZE} is greater than {@code
* src.length}.
*/
public static TraceOptions fromBytes(byte[] src, int srcOffset) {
checkElementIndex(srcOffset, src.length);
return new TraceOptions(src[srcOffset]);
}
/**
* Returns the 1-byte array representation of the {@code TraceOptions}.
*
* @return the 1-byte array representation of the {@code TraceOptions}.
*/
public byte[] getBytes() {
byte[] bytes = new byte[SIZE];
bytes[0] = options;
return bytes;
}
/**
* Copies the byte representations of the {@code TraceOptions} into the {@code dest} beginning at
* the {@code destOffset} offset.
*
* Equivalent with (but faster because it avoids any new allocations):
*
*
{@code
* System.arraycopy(getBytes(), 0, dest, destOffset, TraceOptions.SIZE);
* }
*
* @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+TraceOptions.SIZE} is greater than
* {@code dest.length}.
*/
public void copyBytesTo(byte[] dest, int destOffset) {
checkElementIndex(destOffset, dest.length);
dest[destOffset] = options;
}
/**
* Returns a new {@link Builder} with default options.
*
* @return a new {@code Builder} with default options.
*/
public static Builder builder() {
return new Builder(DEFAULT_OPTIONS);
}
/**
* Returns a new {@link Builder} with all given options set.
*
* @param traceOptions the given options set.
* @return a new {@code Builder} with all given options set.
*/
public static Builder builder(TraceOptions traceOptions) {
return new Builder(traceOptions.options);
}
/**
* Returns a boolean indicating whether this {@code Span} is part of a sampled trace and data
* should be exported to a persistent store.
*
* @return a boolean indicating whether the trace is sampled.
*/
public boolean isSampled() {
return hasOption(IS_SAMPLED);
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof TraceOptions)) {
return false;
}
TraceOptions that = (TraceOptions) obj;
return options == that.options;
}
@Override
public int hashCode() {
return Objects.hashCode(options);
}
@Override
public String toString() {
return MoreObjects.toStringHelper(this).add("sampled", isSampled()).toString();
}
/** Builder class for {@link TraceOptions}. */
public static final class Builder {
private byte options;
private Builder(byte options) {
this.options = options;
}
/**
* @deprecated Use {@code Builder.setIsSampled(true)}.
* @return this.
*/
@Deprecated
public Builder setIsSampled() {
return setIsSampled(true);
}
/**
* Sets the sampling bit in the options.
*
* @param isSampled the sampling bit.
* @return this.
*/
public Builder setIsSampled(boolean isSampled) {
if (isSampled) {
options = (byte) (options | IS_SAMPLED);
} else {
options = (byte) (options & ~IS_SAMPLED);
;
}
return this;
}
/**
* Builds and returns a {@code TraceOptions} with the desired options.
*
* @return a {@code TraceOptions} with the desired options.
*/
public TraceOptions build() {
return new TraceOptions(options);
}
}
// Returns the current set of options bitmask.
@VisibleForTesting
byte getOptions() {
return options;
}
private boolean hasOption(int mask) {
return (this.options & mask) != 0;
}
}