1 /* 2 * Copyright 2017, OpenCensus Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.opencensus.tags.propagation; 18 19 import io.opencensus.tags.Tag; 20 import io.opencensus.tags.TagContext; 21 import io.opencensus.tags.TagMetadata; 22 import io.opencensus.tags.TagMetadata.TagTtl; 23 24 /** 25 * Object for serializing and deserializing {@link TagContext}s with the binary format. 26 * 27 * <p>See <a 28 * href="https://github.com/census-instrumentation/opencensus-specs/blob/master/encodings/BinaryEncoding.md#tag-context">opencensus-specs</a> 29 * for the specification of the cross-language binary serialization format. 30 * 31 * @since 0.8 32 */ 33 public abstract class TagContextBinarySerializer { 34 35 /** 36 * Serializes the {@code TagContext} into the on-the-wire representation. 37 * 38 * <p>This method should be the inverse of {@link #fromByteArray}. 39 * 40 * <p>{@link Tag}s that have a {@link TagMetadata} with {@link TagTtl#NO_PROPAGATION} will not be 41 * serialized. 42 * 43 * @param tags the {@code TagContext} to serialize. 44 * @return the on-the-wire representation of a {@code TagContext}. 45 * @throws TagContextSerializationException if the result would be larger than the maximum allowed 46 * serialized size. 47 * @since 0.8 48 */ toByteArray(TagContext tags)49 public abstract byte[] toByteArray(TagContext tags) throws TagContextSerializationException; 50 51 /** 52 * Creates a {@code TagContext} from the given on-the-wire encoded representation. 53 * 54 * <p>This method should be the inverse of {@link #toByteArray}. 55 * 56 * @param bytes on-the-wire representation of a {@code TagContext}. 57 * @return a {@code TagContext} deserialized from {@code bytes}. 58 * @throws TagContextDeserializationException if there is a parse error, the input contains 59 * invalid tags, or the input is larger than the maximum allowed serialized size. 60 * @since 0.8 61 */ fromByteArray(byte[] bytes)62 public abstract TagContext fromByteArray(byte[] bytes) throws TagContextDeserializationException; 63 } 64