kafka-rest/lib/avroSchema.js

NodeJS wrapper for the Kafka REST Proxy

/**
 * Copyright 2015 Confluent Inc.
 *
 * 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.
 */
"use strict";

var Schema = require('./schema'),
    util = require('util');

/**
 * AvroSchema represents an Avro schema. Since Avro schemas are just JSON data,
 * this currently doesn't do any parsing/validation, it just serializes itself
 * for the producer.
 */
var AvroSchema = module.exports = function(schema) {
    // Since we don't parse, there's a limited amount of validation we can do
    // here.
    if (typeof(schema) != "object" && typeof("schema") != "string") {
        throw new Error("AvroSchemas can only be strings or objects.");
    }
    this.schema = schema;

    this.serialized = this.schema;
    if (typeof(schema) === "object") {
        this.serialized = JSON.stringify(this.schema);
    }
};
util.inherits(AvroSchema, Schema);

AvroSchema.prototype.toSchemaString = function() {
    return this.serialized;
};

AvroSchema.prototype.getContentType = function(client) {
    return "application/vnd.kafka.avro.v" + client.config.version + "+json";
};

AvroSchema.getContentType = AvroSchema.prototype.getContentType;

AvroSchema.decodeMessage = function(msg) {
    // Avro data is returned in JSON format, nothing to do here.
    return msg;
};