T1B0 commented on code in PR #2165: URL: https://github.com/apache/iggy/pull/2165#discussion_r2344498398
########## examples/nodejs/src/basic-js/consumer.js: ########## @@ -0,0 +1,158 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ + +import { Client, PollingStrategy, Consumer } from 'apache-iggy'; +import debug from 'debug'; + +const log = debug('iggy:basic:consumer'); + +const STREAM_ID = 1; +const TOPIC_ID = 1; +const PARTITION_ID = 1; +const BATCHES_LIMIT = 5; +const MESSAGES_PER_BATCH = 10; + +function parseArgs() { + const args = process.argv.slice(2); + const connectionString = args[0] || 'iggy+tcp://iggy:iggy@127.0.0.1:8090'; + + if (args.length > 0 && (args[0] === '-h' || args[0] === '--help')) { + console.log('Usage: node consumer.js [connection_string]'); + console.log('Example: node consumer.js iggy+tcp://iggy:iggy@127.0.0.1:8090'); + process.exit(0); + } + + return { connectionString }; +} + +function handleMessage(message) { + const payload = message.payload.toString(); + const offset = message.headers.offset; + const timestamp = message.headers.timestamp; + + log('Received message: %s (offset: %d, timestamp: %d)', payload, offset, timestamp); +} + +async function consumeMessages(client) { + const interval = 500; // 500 milliseconds + log( + 'Messages will be consumed from stream: %d, topic: %d, partition: %d with interval %d ms.', + STREAM_ID, + TOPIC_ID, + PARTITION_ID, + interval + ); + + let offset = 0; + let consumedBatches = 0; + + while (consumedBatches < BATCHES_LIMIT) { + try { + log('Polling for messages...'); + const polledMessages = await client.message.poll({ + streamId: STREAM_ID, + topicId: TOPIC_ID, + consumer: Consumer.Single, + partitionId: PARTITION_ID, + pollingStrategy: PollingStrategy.Offset(BigInt(offset)), + count: MESSAGES_PER_BATCH, + autocommit: false + }); + + if (!polledMessages || polledMessages.messages.length === 0) { + log('No messages found in current poll - this is expected if the producer had issues sending messages'); + consumedBatches++; // Increment even when no messages found + log('Completed poll attempt %d (no messages).', consumedBatches); + await new Promise(resolve => setTimeout(resolve, interval)); + continue; + } + + offset += polledMessages.messages.length; + + for (const message of polledMessages.messages) { + handleMessage(message); + } + + consumedBatches++; + log('Consumed %d message(s) in batch %d.', polledMessages.messages.length, consumedBatches); + + await new Promise(resolve => setTimeout(resolve, interval)); + } catch (error) { + log('Error consuming messages: %o', error); + consumedBatches++; Review Comment: consumedBatches increment and wait could be handled in a finally{} block to avoid code duplication -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@iggy.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org