@azure/event-hubs
Version:
Azure Event Hubs SDK for JS.
92 lines • 4.35 kB
JavaScript
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
import { throwTypeErrorIfParameterMissing } from "./util/error.js";
import { getRandomName } from "./util/utils.js";
/**
* The `EventProcessor` relies on a `CheckpointStore` to store checkpoints and handle partition
* ownerships. `InMemoryCheckpointStore` is simple partition manager that stores checkpoints and
* partition ownerships in memory of your program.
*
* You can use the `InMemoryCheckpointStore` to get started with using the `EventProcessor`.
* But in production, you should choose an implementation of the `CheckpointStore` interface that will
* store the checkpoints and partition ownerships to a durable store instead.
*
* @internal
*/
export class InMemoryCheckpointStore {
constructor() {
this._partitionOwnershipMap = new Map();
this._committedCheckpoints = new Map();
}
/**
* Get the list of all existing partition ownership from the underlying data store. Could return empty
* results if there are is no existing ownership information.
*
* @param fullyQualifiedNamespace - The fully qualified Event Hubs namespace. This is likely to be similar to
* <yournamespace>.servicebus.windows.net.
* @param eventHubName - The event hub name.
* @param consumerGroup - The consumer group name.
* @returns Partition ownership details of all the partitions that have/had an owner..
*/
async listOwnership(_fullyQualifiedNamespace, _eventHubName, _consumerGroup) {
const ownerships = [];
for (const value of this._partitionOwnershipMap.values()) {
ownerships.push(Object.assign({}, value));
}
return ownerships;
}
/**
* Claim ownership of a list of partitions. This will return the list of partitions that were owned
* successfully.
*
* @param partitionOwnership - The list of partition ownership this instance is claiming to own.
* @returns A list partitions this instance successfully claimed ownership.
*/
async claimOwnership(partitionOwnership) {
const claimedOwnerships = [];
for (const ownership of partitionOwnership) {
if (!this._partitionOwnershipMap.has(ownership.partitionId) ||
this._partitionOwnershipMap.get(ownership.partitionId).etag === ownership.etag) {
const date = new Date();
const newOwnership = Object.assign(Object.assign({}, ownership), { etag: getRandomName(), lastModifiedTimeInMs: date.getTime() });
this._partitionOwnershipMap.set(newOwnership.partitionId, newOwnership);
claimedOwnerships.push(newOwnership);
}
}
return claimedOwnerships;
}
/**
* Updates the checkpoint in the data store for a partition.
*
* @param checkpoint - The checkpoint.
*/
async updateCheckpoint(checkpoint) {
throwTypeErrorIfParameterMissing("", "updateCheckpoint", "sequenceNumber", checkpoint.sequenceNumber);
throwTypeErrorIfParameterMissing("", "updateCheckpoint", "offset", checkpoint.offset);
checkpoint = Object.assign({}, checkpoint);
const partitionOwnership = this._partitionOwnershipMap.get(checkpoint.partitionId);
if (partitionOwnership) {
partitionOwnership.etag = getRandomName();
const key = `${checkpoint.fullyQualifiedNamespace}:${checkpoint.eventHubName}:${checkpoint.consumerGroup}`;
let partitionMap = this._committedCheckpoints.get(key);
if (partitionMap == null) {
partitionMap = new Map();
this._committedCheckpoints.set(key, partitionMap);
}
partitionMap.set(checkpoint.partitionId, checkpoint);
}
}
async listCheckpoints(fullyQualifiedNamespace, eventHubName, consumerGroup) {
const key = `${fullyQualifiedNamespace}:${eventHubName}:${consumerGroup}`;
const partitionMap = this._committedCheckpoints.get(key);
if (partitionMap == null) {
return [];
}
const checkpoints = [];
for (const value of partitionMap.values()) {
checkpoints.push(Object.assign({}, value));
}
return checkpoints;
}
}
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