事件

在执行期间，某些操作会生成事件。 以下部分描述了作为默认 Gear 运行时一部分的事件。

订阅所有事件：

import { GearApi } from "@gear-js/api";

GearApi.query.system.events((events) => {
    console.log(events)
}

Gear 事件 类型

MessageEnqueued

Summary: 当用户成功向程序发送消息并将其添加到 Gear 消息队列时。

MessageEnqueued {
    /// Generated id of the message.
    id: MessageId,
    /// Account id of the source of the message.
    source: T::AccountId,
    /// Program id, who is a destination of the message.
    destination: ProgramId,
    /// Entry point for processing of the message.
    /// On the sending stage, processing function
    /// of program is always known.
    entry: Entry,
}

UserMessageSent

Summary: 当有人向用户发送消息时。

UserMessageSent {
    /// Message sent.
    message: StoredMessage,
    /// Block number of expiration from `Mailbox`.
    ///
    /// Equals `Some(_)` with block number when message
    /// will be removed from `Mailbox` due to some
    /// reasons (see #642, #646 and #1010).
    ///
    /// Equals `None` if message wasn't inserted to
    /// `Mailbox` and appears as only `Event`.
    expiration: Option<T::BlockNumber>,
}

UserMessageSent

Summary: 当消息被标记为“已读”并且已从Mailbox中删除时。 此事件仅影响先前已插入到Mailbox的消息。

UserMessageRead {
    /// Id of the message read.
    id: MessageId,
    /// The reason of the reading (removal from `Mailbox`).
    ///
    /// NOTE: See more docs about reasons at `gear_common::event`.
    reason: UserMessageReadReason,
}

MessagesDispatched

Summary: 当一个消息在块内被处理的结果。

MessagesDispatched {
    /// Total amount of messages removed from message queue.
    total: MessengerCapacityOf<T>,
    /// Execution statuses of the messages, which were already known
    /// by `Event::MessageEnqueued` (sent from user to program).
    statuses: BTreeMap<MessageId, DispatchStatus>,
    /// Ids of programs, which state changed during queue processing.
    state_changes: BTreeSet<ProgramId>,
}

MessageWaited

Summary: 当一个消息的执行被推迟，并被添加到Gear等待列表中。

MessageWaited {
    /// Id of the message waited.
    id: MessageId,
    /// Origin message id, which started messaging chain with programs,
    /// where currently waited message was created.
    ///
    /// Used for identifying by user, that this message associated
    /// with him and with the concrete initial message.
    origin: Option<MessageId>,
    /// The reason of the waiting (addition to `Waitlist`).
    ///
    /// NOTE: See more docs about reasons at `gear_common::event`.
    reason: MessageWaitedReason,
    /// Block number of expiration from `Waitlist`.
    ///
    /// Equals block number when message will be removed from `Waitlist`
    /// due to some reasons (see #642, #646 and #1010).
    expiration: T::BlockNumber,
}

MessageWoken

Summary: 当一条消息准备好继续执行并从 Waitlist 中删除时。

MessageWoken {
    /// Id of the message woken.
    id: MessageId,
    /// The reason of the waking (removal from `Waitlist`).
    ///
    /// NOTE: See more docs about reasons at `gear_common::event`.
    reason: MessageWokenReason,
}

CodeChanged

Summary: 当程序代码被改变时。

CodeChanged {
    /// Id of the code affected.
    id: CodeId,
    /// Change applied on code with current id.
    ///
    /// NOTE: See more docs about change kinds at `gear_common::event`.
    change: CodeChangeKind<T::BlockNumber>,
}

ProgramChanged

Summary: 与程序有关的任何数据改变时。

ProgramChanged {
    /// Id of the program affected.
    id: ProgramId,
    /// Change applied on program with current id.
    ///
    /// NOTE: See more docs about change kinds at `gear_common::event`.
    change: ProgramChangeKind<T::BlockNumber>,
}

Cookbook

获取事件以检查指定程序是否已被初始化的例子。

import { GearApi, Hex, MessageEnqueued, ProgramChanged, UserMessageSent } from '@gear-js/api';
import { UnsubscribePromise } from '@polkadot/api/types';

export function waitForInit(api: GearApi, programId: string): Promise<UnsubscribePromise> {
  let messageId: Hex;
  return new Promise((resolve, reject) => {
    const unsub = api.query.system.events((events) => {
      events.forEach(({ event }) => {
        switch (event.method) {
          case 'MessageEnqueued':
            const meEvent = event as MessageEnqueued;
            if (meEvent.data.destination.eq(programId) && meEvent.data.entry.isInit) {
              messageId = meEvent.data.id.toHex();
            }
            break;
          case 'UserMessageSent':
            const {
              data: {
                message: { source, reply, payload },
              },
            } = event as UserMessageSent;
            if (source.eq(programId) && reply.isSome && reply.unwrap()[0].eq(messageId) && reply.unwrap()[1].eq(1)) {
              reject(payload.toHuman());
            }
            break;
          case 'ProgramChanged':
            const pcEvent = event as ProgramChanged;
            if (pcEvent.data.id.eq(programId) && pcEvent.data.change.isActive) {
              resolve(unsub);
            }
            break;
        }
      });
    });
  });
}