csharp-sdk-upm/LiveQuery/Source/AVLiveQuery.cs

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2019-07-19 15:01:34 +08:00
using System;
using System.Threading;
using System.Threading.Tasks;
using System.Collections;
using System.Collections.Generic;
using LeanCloud.Storage.Internal;
using LeanCloud.Realtime;
using LeanCloud.Realtime.Internal;
using System.Linq;
using System.Linq.Expressions;
namespace LeanCloud.LiveQuery
{
/// <summary>
/// AVLiveQuery 类
/// </summary>
public static class AVLiveQuery
{
/// <summary>
/// LiveQuery 传输数据的 AVRealtime 实例
/// </summary>
public static AVRealtime Channel {
get; set;
}
internal static long ClientTs {
get; set;
}
internal static bool Inited {
get; set;
}
internal static string InstallationId {
get; set;
}
}
/// <summary>
/// AVLiveQuery 对象
/// </summary>
/// <typeparam name="T"></typeparam>
public class AVLiveQuery<T> where T : AVObject
{
internal static Dictionary<string, WeakReference<AVLiveQuery<T>>> liveQueryDict = new Dictionary<string, WeakReference<AVLiveQuery<T>>>();
/// <summary>
/// 当前 AVLiveQuery 对象的 Id
/// </summary>
public string Id { get; set; }
/// <summary>
/// 根据 AVQuery 创建 AVLiveQuery 对象
/// </summary>
/// <param name="query"></param>
public AVLiveQuery(AVQuery<T> query) {
this.Query = query;
}
/// <summary>
/// AVLiveQuery 对应的 AVQuery 对象
/// </summary>
public AVQuery<T> Query { get; set; }
/// <summary>
/// 数据推送的触发的事件通知
/// </summary>
public event EventHandler<AVLiveQueryEventArgs<T>> OnLiveQueryReceived;
/// <summary>
/// 推送抵达时触发事件通知
/// </summary>
/// <param name="scope">产生这条推送的原因。
/// <remarks>
/// create:符合查询条件的对象创建;
/// update:符合查询条件的对象属性修改。
/// enter:对象修改事件,从不符合查询条件变成符合。
/// leave:对象修改时间,从符合查询条件变成不符合。
/// delete:对象删除
/// login:只对 _User 对象有效,表示用户登录。
/// </remarks>
/// </param>
/// <param name="onRecevived"></param>
public void On(string scope, Action<T> onRecevived)
{
this.OnLiveQueryReceived += (sender, e) =>
{
if (e.Scope == scope)
{
onRecevived.Invoke(e.Payload);
}
};
}
/// <summary>
/// 订阅操作
/// </summary>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public async Task<AVLiveQuery<T>> SubscribeAsync(CancellationToken cancellationToken = default(CancellationToken)) {
if (Query == null) {
throw new Exception("Query can not be null when subcribe.");
}
if (!AVLiveQuery.Inited) {
await Login();
AVLiveQuery.Channel.OnReconnected += OnChannelReconnected;
AVLiveQuery.Channel.NoticeReceived += OnChannelNoticeReceived;
AVLiveQuery.Inited = true;
}
await InternalSubscribe();
var liveQueryRef = new WeakReference<AVLiveQuery<T>>(this);
liveQueryDict.Add(Id, liveQueryRef);
return this;
}
static async void OnChannelReconnected(object sender, AVIMReconnectedEventArgs e) {
await Login();
lock (liveQueryDict) {
foreach (var kv in liveQueryDict) {
if (kv.Value.TryGetTarget(out var liveQuery)) {
liveQuery.InternalSubscribe().ContinueWith(_ => { });
}
}
}
}
static async Task Login() {
var installation = await AVPlugins.Instance.InstallationIdController.GetAsync();
AVLiveQuery.InstallationId = installation.ToString();
AVLiveQuery.Channel.ToggleNotification(true);
await AVLiveQuery.Channel.OpenAsync();
AVLiveQuery.ClientTs = (long) DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1)).TotalSeconds;
var liveQueryLogInCmd = new AVIMCommand().Command("login")
.Argument("installationId", AVLiveQuery.InstallationId)
.Argument("clientTs", AVLiveQuery.ClientTs)
.Argument("service", 1).AppId(AVClient.CurrentConfiguration.ApplicationId);
// open the session for LiveQuery.
try {
await AVLiveQuery.Channel.AVIMCommandRunner.RunCommandAsync(liveQueryLogInCmd);
} catch (Exception e) {
AVRealtime.PrintLog(e.Message);
}
}
static void OnChannelNoticeReceived(object sender, AVIMNotice e) {
if (e.CommandName == "data") {
var ids = AVDecoder.Instance.DecodeList<string>(e.RawData["ids"]);
if (e.RawData["msg"] is IEnumerable<object> msg) {
var receivedPayloads = from item in msg
select item as Dictionary<string, object>;
if (receivedPayloads != null) {
foreach (var payload in receivedPayloads) {
var liveQueryId = payload["query_id"] as string;
if (liveQueryDict.TryGetValue(liveQueryId, out var liveQueryRef) &&
liveQueryRef.TryGetTarget(out var liveQuery)) {
var scope = payload["op"] as string;
var objectPayload = payload["object"] as Dictionary<string, object>;
string[] keys = null;
if (payload.TryGetValue("updatedKeys", out object updatedKeys)) {
// enter, leave, update
keys = (updatedKeys as List<object>).Select(x => x.ToString()).ToArray();
}
liveQuery.Emit(scope, objectPayload, keys);
}
}
}
}
}
}
async Task InternalSubscribe() {
var queryMap = new Dictionary<string, object> {
{ "where", Query.Condition},
{ "className", Query.GetClassName()}
};
Dictionary<string, object> data = new Dictionary<string, object> {
{ "query", queryMap },
{ "id", AVLiveQuery.InstallationId },
{ "clientTimestamp", AVLiveQuery.ClientTs }
};
string sessionToken = AVUser.CurrentUser != null ? AVUser.CurrentUser.SessionToken : string.Empty;
if (!string.IsNullOrEmpty(sessionToken)) {
data.Add("sessionToken", sessionToken);
}
var command = new AVCommand("LiveQuery/subscribe",
"POST",
sessionToken,
data: data);
var res = await AVPlugins.Instance.CommandRunner.RunCommandAsync(command);
Id = res.Item2["query_id"] as string;
}
/// <summary>
/// 取消对当前 LiveQuery 对象的订阅
/// </summary>
/// <returns></returns>
public async Task UnsubscribeAsync() {
Dictionary<string, object> strs = new Dictionary<string, object> {
{ "id", AVLiveQuery.InstallationId },
{ "query_id", Id },
};
string sessionToken = AVUser.CurrentUser != null ? AVUser.CurrentUser.SessionToken : string.Empty;
var command = new AVCommand("LiveQuery/unsubscribe",
"POST",
sessionToken,
data: strs);
await AVPlugins.Instance.CommandRunner.RunCommandAsync(command);
lock (liveQueryDict) {
liveQueryDict.Remove(Id);
}
}
void Emit(string scope, IDictionary<string, object> payloadMap, string[] keys) {
var objectState = AVObjectCoder.Instance.Decode(payloadMap, AVDecoder.Instance);
var payloadObject = AVObject.FromState<T>(objectState, Query.GetClassName<T>());
var args = new AVLiveQueryEventArgs<T> {
Scope = scope,
Keys = keys,
Payload = payloadObject
};
OnLiveQueryReceived?.Invoke(this, args);
}
}
}