Redis比键值存储更重要。
因此,您需要以下内容:
对于每个用户,您必须存储他发送的消息。比方说APP_NAMESPACE:MESSAGES:<USER_ID>:<MESSAGE_ID>
。我们在此处添加userId,以便我们可以轻松检索单个用户发送的所有消息。
并且,对于每两个用户,您需要跟踪他们的对话。作为键,您可以简单地使用他们的用户IDAPP_NAMESPACE:CONVERSATIONS:<USER1_ID>-<USER2_ID>
。为了确保两个用户始终获得相同的共享对话,可以对他们的ID进行排序,以便用户132和145都将132:145作为对话密钥
那么在“对话”中存储什么呢?让我们使用一个列表:[messageKey, messageKey, messageKey]
。
好的,但是messageKey现在是什么?上面的userId和messageId的组合(因此我们可以获得实际的消息)。
因此,基本上,您需要两件事:
使用节点和标准redis / hiredis客户端,这有点像(我将跳过明显的错误等检查,而我将编写ES6。如果您仍然无法阅读ES6,只需将其粘贴到babel即可):
// assuming the init connects to redis and exports a redisClient
import redisClient from './redis-init';
import uuid from `node-uuid`;
export function storeMessage(userId, toUserId, message) {
return new Promise(function(resolve, reject) {
// give it an id.
let messageId = uuid.v4(); // gets us a random uid.
let messageKey = `${userId}:${messageId}`;
let key = `MY_APP:MESSAGES:${messageKey}`;
client.hmset(key, [
"message", message,
"timestamp", new Date(),
"toUserId", toUserId
], function(err) {
if (err) { return reject(err); }
// Now we stored the message. But we also want to store a reference to the messageKey
let convoKey = `MY_APP:CONVERSATIONS:${userId}-${toUserId}`;
client.lpush(convoKey, messageKey, function(err) {
if (err) { return reject(err); }
return resolve();
});
});
});
}
// We also need to retreive the messages for the users.
export function getConversation(userId, otherUserId, page = 1, limit = 10) {
return new Promise(function(resolve, reject) {
let [userId1, userId2] = [userId, otherUserId].sort();
let convoKey = `MY_APP:CONVERSATIONS:${userId1}-${userId2}`;
// lets sort out paging stuff.
let start = (page - 1) * limit; // we're zero-based here.
let stop = page * limit - 1;
client.lrange(convoKey, start, stop, function(err, messageKeys) {
if (err) { return reject(err); }
// we have message keys, Now get all messages.
let keys = messageKeys.map(key => `MY_APP:MESSAGES:${key}`);
let promises = keys.map(key => getMessage(key));
Promise.all(promises)
.then(function(messages) {
// Now we have them. We can sort them too
return resolve(messages.sort((m1, m2) => m1.timestamp - m2.timestamp));
})
.catch(reject);
});
});
}
// we also need the getMessage here as a promise. We Could also have used some Promisify implementation but hey.
export function getMessage(key) {
return new Promise(function(resolve, reject) {
client.hgetall(key, function(err, message) {
if (err) { return reject(err); }
resolve(message);
});
});
}
现在这还很粗糙,还没有经过测试,但这就是您如何做到这一点的要旨。