public void StoreQuestion(Question question)
{
using (var redis = RedisManager.GetClient())
{
var redisQuestions = redis.As <Question>();
if (question.Tags == null)
{
question.Tags = new List <string>();
}
if (question.Id == default(long))
{
question.Id = redisQuestions.GetNextSequence();
question.CreatedDate = DateTime.UtcNow;
//Increment the popularity for each new question tag
question.Tags.ForEach(tag => redis.IncrementItemInSortedSet(TagIndex.All, tag, 1));
}
redisQuestions.Store(question);
redisQuestions.AddToRecentsList(question);
redis.AddItemToSet(UserQuestionIndex.Questions(question.UserId), question.Id.ToString());
//Populate tag => questions index for each tag
question.Tags.ForEach(tag => redis.AddItemToSet(TagIndex.Questions(tag), question.Id.ToString()));
}
}
/// <summary>
/// Delete question by performing compensating actions to StoreQuestion() to keep the datastore in a consistent state
/// </summary>
/// <param name="questionId"></param>
public void DeleteQuestion(long questionId)
{
using (var redis = RedisManager.GetClient())
{
var redisQuestions = redis.As <Question>();
var question = redisQuestions.GetById(questionId);
if (question == null)
{
return;
}
//decrement score in tags list
question.Tags.ForEach(tag => redis.IncrementItemInSortedSet(TagIndex.All, tag, -1));
//remove all related answers
redisQuestions.DeleteRelatedEntities <Answer>(questionId);
//remove this question from user index
redis.RemoveItemFromSet(UserQuestionIndex.Questions(question.UserId), questionId.ToString());
//remove tag => questions index for each tag
question.Tags.ForEach(tag => redis.RemoveItemFromSet(TagIndex.Questions(tag), questionId.ToString()));
redisQuestions.DeleteById(questionId);
}
}
public List <QuestionResult> GetQuestionsByUser(long userId)
{
using var redis = RedisManager.GetReadOnlyClient();
var questionIds = redis.GetAllItemsFromSet(UserQuestionIndex.Questions(userId));
var questions = redis.As <Question>().GetByIds(questionIds);
return(ToQuestionResults(questions));
}
public UserStat GetUserStats(long userId)
{
using var redis = RedisManager.GetClient();
return(new UserStat
{
UserId = userId,
QuestionsCount = redis.GetSetCount(UserQuestionIndex.Questions(userId)),
AnswersCount = redis.GetSetCount(UserAnswerIndex.Answers(userId)),
});
}
public void VoteQuestionDown(long userId, long questionId)
{
//Populate Question => User and User => Question set indexes in a single transaction
RedisManager.ExecTrans(trans =>
{
//Register downvote against question and remove any upvotes if any
trans.QueueCommand(redis => redis.AddItemToSet(QuestionUserIndex.DownVotes(questionId), userId.ToString()));
trans.QueueCommand(redis => redis.RemoveItemFromSet(QuestionUserIndex.UpVotes(questionId), userId.ToString()));
//Register downvote against user and remove any upvotes if any
trans.QueueCommand(redis => redis.AddItemToSet(UserQuestionIndex.DownVotes(userId), questionId.ToString()));
trans.QueueCommand(redis => redis.RemoveItemFromSet(UserQuestionIndex.UpVotes(userId), questionId.ToString()));
});
}
