@ -0,0 +1,27 @@ | |||||
class Feed | |||||
def initialize(type, account) | |||||
@type = type | |||||
@account = account | |||||
end | |||||
def get(limit, offset = 0) | |||||
unhydrated = redis.zrevrange(key, offset, limit) | |||||
status_map = Hash.new | |||||
# If we're after most recent items and none are there, we need to precompute the feed | |||||
return PrecomputeFeedService.new.(@type, @account).take(limit) if unhydrated.empty? && offset == 0 | |||||
Status.where(id: unhydrated).each { |status| status_map[status.id.to_s] = status } | |||||
return unhydrated.map { |id| status_map[id] } | |||||
end | |||||
private | |||||
def key | |||||
"feed:#{@type}:#{@account.id}" | |||||
end | |||||
def redis | |||||
$redis | |||||
end | |||||
end |
@ -0,0 +1,46 @@ | |||||
class FanOutOnWriteService < BaseService | |||||
MAX_FEED_SIZE = 800 | |||||
# Push a status into home and mentions feeds | |||||
# @param [Status] status | |||||
def call(status) | |||||
replied_to_user = status.reply? ? status.thread.account : nil | |||||
# Deliver to local self | |||||
push(:home, status.account.id, status) if status.account.local? | |||||
# Deliver to local followers | |||||
status.account.followers.each do |follower| | |||||
next if (status.reply? && !follower.following?(replied_to_user)) || !follower.local? | |||||
push(:home, follower.id, status) | |||||
end | |||||
# Deliver to local mentioned | |||||
status.mentions.each do |mentioned_account| | |||||
next unless mentioned_account.local? | |||||
push(:mentions, mentioned_account.id, status) | |||||
end | |||||
end | |||||
private | |||||
def push(type, receiver_id, status) | |||||
redis.zadd(key(type, receiver_id), status.created_at.to_i, status.id) | |||||
trim(type, receiver_id) | |||||
end | |||||
def trim(type, receiver_id) | |||||
return unless redis.zcard(key(type, receiver_id)) > MAX_FEED_SIZE | |||||
last = redis.zrevrange(key(type, receiver_id), MAX_FEED_SIZE - 1, MAX_FEED_SIZE - 1) | |||||
redis.zremrangebyscore(key(type, receiver_id), '-inf', "(#{last.last}") | |||||
end | |||||
def key(type, id) | |||||
"feed:#{type}:#{id}" | |||||
end | |||||
def redis | |||||
$redis | |||||
end | |||||
end |
@ -0,0 +1,35 @@ | |||||
class PrecomputeFeedService < BaseService | |||||
MAX_FEED_SIZE = 800 | |||||
# Fill up a user's home/mentions feed from DB and return it | |||||
# @param [Symbol] type :home or :mentions | |||||
# @param [Account] account | |||||
# @return [Array] | |||||
def call(type, account) | |||||
statuses = send(type.to_s, account).order('created_at desc').limit(MAX_FEED_SIZE) | |||||
statuses.each { |status| push(type, account.id, status) } | |||||
statuses | |||||
end | |||||
private | |||||
def push(type, receiver_id, status) | |||||
redis.zadd(key(type, receiver_id), status.created_at.to_i, status.id) | |||||
end | |||||
def home(account) | |||||
Status.where(account: [account] + account.following) | |||||
end | |||||
def mentions(account) | |||||
Status.where(id: Mention.where(account: account).pluck(:status_id)) | |||||
end | |||||
def key(type, id) | |||||
"feed:#{type}:#{id}" | |||||
end | |||||
def redis | |||||
$redis | |||||
end | |||||
end |
@ -0,0 +1 @@ | |||||
$redis = Redis.new(host: ENV['REDIS_HOST'] || 'localhost', port: ENV['REDIS_PORT'] || 6379) |