wxmn · March 31, 2011 13:23 · Apr 1, 2011 · Mar 31, 2011 · Mar 31, 2011
diff --git a/status.rb b/status.rb
@@ -8,6 +8,8 @@ def feed(obj=true, count=FEED_COUNT)
     results=$redis.zrevrange key(:feed), 0, count
     if obj && results.size > 0
       results.collect {|r| Status.decode(r)}
+    else
+      results
     end
   end
 
@@ -16,6 +18,8 @@ def ofeed(max, obj=true, id=self.id_s, limit=FEED_COUNT, scores=false)
     results=$redis.zrevrangebyscore(key(:feed), "(#{max}", "-inf", :limit => [0, limit], :with_scores => scores)
     if obj && results.size > 0
       results.collect {|r| Status.decode(r)}
+    else
+      results
     end     
   end
 

diff --git a/base.rb → redis_helper.rb b/base.rb → redis_helper.rb
@@ -1,3 +1,4 @@
+module RedisHelper
   # decode Redis value back to Ruby object
   def self.decode(json)
     self.new(ActiveSupport::JSON.decode(json)["#{self.name.downcase}"])
@@ -25,3 +26,4 @@ def ukey(str, uid=self.user_id) #for keys needing user_id
   def id_s
     id.to_s
   end
+end
diff --git a/status.rb b/status.rb
@@ -1,3 +1,5 @@
+class User 
+
   FEED_COUNT=30
 
   # get latest feed using reverse range lookup of sorted set
@@ -17,6 +19,11 @@ def ofeed(max, obj=true, id=self.id_s, limit=FEED_COUNT, scores=false)
     end     
   end
 
+end
+
+
+class Status
+
   # push status to a specific feed
     def push(id, location="feed")
       $redis.zadd key(location, id), timestamp, encoded
@@ -29,6 +36,10 @@ def push_to_followers
     end
   end
 
+end
+
+# also in user.rb: 
+
   # since most sorted set commands are a variation on O(log(N)) 
   # where N is the size of the set, in makes sense to trim the
   # feed when it gets beyond a certain length

diff --git a/base.rb b/base.rb
@@ -0,0 +1,27 @@
+  # decode Redis value back to Ruby object
+  def self.decode(json)
+    self.new(ActiveSupport::JSON.decode(json)["#{self.name.downcase}"])
+  end
+
+  # encode Ruby object for Redis
+  def encoded
+    self.updated_at = nil
+    self.to_json
+  end
+
+  # helpers to generate Redis keys
+  def timestamp
+    "#{self.created_at.to_i}"
+  end
+
+  def key(str, uid=self.id)
+    "#{str}:#{uid}"
+  end
+
+  def ukey(str, uid=self.user_id) #for keys needing user_id
+    "#{str}:#{uid}"
+  end
+
+  def id_s
+    id.to_s
+  end
diff --git a/status.rb b/status.rb
@@ -0,0 +1,50 @@
+  FEED_COUNT=30
+
+  # get latest feed using reverse range lookup of sorted set
+  # then decode raw JSON back into Ruby objects
+  def feed(obj=true, count=FEED_COUNT)
+    results=$redis.zrevrange key(:feed), 0, count
+    if obj && results.size > 0
+      results.collect {|r| Status.decode(r)}
+    end
+  end
+
+  # get older statuses by using reverse range by score lookup
+  def ofeed(max, obj=true, id=self.id_s, limit=FEED_COUNT, scores=false)
+    results=$redis.zrevrangebyscore(key(:feed), "(#{max}", "-inf", :limit => [0, limit], :with_scores => scores)
+    if obj && results.size > 0
+      results.collect {|r| Status.decode(r)}
+    end     
+  end
+
+  # push status to a specific feed
+    def push(id, location="feed")
+      $redis.zadd key(location, id), timestamp, encoded
+    end
+
+  # push to followers (assumes an array of follower ids)
+  def push_to_followers
+    @follower_ids.each do |follower_id|
+      push(follower_id)
+    end
+  end
+
+  # since most sorted set commands are a variation on O(log(N)) 
+  # where N is the size of the set, in makes sense to trim the
+  # feed when it gets beyond a certain length
+
+  FEED_LENGTH=240
+
+  # there may be a more efficient way to do this
+  # but I check the length of the set
+  # then I get the score of the last value I want to keep
+  # then remove all keys with a lower score
+  def trim_feed(id=self.id_s, location="feed", indx=FEED_LENGTH)
+    k = key(:feed)
+    if ($redis.zcard k) >= indx
+      n = indx - 1
+      if (r = $redis.zrevrange k, n, n, :with_scores => true)
+        $redis.zremrangebyscore k, "-inf", "(#{r.last}"
+      end
+    end
+  end
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