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http://arclanguage.com/install http://arclanguage.com/install contains the source code less some of the secret bits and bytes.

by cd34 15y ago

jgannonjr 15y ago
Thanks for the link. I by no means have any experience reading lisp, not to mention there is a lot of code here to sort through (especially for someone not versed in lisp), but from what I can make out from a quick glance seems to confirm my initial guess. It looks like rank is calculated when an item is voted on. Also, it looks like a random front page story is reranked regularly to ensure no items get "stuck" at the top if voting stops (rerank-random). There's also a function (gen-topstories) to generate the rankings for the top 1000 stories, although I can't tell if this is being run regularly (it looks like it is just used to initialize the rankings). However, I could definitely be wrong. I'm not able to determine how often the rerank-random function is called (looks like every 30ms maybe?) or how often the gen-topstories function is called (if it is even being called regularly or not). Can you verify what I'm saying here is correct, or correct me if I'm wrong? Also, any insight would be much appreciated.
- cd34 15y ago
  It has been a while since I looked - the one thing I wanted to fix was the expired link issue. It is rare that I can get past page 2 of the /newest listings before getting the Expired link notification, so, I probably miss quite a few submissions. Basically, the link code that you see is a closure that contains the results for your particular view of the articles. In that snapshot in time, your list remains 'constant' until you refresh it with a few to /newest or / allowing pagination to work consistently as you move through the list. When you get the expired link notification, it means that your closure has been removed due to GC or a server restart. Each time a story is voted on, the global pool is updated, but, until your closure is recreated, you would not see the effect of the vote. Therefore, the shuffling you would see when you or others upvote a story that might change pagination won't affect you. I believe the top 1000 is separate from the normal operation of the site and is run 'at some interval'. I don't recall, but I don't think it is recalculated frequently. Ranking is a function of vote velocity over time. A story that gets a rapid number of upvotes will get pushed up higher than one that has a lot of upvotes, but was submitted hours ago. i.e. 100 votes in the last 20 minutes will be pushed above 140 upvotes in the last 60 minutes. I'm in the middle of some code, but, if I get a chance this weekend, I'll take a look. My lisp is rusty - haven't used it since the late 80s.

http://arclanguage.com/install http://arclanguage.com/install contains the source code less some of the secret bits and bytes.

by cd34 15y ago

http://arclanguage.com/install http://arclanguage.com/install contains the source code less some of the secret bits and bytes.

jgannonjr 15y ago

Thanks for the link. I by no means have any experience reading lisp, not to mention there is a lot of code here to sort through (especially for someone not versed in lisp), but from what I can make out from a quick glance seems to confirm my initial guess. It looks like rank is calculated when an item is voted on. Also, it looks like a random front page story is reranked regularly to ensure no items get "stuck" at the top if voting stops (rerank-random). There's also a function (gen-topstories) to generate the rankings for the top 1000 stories, although I can't tell if this is being run regularly (it looks like it is just used to initialize the rankings). However, I could definitely be wrong. I'm not able to determine how often the rerank-random function is called (looks like every 30ms maybe?) or how often the gen-topstories function is called (if it is even being called regularly or not). Can you verify what I'm saying here is correct, or correct me if I'm wrong? Also, any insight would be much appreciated.

cd34 15y ago
It has been a while since I looked - the one thing I wanted to fix was the expired link issue. It is rare that I can get past page 2 of the /newest listings before getting the Expired link notification, so, I probably miss quite a few submissions. Basically, the link code that you see is a closure that contains the results for your particular view of the articles. In that snapshot in time, your list remains 'constant' until you refresh it with a few to /newest or / allowing pagination to work consistently as you move through the list. When you get the expired link notification, it means that your closure has been removed due to GC or a server restart. Each time a story is voted on, the global pool is updated, but, until your closure is recreated, you would not see the effect of the vote. Therefore, the shuffling you would see when you or others upvote a story that might change pagination won't affect you. I believe the top 1000 is separate from the normal operation of the site and is run 'at some interval'. I don't recall, but I don't think it is recalculated frequently. Ranking is a function of vote velocity over time. A story that gets a rapid number of upvotes will get pushed up higher than one that has a lot of upvotes, but was submitted hours ago. i.e. 100 votes in the last 20 minutes will be pushed above 140 upvotes in the last 60 minutes. I'm in the middle of some code, but, if I get a chance this weekend, I'll take a look. My lisp is rusty - haven't used it since the late 80s.