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63 lines
1.5 KiB
Markdown
63 lines
1.5 KiB
Markdown
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# Common thrift types
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GFS uses several thrift datastructures which are common to multiple queries. They are listed below.
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## EdgeType
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`EdgeType` is a thrift enum which specifies which edge types to query for the graph.
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```thrift
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enum EdgeType {
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FOLLOWING,
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FOLLOWED_BY,
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FAVORITE,
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FAVORITED_BY,
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RETWEET,
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RETWEETED_BY,
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REPLY,
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REPLYED_BY,
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MENTION,
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MENTIONED_BY,
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MUTUAL_FOLLOW,
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SIMILAR_TO, // more edge types (like block, report, etc.) can be supported later.
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RESERVED_12,
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RESERVED_13,
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RESERVED_14,
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RESERVED_15,
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RESERVED_16,
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RESERVED_17,
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RESERVED_18,
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RESERVED_19,
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RESERVED_20
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}
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```
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For an example of how this is used, consider the `GetNeighbors` query. If we set the `edgeType` field
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of the `GfsNeighborsRequest`, the response will contain all the users that the specified user follows.
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If, on the other hand, we set `edgeType` to be `FollowedBy` it will return all the users who are
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followed by the specified user.
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## FeatureType
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`FeatureType` is a thrift struct which is used in queries which require two edge types.
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```thrift
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struct FeatureType {
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1: required EdgeType leftEdgeType // edge type from source user
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2: required EdgeType rightEdgeType // edge type from candidate user
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}(persisted="true")
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```
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## UserWithScore
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The candidate generation queries return lists of candidates together with a computed score for the
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relevant feature. `UserWithScore` is a thrift struct which bundles together a candidate's ID with
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the score.
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```thrift
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struct UserWithScore {
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1: required i64 userId
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2: required double score
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}
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```
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