Support two-way traversal in blob feed API #1286
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disperser/dataapi/v2/blobs.go
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| c.JSON(http.StatusOK, response) | ||
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| // TODO(jianxiao): this is just a placeholder as GetBlobMetadataByRequested is doing forward retrieval | ||
| blobs, nextCursor, err := s.blobMetadataStore.GetBlobMetadataByRequestedAt( |
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This one is TBD in followup
disperser/dataapi/v2/server_v2.go
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| @@ -263,7 +263,8 @@ func (s *ServerV2) Start() error { | |||
| { | |||
| blobs := v2.Group("/blobs") | |||
| { | |||
| blobs.GET("/feed", s.FetchBlobFeed) | |||
| blobs.GET("/feed/forward", s.FetchBlobFeedForward) | |||
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Didn't take a deep look into logic but is this simpler than just adding a query param to determine the direction?
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It looks more clear to have separate APIs, but am open to merge them if these params can have clear semantics when they are used for both directions.
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(mostly parameters have to remain clear in semantics in both contexts, e.g. start and end makes sense in forward but not in backward any more)
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thinking it more, maybe using before and after naturally addresses this, like
- direction: string // "forward" or "backward"
- after: string // exclusive lower bound
- before: string // exclusive upper bound
- cursor: string // if present, must be within (after, before)
- limit: int // max items to return
For backward: fetches (after, cursor) in DESC order
For forward: fetches (cursor, before) in ASC order
jianoaix
changed the title
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ping? |
Why are these changes needed?
To make it easy and reliable to traverse the feed backward and forward in time
This PR changes the APIs to support this.
Note: the existing API is forward iteration, so
forwardmode works here already; butbackwardwill need a change in DB layer (in a followup later)Checks