osmsharp / tiled-db Goto Github PK

Not all tiles change, add a method returning in what db the latest version of a tile is located relative to the current database.

https://github.com/xoofx/zio/blob/master/readme.md

Implement indexer based just on tiles alone.

The read-me mentions a nuget package and suggests running Install-Package OsmSharp.Db.Tiled which fails. Nuget.org doesn't show anything for "OsmSharp.Db.Tiled" and there are no packages listed here on the github project.

Where can I find the nuget package?

Now we convert from and to (x,y) <-> (localid) all the time, we should use uint ids internally and only convert them when they become public.

Diff encode tile ids in tiled streams, there can be a lot and they are usually close together.

Implement diffs that only store changes. For example if a node position doesn't change we don't store the lat/lon again. The same for its tags or a relation's members or a node's ways.

• Node:
  • Tags
  • Lat/Lon
• Way:
  • Nodes
  • Tags.
• Relation:
  • Members
  • Tags.

Reasoning:

In a lot of cases only tags will change or only positions. When splitting a way only the nodes set changes. This will reduce diskspace used for a diff even further.

Postprocess the tile stream to reduce its size:

• Diff encode pointers with a 1 off to indicate last elements.
• Use VarUInt64 to store pointers.
• Store pointers after the actual objects: When we move to a next object we are always reading the objects but sometimes we need to read objects without needing pointers.

Implement compressed tiling. Tiles are too big for now.