This is a simple project that defines a proposed API for working with space-filling curves (and their attendant utility classes) for the purposes of multi-dimensional indexing in NoSQL data stores.
For an example of an existing space-filling curve library, please see LocationTech's SFCurve project on GitHub. (Full disclosure: I'm a committer on that project, and hope that parts of this API may some day be useful to SFCurve.)
| area | API | example implementation | notes |
|---|---|---|---|
| discretizer | Yes | Yes | translates between user space and index space |
| field range | Yes | Yes | a contiguous subset of an ordered field |
| space | Yes | Yes | a collection of one or more field ranges that together define a sub-space |
| dimension | Kinda' | No | needs to include more metadata? standard type information? |
| curve | Yes | Yes | keep this lossless, operating strictly within index-space; helpers can be used to translate to/from user space |
| query | No | No | this needs to include not only routines for correctness, but for short-circuiting to be faster at the cost of more false positives |
- The issue of floating-point precision for discretization and bin ranges needs to be reconsidered. Having assumed that the end-points are calculated without error will turn out to be a Bad Idea.