| | 43 | === Data Exchange == |
| | 44 | |
| | 45 | First it must be determinate what data structures should be exchanged between server and client applications (this proposal is thrift specific): |
| | 46 | |
| | 47 | * Strings, integer, double and boolean types as argument for functions and return values |
| | 48 | * Map metadata (raster, vector, voxel), region information, projection information as specific thrift structures using strings internally |
| | 49 | * Time stamps as specific thrift structure using integers, strings and double types |
| | 50 | * Raster data (single row and whole map) as byte array (RGB map), integer array (CELL type), double array (FCELL and DCELL) |
| | 51 | * Vector data (single line/feature) as specific thrift structure with metadata (line type, ...), integer array for line_cats and double array for line_points |
| | 52 | * Several vector lines as ordered list using the specific thrift structure |
| | 53 | * Vector data (single line/feature) as well known binary format stored in a binary array |
| | 54 | * Vector data (whole map) as well known binary format (wkb) stored in a binary array |
| | 55 | * Voxel data (single value, tile and whole map) as byte array (RGB map) and double array (FCELL and DCELL) |
| | 56 | * A hash table (map) structure with internal string, integer and double arrays that represent single columns of a database table |
| | 57 | |
| | 58 | == Higher level API == |
| | 59 | |
| | 60 | The server process should be able to keep maps open in read only mode, to allow fast access to raster and vector data for analysis. Maps are identified by their name@mapset id, hence a hash table will be used to store the file descriptors and map structures in the server process. Hence open and close map functions must be provided by the RPC interface. |
| | 61 | |
| | 62 | A single vector map should be kept open in editing mode for vector editing purposes. |
| | 63 | |
| | 64 | Proposed higher level functions: |
| | 65 | * Read a whole raster map as RGB array, integer array or double array using a specific extent and resolution informations |
| | 66 | * Read a whole vector map as wkb |
| | 67 | * Read a portion or a whole vector map attribute table |
| | 68 | * Get all metadata for vector, raster and voxel maps (spatio-temporal extent, resolution, ...) using a single function call |
| | 69 | * Call a GRASS module, using the server process specific location/mapset and region settings |
| | 70 | * List all available maps (raster, vector and voxel) |
| | 71 | |
| | 72 | |
