Add a SourceName field into RasterSources (#224)

* Introduce name for virtual RasterSources that doesn't have a path to the file
* Refactor Metadata and make it lazy

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Expose GDAL Metadata API, expose RasterSources Metadata API 
 - LayoutTileSource[K] implementation
+- Add Named RasterSources
 
 ## [3.17.0] - 2019-07-23
 

gdal/src/main/scala/geotrellis/contrib/vlm/gdal/GDALMetadata.scala

@@ -16,15 +16,20 @@
 
 package geotrellis.contrib.vlm.gdal
 
-import geotrellis.contrib.vlm.{RasterMetadata, RasterSourceMetadata}
-import geotrellis.contrib.vlm.effect.RasterSourceF
+import geotrellis.contrib.vlm.{RasterMetadata, SourceName}
+import geotrellis.contrib.vlm.effect.RasterMetadataF
 import geotrellis.proj4.CRS
 import geotrellis.raster.{CellType, GridExtent}
 
 import cats.Monad
+import cats.instances.list._
+import cats.syntax.functor._
+import cats.syntax.flatMap._
+import cats.syntax.traverse._
 import cats.syntax.apply._
 
 case class GDALMetadata(
+  name: SourceName,
   crs: CRS,
   bandCount: Int,
   cellType: CellType,
@@ -34,38 +39,63 @@ case class GDALMetadata(
   baseMetadata: Map[GDALMetadataDomain, Map[String, String]] = Map.empty,
   /** GDAL per band per domain metadata */
   bandsMetadata: List[Map[GDALMetadataDomain, Map[String, String]]] = Nil
-) extends RasterSourceMetadata {
+) extends RasterMetadata {
   /** Returns the GDAL metadata merged into a single metadata domain. */
   def attributes: Map[String, String] = baseMetadata.flatMap(_._2)
   /** Returns the GDAL per band metadata merged into a single metadata domain. */
   def attributesForBand(band: Int): Map[String, String] = bandsMetadata.map(_.flatMap(_._2)).lift(band).getOrElse(Map.empty)
 }
 
 object GDALMetadata {
-  def apply(rasterSource: RasterMetadata, dataset: GDALDataset, domains: List[GDALMetadataDomain]): GDALMetadata = {
+  def apply(rasterMetadata: RasterMetadata, dataset: GDALDataset, domains: List[GDALMetadataDomain]): GDALMetadata =
     domains match {
       case Nil =>
-        GDALMetadata(rasterSource.crs, rasterSource.bandCount, rasterSource.cellType, rasterSource.gridExtent, rasterSource.resolutions)
+        GDALMetadata(rasterMetadata.name, rasterMetadata.crs, rasterMetadata.bandCount, rasterMetadata.cellType, rasterMetadata.gridExtent, rasterMetadata.resolutions)
       case _ =>
         GDALMetadata(
-          rasterSource.crs, rasterSource.bandCount, rasterSource.cellType, rasterSource.gridExtent, rasterSource.resolutions,
+          rasterMetadata.name, rasterMetadata.crs, rasterMetadata.bandCount, rasterMetadata.cellType, rasterMetadata.gridExtent, rasterMetadata.resolutions,
           dataset.getMetadata(GDALDataset.SOURCE, domains, 0),
           (1 until dataset.bandCount).toList.map(dataset.getMetadata(GDALDataset.SOURCE, domains, _))
         )
     }
-  }
 
-  def apply(rasterSource: RasterMetadata, dataset: GDALDataset): GDALMetadata = {
+  def apply(rasterMetadata: RasterMetadata, dataset: GDALDataset): GDALMetadata =
     GDALMetadata(
-      rasterSource.crs, rasterSource.bandCount, rasterSource.cellType, rasterSource.gridExtent, rasterSource.resolutions,
+      rasterMetadata.name, rasterMetadata.crs, rasterMetadata.bandCount, rasterMetadata.cellType, rasterMetadata.gridExtent, rasterMetadata.resolutions,
       dataset.getAllMetadata(GDALDataset.SOURCE, 0),
       (1 until dataset.bandCount).toList.map(dataset.getAllMetadata(GDALDataset.SOURCE, _))
     )
-  }
 
-  def apply[F[_] : Monad](rasterSource: RasterSourceF[F], dataset: F[GDALDataset], domains: List[GDALMetadataDomain]): F[GDALMetadata] =
-    (rasterSource: F[RasterMetadata], dataset).mapN(GDALMetadata.apply(_, _, domains))
+  def apply[F[_] : Monad](rasterMetadata: RasterMetadataF[F], dataset: F[GDALDataset], domains: List[GDALMetadataDomain]): F[GDALMetadata] =
+    domains match {
+      case Nil =>
+        (Monad[F].pure(rasterMetadata.name), rasterMetadata.crs, rasterMetadata.bandCount, rasterMetadata.cellType, rasterMetadata.gridExtent, rasterMetadata.resolutions).mapN(GDALMetadata(_, _, _, _, _, _))
+      case _ =>
+        (Monad[F].pure(rasterMetadata.name),
+          rasterMetadata.crs,
+          rasterMetadata.bandCount,
+          rasterMetadata.cellType,
+          rasterMetadata.gridExtent,
+          rasterMetadata.resolutions,
+          dataset.map(_.getAllMetadata(GDALDataset.SOURCE, 0)),
+          dataset >>= { ds =>
+            (1 until ds.bandCount).toList.traverse { list =>
+              dataset.map(_.getMetadata(GDALDataset.SOURCE, domains, list))
+            }
+          }).mapN(apply)
+    }
 
-  def apply[F[_] : Monad](rasterSource: RasterSourceF[F], dataset: F[GDALDataset]): F[GDALMetadata] =
-    (rasterSource: F[RasterMetadata], dataset).mapN(GDALMetadata.apply)
+  def apply[F[_] : Monad](rasterMetadata: RasterMetadataF[F], dataset: F[GDALDataset]): F[GDALMetadata] =
+    (Monad[F].pure(rasterMetadata.name),
+     rasterMetadata.crs,
+     rasterMetadata.bandCount,
+     rasterMetadata.cellType,
+     rasterMetadata.gridExtent,
+     rasterMetadata.resolutions,
+     dataset.map(_.getAllMetadata(GDALDataset.SOURCE, 0)),
+     dataset >>= { ds =>
+       (1 until ds.bandCount).toList.traverse { list =>
+         dataset.map(_.getAllMetadata(GDALDataset.SOURCE, list))
+       }
+     }).mapN(apply)
 }

gdal/src/main/scala/geotrellis/contrib/vlm/gdal/GDALDataPath.scala → gdal/src/main/scala/geotrellis/contrib/vlm/gdal/GDALPath.scala

@@ -16,7 +16,7 @@
 
 package geotrellis.contrib.vlm.gdal
 
-import geotrellis.contrib.vlm.DataPath
+import geotrellis.contrib.vlm.SourcePath
 
 import cats.syntax.option._
 import io.lemonlabs.uri._
@@ -26,7 +26,7 @@ import java.net.MalformedURLException
 
 /** Represents and formats a path that points to a files to be read by GDAL.
  *
- *  @param path Path to the file. This path can be formatted in the following
+ *  @param value Path to the file. This path can be formatted in the following
  *    styles: `VSI`, `URI`, or relative path if the file is local. In addition,
  *    this path can be prefixed with, '''gdal+''' to signify that the target GeoTiff
  *    is to be read in only by [[GDALRasterSource]].
@@ -39,18 +39,18 @@ import java.net.MalformedURLException
  *
  *  @example "zip+s3://bucket/prefix/zipped-data.zip!data.tif"
  */
-case class GDALDataPath(path: String) extends DataPath
+case class GDALPath(value: String) extends SourcePath
 
-object GDALDataPath {
+object GDALPath {
   val PREFIX = "gdal+"
 
-  implicit def toGDALDataPath(path: String): GDALDataPath = GDALDataPath.parse(path)
+  implicit def toGDALDataPath(path: String): GDALPath = GDALPath.parse(path)
 
   def parseOption(
     path: String,
     compressedFileDelimiter: Option[String] = "!".some,
     percentEncoder: PercentEncoder = PercentEncoder(PATH_CHARS_TO_ENCODE ++ Set('%', '?', '#'))
-  ): Option[GDALDataPath] = {
+  ): Option[GDALPath] = {
     import Schemes._
 
     // Trying to read something locally on Windows matters
@@ -108,14 +108,14 @@ object GDALDataPath {
             }
           }
 
-    vsiPath.map(GDALDataPath(_))
+    vsiPath.map(GDALPath(_))
   }
 
   def parse(
     path: String,
     compressedFileDelimiter: Option[String] = "!".some,
     percentEncoder: PercentEncoder = PercentEncoder(PATH_CHARS_TO_ENCODE ++ Set('%', '?', '#'))
-  ): GDALDataPath =
+  ): GDALPath =
     parseOption(path, compressedFileDelimiter, percentEncoder)
       .getOrElse(throw new MalformedURLException(s"Unable to parse GDALDataPath: $path"))
 }

gdal/src/main/scala/geotrellis/contrib/vlm/gdal/GDALRasterSource.scala

@@ -26,7 +26,7 @@ import geotrellis.raster.resample.{NearestNeighbor, ResampleMethod}
 import geotrellis.vector._
 
 case class GDALRasterSource(
-  dataPath: GDALDataPath,
+  dataPath: GDALPath,
   options: GDALWarpOptions = GDALWarpOptions.EMPTY,
   private[vlm] val targetCellType: Option[TargetCellType] = None
 ) extends RasterSource {
@@ -45,7 +45,8 @@ case class GDALRasterSource(
     *
     */
 
-  val path: String = dataPath.path
+  def name: GDALPath = dataPath
+  val path: String = dataPath.value
 
   lazy val datasetType: DatasetType = options.datasetType
 
@@ -59,6 +60,17 @@ case class GDALRasterSource(
     */
   lazy val metadata: GDALMetadata = GDALMetadata(this, dataset, DefaultDomain :: Nil)
 
+  /**
+    * Return the "base" metadata, usually it is a zero band metadata,
+    * a metadata that is valid for the entire source and for the zero band
+    */
+  def attributes: Map[String, String] = metadata.attributes
+
+  /**
+    * Return a per band metadata
+    */
+  def attributesForBand(band: Int): Map[String, String] = metadata.attributesForBand(band)
+
   /**
     * Fetches a metadata from the specified [[GDALMetadataDomain]] list.
     */

gdal/src/main/scala/geotrellis/contrib/vlm/gdal/GDALRasterSourceProvider.scala

@@ -17,12 +17,12 @@
 package geotrellis.contrib.vlm.gdal
 
 import geotrellis.contrib.vlm.RasterSourceProvider
-import geotrellis.contrib.vlm.avro.GeoTrellisDataPath
-import geotrellis.contrib.vlm.geotiff.GeoTiffDataPath
+import geotrellis.contrib.vlm.avro.GeoTrellisPath
+import geotrellis.contrib.vlm.geotiff.GeoTiffPath
 
 class GDALRasterSourceProvider extends RasterSourceProvider {
   def canProcess(path: String): Boolean =
-    (!path.startsWith(GeoTiffDataPath.PREFIX) && !path.startsWith(GeoTrellisDataPath.PREFIX)) && GDALDataPath.parseOption(path).nonEmpty && path.nonEmpty
+    (!path.startsWith(GeoTiffPath.PREFIX) && !path.startsWith(GeoTrellisPath.PREFIX)) && GDALPath.parseOption(path).nonEmpty && path.nonEmpty
 
   def rasterSource(path: String): GDALRasterSource = GDALRasterSource(path)
 }

gdal/src/main/scala/geotrellis/contrib/vlm/gdal/effect/GDALRasterSource.scala

@@ -17,7 +17,7 @@
 package geotrellis.contrib.vlm.gdal.effect
 
 import geotrellis.contrib.vlm._
-import geotrellis.contrib.vlm.gdal.{DefaultDomain, GDALDataPath, GDALDataset, GDALMetadata, GDALMetadataDomain, GDALWarpOptions}
+import geotrellis.contrib.vlm.gdal.{DefaultDomain, GDALPath, GDALDataset, GDALMetadata, GDALMetadataDomain, GDALWarpOptions}
 import geotrellis.contrib.vlm.gdal.GDALDataset.DatasetType
 import geotrellis.contrib.vlm.effect._
 import geotrellis.contrib.vlm.effect.geotiff.UnsafeLift
@@ -34,11 +34,12 @@ import cats.syntax.apply._
 import cats.syntax.functor._
 
 case class GDALRasterSource[F[_]: Monad: UnsafeLift](
-  dataPath: GDALDataPath,
+  dataPath: GDALPath,
   options: F[GDALWarpOptions] = GDALWarpOptions.EMPTY,
   private[vlm] val targetCellType: Option[TargetCellType] = None
 ) extends RasterSourceF[F] {
-  val path: String = dataPath.path
+  def name: GDALPath = dataPath
+  val path: String = dataPath.value
 
   lazy val datasetType: F[DatasetType] = options.map(_.datasetType)
 
@@ -76,6 +77,17 @@ case class GDALRasterSource[F[_]: Monad: UnsafeLift](
     */
   lazy val metadata: F[GDALMetadata] = GDALMetadata(this, datasetF, DefaultDomain :: Nil)
 
+  /**
+    * Return the "base" metadata, usually it is a zero band metadata,
+    * a metadata that is valid for the entire source and for the zero band
+    */
+  def attributes: F[Map[String, String]] = metadata.map(_.attributes)
+
+  /**
+    * Return a per band metadata
+    */
+  def attributesForBand(band: Int): F[Map[String, String]] = metadata.map(_.attributesForBand(band))
+
   /**
     * Fetches a metadata from the specified [[GDALMetadataDomain]] list.
     */