grib2: Support for General Unstructured Grid (template 101)

cdm/core/src/main/java/ucar/nc2/NetcdfFile.java

@@ -631,15 +631,15 @@ private static String makeUncompressed(String filename) throws IOException {
 
       try {
         if (suffix.equalsIgnoreCase("Z")) {
-          try (InputStream in = new UncompressInputStream(new FileInputStream(filename))) {
+          try (InputStream in = new UncompressInputStream(new BufferedInputStream(new FileInputStream(filename)))) {
             copy(in, fout, 100000);
           }
           if (debugCompress)
             log.info("uncompressed {} to {}", filename, uncompressedFile);
 
         } else if (suffix.equalsIgnoreCase("zip")) {
 
-          try (ZipInputStream zin = new ZipInputStream(new FileInputStream(filename))) {
+          try (ZipInputStream zin = new ZipInputStream(new BufferedInputStream(new FileInputStream(filename)))) {
             ZipEntry ze = zin.getNextEntry();
             if (ze != null) {
               copy(zin, fout, 100000);
@@ -649,15 +649,15 @@ private static String makeUncompressed(String filename) throws IOException {
           }
 
         } else if (suffix.equalsIgnoreCase("bz2")) {
-          try (InputStream in = new CBZip2InputStream(new FileInputStream(filename), true)) {
+          try (InputStream in = new CBZip2InputStream(new BufferedInputStream(new FileInputStream(filename)), true)) {
             copy(in, fout, 100000);
           }
           if (debugCompress)
             log.info("unbzipped {} to {}", filename, uncompressedFile);
 
         } else if (suffix.equalsIgnoreCase("gzip") || suffix.equalsIgnoreCase("gz")) {
 
-          try (InputStream in = new GZIPInputStream(new FileInputStream(filename))) {
+          try (InputStream in = new GZIPInputStream(new BufferedInputStream(new FileInputStream(filename)))) {
             copy(in, fout, 100000);
           }
 

cdm/core/src/main/java/ucar/nc2/NetcdfFiles.java

@@ -575,7 +575,7 @@ private static String makeUncompressed(String filename) throws Exception {
       try {
         if (suffix.equalsIgnoreCase("Z")) {
           // Z file can only contain one file - copy the whole thing
-          try (InputStream in = new UncompressInputStream(new FileInputStream(baseFilename))) {
+          try (InputStream in = new UncompressInputStream(new BufferedInputStream(new FileInputStream(baseFilename)))) {
             copy(in, fout, 100000);
           }
           if (NetcdfFile.debugCompress) {
@@ -584,7 +584,7 @@ private static String makeUncompressed(String filename) throws Exception {
 
         } else if (suffix.equalsIgnoreCase("zip")) {
           // find specified zip entry, if it exists
-          try (ZipInputStream zin = new ZipInputStream(new FileInputStream(baseFilename))) {
+          try (ZipInputStream zin = new ZipInputStream(new BufferedInputStream(new FileInputStream(baseFilename)))) {
             // If a desired zipentry ID was appended to method's filename parameter, then itempath
             // is of length > 1 and ID starts at itempath char offset 1.
             String itemName = (itempath.length() > 1) ? itempath.substring(1) : "";
@@ -606,15 +606,16 @@ private static String makeUncompressed(String filename) throws Exception {
 
         } else if (suffix.equalsIgnoreCase("bz2")) {
           // bz2 can only contain one file - copy the whole thing
-          try (InputStream in = new CBZip2InputStream(new FileInputStream(baseFilename), true)) {
+          try (InputStream in =
+              new CBZip2InputStream(new BufferedInputStream(new FileInputStream(baseFilename)), true)) {
             copy(in, fout, 100000);
           }
           if (NetcdfFile.debugCompress)
             log.info("unbzipped {} to {}", filename, uncompressedFile);
 
         } else if (suffix.equalsIgnoreCase("gzip") || suffix.equalsIgnoreCase("gz")) {
           // gzip/gz concatenates streams - copy the whole thing
-          try (InputStream in = new GZIPInputStream(new FileInputStream(baseFilename))) {
+          try (InputStream in = new GZIPInputStream(new BufferedInputStream(new FileInputStream(baseFilename)))) {
             copy(in, fout, 100000);
           }
 

cdm/core/src/main/java/ucar/unidata/geoloc/projection/UnstructuredProjection.java

@@ -0,0 +1,99 @@
+package ucar.unidata.geoloc.projection;
+
+import ucar.unidata.geoloc.*;
+
+import java.util.Objects;
+
+/**
+ * A dummy ProjectionImpl subclass for unstructured grids.
+ * Since unstructured grids do not follow a single mathematical projection,
+ * this class does not implement real forward/inverse transformations.
+ * Instead, it serves as a placeholder so netCDF-Java can represent the
+ * grid in a coordinate system, while actual lat/lon positions are handled
+ * separately (e.g., by per-cell coordinate arrays).
+ */
+public class UnstructuredProjection extends ProjectionImpl {
+
+  public static final String EARTH_SHAPE = "earth_shape";
+  public static final String NUMBER_OF_GRID_USED = "number_of_grid_used";
+  public static final String NUMBER_OF_GRID_IN_REFERENCE = "number_of_grid_in_reference";
+  public static final String UUID = "uuid";
+
+  int earthShape, numberOfGridUsed, numberOfGridInReference;
+  String uuid;
+
+  /**
+   * Create a new UnstructuredProjection with a given name.
+   */
+  public UnstructuredProjection(int earthShape, int numberOfGridUsed, int numberOfGridInReference, String uuid) {
+    super("UnstructuredProjection", false); // false => not lat/lon
+
+    this.earthShape = earthShape;
+    this.numberOfGridUsed = numberOfGridUsed;
+    this.numberOfGridInReference = numberOfGridInReference;
+    this.uuid = uuid;
+
+    addParameter(EARTH_SHAPE, earthShape);
+    addParameter(NUMBER_OF_GRID_USED, numberOfGridUsed);
+    addParameter(NUMBER_OF_GRID_IN_REFERENCE, numberOfGridInReference);
+    addParameter(UUID, uuid);
+  }
+
+  /**
+   * Copy constructor for UnstructuredProjection.
+   */
+  private UnstructuredProjection(UnstructuredProjection that) {
+    this(that.earthShape, that.numberOfGridUsed, that.numberOfGridInReference, that.uuid);
+  }
+
+  @Override
+  public ProjectionImpl constructCopy() {
+    // Return a new instance with the same name, etc.
+    return new UnstructuredProjection(this);
+  }
+
+  /**
+   * Since we do not have a formula for an unstructured grid,
+   * throw an exception if someone tries to do forward transform.
+   */
+  @Override
+  public ProjectionPoint latLonToProj(LatLonPoint latlon, ProjectionPointImpl dest) {
+    throw new UnsupportedOperationException("UnstructuredProjection: no formula-based transform available");
+  }
+
+  /**
+   * Similarly, inverse transform is not defined for unstructured grids.
+   */
+  @Override
+  public LatLonPoint projToLatLon(ProjectionPoint world, LatLonPointImpl dest) {
+    throw new UnsupportedOperationException("UnstructuredProjection: no formula-based transform available");
+  }
+
+  /**
+   * For unstructured grids, the notion of crossing a seam is irrelevant,
+   * so we return false (or you could throw an exception).
+   */
+  @Override
+  public boolean crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) {
+    return false;
+  }
+
+  @Override
+  public String paramsToString() {
+    return "UnstructuredProjection: no transform parameters";
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (!(o instanceof UnstructuredProjection))
+      return false;
+    UnstructuredProjection that = (UnstructuredProjection) o;
+    return earthShape == that.earthShape && numberOfGridUsed == that.numberOfGridUsed
+        && numberOfGridInReference == that.numberOfGridInReference && Objects.equals(uuid, that.uuid);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(earthShape, numberOfGridUsed, numberOfGridInReference, uuid);
+  }
+}