Merge pull request #90 from TileDB-Inc/an/ch59/get_subarray_from_query

Get subarray from query

Author: antalakas

.gitignore

@@ -11,4 +11,5 @@
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
 
-.idea
+.idea
+.vscode

examples/range_test.go

@@ -126,22 +126,16 @@ func addRange() {
 	query, err := tiledb.NewQuery(ctx, array)
 	checkError(err)
 
-	var startFloat float32 = 1
-	var endFloat float32 = 3
-
 	// Try with invalid dimension types
-	err = query.AddRange(0, &startFloat, &endFloat)
+	err = query.AddRange(0, float32(1), float32(3))
 	fmt.Println(err)
 
-	var start int32 = 1
-	var end int32 = 3
-
 	// Try with invalid dimension index
-	err = query.AddRange(2, &start, &end)
+	err = query.AddRange(2, int32(1), int32(3))
 	fmt.Println(err)
 
 	// Try using valid index, range
-	err = query.AddRange(0, &start, &end)
+	err = query.AddRange(0, int32(1), int32(3))
 	checkError(err)
 
 	err = array.Close()

examples/reading_range_test.go

@@ -0,0 +1,197 @@
+/**
+ * @file   rerading_range_test.go
+ *
+ * @section LICENSE
+ *
+ * The MIT License
+ *
+ * @copyright Copyright (c) 2019 TileDB, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @section DESCRIPTION
+ *
+ * This is a part of the TileDB reading_range tutorial:
+ *   https://docs.tiledb.io/en/latest/reading_range.html
+ *
+ * When run, this program will create a simple 2D dense array, write some data
+ * to it, and read a slice of the data back in the layout of the user's choice
+ * (passed as an argument to the program: "row", "col", or "global").
+ *
+ */
+
+package examples
+
+import (
+	"fmt"
+	"os"
+
+	tiledb "github.com/TileDB-Inc/TileDB-Go"
+)
+
+// Name of array.
+var readRangeArrayName = "read_range_array"
+
+func createReadRangeArray() {
+	// Create a TileDB context.
+	ctx, err := tiledb.NewContext(nil)
+	checkError(err)
+
+	// The array will be 4x4 with dimensions "rows" and "cols", with domain [1,4].
+	domain, err := tiledb.NewDomain(ctx)
+	checkError(err)
+	rowDim, err := tiledb.NewDimension(ctx, "rows", []int32{1, 4}, int32(4))
+	checkError(err)
+	colDim, err := tiledb.NewDimension(ctx, "cols", []int32{1, 4}, int32(4))
+	checkError(err)
+	err = domain.AddDimensions(rowDim, colDim)
+	checkError(err)
+
+	// The array will be dense.
+	schema, err := tiledb.NewArraySchema(ctx, tiledb.TILEDB_DENSE)
+	err = schema.SetDomain(domain)
+	checkError(err)
+	err = schema.SetCellOrder(tiledb.TILEDB_ROW_MAJOR)
+	checkError(err)
+	err = schema.SetTileOrder(tiledb.TILEDB_ROW_MAJOR)
+	checkError(err)
+
+	// Add a single attribute "a" so each (i,j) cell can store an integer.
+	a, err := tiledb.NewAttribute(ctx, "a", tiledb.TILEDB_INT32)
+	checkError(err)
+	err = schema.AddAttributes(a)
+	checkError(err)
+
+	// Create the (empty) array on disk.
+	array, err := tiledb.NewArray(ctx, readRangeArrayName)
+	checkError(err)
+	err = array.Create(schema)
+	checkError(err)
+}
+
+func writeRearRangeArray() {
+	ctx, err := tiledb.NewContext(nil)
+	checkError(err)
+
+	// Prepare some data for the array
+	data := []int32{
+		1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
+
+	// Open the array for writing and create the query.
+	array, err := tiledb.NewArray(ctx, readRangeArrayName)
+	checkError(err)
+	err = array.Open(tiledb.TILEDB_WRITE)
+	checkError(err)
+	query, err := tiledb.NewQuery(ctx, array)
+	checkError(err)
+	err = query.SetLayout(tiledb.TILEDB_ROW_MAJOR)
+	checkError(err)
+	_, err = query.SetBuffer("a", data)
+	checkError(err)
+
+	// Perform the write and close the array.
+	err = query.Submit()
+	checkError(err)
+	err = array.Close()
+	checkError(err)
+}
+
+func readReadRangeArray(dimIdx uint32) {
+	ctx, err := tiledb.NewContext(nil)
+	checkError(err)
+
+	// Prepare the array for reading
+	array, err := tiledb.NewArray(ctx, readRangeArrayName)
+	checkError(err)
+	err = array.Open(tiledb.TILEDB_READ)
+	checkError(err)
+
+	// Prepare the vector that will hold the result (of size 6 elements)
+	data := make([]int32, 12)
+
+	// Prepare the query
+	query, err := tiledb.NewQuery(ctx, array)
+	checkError(err)
+
+	err = query.AddRange(dimIdx, int32(1), int32(1))
+	checkError(err)
+	err = query.AddRange(dimIdx, int32(3), int32(4))
+	checkError(err)
+
+	numOfRanges, err := query.GetRangeNum(dimIdx)
+	checkError(err)
+	fmt.Printf("Num of Ranges: %d\n", *numOfRanges)
+
+	var I uint64
+	for I = 0; I < *numOfRanges; I++ {
+		start, end, err := query.GetRange(dimIdx, I)
+		checkError(err)
+		fmt.Printf("Range for dimension: %d, start: %v, end: %v\n", dimIdx, start, end)
+	}
+
+	ranges, err := query.GetRanges()
+	checkError(err)
+
+	fmt.Printf("Ranges: %v\n", ranges)
+
+	_, err = query.SetBuffer("a", data)
+	checkError(err)
+
+	// Submit the query and close the array.
+	err = query.Submit()
+	checkError(err)
+	err = array.Close()
+	checkError(err)
+
+	// Print out the results.
+	fmt.Println(data)
+}
+
+// ExampleReadRangeArray shows and example creation, writing and range reading
+// of a dense array
+func ExampleReadRangeArray() {
+	createReadRangeArray()
+	writeRearRangeArray()
+	// Rows
+	readReadRangeArray(0)
+	// Columns
+	readReadRangeArray(1)
+
+	// Cleanup example so unit tests are clean
+	if _, err := os.Stat(readRangeArrayName); err == nil {
+		err = os.RemoveAll(readRangeArrayName)
+		checkError(err)
+	}
+
+	// Output: Num of Ranges: 2
+	// Range for dimension: 0, start: 1, end: 1
+	// Range for dimension: 0, start: 3, end: 4
+	// Ranges: [[{1 1} {3 4}] [{1 4}]]
+	// [1 2 3 4 9 10 11 12 13 14 15 16]
+	// Num of Ranges: 2
+	// Range for dimension: 1, start: 1, end: 1
+	// Range for dimension: 1, start: 3, end: 4
+	// Ranges: [[{1 4}] [{1 1} {3 4}]]
+	// [1 3 4 5 7 8 9 11 12 13 15 16]
+}
+
+//  1  2  3  4
+//  5  6  7  8
+//  9 10 11 12
+// 13 14 15 16