ARROW-2146: [GLib] Add Slice api to ChunkedArray

c_glib/arrow-glib/chunked-array.cpp

@@ -274,6 +274,26 @@ garrow_chunked_array_get_chunks(GArrowChunkedArray *chunked_array)
   return g_list_reverse(chunks);
 }
 
+/**
+ * garrow_chunked_array_slice:
+ * @chunked_array: A #GArrowChunkedArray.
+ * @offset: The offset of sub #GArrowChunkedArray.
+ * @length: The length of sub #GArrowChunkedArray.
+ *
+ * Returns: (transfer full): The sub #GArrowChunkedArray. It covers only from
+ *   `offset` to `offset + length` range. The sub #GArrowChunkedArray shares
+ *   values with the base #GArrowChunkedArray.
+ */
+GArrowChunkedArray  *
+garrow_chunked_array_slice(GArrowChunkedArray *chunked_array,
+                           guint64 offset,
+                           guint64 length)
+{
+  const auto arrow_chunked_array = garrow_chunked_array_get_raw(chunked_array);
+  auto arrow_sub_chunked_array = arrow_chunked_array->Slice(offset, length);
+  return garrow_chunked_array_new_raw(&arrow_sub_chunked_array);
+}
+
 G_END_DECLS
 
 GArrowChunkedArray *

c_glib/arrow-glib/chunked-array.h

@@ -82,5 +82,8 @@ guint   garrow_chunked_array_get_n_chunks (GArrowChunkedArray *chunked_array);
 GArrowArray *garrow_chunked_array_get_chunk(GArrowChunkedArray *chunked_array,
                                             guint i);
 GList *garrow_chunked_array_get_chunks(GArrowChunkedArray *chunked_array);
+GArrowChunkedArray *garrow_chunked_array_slice(GArrowChunkedArray *chunked_array,
+                                               guint64 offset,
+                                               guint64 length);
 
 G_END_DECLS

c_glib/test/test-chunked-array.rb

@@ -95,4 +95,18 @@ def test_chunks
     assert_equal([2, 1],
                  chunked_array.chunks.collect(&:length))
   end
+
+  def test_slice
+    chunks1 = [
+      build_boolean_array([true, false, true]),
+      build_boolean_array([false, true]),
+    ]
+    chunks2 = [
+      build_boolean_array([false, true]),
+      build_boolean_array([false]),
+    ]
+    chunked_array = Arrow::ChunkedArray.new(chunks1)
+    sub_chunked_array = chunked_array.slice(1, 3)
+    assert_equal(chunks2, sub_chunked_array.chunks)
+  end
 end