ARROW-3319: [GLib] Add align() to GArrowInputStream and GArrowOutputS…

…tream

Author: Kouhei Sutou <[email protected]>

Closes apache#2626 from kou/glib-add-align-to-stream and squashes the following commits:

9bc5d0b <Kouhei Sutou> Fix wrong method call
73f3476 <Kouhei Sutou>  Add align() to GArrowInputStream and GArrowOutputStream

c_glib/arrow-glib/input-stream.cpp

@@ -177,6 +177,47 @@ garrow_input_stream_class_init(GArrowInputStreamClass *klass)
   g_object_class_install_property(gobject_class, PROP_INPUT_STREAM, spec);
 }
 
+/**
+ * garrow_input_stream_advance:
+ * @input_stream: A #GArrowInputStream.
+ * @n_bytes: The number of bytes to be advanced.
+ * @error: (nullable): Return location for a #GError or %NULL.
+ *
+ * Returns: %TRUE on success, %FALSE on error.
+ *
+ * Since: 0.11.0
+ */
+gboolean
+garrow_input_stream_advance(GArrowInputStream *input_stream,
+                            gint64 n_bytes,
+                            GError **error)
+{
+  auto arrow_input_stream = garrow_input_stream_get_raw(input_stream);
+  auto status = arrow_input_stream->Advance(n_bytes);
+  return garrow_error_check(error, status, "[input-stream][advance]");
+}
+
+/**
+ * garrow_input_stream_align:
+ * @input_stream: A #GArrowInputStream.
+ * @alignment: The byte multiple for the metadata prefix, usually 8
+ *   or 64, to ensure the body starts on a multiple of that alignment.
+ * @error: (nullable): Return location for a #GError or %NULL.
+ *
+ * Returns: %TRUE on success, %FALSE on error.
+ *
+ * Since: 0.11.0
+ */
+gboolean
+garrow_input_stream_align(GArrowInputStream *input_stream,
+                          gint32 alignment,
+                          GError **error)
+{
+  auto arrow_input_stream = garrow_input_stream_get_raw(input_stream);
+  auto status = arrow::ipc::AlignStream(arrow_input_stream.get(),
+                                        alignment);
+  return garrow_error_check(error, status, "[input-stream][align]");
+}
 
 /**
  * garrow_input_stream_read_tensor:
@@ -204,6 +245,7 @@ garrow_input_stream_read_tensor(GArrowInputStream *input_stream,
   }
 }
 
+
 G_DEFINE_TYPE(GArrowSeekableInputStream,                \
               garrow_seekable_input_stream,             \
               GARROW_TYPE_INPUT_STREAM);

c_glib/arrow-glib/input-stream.h

@@ -37,6 +37,12 @@ struct _GArrowInputStreamClass
   GObjectClass parent_class;
 };
 
+gboolean garrow_input_stream_advance(GArrowInputStream *input_stream,
+                                     gint64 n_bytes,
+                                     GError **error);
+gboolean garrow_input_stream_align(GArrowInputStream *input_stream,
+                                   gint32 alignment,
+                                   GError **error);
 GArrowTensor *garrow_input_stream_read_tensor(GArrowInputStream *input_stream,
                                               GError **error);
 

c_glib/arrow-glib/output-stream.cpp

@@ -175,6 +175,27 @@ garrow_output_stream_class_init(GArrowOutputStreamClass *klass)
   g_object_class_install_property(gobject_class, PROP_OUTPUT_STREAM, spec);
 }
 
+/**
+ * garrow_output_stream_align:
+ * @stream: A #GArrowWritable.
+ * @alignment: The byte multiple for the metadata prefix, usually 8
+ *   or 64, to ensure the body starts on a multiple of that alignment.
+ * @error: (nullable): Return location for a #GError or %NULL.
+ *
+ * Returns: %TRUE on success, %FALSE on error.
+ *
+ * Since: 0.11.0
+ */
+gboolean
+garrow_output_stream_align(GArrowOutputStream *stream,
+                           gint32 alignment,
+                           GError **error)
+{
+  auto arrow_stream = garrow_output_stream_get_raw(stream);
+  auto status = arrow::ipc::AlignStream(arrow_stream.get(), alignment);
+  return garrow_error_check(error, status, "[output-stream][align]");
+}
+
 /**
  * garrow_output_stream_write_tensor:
  * @stream: A #GArrowWritable.

c_glib/arrow-glib/output-stream.h

@@ -37,6 +37,9 @@ struct _GArrowOutputStreamClass
   GObjectClass parent_class;
 };
 
+gboolean garrow_output_stream_align(GArrowOutputStream *stream,
+                                    gint32 alignment,
+                                    GError **error);
 gint64 garrow_output_stream_write_tensor(GArrowOutputStream *stream,
                                          GArrowTensor *tensor,
                                          GError **error);

c_glib/test/test-buffer-input-stream.rb

@@ -22,4 +22,21 @@ def test_read
     read_buffer = buffer_input_stream.read(5)
     assert_equal("Hello", read_buffer.data.to_s)
   end
+
+  def test_advance
+    buffer = Arrow::Buffer.new("Hello World")
+    buffer_input_stream = Arrow::BufferInputStream.new(buffer)
+    buffer_input_stream.advance(6)
+    read_buffer = buffer_input_stream.read(5)
+    assert_equal("World", read_buffer.data.to_s)
+  end
+
+  def test_align
+    buffer = Arrow::Buffer.new("Hello World")
+    buffer_input_stream = Arrow::BufferInputStream.new(buffer)
+    buffer_input_stream.advance(3)
+    buffer_input_stream.align(8)
+    read_buffer = buffer_input_stream.read(3)
+    assert_equal("rld", read_buffer.data.to_s)
+  end
 end

c_glib/test/test-buffer-output-stream.rb

@@ -23,4 +23,13 @@ def test_new
     output_stream.close
     assert_equal("Hello", buffer.data.to_s)
   end
+
+  def test_align
+    buffer = Arrow::ResizableBuffer.new(0)
+    output_stream = Arrow::BufferOutputStream.new(buffer)
+    output_stream.write("Hello")
+    output_stream.align(8)
+    output_stream.close
+    assert_equal("Hello\x00\x00\x00", buffer.data.to_s)
+  end
 end

c_glib/test/test-memory-mapped-input-stream.rb

@@ -67,7 +67,6 @@ def test_read_at
     end
   end
 
-
   def test_mode
     tempfile = Tempfile.open("arrow-memory-mapped-input-stream")
     tempfile.write("Hello World")