1 files changed, 114 insertions, 0 deletions
diff --git a/src/arrow/c_glib/arrow-glib/readable.cpp b/src/arrow/c_glib/arrow-glib/readable.cpp
new file mode 100644
index 000000000..fbe5270c7
--- /dev/null
+++ b/src/arrow/c_glib/arrow-glib/readable.cpp
@@ -0,0 +1,114 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <arrow/api.h>
+
+#include <arrow-glib/buffer.hpp>
+#include <arrow-glib/error.hpp>
+#include <arrow-glib/readable.hpp>
+
+G_BEGIN_DECLS
+
+/**
+ * SECTION: readable
+ * @title: GArrowReadable
+ * @short_description: Input interface
+ *
+ * #GArrowReadable is an interface for input. Input must be
+ * readable.
+ */
+
+G_DEFINE_INTERFACE(GArrowReadable,
+                   garrow_readable,
+                   G_TYPE_OBJECT)
+
+static void
+garrow_readable_default_init (GArrowReadableInterface *iface)
+{
+  iface->buffer_new_raw = garrow_buffer_new_raw;
+}
+
+/**
+ * garrow_readable_read:
+ * @readable: A #GArrowReadable.
+ * @n_bytes: The number of bytes to be read.
+ * @error: (nullable): Return location for a #GError or %NULL.
+ *
+ * Returns: (transfer full) (nullable): #GArrowBuffer that has read
+ *   data on success, %NULL if there was an error.
+ */
+GArrowBuffer *
+garrow_readable_read(GArrowReadable *readable,
+                     gint64 n_bytes,
+                     GError **error)
+{
+  const auto arrow_readable = garrow_readable_get_raw(readable);
+
+  auto arrow_buffer = arrow_readable->Read(n_bytes);
+  if (garrow::check(error, arrow_buffer, "[readable][read]")) {
+    auto *iface = GARROW_READABLE_GET_IFACE(readable);
+    return iface->buffer_new_raw(&(arrow_buffer.ValueOrDie()));
+  } else {
+    return NULL;
+  }
+}
+
+/**
+ * garrow_readable_read_bytes:
+ * @readable: A #GArrowReadable.
+ * @n_bytes: The number of bytes to be read.
+ * @error: (nullable): Return location for a #GError or %NULL.
+ *
+ * Returns: (transfer full) (nullable): #GBytes that has read data on
+ * success, %NULL if there was an error.
+ *
+ * Since: 0.17.0
+ */
+GBytes *
+garrow_readable_read_bytes(GArrowReadable *readable,
+                           gint64 n_bytes,
+                           GError **error)
+{
+  const auto arrow_readable = garrow_readable_get_raw(readable);
+
+  auto arrow_buffer_result = arrow_readable->Read(n_bytes);
+  if (!garrow::check(error, arrow_buffer_result, "[readable][read-bytes]")) {
+    return NULL;
+  }
+  auto arrow_cpu_buffer_result =
+    arrow::Buffer::ViewOrCopy(*arrow_buffer_result,
+                              arrow::default_cpu_memory_manager());
+  if (!garrow::check(error,
+                     arrow_cpu_buffer_result,
+                     "[readable][read-bytes][view-or-copy]")) {
+    return NULL;
+  }
+  auto arrow_cpu_buffer = *arrow_cpu_buffer_result;
+  return g_bytes_new(arrow_cpu_buffer->data(),
+                     arrow_cpu_buffer->size());
+}
+
+G_END_DECLS
+
+std::shared_ptr<arrow::io::Readable>
+garrow_readable_get_raw(GArrowReadable *readable)
+{
+  auto *iface = GARROW_READABLE_GET_IFACE(readable);
+  return iface->get_raw(readable);
+}