Added data_type and array_data structures (#18)

CMakeLists.txt

@@ -50,7 +50,9 @@ OPTION(BUILD_TESTS "sparrow test suite" OFF)
 # =====
 
 set(SPARROW_HEADERS
+    ${SPARROW_INCLUDE_DIR}/sparrow/array_data.hpp
     ${SPARROW_INCLUDE_DIR}/sparrow/buffer.hpp
+    ${SPARROW_INCLUDE_DIR}/sparrow/data_type.hpp
     ${SPARROW_INCLUDE_DIR}/sparrow/dynamic_bitset.hpp
     ${SPARROW_INCLUDE_DIR}/sparrow/iterator.hpp
     ${SPARROW_INCLUDE_DIR}/sparrow/sparrow_version.hpp

include/sparrow/array_data.hpp

@@ -0,0 +1,43 @@
+// Copyright 2024 Man Group Operations Limited
+//
+// Licensed 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.
+
+#pragma once
+
+#include "sparrow/buffer.hpp"
+#include "sparrow/data_type.hpp"
+#include "sparrow/dynamic_bitset.hpp"
+
+namespace sparrow
+{
+    struct array_data
+    {
+        using block_type = std::uint8_t;
+        using bitmap_type = dynamic_bitset<block_type>;
+        using buffer_type = buffer<block_type>;
+
+        data_descriptor type;
+        std::int64_t length = 0;
+        std::int64_t offset = 0;
+        // bitmap buffer and null_count
+        bitmap_type bitmap;
+        // Other buffers
+        std::vector<buffer_type> buffers;
+        std::vector<array_data> child_data;
+    };
+
+    struct null_type
+    {
+    };
+    constexpr null_type null;
+}

include/sparrow/data_type.hpp

@@ -0,0 +1,67 @@
+// Copyright 2024 Man Group Operations Limited
+//
+// Licensed 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.
+
+#pragma once
+
+namespace sparrow
+{
+    // TODO: does not support all types specified by the Arrow specification
+    // yet
+    enum class data_type
+    {
+        NA = 0,
+        BOOL,
+        UINT8,
+        INT8,
+        UINT16,
+        INT16,
+        UINT32,
+        INT32,
+        UINT64,
+        INT64,
+        HALF_FLOAT,
+        FLOAT,
+        DOUBLE,
+        // UTF8 variable-length string
+        STRING,
+        // Variable-length bytes (no guarantee of UTF8-ness)
+        BINARY,
+        // Fixed-size binary. Each value occupies the same number of bytes
+        FIXED_SIZE_BINARY
+    };
+
+    // For now, a tiny wrapper around data_type
+    // More data and functions to come
+    class data_descriptor
+    {
+    public:
+
+        constexpr data_descriptor()
+            : data_descriptor(data_type::UINT8)
+        {
+        }
+
+        constexpr explicit data_descriptor(data_type id)
+            : m_id(id)
+        {
+        }
+
+        constexpr data_type id() const { return m_id; }
+
+    private:
+
+        data_type m_id;
+    };
+}
+

include/sparrow/dynamic_bitset.hpp

@@ -1,3 +1,4 @@
+// Copyright 2024 Man Group Operations Limited
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.