Support for timestamps

CMakeLists.txt

@@ -43,6 +43,22 @@ message(STATUS "Building sparrow v${${PROJECT_NAME}_VERSION}")
 
 OPTION(BUILD_TESTS "sparrow test suite" OFF)
 
+include(CheckCXXSymbolExists)
+
+if(cxx_std_20 IN_LIST CMAKE_CXX_COMPILE_FEATURES)
+ set(header version)
+else()
+ set(header ciso646)
+endif()
+
+check_cxx_symbol_exists(_LIBCPP_VERSION ${header} LIBCPP)
+if(LIBCPP)
+ message(STATUS "Using libc++")
+ # Allow the use of not visible yet availabile features, such
+ # as some formatter for new types.
+ add_compile_definitions(_LIBCPP_DISABLE_AVAILABILITY)
+endif()
+
 # Linter options
 # =============
 
@@ -55,6 +71,11 @@ endif()
 # Dependencies
 # ============
 
+set(SPARROW_INTERFACE_DEPENDENCIES "" CACHE STRING "List of dependencies to be linked to the sparrow target")
+
+find_package(date CONFIG REQUIRED)
+list(APPEND SPARROW_INTERFACE_DEPENDENCIES date::date)
+
 # Build
 # =====
 
@@ -65,7 +86,7 @@ set(SPARROW_HEADERS
  ${SPARROW_INCLUDE_DIR}/sparrow/buffer.hpp
  ${SPARROW_INCLUDE_DIR}/sparrow/buffer_view.hpp
  ${SPARROW_INCLUDE_DIR}/sparrow/config.hpp
- ${SPARROW_INCLUDE_DIR}/sparrow/contracts.hpp
+ ${SPARROW_INCLUDE_DIR}/sparrow/contracts.hpp
  ${SPARROW_INCLUDE_DIR}/sparrow/data_traits.hpp
  ${SPARROW_INCLUDE_DIR}/sparrow/data_type.hpp
  ${SPARROW_INCLUDE_DIR}/sparrow/dynamic_bitset.hpp
@@ -86,6 +107,8 @@ target_include_directories(sparrow INTERFACE
  $<BUILD_INTERFACE:${SPARROW_INCLUDE_DIR}>
  $<INSTALL_INTERFACE:include>)
 
+target_link_libraries(sparrow INTERFACE ${SPARROW_INTERFACE_DEPENDENCIES})
+
 # We do not use non-standard C++
 set_target_properties(sparrow PROPERTIES CMAKE_CXX_EXTENSIONS OFF)
 target_compile_features(sparrow INTERFACE cxx_std_20)

environment-dev.yml

@@ -7,3 +7,8 @@ dependencies:
  - ninja
  # Tests
  - doctest
+ # P0355R7 (Extending chrono to Calendars and Time Zones) has not been entirely implemented in libc++ yet.
+ # See: https://libcxx.llvm.org/Status/Cxx20.html#note-p0355
+ # For now, we use HowardHinnant/date as a replacement if we are compiling with libc++.
+ # TODO: remove this once libc++ has full support for P0355R7.
+ - howardhinnant_date

include/sparrow/data_traits.hpp

@@ -125,6 +125,12 @@ namespace sparrow
  using default_layout = variable_size_binary_layout<value_type, std::span<byte_t>, const std::span<byte_t>>; // FIXME: this is incorrect, change when we have the right types
  };
 
+ template <>
+ struct arrow_traits<timestamp> : common_native_types_traits<timestamp>
+ {
+ static constexpr data_type type_id = data_type::TIMESTAMP;
+ };
+
  namespace predicate
  {
 
@@ -147,4 +153,4 @@ namespace sparrow
  } constexpr has_arrow_traits;
  }
 
-}
+}

include/sparrow/data_type.hpp

@@ -1,4 +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.
@@ -14,6 +14,15 @@
 
 #pragma once
 
+#include <version>
+#include <chrono>
+
+// P0355R7 (Extending chrono to Calendars and Time Zones) has not been entirely implemented in libc++ yet.
+// See: https://libcxx.llvm.org/Status/Cxx20.html#note-p0355
+// For now, we use HowardHinnant/date as a replacement if we are compiling with libc++.
+// TODO: remove this once libc++ has full support for P0355R7.
+#include <date/tz.h>
+
 #include <climits>
 #include <cstdint>
 #include <optional>
@@ -45,6 +54,13 @@
  using float64_t = std::float64_t;
 #endif
 
+ // P0355R7 (Extending chrono to Calendars and Time Zones) has not been entirely implemented in libc++ yet.
+ // See: https://libcxx.llvm.org/Status/Cxx20.html#note-p0355
+ // For now, we use HowardHinnant/date as a replacement if we are compiling with libc++.
+ // TODO: use the following once libc++ has full support for P0355R7.
+ // using timestamp = std::chrono::time_point<std::chrono::system_clock, std::chrono::nanoseconds>;
+ using timestamp = date::zoned_time<std::chrono::nanoseconds>;
+
  // We need to be sure the current target platform is setup to support correctly these types.
  static_assert(sizeof(float16_t) == 2);
  static_assert(sizeof(float32_t) == 4);
@@ -82,14 +98,15 @@
  BINARY,
  // Fixed-size binary. Each value occupies the same number of bytes
  FIXED_SIZE_BINARY,
+ // Number of nanoseconds since the UNIX epoch with an optional timezone.
+ // See: https://arrow.apache.org/docs/python/timestamps.html#timestamps
+ TIMESTAMP,
  };
 
  /// C++ types value representation types matching Arrow types.
  // NOTE: this needs to be in sync-order with `data_type`
  using all_base_types_t = mpl::typelist<
- std::nullopt_t // REVIEW: not sure about if we need to have this one? for representing NA? is this
- // the right type?
- ,
+ std::nullopt_t,
  bool,
  std::uint8_t,
  std::int8_t,
@@ -103,7 +120,8 @@
  float32_t,
  float64_t,
  std::string,
- std::vector<byte_t>
+ std::vector<byte_t>,
+ sparrow::timestamp
  // TODO: add missing fundamental types here
  >;