ceph/src/arrow/cpp/src/arrow/python/decimal.h

   1 // Licensed to the Apache Software Foundation (ASF) under one
   2 // or more contributor license agreements.  See the NOTICE file
   3 // distributed with this work for additional information
   4 // regarding copyright ownership.  The ASF licenses this file
   5 // to you under the Apache License, Version 2.0 (the
   6 // "License"); you may not use this file except in compliance
   7 // with the License.  You may obtain a copy of the License at
   8 //
   9 //   http://www.apache.org/licenses/LICENSE-2.0
  10 //
  11 // Unless required by applicable law or agreed to in writing,
  12 // software distributed under the License is distributed on an
  13 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  14 // KIND, either express or implied.  See the License for the
  15 // specific language governing permissions and limitations
  16 // under the License.
  17
  18 #pragma once
  19
  20 #include <string>
  21
  22 #include "arrow/python/visibility.h"
  23 #include "arrow/type.h"
  24
  25 namespace arrow {
  26
  27 class Decimal128;
  28 class Decimal256;
  29
  30 namespace py {
  31
  32 class OwnedRef;
  33
  34 //
  35 // Python Decimal support
  36 //
  37
  38 namespace internal {
  39
  40 // \brief Import the Python Decimal type
  41 ARROW_PYTHON_EXPORT
  42 Status ImportDecimalType(OwnedRef* decimal_type);
  43
  44 // \brief Convert a Python Decimal object to a C++ string
  45 // \param[in] python_decimal A Python decimal.Decimal instance
  46 // \param[out] The string representation of the Python Decimal instance
  47 // \return The status of the operation
  48 ARROW_PYTHON_EXPORT
  49 Status PythonDecimalToString(PyObject* python_decimal, std::string* out);
  50
  51 // \brief Convert a C++ std::string to a Python Decimal instance
  52 // \param[in] decimal_constructor The decimal type object
  53 // \param[in] decimal_string A decimal string
  54 // \return An instance of decimal.Decimal
  55 ARROW_PYTHON_EXPORT
  56 PyObject* DecimalFromString(PyObject* decimal_constructor,
  57                             const std::string& decimal_string);
  58
  59 // \brief Convert a Python decimal to an Arrow Decimal128 object
  60 // \param[in] python_decimal A Python decimal.Decimal instance
  61 // \param[in] arrow_type An instance of arrow::DecimalType
  62 // \param[out] out A pointer to a Decimal128
  63 // \return The status of the operation
  64 ARROW_PYTHON_EXPORT
  65 Status DecimalFromPythonDecimal(PyObject* python_decimal, const DecimalType& arrow_type,
  66                                 Decimal128* out);
  67
  68 // \brief Convert a Python object to an Arrow Decimal128 object
  69 // \param[in] python_decimal A Python int or decimal.Decimal instance
  70 // \param[in] arrow_type An instance of arrow::DecimalType
  71 // \param[out] out A pointer to a Decimal128
  72 // \return The status of the operation
  73 ARROW_PYTHON_EXPORT
  74 Status DecimalFromPyObject(PyObject* obj, const DecimalType& arrow_type, Decimal128* out);
  75
  76 // \brief Convert a Python decimal to an Arrow Decimal256 object
  77 // \param[in] python_decimal A Python decimal.Decimal instance
  78 // \param[in] arrow_type An instance of arrow::DecimalType
  79 // \param[out] out A pointer to a Decimal256
  80 // \return The status of the operation
  81 ARROW_PYTHON_EXPORT
  82 Status DecimalFromPythonDecimal(PyObject* python_decimal, const DecimalType& arrow_type,
  83                                 Decimal256* out);
  84
  85 // \brief Convert a Python object to an Arrow Decimal256 object
  86 // \param[in] python_decimal A Python int or decimal.Decimal instance
  87 // \param[in] arrow_type An instance of arrow::DecimalType
  88 // \param[out] out A pointer to a Decimal256
  89 // \return The status of the operation
  90 ARROW_PYTHON_EXPORT
  91 Status DecimalFromPyObject(PyObject* obj, const DecimalType& arrow_type, Decimal256* out);
  92
  93 // \brief Check whether obj is an instance of Decimal
  94 ARROW_PYTHON_EXPORT
  95 bool PyDecimal_Check(PyObject* obj);
  96
  97 // \brief Check whether obj is nan. This function will abort the program if the argument
  98 // is not a Decimal instance
  99 ARROW_PYTHON_EXPORT
 100 bool PyDecimal_ISNAN(PyObject* obj);
 101
 102 // \brief Helper class to track and update the precision and scale of a decimal
 103 class ARROW_PYTHON_EXPORT DecimalMetadata {
 104  public:
 105   DecimalMetadata();
 106   DecimalMetadata(int32_t precision, int32_t scale);
 107
 108   // \brief Adjust the precision and scale of a decimal type given a new precision and a
 109   // new scale \param[in] suggested_precision A candidate precision \param[in]
 110   // suggested_scale A candidate scale \return The status of the operation
 111   Status Update(int32_t suggested_precision, int32_t suggested_scale);
 112
 113   // \brief A convenient interface for updating the precision and scale based on a Python
 114   // Decimal object \param object A Python Decimal object \return The status of the
 115   // operation
 116   Status Update(PyObject* object);
 117
 118   int32_t precision() const { return precision_; }
 119   int32_t scale() const { return scale_; }
 120
 121  private:
 122   int32_t precision_;
 123   int32_t scale_;
 124 };
 125
 126 }  // namespace internal
 127 }  // namespace py
 128 }  // namespace arrow