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150 | -----------------------------------------------------------------------
-- ADO Databases -- Database Objects
-- Copyright (C) 2009, 2010, 2011, 2012, 2015, 2018, 2019 Stephane Carrez
-- Written by Stephane Carrez (Stephane.Carrez@gmail.com)
--
-- 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.
-----------------------------------------------------------------------
with Ada.Strings.Unbounded;
with Ada.Streams;
with Ada.Calendar;
with Util.Refs;
with Util.Nullables;
package ADO is
type Int64 is range -2**63 .. 2**63 - 1;
for Int64'Size use 64;
type Unsigned64 is mod 2**64;
for Unsigned64'Size use 64;
DEFAULT_TIME : constant Ada.Calendar.Time;
-- ------------------------------
-- Database Identifier
-- ------------------------------
--
type Identifier is range -2**47 .. 2**47 - 1;
NO_IDENTIFIER : constant Identifier := -1;
type Entity_Type is range 0 .. 2**16 - 1;
NO_ENTITY_TYPE : constant Entity_Type := 0;
type Object_Id is record
Id : Identifier;
Kind : Entity_Type;
end record;
pragma Pack (Object_Id);
-- ------------------------------
-- Nullable Types
-- ------------------------------
-- Most database allow to store a NULL instead of an actual integer, date or string value.
-- Unlike Java, there is no easy way to distinguish between a NULL and an actual valid value.
-- The <b>Nullable_T</b> types provide a way to specify and check whether a value is null
-- or not.
subtype Nullable_Boolean is Util.Nullables.Nullable_Boolean;
function "=" (Left, Right : in Nullable_Boolean) return Boolean
renames Util.Nullables."=";
Null_Boolean : constant Nullable_Boolean;
-- An integer which can be null.
subtype Nullable_Integer is Util.Nullables.Nullable_Integer;
function "=" (Left, Right : in Nullable_Integer) return Boolean
renames Util.Nullables."=";
Null_Integer : constant Nullable_Integer;
-- A string which can be null.
subtype Nullable_String is Util.Nullables.Nullable_String;
Null_String : constant Nullable_String;
-- A date which can be null.
subtype Nullable_Time is Util.Nullables.Nullable_Time;
Null_Time : constant Nullable_Time;
-- Return True if the two nullable times are identical (both null or both same time).
function "=" (Left, Right : in Nullable_Time) return Boolean;
type Nullable_Entity_Type is record
Value : Entity_Type := 0;
Is_Null : Boolean := True;
end record;
Null_Entity_Type : constant Nullable_Entity_Type;
-- ------------------------------
-- Blob data type
-- ------------------------------
-- The <b>Blob</b> type is used to represent database blobs. The data is stored
-- in an <b>Ada.Streams.Stream_Element_Array</b> pointed to by the <b>Data</b> member.
-- The query statement and bind parameter will use a <b>Blob_Ref</b> which represents
-- a reference to the blob data. This is intended to minimize data copy.
type Blob (Len : Ada.Streams.Stream_Element_Offset) is new Util.Refs.Ref_Entity with record
Data : Ada.Streams.Stream_Element_Array (1 .. Len);
end record;
type Blob_Access is access all Blob;
package Blob_References is new Util.Refs.Indefinite_References (Blob, Blob_Access);
subtype Blob_Ref is Blob_References.Ref;
subtype Blob_Accessor is Blob_References.Element_Accessor;
-- Create a blob with an allocated buffer of <b>Size</b> bytes.
function Create_Blob (Size : in Natural) return Blob_Ref;
-- Create a blob initialized with the given data buffer.
function Create_Blob (Data : in Ada.Streams.Stream_Element_Array) return Blob_Ref;
-- Create a blob initialized with the content from the file whose path is <b>Path</b>.
-- Raises an IO exception if the file does not exist.
function Create_Blob (Path : in String) return Blob_Ref;
-- Return a null blob.
function Null_Blob return Blob_Ref;
private
DEFAULT_TIME : constant Ada.Calendar.Time := Ada.Calendar.Time_Of (Year => 1901,
Month => 1,
Day => 2,
Seconds => 0.0);
Null_Boolean : constant Nullable_Boolean
:= Nullable_Boolean '(Is_Null => True,
Value => False);
Null_Integer : constant Nullable_Integer
:= Nullable_Integer '(Is_Null => True,
Value => 0);
Null_String : constant Nullable_String
:= Nullable_String '(Is_Null => True,
Value => Ada.Strings.Unbounded.Null_Unbounded_String);
Null_Time : constant Nullable_Time
:= Nullable_Time '(Is_Null => True,
Value => DEFAULT_TIME);
Null_Entity_Type : constant Nullable_Entity_Type
:= Nullable_Entity_Type '(Is_Null => True,
Value => 0);
end ADO;
|