1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
------------------------------------------------------------------------------
-- G N A T C O L L --
-- --
-- Copyright (C) 2005-2018, AdaCore --
-- --
-- This library is free software; you can redistribute it and/or modify it --
-- under terms of the GNU General Public License as published by the Free --
-- Software Foundation; either version 3, or (at your option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- --
-- --
-- --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
------------------------------------------------------------------------------
-- This package instantiates the GNATCOLL.SQL hierarchy for the sqlite3
-- DBMS
with GNATCOLL.SQL.Exec; use GNATCOLL.SQL.Exec;
with GNAT.Strings; use GNAT.Strings;
with System;
package GNATCOLL.SQL.Sqlite is
Sqlite_Always_Use_Transactions : Boolean := False;
-- Sqlite is faster if we always use transactions, even for SELECT
-- statements, according to
-- http://web.utk.edu/~jplyon/sqlite/SQLite_optimization_FAQ.html
-- You might still want to disable this settings if that doesn't match
-- your expectation. It is recommended to set this variable before getting
-- the first connection, and then no longer touch it.
-- Changing the setting will not impact existing connections.
--
-- This setting is mostly experimental, and can be tricky in your
-- application. It is recommend that you create the transactions yourself
-- in a controlled fashion.
-- Otherwise, it is easy to have a deadlock in your application if one
-- thread is using more than one connection (the first connection does a
-- BEGIN and a SELECT and gets a shared lock, then the second connection
-- tries to write to the database but cannot obtain a write lock).
Max_Ms_On_Busy : Natural := 0;
-- Maximum number of milliseconds we are willing to wait when sqlite
-- reports that it was enable to perform an action because it is already
-- busy.
-- Set this to 0 to disable retries altogether, although this means that
-- some queries might fail as a result.
On_Busy : access function
(Data : System.Address; Count : Integer) return Integer
with Convention => C;
-- Callback function that might be invoked whenever an
-- attempt is made to open a database table that another thread or process
-- has locked. See more information in Busy_Handler routine comment in
-- GNATCOLL.SQL.Sqlite.Gnade
type Sqlite_Description (<>)
is new Database_Description_Record with private;
type Sqlite_Description_Access is access all Sqlite_Description'Class;
overriding procedure Free (Self : in out Sqlite_Description);
overriding function Build_Connection
(Self : access Sqlite_Description) return Database_Connection;
function Setup
(Database : String;
Cache_Support : Boolean := False;
Errors : access Error_Reporter'Class := null;
Is_URI : Boolean := False)
return Database_Description;
-- Return a database description for sqlite
-- If sqlite was not detected at installation time, this function will
-- return null.
-- Errors (if specified) will be used to report errors and warnings to the
-- application. Errors is never freed.
-- If Is_URI is true, the name of the database is interpreted according
-- to the rules given at https://sqlite.org/c3ref/open.html.
function Is_Sqlite
(DB : access Database_Connection_Record'Class)
return Boolean;
-- Whether the connection is to a sqlite database
function DB_Name
(DB : access Database_Connection_Record'Class) return String;
-- Return the name of the file DB is connecting to (or ":memory:" when
-- in memory.
function Backup
(DB1 : access Database_Connection_Record'Class;
DB2 : String;
From_DB1_To_DB2 : Boolean := True) return Boolean;
function Backup
(From : access Database_Connection_Record'Class;
To : access Database_Connection_Record'Class) return Boolean;
-- Backup the database DB1 to a new database with the given file name
-- (or ":memory:"). It is possible to revert the direction of the backup
-- by changing the value of From_DB1_To_DB2
-- Returns False in case of error
private
type Sqlite_Description is new Database_Description_Record with record
Dbname : GNAT.Strings.String_Access;
Is_URI : Boolean;
end record;
end GNATCOLL.SQL.Sqlite;
|
