xref: /freebsd/contrib/kyua/store/read_backend.cpp (revision b0d29bc4)
1*b0d29bc4SBrooks Davis // Copyright 2011 The Kyua Authors.
2*b0d29bc4SBrooks Davis // All rights reserved.
3*b0d29bc4SBrooks Davis //
4*b0d29bc4SBrooks Davis // Redistribution and use in source and binary forms, with or without
5*b0d29bc4SBrooks Davis // modification, are permitted provided that the following conditions are
6*b0d29bc4SBrooks Davis // met:
7*b0d29bc4SBrooks Davis //
8*b0d29bc4SBrooks Davis // * Redistributions of source code must retain the above copyright
9*b0d29bc4SBrooks Davis //   notice, this list of conditions and the following disclaimer.
10*b0d29bc4SBrooks Davis // * Redistributions in binary form must reproduce the above copyright
11*b0d29bc4SBrooks Davis //   notice, this list of conditions and the following disclaimer in the
12*b0d29bc4SBrooks Davis //   documentation and/or other materials provided with the distribution.
13*b0d29bc4SBrooks Davis // * Neither the name of Google Inc. nor the names of its contributors
14*b0d29bc4SBrooks Davis //   may be used to endorse or promote products derived from this software
15*b0d29bc4SBrooks Davis //   without specific prior written permission.
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19*b0d29bc4SBrooks Davis // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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28*b0d29bc4SBrooks Davis 
29*b0d29bc4SBrooks Davis #include "store/read_backend.hpp"
30*b0d29bc4SBrooks Davis 
31*b0d29bc4SBrooks Davis #include "store/exceptions.hpp"
32*b0d29bc4SBrooks Davis #include "store/metadata.hpp"
33*b0d29bc4SBrooks Davis #include "store/read_transaction.hpp"
34*b0d29bc4SBrooks Davis #include "store/write_backend.hpp"
35*b0d29bc4SBrooks Davis #include "utils/format/macros.hpp"
36*b0d29bc4SBrooks Davis #include "utils/fs/path.hpp"
37*b0d29bc4SBrooks Davis #include "utils/noncopyable.hpp"
38*b0d29bc4SBrooks Davis #include "utils/sqlite/database.hpp"
39*b0d29bc4SBrooks Davis #include "utils/sqlite/exceptions.hpp"
40*b0d29bc4SBrooks Davis 
41*b0d29bc4SBrooks Davis namespace fs = utils::fs;
42*b0d29bc4SBrooks Davis namespace sqlite = utils::sqlite;
43*b0d29bc4SBrooks Davis 
44*b0d29bc4SBrooks Davis 
45*b0d29bc4SBrooks Davis /// Opens a database and defines session pragmas.
46*b0d29bc4SBrooks Davis ///
47*b0d29bc4SBrooks Davis /// This auxiliary function ensures that, every time we open a SQLite database,
48*b0d29bc4SBrooks Davis /// we define the same set of pragmas for it.
49*b0d29bc4SBrooks Davis ///
50*b0d29bc4SBrooks Davis /// \param file The database file to be opened.
51*b0d29bc4SBrooks Davis /// \param flags The flags for the open; see sqlite::database::open.
52*b0d29bc4SBrooks Davis ///
53*b0d29bc4SBrooks Davis /// \return The opened database.
54*b0d29bc4SBrooks Davis ///
55*b0d29bc4SBrooks Davis /// \throw store::error If there is a problem opening or creating the database.
56*b0d29bc4SBrooks Davis sqlite::database
open_and_setup(const fs::path & file,const int flags)57*b0d29bc4SBrooks Davis store::detail::open_and_setup(const fs::path& file, const int flags)
58*b0d29bc4SBrooks Davis {
59*b0d29bc4SBrooks Davis     try {
60*b0d29bc4SBrooks Davis         sqlite::database database = sqlite::database::open(file, flags);
61*b0d29bc4SBrooks Davis         database.exec("PRAGMA foreign_keys = ON");
62*b0d29bc4SBrooks Davis         return database;
63*b0d29bc4SBrooks Davis     } catch (const sqlite::error& e) {
64*b0d29bc4SBrooks Davis         throw store::error(F("Cannot open '%s': %s") % file % e.what());
65*b0d29bc4SBrooks Davis     }
66*b0d29bc4SBrooks Davis }
67*b0d29bc4SBrooks Davis 
68*b0d29bc4SBrooks Davis 
69*b0d29bc4SBrooks Davis /// Internal implementation for the backend.
70*b0d29bc4SBrooks Davis struct store::read_backend::impl : utils::noncopyable {
71*b0d29bc4SBrooks Davis     /// The SQLite database this backend talks to.
72*b0d29bc4SBrooks Davis     sqlite::database database;
73*b0d29bc4SBrooks Davis 
74*b0d29bc4SBrooks Davis     /// Constructor.
75*b0d29bc4SBrooks Davis     ///
76*b0d29bc4SBrooks Davis     /// \param database_ The SQLite database instance.
77*b0d29bc4SBrooks Davis     /// \param metadata_ The metadata for the loaded database.  This must match
78*b0d29bc4SBrooks Davis     ///     the schema version we implement in this module; otherwise, a
79*b0d29bc4SBrooks Davis     ///     migration is necessary.
80*b0d29bc4SBrooks Davis     ///
81*b0d29bc4SBrooks Davis     /// \throw integrity_error If the schema in the database is too modern,
82*b0d29bc4SBrooks Davis     ///     which might indicate some form of corruption or an old binary.
83*b0d29bc4SBrooks Davis     /// \throw old_schema_error If the schema in the database is older than our
84*b0d29bc4SBrooks Davis     ///     currently-implemented version and needs an upgrade.  The caller can
85*b0d29bc4SBrooks Davis     ///     use migrate_schema() to fix this problem.
implstore::read_backend::impl86*b0d29bc4SBrooks Davis     impl(sqlite::database& database_, const metadata& metadata_) :
87*b0d29bc4SBrooks Davis         database(database_)
88*b0d29bc4SBrooks Davis     {
89*b0d29bc4SBrooks Davis         const int database_version = metadata_.schema_version();
90*b0d29bc4SBrooks Davis 
91*b0d29bc4SBrooks Davis         if (database_version == detail::current_schema_version) {
92*b0d29bc4SBrooks Davis             // OK.
93*b0d29bc4SBrooks Davis         } else if (database_version < detail::current_schema_version) {
94*b0d29bc4SBrooks Davis             throw old_schema_error(database_version);
95*b0d29bc4SBrooks Davis         } else if (database_version > detail::current_schema_version) {
96*b0d29bc4SBrooks Davis             throw integrity_error(
97*b0d29bc4SBrooks Davis                 F("Database at schema version %s, which is newer than the "
98*b0d29bc4SBrooks Davis                   "supported version %s")
99*b0d29bc4SBrooks Davis                 % database_version % detail::current_schema_version);
100*b0d29bc4SBrooks Davis         }
101*b0d29bc4SBrooks Davis     }
102*b0d29bc4SBrooks Davis };
103*b0d29bc4SBrooks Davis 
104*b0d29bc4SBrooks Davis 
105*b0d29bc4SBrooks Davis /// Constructs a new backend.
106*b0d29bc4SBrooks Davis ///
107*b0d29bc4SBrooks Davis /// \param pimpl_ The internal data.
read_backend(impl * pimpl_)108*b0d29bc4SBrooks Davis store::read_backend::read_backend(impl* pimpl_) :
109*b0d29bc4SBrooks Davis     _pimpl(pimpl_)
110*b0d29bc4SBrooks Davis {
111*b0d29bc4SBrooks Davis }
112*b0d29bc4SBrooks Davis 
113*b0d29bc4SBrooks Davis 
114*b0d29bc4SBrooks Davis /// Destructor.
~read_backend(void)115*b0d29bc4SBrooks Davis store::read_backend::~read_backend(void)
116*b0d29bc4SBrooks Davis {
117*b0d29bc4SBrooks Davis }
118*b0d29bc4SBrooks Davis 
119*b0d29bc4SBrooks Davis 
120*b0d29bc4SBrooks Davis /// Opens a database in read-only mode.
121*b0d29bc4SBrooks Davis ///
122*b0d29bc4SBrooks Davis /// \param file The database file to be opened.
123*b0d29bc4SBrooks Davis ///
124*b0d29bc4SBrooks Davis /// \return The backend representation.
125*b0d29bc4SBrooks Davis ///
126*b0d29bc4SBrooks Davis /// \throw store::error If there is any problem opening the database.
127*b0d29bc4SBrooks Davis store::read_backend
open_ro(const fs::path & file)128*b0d29bc4SBrooks Davis store::read_backend::open_ro(const fs::path& file)
129*b0d29bc4SBrooks Davis {
130*b0d29bc4SBrooks Davis     sqlite::database db = detail::open_and_setup(file, sqlite::open_readonly);
131*b0d29bc4SBrooks Davis     return read_backend(new impl(db, metadata::fetch_latest(db)));
132*b0d29bc4SBrooks Davis }
133*b0d29bc4SBrooks Davis 
134*b0d29bc4SBrooks Davis 
135*b0d29bc4SBrooks Davis /// Closes the SQLite database.
136*b0d29bc4SBrooks Davis void
close(void)137*b0d29bc4SBrooks Davis store::read_backend::close(void)
138*b0d29bc4SBrooks Davis {
139*b0d29bc4SBrooks Davis     _pimpl->database.close();
140*b0d29bc4SBrooks Davis }
141*b0d29bc4SBrooks Davis 
142*b0d29bc4SBrooks Davis 
143*b0d29bc4SBrooks Davis /// Gets the connection to the SQLite database.
144*b0d29bc4SBrooks Davis ///
145*b0d29bc4SBrooks Davis /// \return A database connection.
146*b0d29bc4SBrooks Davis sqlite::database&
database(void)147*b0d29bc4SBrooks Davis store::read_backend::database(void)
148*b0d29bc4SBrooks Davis {
149*b0d29bc4SBrooks Davis     return _pimpl->database;
150*b0d29bc4SBrooks Davis }
151*b0d29bc4SBrooks Davis 
152*b0d29bc4SBrooks Davis 
153*b0d29bc4SBrooks Davis /// Opens a read-only transaction.
154*b0d29bc4SBrooks Davis ///
155*b0d29bc4SBrooks Davis /// \return A new transaction.
156*b0d29bc4SBrooks Davis store::read_transaction
start_read(void)157*b0d29bc4SBrooks Davis store::read_backend::start_read(void)
158*b0d29bc4SBrooks Davis {
159*b0d29bc4SBrooks Davis     return read_transaction(*this);
160*b0d29bc4SBrooks Davis }
161