package Mojo::SQLite; use Mojo::Base 'Mojo::EventEmitter'; use Carp 'croak'; use DBI; use File::Spec::Functions 'catfile'; use File::Temp; use Mojo::SQLite::Database; use Mojo::SQLite::Migrations; use Mojo::SQLite::PubSub; use Scalar::Util 'weaken'; use URI; use URI::db; use URI::QueryParam; our $VERSION = '0.018'; has dsn => sub { _url_from_file(shift->_tempfile)->dbi_dsn }; has max_connections => 5; has migrations => sub { my $migrations = Mojo::SQLite::Migrations->new(sqlite => shift); weaken $migrations->{sqlite}; return $migrations; }; has options => sub { { AutoCommit => 1, AutoInactiveDestroy => 1, PrintError => 0, RaiseError => 1, sqlite_unicode => 1, }; }; has pubsub => sub { my $pubsub = Mojo::SQLite::PubSub->new(sqlite => shift); weaken $pubsub->{sqlite}; return $pubsub; }; sub new { @_ > 1 ? shift->SUPER::new->from_string(@_) : shift->SUPER::new } sub db { my $self = shift; # Fork-safety delete @$self{qw(pid queue)} unless ($self->{pid} //= $$) eq $$; return Mojo::SQLite::Database->new(dbh => $self->_dequeue, sqlite => $self); } sub from_filename { shift->from_string(_url_from_file(shift, shift)) } sub from_string { my ($self, $str) = @_; return $self unless $str; my $url = URI->new($str); # Options my $options = $url->query_form_hash; $url->query_param_delete($_) for $url->query_param; @{$self->options}{keys %$options} = values %$options; # Parse URL based on scheme $url->scheme('file') unless $url->has_recognized_scheme; if ($url->scheme eq 'file') { $url = _url_from_file($url->file); } elsif ($url->scheme ne 'db') { $url = URI::db->new($url); } croak qq{Invalid SQLite connection string "$str"} unless $url->has_recognized_engine and $url->canonical_engine eq 'sqlite' and (($url->host // '') eq '' or $url->host eq 'localhost'); # Temp database file $url->dbname($self->_tempfile) if $url->dbname eq ':temp:'; return $self->dsn($url->dbi_dsn); } sub _dequeue { my $self = shift; while (my $dbh = shift @{$self->{queue} || []}) { return $dbh if $dbh->ping } my $dbh = DBI->connect($self->dsn, undef, undef, $self->options); if (defined $dbh) { $dbh->do('pragma journal_mode=WAL'); $dbh->do('pragma synchronous=NORMAL'); } $self->emit(connection => $dbh); return $dbh; } sub _enqueue { my ($self, $dbh) = @_; my $queue = $self->{queue} ||= []; push @$queue, $dbh if $dbh->{Active}; shift @$queue while @$queue > $self->max_connections; } sub _tempfile { catfile(shift->{tempdir} = File::Temp->newdir, 'sqlite.db') } sub _url_from_file { my $url = URI::db->new; $url->engine('sqlite'); $url->dbname(shift); if (my $options = shift) { $url->query_form_hash($options) } return $url; } 1; =head1 NAME Mojo::SQLite - A tiny Mojolicious wrapper for SQLite =head1 SYNOPSIS use Mojo::SQLite; # Create a table my $sql = Mojo::SQLite->new('sqlite:test.db'); $sql->db->query('create table names (id integer primary key autoincrement, name text)'); # Insert a few rows my $db = $sql->db; $db->query('insert into names (name) values (?)', 'Sara'); $db->query('insert into names (name) values (?)', 'Stefan'); # Insert more rows in a transaction eval { my $tx = $db->begin; $db->query('insert into names (name) values (?)', 'Baerbel'); $db->query('insert into names (name) values (?)', 'Wolfgang'); $tx->commit; }; say $@ if $@; # Insert another row and return the generated id say $db->query('insert into names (name) values (?)', 'Daniel') ->last_insert_id; # Select one row at a time my $results = $db->query('select * from names'); while (my $next = $results->hash) { say $next->{name}; } # Select all rows $db->query('select * from names') ->hashes->map(sub { $_->{name} })->join("\n")->say; # Send and receive notifications non-blocking $sql->pubsub->listen(foo => sub { my ($pubsub, $payload) = @_; say "foo: $payload"; $pubsub->notify(bar => $payload); }); $sql->pubsub->listen(bar => sub { my ($pubsub, $payload) = @_; say "bar: $payload"; }); $sql->pubsub->notify(foo => 'SQLite rocks!'); Mojo::IOLoop->start unless Mojo::IOLoop->is_running; =head1 DESCRIPTION L<Mojo::SQLite> is a tiny wrapper around L<DBD::SQLite> that makes L<SQLite|https://www.sqlite.org/> a lot of fun to use with the L<Mojolicious|https://mojolico.us> real-time web framework. Database and statement handles are cached automatically, so they can be reused transparently to increase performance. And you can handle connection timeouts gracefully by holding on to them only for short amounts of time. use Mojolicious::Lite; use Mojo::SQLite; helper sqlite => sub { state $sql = Mojo::SQLite->new('sqlite:sqlite.db') }; get '/' => sub { my $c = shift; my $db = $c->sqlite->db; $c->render(json => $db->query('select datetime("now","localtime") as time')->hash); }; app->start; All I/O and queries are performed synchronously. However, the "Write-Ahead Log" journal is enabled for all connections, allowing multiple processes to read and write concurrently to the same database file (but only one can write at a time). See L<http://sqlite.org/wal.html> for more information. # Performed concurrently my $pid = fork || die $!; say $sql->db->query('select datetime("now","localtime") as time')->hash->{time}; exit unless $pid; All cached database handles will be reset automatically if a new process has been forked, this allows multiple processes to share the same L<Mojo::SQLite> object safely. Any database errors will throw an exception as C<RaiseError> is automatically enabled, so use C<eval> or L<Try::Tiny> to catch them. This makes transactions with L<Mojo::SQLite::Database/"begin"> easy. While passing a file path of C<:memory:> (or a custom L</"dsn"> with C<mode=memory>) will create a temporary database, in-memory databases cannot be shared between connections, so subsequent calls to L</"db"> may return connections to completely different databases. For a temporary database that can be shared between connections and processes, pass a file path of C<:temp:> to store the database in a temporary directory (this is the default), or consider constructing a temporary directory yourself with L<File::Temp> if you need to reuse the filename. A temporary directory allows SQLite to create L<additional temporary files|https://www.sqlite.org/tempfiles.html> safely. use File::Spec::Functions 'catfile'; use File::Temp; use Mojo::SQLite; my $tempdir = File::Temp->newdir; # Deleted when object goes out of scope my $tempfile = catfile $tempdir, 'sqlite.db'; my $sql = Mojo::SQLite->new->from_filename($tempfile); =head1 EVENTS L<Mojo::SQLite> inherits all events from L<Mojo::EventEmitter> and can emit the following new ones. =head2 connection $sql->on(connection => sub { my ($sql, $dbh) = @_; ... }); Emitted when a new database connection has been established. =head1 ATTRIBUTES L<Mojo::SQLite> implements the following attributes. =head2 dsn my $dsn = $sql->dsn; $sql = $sql->dsn('dbi:SQLite:uri=file:foo.db'); Data source name, defaults to C<dbi:SQLite:dbname=> followed by a path to a temporary file. =head2 max_connections my $max = $sql->max_connections; $sql = $sql->max_connections(3); Maximum number of idle database handles to cache for future use, defaults to C<5>. =head2 migrations my $migrations = $sql->migrations; $sql = $sql->migrations(Mojo::SQLite::Migrations->new); L<Mojo::SQLite::Migrations> object you can use to change your database schema more easily. # Load migrations from file and migrate to latest version $sql->migrations->from_file('/home/dbook/migrations.sql')->migrate; =head2 options my $options = $sql->options; $sql = $sql->options({AutoCommit => 1, RaiseError => 1}); Options for database handles, defaults to activating C<sqlite_unicode>, C<AutoCommit>, C<AutoInactiveDestroy> as well as C<RaiseError> and deactivating C<PrintError>. Note that C<AutoCommit> and C<RaiseError> are considered mandatory, so deactivating them would be very dangerous. See L<DBI/"ATTRIBUTES COMMON TO ALL HANDLES"> and L<DBD::SQLite/"DRIVER PRIVATE ATTRIBUTES"> for more information on available options. =head2 pubsub my $pubsub = $sql->pubsub; $sql = $sql->pubsub(Mojo::SQLite::PubSub->new); L<Mojo::SQLite::PubSub> object you can use to send and receive notifications very efficiently, by sharing a single database connection with many consumers. # Subscribe to a channel $sql->pubsub->listen(news => sub { my ($pubsub, $payload) = @_; say "Received: $payload"; }); # Notify a channel $sql->pubsub->notify(news => 'SQLite rocks!'); =head1 METHODS L<Mojo::SQLite> inherits all methods from L<Mojo::EventEmitter> and implements the following new ones. =head2 new my $sql = Mojo::SQLite->new; my $sql = Mojo::SQLite->new('file:test.db); my $sql = Mojo::SQLite->new('sqlite:test.db'); Construct a new L<Mojo::SQLite> object and parse connection string with L</"from_string"> if necessary. # Customize configuration further my $sql = Mojo::SQLite->new->dsn('dbi:SQLite:dbname=test.db'); my $sql = Mojo::SQLite->new->dsn('dbi:SQLite:uri=file:test.db?mode=memory'); # Pass filename directly my $sql = Mojo::SQLite->new->from_filename($filename); =head2 db my $db = $sql->db; Get L<Mojo::SQLite::Database> object for a cached or newly established database connection. The L<DBD::SQLite> database handle will be automatically cached again when that object is destroyed, so you can handle connection timeouts gracefully by holding on to it only for short amounts of time. # Add up all the money say $sql->db->query('select * from accounts') ->hashes->reduce(sub { $a->{money} + $b->{money} }); =head2 from_filename $sql = $sql->from_filename('C:\\Documents and Settings\\foo & bar.db', $options); Parse database filename directly. Unlike L</"from_string">, the filename is parsed as a local filename and not a URL. A hashref of L</"options"> may be passed as the second argument. # Absolute filename $sql->from_filename('/home/fred/data.db'); # Relative to current directory $sql->from_filename('data.db'); # Temporary file database (default) $sql->from_filename(':temp:'); # In-memory temporary database (single connection only) my $db = $sql->from_filename(':memory:')->db; # Additional options $sql->from_filename($filename, { PrintError => 1 }); =head2 from_string $sql = $sql->from_string('test.db'); $sql = $sql->from_string('file:test.db'); $sql = $sql->from_string('file:///C:/foo/bar.db'); $sql = $sql->from_string('sqlite:C:%5Cfoo%5Cbar.db'); Parse configuration from connection string. Connection strings are parsed as URLs, so you should construct them using a module like L<Mojo::URL>, L<URI::file>, or L<URI::db>. For portability on non-Unix-like systems, either construct the URL with the C<sqlite> scheme, or use L<URI::file/"new"> to construct a URL with the C<file> scheme. A URL with no scheme will be parsed as a C<file> URL, and C<file> URLs are parsed according to the current operating system. If specified, the hostname must be C<localhost>. If the URL has a query string, it will be parsed and applied to L</"options">. # Absolute filename $sql->from_string('sqlite:////home/fred/data.db'); $sql->from_string('sqlite://localhost//home/fred/data.db'); $sql->from_string('sqlite:/home/fred/data.db'); $sql->from_string('file:///home/fred/data.db'); $sql->from_string('file://localhost/home/fred/data.db'); $sql->from_string('file:/home/fred/data.db'); $sql->from_string('///home/fred/data.db'); $sql->from_string('//localhost/home/fred/data.db'); $sql->from_string('/home/fred/data.db'); # Relative to current directory $sql->from_string('sqlite:data.db'); $sql->from_string('file:data.db'); $sql->from_string('data.db'); # Connection string must be a valid URL $sql->from_string(Mojo::URL->new->scheme('sqlite')->path($filename)); $sql->from_string(URI::db->new->Mojo::Base::tap(engine => 'sqlite')->Mojo::Base::tap(dbname => $filename)); $sql->from_string(URI::file->new($filename)); # Temporary file database (default) $sql->from_string(':temp:'); # In-memory temporary database (single connection only) my $db = $sql->from_string(':memory:')->db; # Additional options $sql->from_string('data.db?PrintError=1&sqlite_allow_multiple_statements=1'); $sql->from_string(Mojo::URL->new->scheme('sqlite')->path($filename)->query(sqlite_see_if_its_a_number => 1)); $sql->from_string(URI::file->new($filename)->Mojo::Base::tap(query_form_hash => {PrintError => 1})); =head1 REFERENCE This is the class hierarchy of the L<Mojo::SQLite> distribution. =over 2 =item * L<Mojo::SQLite> =item * L<Mojo::SQLite::Database> =item * L<Mojo::SQLite::Migrations> =item * L<Mojo::SQLite::PubSub> =item * L<Mojo::SQLite::Results> =item * L<Mojo::SQLite::Transaction> =back =head1 BUGS Report any issues on the public bugtracker. =head1 AUTHOR Dan Book, C<dbook@cpan.org> =head1 CREDITS Sebastian Riedel, author of L<Mojo::Pg>, which this distribution is based on. =head1 COPYRIGHT AND LICENSE Copyright 2015, Dan Book. This library is free software; you may redistribute it and/or modify it under the terms of the Artistic License version 2.0. =head1 SEE ALSO L<Mojolicious>, L<Mojo::Pg>, L<DBD::SQLite>