DBD-SQLite: applied the online backup patch from Toby Corkindale (with a little modification)

Changes

@@ -3,6 +3,7 @@ Changes for Perl extension DBD-SQLite
 1.26_02 to be released
     - Started using install_method() suggested by TIMB (#44882)
       Ported last_insert_rowid as the first attempt (ISHIGAKI)
+    - Added access to Online Backup functionality. (TJC)
 
 1.26_01 Tue  5 May 2009
     - Added ORDINAL_POSITION support for $dbh->column_info (ADAMK)

SQLite.xs

@@ -94,6 +94,29 @@ busy_timeout(dbh, timeout=0)
   OUTPUT:
     RETVAL
 
+static int
+backup_from_file(dbh, filename)
+  SV *dbh
+  char *filename
+  ALIAS:
+     DBD::SQLite::db::sqlite_backup_from_file = 1
+  CODE:
+    RETVAL = sqlite_db_backup_from_file(aTHX_ dbh, filename);
+  OUTPUT:
+    RETVAL
+
+static int
+backup_to_file(dbh, filename)
+  SV *dbh
+  char *filename
+  ALIAS:
+     DBD::SQLite::db::sqlite_backup_to_file = 1
+  CODE:
+    RETVAL = sqlite_db_backup_to_file(aTHX_ dbh, filename);
+  OUTPUT:
+    RETVAL
+
+
 MODULE = DBD::SQLite          PACKAGE = DBD::SQLite::st
 
 PROTOTYPES: DISABLE

dbdimp.c

@@ -1254,7 +1254,6 @@ sqlite_db_collation_dispatcher_utf8(
     return cmp;
 }
 
-
 void
 sqlite3_db_create_collation(pTHX_ SV *dbh, const char *name, SV *func )
 {
@@ -1293,7 +1292,6 @@ sqlite3_db_create_collation(pTHX_ SV *dbh, const char *name, SV *func )
     }
 }
 
-
 static int
 sqlite_db_progress_handler_dispatcher( void *handler )
 {
@@ -1318,8 +1316,6 @@ sqlite_db_progress_handler_dispatcher( void *handler )
     return retval;
 }
 
-
-
 void
 sqlite3_db_progress_handler(pTHX_ SV *dbh, int n_opcodes, SV *handler )
 {
@@ -1342,4 +1338,60 @@ sqlite3_db_progress_handler(pTHX_ SV *dbh, int n_opcodes, SV *handler )
     }
 }
 
+/* Accesses the SQLite Online Backup API, and fills the currently loaded
+ * database from the passed filename.
+ * Usual usage of this would be when you're operating on the :memory:
+ * special database connection and want to copy it in from a real db.
+ */
+int
+sqlite_db_backup_from_file(pTHX_ SV *dbh, char *filename)
+{
+    int rc;
+    sqlite3 *pFrom;
+    sqlite3_backup *pBackup;
+
+    D_imp_dbh(dbh);
+
+    rc = sqlite3_open(filename, &pFrom);
+    if (rc==SQLITE_OK) {
+
+        pBackup = sqlite3_backup_init(imp_dbh->db, "main", pFrom, "main");
+        if (pBackup) {
+            (void)sqlite3_backup_step(pBackup, -1);
+            (void)sqlite3_backup_finish(pBackup);
+        }
+        rc = sqlite3_errcode(imp_dbh->db);
+        (void)sqlite3_close(pFrom);
+    }
+    return rc;
+}
+
+/* Accesses the SQLite Online Backup API, and copies the currently loaded
+ * database into the passed filename.
+ * Usual usage of this would be when you're operating on the :memory:
+ * special database connection, and want to back it up to an on-disk file.
+ */
+int
+sqlite_db_backup_to_file(pTHX_ SV *dbh, char *filename)
+{
+    int rc;
+    sqlite3 *pTo;
+    sqlite3_backup *pBackup;
+
+    D_imp_dbh(dbh);
+
+    rc = sqlite3_open(filename, &pTo);
+    if (rc==SQLITE_OK) {
+
+        pBackup = sqlite3_backup_init(pTo, "main", imp_dbh->db, "main");
+        if (pBackup) {
+            (void)sqlite3_backup_step(pBackup, -1);
+            (void)sqlite3_backup_finish(pBackup);
+        }
+        rc = sqlite3_errcode(pTo);
+        (void)sqlite3_close(pTo);
+    }
+    return rc;
+}
+
 /* end */

dbdimp.h

@@ -79,6 +79,8 @@ void sqlite3_db_progress_handler(pTHX_ SV *dbh, int n_opcodes, SV *handler);
 void sqlite_st_reset(pTHX_ SV *sth );
 int sqlite_bind_col( SV *sth, imp_sth_t *imp_sth, SV *col, SV *ref, IV sql_type, SV *attribs );
 int dbd_set_sqlite3_busy_timeout (pTHX_ SV *dbh, int timeout );
+int sqlite_db_backup_from_file(pTHX_ SV *dbh, char *filename);
+int sqlite_db_backup_to_file(pTHX_ SV *dbh, char *filename);
 
 #ifdef SvUTF8_on
 

lib/DBD/SQLite.pm

@@ -32,6 +32,8 @@ sub driver {
     if (!$methods_are_installed && $DBI::VERSION >= 1.608) {
         DBI->setup_driver('DBD::SQLite');
         DBD::SQLite::db->install_method('sqlite_last_insert_rowid');
+        DBD::SQLite::db->install_method('sqlite_backup_from_file');
+        DBD::SQLite::db->install_method('sqlite_backup_to_file');
         $methods_are_installed++;
     }
 
@@ -734,6 +736,18 @@ progress handler.
 
 =back
 
+=head2 $dbh->sqlite_backup_from_file( $filename )
+
+This method accesses the SQLite Online Backup API, and will take a backup of
+the named database file, copying it to, and overwriting, your current database
+connection. This can be particularly handy if your current connection is to the
+special :memory: database, and you wish to populate it from an existing DB.
+
+=head2 $dbh->sqlite_backup_to_file( $filename )
+
+This method accesses the SQLite Online Backup API, and will take a backup of
+the currently connected database, and write it out to the named file.
+
 =head1 BLOBS
 
 As of version 1.11, blobs should "just work" in SQLite as text columns.

t/34_online_backup.t

@@ -0,0 +1,64 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More;
+use t::lib::Test;
+use DBI;
+
+BEGIN {
+	plan skip_all => 'requires DBI v1.608' if $DBI::VERSION < 1.608;
+}
+
+plan tests => 4;
+
+# Connect to the test db and add some stuff:
+my $foo = connect_ok( RaiseError => 1 );
+$foo->do(
+    'CREATE TABLE online_backup_test( id INTEGER PRIMARY KEY, foo INTEGER )'
+);
+$foo->do("INSERT INTO online_backup_test (foo) VALUES ($$)");
+
+# That should be in the "foo" database on disk now, so disconnect and try to
+# back it up:
+
+$foo->disconnect;
+
+my $dbh = DBI->connect(
+    'dbi:SQLite:dbname=:memory:',
+    undef, undef,
+    { RaiseError => 1 }
+);
+
+$dbh->sqlite_backup_from_file('foo');
+
+{
+    my ($count) = $dbh->selectrow_array(
+        "SELECT count(foo) FROM online_backup_test WHERE foo=$$"
+    );
+    is($count, 1, "Found our process ID in backed-up table");
+}
+
+# Add more data then attempt to copy it back to file:
+$dbh->do(
+    'CREATE TABLE online_backup_test2 ( id INTEGER PRIMARY KEY, foo INTEGER )'
+);
+$dbh->do("INSERT INTO online_backup_test2 (foo) VALUES ($$)");
+
+# backup to file (foo):
+$dbh->sqlite_backup_to_file('foo');
+
+$dbh->disconnect;
+
+# Reconnect to foo db and check data made it over:
+{
+    my $foo = connect_ok( RaiseError => 1 );
+
+    my ($count) = $foo->selectrow_array(
+        "SELECT count(foo) FROM online_backup_test2 WHERE foo=$$"
+    );
+    is($count, 1, "Found our process ID in table back on disk");
+
+    $foo->disconnect;
+}

t/34_online_backup_func.t

@@ -0,0 +1,58 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More tests => 4;
+use t::lib::Test;
+use DBI;
+
+# Connect to the test db and add some stuff:
+my $foo = connect_ok( RaiseError => 1 );
+$foo->do(
+    'CREATE TABLE online_backup_test( id INTEGER PRIMARY KEY, foo INTEGER )'
+);
+$foo->do("INSERT INTO online_backup_test (foo) VALUES ($$)");
+
+# That should be in the "foo" database on disk now, so disconnect and try to
+# back it up:
+
+$foo->disconnect;
+
+my $dbh = DBI->connect(
+    'dbi:SQLite:dbname=:memory:',
+    undef, undef,
+    { RaiseError => 1 }
+);
+
+$dbh->func('foo', 'backup_from_file');
+
+{
+    my ($count) = $dbh->selectrow_array(
+        "SELECT count(foo) FROM online_backup_test WHERE foo=$$"
+    );
+    is($count, 1, "Found our process ID in backed-up table");
+}
+
+# Add more data then attempt to copy it back to file:
+$dbh->do(
+    'CREATE TABLE online_backup_test2 ( id INTEGER PRIMARY KEY, foo INTEGER )'
+);
+$dbh->do("INSERT INTO online_backup_test2 (foo) VALUES ($$)");
+
+# backup to file (foo):
+$dbh->func('foo', 'backup_to_file');
+
+$dbh->disconnect;
+
+# Reconnect to foo db and check data made it over:
+{
+    my $foo = connect_ok( RaiseError => 1 );
+
+    my ($count) = $foo->selectrow_array(
+        "SELECT count(foo) FROM online_backup_test2 WHERE foo=$$"
+    );
+    is($count, 1, "Found our process ID in table back on disk");
+
+    $foo->disconnect;
+}