Class: SQLite3::Backup

Inherits:
Object
  • Object
show all
Defined in:
ext/sqlite3/backup.c

Instance Method Summary collapse

Constructor Details

#SQLite3::Backup.new(dstdb, dstname, srcdb, srcname) ⇒ Object

Initialize backup the backup.

dstdb:

the destination SQLite3::Database object.

dstname:

the destination's database name.

srcdb:

the source SQLite3::Database object.

srcname:

the source's database name.

The database name is “main”, “temp”, or the name specified in an ATTACH statement.

This feature requires SQLite 3.6.11 or later.

require 'sqlite3'
sdb = SQLite3::Database.new('src.sqlite3')

ddb = SQLite3::Database.new(':memory:')
b = SQLite3::Backup.new(ddb, 'main', sdb, 'main')
p [b.remaining, b.pagecount] # invalid value; for example [0, 0]
begin
  p b.step(1) #=> OK or DONE
  p [b.remaining, b.pagecount]
end while b.remaining > 0
b.finish

ddb = SQLite3::Database.new(':memory:')
b = SQLite3::Backup.new(ddb, 'main', sdb, 'main')
b.step(-1) #=> DONE
b.finish


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
# File 'ext/sqlite3/backup.c', line 72

static VALUE initialize(VALUE self, VALUE dstdb, VALUE dstname, VALUE srcdb, VALUE srcname)
{
  sqlite3BackupRubyPtr ctx;
  sqlite3RubyPtr ddb_ctx, sdb_ctx;
  sqlite3_backup *pBackup;

  TypedData_Get_Struct(self, sqlite3BackupRuby, &backup_type, ctx);
  ddb_ctx = sqlite3_database_unwrap(dstdb);
  sdb_ctx = sqlite3_database_unwrap(srcdb);

  if(!sdb_ctx->db)
    rb_raise(rb_eArgError, "cannot backup from a closed database");
  if(!ddb_ctx->db)
    rb_raise(rb_eArgError, "cannot backup to a closed database");

  pBackup = sqlite3_backup_init(ddb_ctx->db, StringValuePtr(dstname),
    sdb_ctx->db, StringValuePtr(srcname));
  if( pBackup ){
    ctx->p = pBackup;
  }
  else {
    CHECK(ddb_ctx->db, sqlite3_errcode(ddb_ctx->db));
  }

  return self;
}

Instance Method Details

#SQLite3::BackupObject

Destroy the backup object.



123
124
125
126
127
128
129
130
131
132
# File 'ext/sqlite3/backup.c', line 123

static VALUE finish(VALUE self)
{
  sqlite3BackupRubyPtr ctx;

  TypedData_Get_Struct(self, sqlite3BackupRuby, &backup_type, ctx);
  REQUIRE_OPEN_BACKUP(ctx);
  (void)sqlite3_backup_finish(ctx->p);
  ctx->p = NULL;
  return Qnil;
}

#SQLite3::BackupObject

Returns the total number of pages in the source database file.

Note that the value is only updated after step() is called, so before calling step() returned value is invalid.



157
158
159
160
161
162
163
164
# File 'ext/sqlite3/backup.c', line 157

static VALUE pagecount(VALUE self)
{
  sqlite3BackupRubyPtr ctx;

  TypedData_Get_Struct(self, sqlite3BackupRuby, &backup_type, ctx);
  REQUIRE_OPEN_BACKUP(ctx);
  return INT2NUM(sqlite3_backup_pagecount(ctx->p));
}

#SQLite3::BackupObject

Returns the number of pages still to be backed up.

Note that the value is only updated after step() is called, so before calling step() returned value is invalid.



141
142
143
144
145
146
147
148
# File 'ext/sqlite3/backup.c', line 141

static VALUE remaining(VALUE self)
{
  sqlite3BackupRubyPtr ctx;

  TypedData_Get_Struct(self, sqlite3BackupRuby, &backup_type, ctx);
  REQUIRE_OPEN_BACKUP(ctx);
  return INT2NUM(sqlite3_backup_remaining(ctx->p));
}

#SQLite3::BackupObject

Copy database pages up to nPage. If negative, copy all remaining source pages.

If all pages are copied, it returns SQLite3::Constants::ErrorCode::DONE. When coping is not done, it returns SQLite3::Constants::ErrorCode::OK. When some errors occur, it returns the error code.



108
109
110
111
112
113
114
115
116
117
# File 'ext/sqlite3/backup.c', line 108

static VALUE step(VALUE self, VALUE nPage)
{
  sqlite3BackupRubyPtr ctx;
  int status;

  TypedData_Get_Struct(self, sqlite3BackupRuby, &backup_type, ctx);
  REQUIRE_OPEN_BACKUP(ctx);
  status = sqlite3_backup_step(ctx->p, NUM2INT(nPage));
  return INT2NUM(status);
}