public async Task WriteMetadataAsync(IDictionary <string, string> metadata)
{
try
{
using (var command = new SQLiteCommand("create table if not exists metadata (name string, value string)", connection))
{
await command.ExecuteNonQueryAsync();
}
using (var command = new SQLiteCommand("insert or replace into metadata (name, value) values (@n, @v)", connection))
{
foreach (var keyValue in metadata)
{
command.Parameters.AddWithValue("@n", keyValue.Key);
command.Parameters.AddWithValue("@v", keyValue.Value);
await command.ExecuteNonQueryAsync();
}
}
}
catch (Exception ex)
{
Debug.WriteLine("MBTileData: " + ex.Message);
}
}
public async Task WriteImageBufferAsync(int x, int y, int zoomLevel, byte[] imageBuffer)
{
try
{
using (var command = new SQLiteCommand("create table if not exists tiles (zoom_level integer, tile_column integer, tile_row integer, tile_data blob)", connection))
{
await command.ExecuteNonQueryAsync();
}
using (var command = new SQLiteCommand("insert or replace into tiles (zoom_level, tile_column, tile_row, tile_data) values (@z, @x, @y, @b)", connection))
{
command.Parameters.AddWithValue("@z", zoomLevel);
command.Parameters.AddWithValue("@x", x);
command.Parameters.AddWithValue("@y", (1 << zoomLevel) - y - 1);
command.Parameters.AddWithValue("@b", imageBuffer);
await command.ExecuteNonQueryAsync();
}
}
catch (Exception ex)
{
Debug.WriteLine("MBTileData: {0}/{1}/{2}: {3}", zoomLevel, x, y, ex.Message);
}
}
private async Task InitializeAsync(CancellationToken cancel)
{
_logger.LogInformation("Initializing db cache: {ConnectionString}",
_config.ConnectionString);
using (var transaction = _db.BeginTransaction())
{
using (var cmd = new DbCommand(Resources.TableInitCommand, _db))
{
cmd.Transaction = transaction;
await cmd.ExecuteNonQueryAsync(cancel);
}
using (var cmd = new DbCommand(
$"INSERT INTO meta (key, value) " +
$"VALUES " +
$@"(""version"", {SchemaVersion}), " +
$@"(""created"", {DateTimeOffset.UtcNow.Ticks})", _db))
{
cmd.Transaction = transaction;
await cmd.ExecuteNonQueryAsync(cancel);
}
transaction.Commit();
}
}