public async Task <IEnumerable <AssetIndexRecord> > GetAllAssetRecordsAsync(CancellationToken cancellationToken = default(CancellationToken))
{
var result = new ConcurrentBag <AssetIndexRecord>();
try {
LOG.Debug($"Opening Index DB '{_indexDbPath}'");
await _indexDbConnection.OpenAsync(cancellationToken);
var sql = "SELECT asset_id, position, type, created_on, deleted FROM VFSDataIndex";
var command = new SqliteCommand(sql, _indexDbConnection);
using (var reader = await command.ExecuteReaderAsync(cancellationToken)) {
while (await reader.ReadAsync(cancellationToken))
{
var idString = (string)reader["asset_id"];
Guid id;
if (!Guid.TryParse(idString, out id))
{
LOG.Warn($"Found invalid asset ID '{idString}' in '{_indexDbPath}'.");
continue;
}
/* BUG: Invalid cast exceptions...
* var createdOnString = (string)reader["created_on"];
* DateTimeOffset createdOn;
* if (!DateTimeOffset.TryParse(createdOnString, out createdOn)) {
* LOG.Warn($"Found invalid asset creation date '{createdOnString}' in '{_indexDbPath}'.");
* continue;
* }
*/
var position = (long)reader["position"];
var type = (byte)(long)reader["type"]; // Don't you love SQLite?
var deleted = (byte)reader["deleted"] == 1;
var indexRecord = new AssetIndexRecord {
//CreatedOn = createdOn,
DataFilePosition = position,
Deleted = deleted,
Id = id,
Scope = _scope,
Type = type,
};
result.Add(indexRecord);
}
}
_indexDbConnection.Close();
LOG.Debug($"Closed Index DB '{_indexDbPath}'");
}
catch (Exception e) {
LOG.Error($"Error reading all asset index records from Index DB '{_indexDbPath}'", e);
throw;
}
return(result);
}
public async Task <Asset> GetAssetAsync(AssetIndexRecord indexRecord, CancellationToken cancellationToken = default(CancellationToken))
{
Contract.Requires(indexRecord != null);
Contract.Requires(indexRecord.DataFilePosition > 0);
LOG.Debug($"Reading asset ID '{indexRecord.Id}' from Data DB '{_dataDbPath}'");
try {
int assetLength;
using (var stream = _mmf.CreateViewStream(indexRecord.DataFilePosition, 4)) {
// Read the asset size (first 4 bytes) stored in network byte order
var lengthBytes = new byte[4];
await stream.ReadAsync(lengthBytes, 0, 4, cancellationToken);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(lengthBytes);
}
assetLength = BitConverter.ToInt32(lengthBytes, 0);
}
using (var stream = _mmf.CreateViewStream(indexRecord.DataFilePosition + 4, assetLength)) {
// Read in the asset
var assetData = new byte[assetLength];
await stream.ReadAsync(assetData, 0, assetLength, cancellationToken);
return(new Asset {
RawData = assetData,
});
}
}
catch (Exception e) {
LOG.Error($"Error reading asset ID '{indexRecord.Id}' from Data DB '{_dataDbPath}'", e);
throw;
}
}