/// <summary>
/// Construct a new record
/// </summary>
/// <param name="type"></param>
/// <param name="name"></param>
/// <param name="address"></param>
public NameRecord(NameRecordType type, string name, Reference address = null)
{
Name = name;
Id = name;
Address = address ?? new Reference();
Type = type;
}
/// <summary>
/// Match record against address and type
/// </summary>
/// <param name="record"></param>
/// <param name="address"></param>
/// <param name="type"></param>
/// <returns></returns>
public static bool Matches(this INameRecord record, Reference address, NameRecordType type)
{
if (!record.Type.HasFlag(type))
{
return(false);
}
return(address == Reference.All || record.Address.Equals(address));
}
public ResourceRecord(NameRecordType type)
{
Name = String.Empty;
Type = type;
Class = ResourceRecordClass.In;
TTL = (uint)new TimeSpan(7, 0, 0, 0).TotalSeconds;
Data = new byte[0];
}
public ResourceRecord(byte[] buffer, ref int offset)
{
Name = NetBiosUtils.DecodeName(buffer, ref offset);
Type = (NameRecordType)BigEndianReader.ReadUInt16(buffer, ref offset);
Class = (ResourceRecordClass)BigEndianReader.ReadUInt16(buffer, ref offset);
TTL = BigEndianReader.ReadUInt32(buffer, ref offset);
ushort dataLength = BigEndianReader.ReadUInt16(buffer, ref offset);
Data = ByteReader.ReadBytes(buffer, ref offset, dataLength);
}
/// <summary>
/// Match record against name and type
/// </summary>
/// <param name="record"></param>
/// <param name="name"></param>
/// <param name="type"></param>
/// <returns></returns>
public static bool Matches(this INameRecord record, string name, NameRecordType type)
{
if (!record.Type.HasFlag(type))
{
return(false);
}
return(name == null ||
(record.Name.Equals(name, StringComparison.CurrentCultureIgnoreCase) ||
record.Id.Equals(name, StringComparison.CurrentCultureIgnoreCase)));
}
/// <summary>
/// Match record against address
/// </summary>
/// <param name="record"></param>
/// <param name="address"></param>
/// <param name="type"></param>
/// <returns></returns>
public static bool Matches(this INameRecord record, SocketAddress address,
NameRecordType type)
{
if (address.Family == AddressFamily.Collection)
{
return(Matches(record, (SocketAddressCollection)address, type));
}
if (Matches(record, address.ToString(), type))
{
return(true);
}
if (address.Family == AddressFamily.InterNetworkV6)
{
return(Matches(record, Reference.FromSocketAddress((Inet6SocketAddress)address), type));
}
return(false);
}
/// <summary>
/// Create record type expression from type
/// </summary>
/// <param name="type"></param>
/// <returns></returns>
private static string CreateQueryString(NameRecordType type, bool filterAlive = false)
{
var sql = new StringBuilder("SELECT * FROM devices WHERE ");
var concat = false;
// No support for bit queries ...
if (0 != (type & NameRecordType.Proxy))
{
sql.Append("(");
sql.Append("tags.proxy=1");
concat = true;
}
if (0 != (type & NameRecordType.Host))
{
sql.Append(concat ? " OR " : "(");
sql.Append("tags.host=1");
concat = true;
}
if (0 != (type & NameRecordType.Link))
{
sql.Append(concat ? " OR " : "(");
sql.Append("tags.link=1");
concat = true;
}
if (concat)
{
sql.Append(")");
if (filterAlive)
{
sql.Append(" AND ");
}
}
if (filterAlive)
{
sql.Append("properties.reported.alive = 1");
}
return(sql.ToString());
}
/// <summary>
/// Lookup record by record type
/// </summary>
/// <param name="name"></param>
/// <param name="type"></param>
/// <param name="ct"></param>
/// <returns></returns>
public async Task <IEnumerable <INameRecord> > LookupAsync(string name, NameRecordType type,
CancellationToken ct)
{
if (string.IsNullOrEmpty(name))
{
throw new ArgumentException(nameof(name));
}
name = name.ToLowerInvariant();
if (NameRecordType.Host == (type & NameRecordType.Host))
{
// Use cache to look up a host record
INameRecord record;
if (_cache.TryGetValue(name, out record) && record.References.Any())
{
return(new NameRecord(record).AsEnumerable());
}
}
var sql = new StringBuilder("SELECT * FROM devices WHERE ");
sql.Append("(deviceId = '");
sql.Append(name);
if (NameRecordType.Proxy == (type & NameRecordType.Proxy))
{
sql.Append("' OR tags.name = '");
sql.Append(name);
}
Reference address;
if (Reference.TryParse(name, out address))
{
sql.Append("' OR tags.address = '");
sql.Append(address.ToString().ToLower());
}
sql.Append("') AND ");
sql.Append(IoTHubRecord.CreateTypeQueryString(type));
return(await LookupAsync(sql.ToString(), ct).ConfigureAwait(false));
}
/// <summary>
/// Create record type expression from type
/// </summary>
/// <param name="type"></param>
/// <returns></returns>
internal static string CreateTypeQueryString(NameRecordType type)
{
var sql = new StringBuilder("(");
bool concat = false;
// No support for bit queries ...
if (0 != (type & NameRecordType.Proxy))
{
sql.Append("tags.proxy=1");
concat = true;
}
if (0 != (type & NameRecordType.Host))
{
if (concat)
{
sql.Append(" OR ");
}
sql.Append("tags.host=1");
concat = true;
}
if (0 != (type & NameRecordType.Link))
{
if (concat)
{
sql.Append(" OR ");
}
sql.Append("tags.link=1");
concat = true;
}
if (!concat)
{
return("");
}
sql.Append(")");
return(sql.ToString());
}
/// <summary>
/// Lookup records by address
/// </summary>
/// <param name="address"></param>
/// <param name="type"></param>
/// <param name="ct"></param>
/// <returns></returns>
public static Task <IEnumerable <INameRecord> > LookupAsync(this INameService service,
Reference address, NameRecordType type, CancellationToken ct) =>
LookupAsync(service, r => r.Matches(address, type), ct);
/// <summary>
/// Lookup records by name
/// </summary>
/// <param name="name"></param>
/// <param name="type"></param>
/// <param name="ct"></param>
/// <returns></returns>
public static Task <IEnumerable <INameRecord> > LookupAsync(this INameService service,
string name, NameRecordType type, CancellationToken ct) =>
LookupAsync(service, r => r.Matches(name, type), ct);
/// <summary>
/// Match record against list of addresses
/// </summary>
/// <param name="record"></param>
/// <param name="addresses"></param>
/// <param name="type"></param>
/// <returns></returns>
public static bool Matches(this INameRecord record, SocketAddressCollection addresses,
NameRecordType type) =>
addresses.Addresses().Any(a => record.Matches(a, type));
/// <summary>
/// Match record against address and type
/// </summary>
/// <param name="record"></param>
/// <param name="addresses"></param>
/// <param name="type"></param>
/// <returns></returns>
public static bool Matches(this INameRecord record, IEnumerable <Reference> addresses,
NameRecordType type) =>
addresses.Any(a => record.Matches(a, type));
public QuestionSection(byte[] buffer, ref int offset)
{
Name = NetBiosUtils.DecodeName(buffer, ref offset);
Type = (NameRecordType)BigEndianReader.ReadUInt16(buffer, ref offset);
Class = (QuestionClass)BigEndianReader.ReadUInt16(buffer, ref offset);
}
/// <summary>
/// Lookup record by address
/// </summary>
/// <param name="address"></param>
/// <param name="type"></param>
/// <param name="ct"></param>
/// <returns></returns>
public async Task <IEnumerable <INameRecord> > LookupAsync(Reference address, NameRecordType type,
CancellationToken ct)
{
if (address == null || address == Reference.Null)
{
throw new ArgumentException(nameof(address));
}
var sql = new StringBuilder("SELECT * FROM devices WHERE ");
if (address != Reference.All)
{
sql.Append("tags.address = '");
sql.Append(address.ToString().ToLower());
sql.Append("' AND ");
}
sql.Append(IoTHubRecord.CreateTypeQueryString(type));
return(await LookupAsync(sql.ToString(), ct).ConfigureAwait(false));
}
