/// <summary>

/// Delegate called to convert the given native data to its backand representation.

/// </summary>

internal delegate byte[] ConvertNativeToBackendTextHandler(NpgsqlNativeTypeInfo TypeInfo, Object NativeData, Boolean forExtendedQuery, NativeToBackendTypeConverterOptions options, bool arrayElement);

internal delegate byte[] ConvertNativeToBackendBinaryHandler(NpgsqlNativeTypeInfo TypeInfo, Object NativeData, NativeToBackendTypeConverterOptions options);

internal delegate object ConvertProviderTypeToFrameworkTypeHander(object value);

internal delegate object ConvertFrameworkTypeToProviderTypeHander(object value);

/// <summary>

/// Represents a backend data type.

/// This class can be called upon to convert a native object to its backend field representation,

/// </summary>

internal class NpgsqlNativeTypeInfo

{

private static readonly NumberFormatInfo ni;

private readonly ConvertNativeToBackendTextHandler _ConvertNativeToBackendText;

private readonly ConvertNativeToBackendBinaryHandler _ConvertNativeToBackendBinary;

private readonly String _Name;

private readonly string _CastName;

private readonly NpgsqlDbType _NpgsqlDbType;

private readonly DbType _DbType;

private readonly Boolean _Quote;

private readonly Boolean _UseSize;

private Boolean _IsArray = false;

/// <summary>

/// Returns an NpgsqlNativeTypeInfo for an array where the elements are of the type

/// described by the NpgsqlNativeTypeInfo supplied.

/// </summary>

public static NpgsqlNativeTypeInfo ArrayOf(NpgsqlNativeTypeInfo elementType)

{

if (elementType._IsArray)

//we've an array of arrays. It's the inner most elements whose type we care about, so the type we have is fine.

{

return elementType;

}

NpgsqlNativeTypeInfo copy = null;

ArrayNativeToBackendTypeConverter converter = new ArrayNativeToBackendTypeConverter(elementType);

if (elementType._ConvertNativeToBackendBinary != null)

{

copy = new NpgsqlNativeTypeInfo("_" + elementType.Name, NpgsqlDbType.Array | elementType.NpgsqlDbType, elementType.DbType,

false,

converter.ArrayToArrayText,

converter.ArrayToArrayBinary);

}

else

{

copy = new NpgsqlNativeTypeInfo("_" + elementType.Name, NpgsqlDbType.Array | elementType.NpgsqlDbType, elementType.DbType,

false,

converter.ArrayToArrayText);

}

copy._IsArray = true;

return copy;

}

static NpgsqlNativeTypeInfo()

{

ni = (NumberFormatInfo) CultureInfo.InvariantCulture.NumberFormat.Clone();

ni.NumberDecimalDigits = 15;

}

internal static NumberFormatInfo NumberFormat

{

get { return ni; }

}

/// <summary>

/// Construct a new NpgsqlTypeInfo with the given attributes and conversion handlers.

/// </summary>

/// <param name="Name">Type name provided by the backend server.</param>

/// <param name="DbType">DbType</param>

/// <param name="Quote">Quote</param>

/// <param name="NpgsqlDbType">NpgsqlDbType</param>

/// <param name="ConvertNativeToBackendText">Data conversion handler for text backend encoding.</param>

/// <param name="ConvertNativeToBackendBinary">Data conversion handler for binary backend encoding (for extended queries).</param>

public NpgsqlNativeTypeInfo(String Name, NpgsqlDbType NpgsqlDbType, DbType DbType, Boolean Quote,

ConvertNativeToBackendTextHandler ConvertNativeToBackendText = null,

ConvertNativeToBackendBinaryHandler ConvertNativeToBackendBinary = null)

{

_Name = Name;

_CastName = Name.StartsWith("_") ? Name.Substring(1) + "[]" : Name;

_NpgsqlDbType = NpgsqlDbType;

_DbType = DbType;

_Quote = Quote;

_ConvertNativeToBackendText = ConvertNativeToBackendText;

_ConvertNativeToBackendBinary = ConvertNativeToBackendBinary;

// The only parameters types which use length currently supported are char and varchar. Check for them.

if ((NpgsqlDbType == NpgsqlDbType.Char) || (NpgsqlDbType == NpgsqlDbType.Varchar))

{

_UseSize = true;

}

else

{

_UseSize = false;

}

}

/// <summary>

/// Type name provided by the backend server.

/// </summary>

public String Name

{

get { return _Name; }

}

public string CastName

{

get { return _CastName; }

}

public bool IsArray

{

get { return _IsArray; }

}

/// <summary>

/// NpgsqlDbType.

/// </summary>

public NpgsqlDbType NpgsqlDbType

{

get { return _NpgsqlDbType; }

}

/// <summary>

/// DbType.

/// </summary>

public DbType DbType

{

get { return _DbType; }

}

/// <summary>

/// Apply quoting.

/// </summary>

public Boolean Quote

{

get { return _Quote; }

}

/// <summary>

/// Use parameter size information.

/// </summary>

public Boolean UseSize

{

get { return _UseSize; }

}

/// <summary>

/// Perform a data conversion from a native object to

/// a backend representation.

/// DBNull and null values are handled differently depending if a plain query is used

/// When

/// </summary>

/// <param name="NativeData">Native .NET object to be converted.</param>

/// <param name="forExtendedQuery">Specifies that the value should be formatted for the extended query syntax.</param>

/// <param name="options">Options to guide serialization. If null, a default options set is used.</param>

/// <param name="arrayElement">Specifies that the value should be formatted as an extended query array element.</param>

public byte[] ConvertToBackend(Object NativeData, Boolean forExtendedQuery, NativeToBackendTypeConverterOptions options = null, bool arrayElement = false)

{

if (options == null)

{

options = NativeToBackendTypeConverterOptions.Default;

}

if (forExtendedQuery)

{

return ConvertToBackendExtendedQuery(NativeData, options, arrayElement);

}

else

{

return ConvertToBackendPlainQuery(NativeData, options, arrayElement);

}

}

private byte[] ConvertToBackendPlainQuery(Object NativeData, NativeToBackendTypeConverterOptions options, bool arrayElement)

{

if ((NativeData == DBNull.Value) || (NativeData == null))

{

return ASCIIByteArrays.NULL; // Plain queries exptects null values as string NULL.

}

if (_ConvertNativeToBackendText != null)

{

byte[] backendSerialization;

// This path is responsible for escaping, and may also add quoting and the E prefix.

backendSerialization = (_ConvertNativeToBackendText(this, NativeData, false, options, arrayElement));

if (Quote)

{

backendSerialization = QuoteASCIIString(backendSerialization, false, arrayElement);

}

return backendSerialization;

}

else if (NativeData is Enum)

{

byte[] backendSerialization;

// Do a special handling of Enum values.

// Translate enum value to its underlying type.

backendSerialization =

BackendEncoding.UTF8Encoding.GetBytes(

(String)Convert.ChangeType(

Enum.Format(NativeData.GetType(), NativeData, "d"),

typeof(String), CultureInfo.InvariantCulture

)

);

backendSerialization = QuoteASCIIString(backendSerialization, false, arrayElement);

return backendSerialization;

}

else

{

byte[] backendSerialization;

if (NativeData is IFormattable)

{

backendSerialization = BackendEncoding.UTF8Encoding.GetBytes(((IFormattable)NativeData).ToString(null, ni));

}

else

{

backendSerialization = BackendEncoding.UTF8Encoding.GetBytes(NativeData.ToString());

}

if (Quote)

{

backendSerialization = QuoteASCIIString(backendSerialization, false, arrayElement);

}

return backendSerialization;

}

}

private byte[] ConvertToBackendExtendedQuery(Object NativeData, NativeToBackendTypeConverterOptions options, bool arrayElement)

{

if ((NativeData == DBNull.Value) || (NativeData == null))

{

return null; // Extended query expects null values be represented as null.

}

if (! NpgsqlTypesHelper.SuppressBinaryBackendEncoding && _ConvertNativeToBackendBinary != null)

{

return _ConvertNativeToBackendBinary(this, NativeData, options);

}

else if (_ConvertNativeToBackendText != null)

{

byte[] backendSerialization;

backendSerialization = _ConvertNativeToBackendText(this, NativeData, true, options, arrayElement);

if (Quote)

{

backendSerialization = QuoteASCIIString(backendSerialization, true, arrayElement);

}

return backendSerialization;

}

else

{

byte[] backendSerialization;

if (NativeData is Enum)

{

// Do a special handling of Enum values.

// Translate enum value to its underlying type.

backendSerialization = BackendEncoding.UTF8Encoding.GetBytes((String)

Convert.ChangeType(Enum.Format(NativeData.GetType(), NativeData, "d"), typeof (String),

CultureInfo.InvariantCulture));

}

else if (NativeData is IFormattable)

{

backendSerialization = BackendEncoding.UTF8Encoding.GetBytes(((IFormattable) NativeData).ToString(null, ni));

}

else

{

backendSerialization = BackendEncoding.UTF8Encoding.GetBytes(NativeData.ToString());

}

if (Quote)

{

backendSerialization = QuoteASCIIString(backendSerialization, true, arrayElement);

}

return backendSerialization;

}

}

private static byte[] QuoteASCIIString(byte[] src, bool forExtendedQuery, bool arrayElement)

{

byte[] ret = null;

if (arrayElement)

{

// Array elements always require double-quotes

ret = new byte[src.Length + 2];

ret[0] = (byte)ASCIIBytes.DoubleQuote;

src.CopyTo(ret, 1);

ret[ret.Length - 1] = (byte)ASCIIBytes.DoubleQuote;

}

else

{

if (forExtendedQuery)

{

// Non-array-element values sent via Bind are not quoted

ret = src;

}

else

{

// Non-array-element values sent via simple query require single-quotes

ret = new byte[src.Length + 2];

ret[0] = (byte)ASCIIBytes.SingleQuote;

src.CopyTo(ret, 1);

ret[ret.Length - 1] = (byte)ASCIIBytes.SingleQuote;

}

}

return ret;

}

/// <summary>

/// Reports whether a native to backend binary encoder is available for this type.

/// </summary>

public bool SupportsBinaryBackendData

{

get { return (! NpgsqlTypesHelper.SuppressBinaryBackendEncoding && _ConvertNativeToBackendBinary != null); }

}

}