/// <summary>
/// Constructs a <see cref="SourceText"/> from stream content.
/// </summary>
/// <param name="stream">Stream. The stream must be seekable.</param>
/// <param name="encoding">
/// Data encoding to use if the stream doesn't start with Byte Order Mark specifying the encoding.
/// <see cref="Encoding.UTF8"/> if not specified.
/// </param>
/// <param name="checksumAlgorithm">
/// Hash algorithm to use to calculate checksum of the text that's saved to PDB.
/// </param>
/// <param name="throwIfBinaryDetected">If the decoded text contains at least two consecutive NUL
/// characters, then an <see cref="InvalidDataException"/> is thrown.</param>
///
/// <exception cref="ArgumentNullException"><paramref name="stream"/> is null.</exception>
/// <exception cref="ArgumentException">
/// <paramref name="stream"/> doesn't support reading or seeking.
/// <paramref name="checksumAlgorithm"/> is not supported.
/// </exception>
/// <exception cref="DecoderFallbackException">If the given encoding is set to use a throwing decoder as a fallback</exception>
/// <exception cref="InvalidDataException">Two consecutive NUL characters were detected in the decoded text and <paramref name="throwIfBinaryDetected"/> was true.</exception>
/// <exception cref="IOException">An I/O error occurs.</exception>
/// <remarks>Reads from the beginning of the stream. Leaves the stream open.</remarks>
public static SourceText From(
Stream stream,
Encoding?encoding = null,
SourceHashAlgorithm checksumAlgorithm = SourceHashAlgorithm.Sha1,
bool throwIfBinaryDetected = false)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
if (!stream.CanRead)
{
throw new ArgumentException(CodeAnalysisResources.StreamMustSupportReadAndSeek, nameof(stream));
}
ValidateChecksumAlgorithm(checksumAlgorithm);
encoding ??= s_utf8EncodingWithNoBOM;
if (stream.CanSeek)
{
// If the resulting string would end up on the large object heap, then use LargeEncodedText.
if (encoding.GetMaxCharCountOrThrowIfHuge(stream) >= LargeObjectHeapLimitInChars)
{
return(LargeText.Decode(stream, encoding, checksumAlgorithm, throwIfBinaryDetected));
}
}
var text = Decode(stream, encoding, out encoding);
if (throwIfBinaryDetected && IsBinary(text))
{
throw new InvalidDataException();
}
// We must compute the checksum and embedded text blob now while we still have the original bytes in hand.
// We cannot re-encode to obtain checksum and blob as the encoding is not guaranteed to round-trip.
var checksum = CalculateChecksum(stream, checksumAlgorithm);
return(new StringText(text, encoding, checksum, checksumAlgorithm));
}
/// <summary>
/// Constructs a <see cref="SourceText"/> from text in a string.
/// </summary>
/// <param name="reader">TextReader</param>
/// <param name="length">length of content from <paramref name="reader"/></param>
/// <param name="encoding">
/// Encoding of the file that the <paramref name="reader"/> was read from or is going to be saved to.
/// <c>null</c> if the encoding is unspecified.
/// If the encoding is not specified the resulting <see cref="SourceText"/> isn't debuggable.
/// If an encoding-less <see cref="SourceText"/> is written to a file a <see cref="Encoding.UTF8"/> shall be used as a default.
/// </param>
/// <param name="checksumAlgorithm">
/// Hash algorithm to use to calculate checksum of the text that's saved to PDB.
/// </param>
/// <exception cref="ArgumentNullException"><paramref name="reader"/> is null.</exception>
/// <exception cref="ArgumentException"><paramref name="checksumAlgorithm"/> is not supported.</exception>
public static SourceText From(
TextReader reader,
int length,
Encoding?encoding = null,
SourceHashAlgorithm checksumAlgorithm = SourceHashAlgorithm.Sha1)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
// If the resulting string would end up on the large object heap, then use LargeEncodedText.
if (length >= LargeObjectHeapLimitInChars)
{
return(LargeText.Decode(reader, length, encoding, checksumAlgorithm));
}
var text = reader.ReadToEnd();
return(From(text, encoding, checksumAlgorithm));
}