/// <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 || !stream.CanSeek) { throw new ArgumentException(CodeAnalysisResources.StreamMustSupportReadAndSeek, nameof(stream)); } ValidateChecksumAlgorithm(checksumAlgorithm); encoding = encoding ?? s_utf8EncodingWithNoBOM; // If the resulting string would end up on the large object heap, then use LargeEncodedText. if (encoding.GetMaxCharCount((int)stream.Length) >= LargeObjectHeapLimitInChars) { return(LargeEncodedText.Decode(stream, encoding, checksumAlgorithm, throwIfBinaryDetected)); } string text = Decode(stream, encoding, out encoding); if (throwIfBinaryDetected && IsBinary(text)) { throw new InvalidDataException(); } var checksum = CalculateChecksum(stream, checksumAlgorithm); return(new StringText(text, encoding, checksum, checksumAlgorithm)); }
/// <summary> /// Try to create a <see cref="EncodedStringText"/> from the given stream using the given encoding. /// </summary> /// <param name="data">The input stream containing the encoded text. The stream will not be closed.</param> /// <param name="encoding">The expected encoding of the stream. The actual encoding used may be different if byte order marks are detected.</param> /// <param name="checksumAlgorithm">The checksum algorithm to use.</param> /// <param name="throwIfBinaryDetected">Throw <see cref="InvalidDataException"/> if binary (non-text) data is detected.</param> /// <returns>The <see cref="EncodedStringText"/> decoded from the stream.</returns> /// <exception cref="DecoderFallbackException">The decoder was unable to decode the stream with the given encoding.</exception> /// <remarks> /// internal for unit testing /// </remarks> internal static SourceText Decode(Stream data, Encoding encoding, SourceHashAlgorithm checksumAlgorithm, bool throwIfBinaryDetected = false) { data.Seek(0, SeekOrigin.Begin); if (data.Length > LargeObjectHeapLimit) { return(LargeEncodedText.Decode(data, encoding, checksumAlgorithm, throwIfBinaryDetected)); } Encoding actualEncoding; ImmutableArray <byte> checksum = default(ImmutableArray <byte>); string text; byte[] buffer = TryGetByteArrayFromStream(data); if (buffer != null) { text = Decode(buffer, (int)data.Length, encoding, out actualEncoding); // Since we have the buffer, compute the checksum here. This saves allocations if we later // need to write out debugging information. checksum = CalculateChecksum(buffer, offset: 0, count: (int)data.Length, algorithmId: checksumAlgorithm); } else { text = Decode(data, encoding, out actualEncoding); } return(new EncodedStringText(text, actualEncoding, checksum, checksumAlgorithm, throwIfBinary: throwIfBinaryDetected)); }