public static bool HasJpgHeader(this HttpPostedFileBase postedFile)
{
if (!postedFile.ContentType.ToLower().Contains("image/jpg") &&
!postedFile.ContentType.ToLower().Contains("image/jpeg"))
{
return(false);
}
using (var br = new NoCloseBinaryReader(postedFile.InputStream))
{
UInt16 soi = br.ReadUInt16(); // Start of Image (SOI) marker (FFD8)
UInt16 jfif = br.ReadUInt16(); // JFIF marker (FFE0)
return(soi == 0xd8ff && jfif == 0xe0ff);
}
}
public static bool HasPdfHeader(this HttpPostedFileBase postedFile)
{
if (!postedFile.ContentType.ToLower().Contains("application/pdf"))
{
return(false);
}
using (var br = new NoCloseBinaryReader(postedFile.InputStream))
{
var buffer = br.ReadBytes(5);
var enc = new ASCIIEncoding();
var header = enc.GetString(buffer);
return(header.StartsWith("%PDF-"));
}
}
/// <summary>
/// Deserializes counter (metric) data from the stream and adds all objects to provided collection.
/// </summary>
/// <param name="stream">Stream from which data should be deserialized. Stream should be readable and provide randon access.</param>
/// <param name="metricBuilder">An object responsible for creation and further consumption of deserialized data.</param>
/// <param name="maxMetricStringsLength">Maximum length of strings, which represent metric name, dimension names and values.</param>
/// <param name="maxMetricNamespaceStringsLength">Maximum length of metric namespace string.</param>
/// <param name="maxMetricDimensionValueStringsLength">Maximum length of metric dimension value string.</param>
public void Deserialize(Stream stream, IMetricBuilder <TMetadata> metricBuilder, int maxMetricStringsLength, int maxMetricNamespaceStringsLength, int maxMetricDimensionValueStringsLength)
{
if (!stream.CanRead || !stream.CanSeek)
{
throw new ArgumentException(@"Stream should be readable and provide random access.", nameof(stream));
}
try
{
using (var reader = new NoCloseBinaryReader(stream, Encoding.UTF8))
{
var startStreamPosition = stream.Position;
// Read version and type serializers info
var version = reader.ReadUInt16();
if (version > MaxVersion)
{
throw new VersionNotSupportedMetricSerializationException(
string.Format(
CultureInfo.InvariantCulture,
"Version is not supported. Read version:{0}, Max version:{1}.",
version,
MaxVersion));
}
if (version >= 5)
{
// Read CRC. CRC check is done in upper layers.
reader.ReadUInt32();
}
if (reader.ReadUInt32() != TypeSerializerFlags)
{
throw new VersionNotSupportedMetricSerializationException("Type serializers not supported.");
}
metricBuilder.SetSerializationVersion(version);
// Read strings
var deserializerDataPosition = stream.Position;
stream.Position += sizeof(long);
stream.Position = startStreamPosition + reader.ReadInt64();
var count = SerializationUtils.ReadUInt32FromBase128(reader);
for (uint i = 0; i < count; ++i)
{
this.stringsDictionary.Add(reader.ReadString());
}
// Read metrics metadata
stream.Position = deserializerDataPosition;
stream.Position = startStreamPosition + reader.ReadInt64();
count = SerializationUtils.ReadUInt32FromBase128(reader);
for (uint i = 0; i < count; ++i)
{
this.metadataDictionary.Add(this.ReadMetricMetadata(reader, metricBuilder, version, maxMetricStringsLength, maxMetricNamespaceStringsLength));
}
// Read metrics data
stream.Position = deserializerDataPosition + (2 * sizeof(long));
this.ReadMetricsData(reader, metricBuilder, version, maxMetricStringsLength, maxMetricNamespaceStringsLength, maxMetricDimensionValueStringsLength);
}
}
catch (IOException ioException)
{
throw new MetricSerializationException("Failed to deserialize data. Problem with input stream.", ioException);
}
catch (Exception exception)
{
throw new MetricSerializationException("Failed to deserialize data. Likely the incoming stream contains corrupted data.", exception);
}
finally
{
this.metadataDictionary.Clear();
this.stringsDictionary.Clear();
this.histogramBuffer.Clear();
}
}
