private void InflateStream(string fileName)
{
// then we will get it fresh into local deflatedName
// StreamOutput deflatedStream = new StreamOutput(CacheDirectory.CreateOutput(deflatedName));
using (var deflatedStream = new MemoryStream())
{
// get the deflated blob
_blob.DownloadToStream(deflatedStream);
Debug.WriteLine(string.Format("GET {0} RETREIVED {1} bytes", _name, deflatedStream.Length));
// seek back to begininng
deflatedStream.Seek(0, SeekOrigin.Begin);
// open output file for uncompressed contents
using (var fileStream = _azureDirectory.CreateCachedOutputAsStream(fileName))
using (var decompressor = new DeflateStream(deflatedStream, CompressionMode.Decompress))
{
var bytes = new byte[65535];
var nRead = 0;
do
{
nRead = decompressor.Read(bytes, 0, 65535);
if (nRead > 0)
{
fileStream.Write(bytes, 0, nRead);
}
} while (nRead == 65535);
}
}
}
public AzureIndexInput(AzureDirectory azuredirectory, ICloudBlob blob)
{
if (azuredirectory == null)
{
throw new ArgumentNullException(nameof(azuredirectory));
}
_name = blob.Uri.Segments[blob.Uri.Segments.Length - 1];
_azureDirectory = azuredirectory;
#if FULLDEBUG
Debug.WriteLine(String.Format("opening {0} ", _name));
#endif
_fileMutex = SyncMutexManager.GrabMutex(_azureDirectory, _name);
_fileMutex.WaitOne();
try
{
_blobContainer = azuredirectory.BlobContainer;
_blob = blob;
var fileName = _name;
var fFileNeeded = false;
if (!CacheDirectory.FileExists(fileName))
{
fFileNeeded = true;
}
else
{
long cachedLength = CacheDirectory.FileLength(fileName);
string blobLengthMetadata;
bool hasMetadataValue = blob.Metadata.TryGetValue("CachedLength", out blobLengthMetadata);
long blobLength = blob.Properties.Length;
if (hasMetadataValue)
{
long.TryParse(blobLengthMetadata, out blobLength);
}
string blobLastModifiedMetadata;
long longLastModified = 0;
DateTime blobLastModifiedUTC = blob.Properties.LastModified.Value.UtcDateTime;
if (blob.Metadata.TryGetValue("CachedLastModified", out blobLastModifiedMetadata))
{
if (long.TryParse(blobLastModifiedMetadata, out longLastModified))
{
blobLastModifiedUTC = new DateTime(longLastModified).ToUniversalTime();
}
}
if (cachedLength != blobLength)
{
fFileNeeded = true;
}
else
{
// cachedLastModifiedUTC was not ouputting with a date (just time) and the time was always off
long unixDate = CacheDirectory.FileModified(fileName);
DateTime start = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
var cachedLastModifiedUTC = start.AddMilliseconds(unixDate).ToUniversalTime();
if (cachedLastModifiedUTC != blobLastModifiedUTC)
{
var timeSpan = blobLastModifiedUTC.Subtract(cachedLastModifiedUTC);
if (timeSpan.TotalSeconds > 1)
{
fFileNeeded = true;
}
else
{
#if FULLDEBUG
Debug.WriteLine(timeSpan.TotalSeconds);
#endif
// file not needed
}
}
}
}
// if the file does not exist
// or if it exists and it is older then the lastmodified time in the blobproperties (which always comes from the blob storage)
if (fFileNeeded)
{
if (_azureDirectory.ShouldCompressFile(_name))
{
InflateStream(fileName);
}
else
{
using (var fileStream = _azureDirectory.CreateCachedOutputAsStream(fileName))
{
// get the blob
_blob.DownloadToStream(fileStream);
fileStream.Flush();
Debug.WriteLine(string.Format("GET {0} RETREIVED {1} bytes", _name, fileStream.Length));
}
}
// and open it as an input
_indexInput = CacheDirectory.OpenInput(fileName);
}
else
{
#if FULLDEBUG
Debug.WriteLine(String.Format("Using cached file for {0}", _name));
#endif
// open the file in read only mode
_indexInput = CacheDirectory.OpenInput(fileName);
}
}
finally
{
_fileMutex.ReleaseMutex();
}
}