public CachedIndexInput( ICloudProvider CloudProvider, Directory CacheDirectory, string Name )
{
this.name = Name;
#if FULLDEBUG
Debug.WriteLine( "Opening " + this.name );
#endif
this.fileMutex = BlobMutexManager.GrabMutex( this.name );
this.fileMutex.WaitOne();
try {
bool fFileNeeded = false;
FileMetadata cloudMetadata = CloudProvider.FileMetadata( this.name );
if ( !cloudMetadata.Exists ) {
fFileNeeded = false;
// TODO: Delete local if it doesn't exist on cloud?
/*
if (CacheDirectory.FileExists(this.name)) {
CacheDirectory.DeleteFile(this.name);
}
*/
} else if ( !CacheDirectory.FileExists( this.name ) ) {
fFileNeeded = true;
} else {
long cachedLength = CacheDirectory.FileLength( this.name );
long blobLength = cloudMetadata.Length;
DateTime blobLastModifiedUTC = cloudMetadata.LastModified.ToUniversalTime();
if ( !cloudMetadata.Exists || cachedLength != blobLength ) {
fFileNeeded = true;
} else {
// there seems to be an error of 1 tick which happens every once in a while
// for now we will say that if they are within 1 tick of each other and same length
DateTime cachedLastModifiedUTC = new DateTime( CacheDirectory.FileModified( this.name ), DateTimeKind.Local ).ToUniversalTime();
if ( cachedLastModifiedUTC < blobLastModifiedUTC ) {
TimeSpan timeSpan = blobLastModifiedUTC.Subtract( cachedLastModifiedUTC );
if ( timeSpan.TotalSeconds > 1 ) {
fFileNeeded = true;
} else {
#if FULLDEBUG
Debug.WriteLine( "Using cache for " + this.name + ": " + 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 ) {
using ( StreamOutput fileStream = new StreamOutput( CacheDirectory.CreateOutput( this.name ) ) ) {
Stream blobStream = CloudProvider.Download( this.name );
blobStream.CopyTo( fileStream );
fileStream.Flush();
Debug.WriteLine( "GET {0} RETREIVED {1} bytes", this.name, fileStream.Length );
}
} else {
#if FULLDEBUG
if ( !cloudMetadata.Exists ) {
Debug.WriteLine( "Cloud doesn't have " + this.name );
} else {
Debug.WriteLine( "Using cached file for " + this.name );
}
#endif
}
// open the file in read only mode
this.indexInput = CacheDirectory.OpenInput( this.name );
} finally {
this.fileMutex.ReleaseMutex();
}
}
public CachedIndexInput(ICloudProvider CloudProvider, Directory CacheDirectory, string Name)
{
this.name = Name;
#if FULLDEBUG
Debug.WriteLine("Opening " + this.name);
#endif
this.fileMutex = BlobMutexManager.GrabMutex(this.name);
this.fileMutex.WaitOne();
try {
bool fFileNeeded = false;
FileMetadata cloudMetadata = CloudProvider.FileMetadata(this.name);
if (!cloudMetadata.Exists)
{
fFileNeeded = false;
// TODO: Delete local if it doesn't exist on cloud?
/*
* if (CacheDirectory.FileExists(this.name)) {
* CacheDirectory.DeleteFile(this.name);
* }
*/
}
else if (!CacheDirectory.FileExists(this.name))
{
fFileNeeded = true;
}
else
{
long cachedLength = CacheDirectory.FileLength(this.name);
long blobLength = cloudMetadata.Length;
DateTime blobLastModifiedUTC = cloudMetadata.LastModified.ToUniversalTime();
if (!cloudMetadata.Exists || cachedLength != blobLength)
{
fFileNeeded = true;
}
else
{
// there seems to be an error of 1 tick which happens every once in a while
// for now we will say that if they are within 1 tick of each other and same length
DateTime cachedLastModifiedUTC = new DateTime(CacheDirectory.FileModified(this.name), DateTimeKind.Local).ToUniversalTime();
if (cachedLastModifiedUTC < blobLastModifiedUTC)
{
TimeSpan timeSpan = blobLastModifiedUTC.Subtract(cachedLastModifiedUTC);
if (timeSpan.TotalSeconds > 1)
{
fFileNeeded = true;
}
else
{
#if FULLDEBUG
Debug.WriteLine("Using cache for " + this.name + ": " + 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)
{
using (StreamOutput fileStream = new StreamOutput(CacheDirectory.CreateOutput(this.name))) {
Stream blobStream = CloudProvider.Download(this.name);
blobStream.CopyTo(fileStream);
fileStream.Flush();
Debug.WriteLine("GET {0} RETREIVED {1} bytes", this.name, fileStream.Length);
}
}
else
{
#if FULLDEBUG
if (!cloudMetadata.Exists)
{
Debug.WriteLine("Cloud doesn't have " + this.name);
}
else
{
Debug.WriteLine("Using cached file for " + this.name);
}
#endif
}
// open the file in read only mode
this.indexInput = CacheDirectory.OpenInput(this.name);
} finally {
this.fileMutex.ReleaseMutex();
}
}
