public virtual async Task <StorageResponseHolder> Read(string key
, string directory = null
, CancellationToken?cancel = null
, bool useEncryption = true)
{
var request = new StorageRequestHolder(key, cancel, directory);
return(await CallCloudBlockBlob(request,
async (rq, rs, exists) =>
{
if (exists)
{
var sData = new MemoryStream();
await rq.Blob.DownloadToStreamAsync(sData, rq.CancelSet);
rs.Data = new byte[sData.Length];
sData.Position = 0;
sData.Read(rs.Data, 0, rs.Data.Length);
// If encryption provided decrypt the blob
if (useEncryption && mEncryption != null)
{
rs.Data = mEncryption.Decrypt(rs.Data);
}
MetadataGet(rq.Blob, rs);
}
else
{
rq.CopyTo(rs);
}
rs.IsSuccess = exists;
rs.StatusCode = exists ? 200 : 404;
}));
}
public bool MoveNext()
{
if (isDisposed)
{
throw new ObjectDisposedException(nameof(PdfTokenScanner));
}
// Read until we find object-number generation obj, e.g. "69 420 obj".
int tokensRead = 0;
while (coreTokenScanner.MoveNext() && !Equals(coreTokenScanner.CurrentToken, OperatorToken.StartObject))
{
if (coreTokenScanner.CurrentToken is CommentToken)
{
continue;
}
tokensRead++;
previousTokens[0] = previousTokens[1];
previousTokenPositions[0] = previousTokenPositions[1];
previousTokens[1] = previousTokens[2];
previousTokenPositions[1] = previousTokenPositions[2];
previousTokens[2] = coreTokenScanner.CurrentToken;
previousTokenPositions[2] = coreTokenScanner.CurrentTokenStart;
}
// We only read partial tokens.
if (tokensRead < 2)
{
return(false);
}
var startPosition = previousTokenPositions[1];
var objectNumber = previousTokens[1] as NumericToken;
var generation = previousTokens[2] as NumericToken;
if (objectNumber == null || generation == null)
{
// Handle case where the scanner correctly reads most of an object token but includes too much of the first token
// specifically %%EOF1 0 obj where scanning starts from 'F'.
if (generation != null && previousTokens[1] is OperatorToken op)
{
var match = EndsWithNumberRegex.Match(op.Data);
if (match.Success && int.TryParse(match.Value, NumberStyles.Any, CultureInfo.InvariantCulture, out var number))
{
startPosition = previousTokenPositions[1] + match.Index;
objectNumber = new NumericToken(number);
}
else
{
return(false);
}
}
else
{
return(false);
}
}
var readStream = false;
// Read all tokens between obj and endobj.
while (coreTokenScanner.MoveNext() && !Equals(coreTokenScanner.CurrentToken, OperatorToken.EndObject))
{
if (coreTokenScanner.CurrentToken is CommentToken)
{
continue;
}
if (ReferenceEquals(coreTokenScanner.CurrentToken, OperatorToken.StartObject))
{
if (readStream && readTokens[0] is StreamToken streamRead)
{
readTokens.Clear();
readTokens.Add(streamRead);
coreTokenScanner.Seek(previousTokenPositions[0]);
break;
}
if (readTokens.Count == 3 && readTokens[1] is NumericToken extraObjNum && readTokens[2] is NumericToken extraGenNum)
{
// An obj was encountered after reading the actual token and the object and generation number of the following token.
var actualReference = new IndirectReference(objectNumber.Int, generation.Int);
var actualToken = encryptionHandler.Decrypt(actualReference, readTokens[0]);
CurrentToken = new ObjectToken(startPosition, actualReference, actualToken);
readTokens.Clear();
coreTokenScanner.Seek(previousTokenPositions[0]);
return(true);
}
// This should never happen.
Debug.Assert(false, "Encountered a start object 'obj' operator before the end of the previous object.");
return(false);
}
if (ReferenceEquals(coreTokenScanner.CurrentToken, OperatorToken.StartStream))
{
var streamIdentifier = new IndirectReference(objectNumber.Long, generation.Int);
// Prevent an infinite loop where a stream's length references the stream or the stream's offset.
var getLengthFromFile = !isBruteForcing && !(callingObject.HasValue && callingObject.Value.Equals(streamIdentifier));
var outerCallingObject = callingObject;
try
{
callingObject = streamIdentifier;
// Read stream: special case.
if (TryReadStream(coreTokenScanner.CurrentTokenStart, getLengthFromFile, out var stream))
{
readTokens.Clear();
readTokens.Add(stream);
readStream = true;
}
}
finally
{
callingObject = outerCallingObject;
}
}
else
{
readTokens.Add(coreTokenScanner.CurrentToken);
}
previousTokens[0] = previousTokens[1];
previousTokenPositions[0] = previousTokenPositions[1];
previousTokens[1] = previousTokens[2];
previousTokenPositions[1] = previousTokenPositions[2];
previousTokens[2] = coreTokenScanner.CurrentToken;
previousTokenPositions[2] = coreTokenScanner.CurrentTokenStart;
}
if (!readStream && !ReferenceEquals(coreTokenScanner.CurrentToken, OperatorToken.EndObject))
{
readTokens.Clear();
return(false);
}
var reference = new IndirectReference(objectNumber.Long, generation.Int);
IToken token;
if (readTokens.Count == 3 && readTokens[0] is NumericToken objNum &&
readTokens[1] is NumericToken genNum &&
ReferenceEquals(readTokens[2], OperatorToken.R))
{
// I have no idea if this can ever happen.
token = new IndirectReferenceToken(new IndirectReference(objNum.Long, genNum.Int));
}