public static SignatureSearchResult SearchLocalFileForSignatures(string localFilePath, SizeBasedCompleteSignature sig)
{
var result = new SignatureSearchResult();
// length of file.
var tempFile = File.Open(localFilePath, FileMode.Open);
var fileLength = tempFile.Length;
tempFile.Close();
var offset = 0;
var windowSize = ConfigHelper.SignatureSize;
var windowBuffer = new byte[windowSize];
// signatures we can reuse.
var signaturesToReuse = new List <BlockSignature>();
// get sizes of signatures (block sizes) from existing sig.
// then loop through all sizes looking for matches in local file.
// important to search from largest to smallest.
var signatureSizes = sig.Signatures.Keys.ToList();
signatureSizes.Sort();
signatureSizes.Reverse();
// byte ranges that have not been matched to existing blocks yet.
var remainingByteList = new List <RemainingBytes>();
remainingByteList.Add(new RemainingBytes {
BeginOffset = 0, EndOffset = fileLength - 1
});
// Create the memory-mapped file.
using (var mmf = MemoryMappedFile.CreateFromFile(localFilePath, FileMode.Open))
{
using (var accessor = mmf.CreateViewAccessor())
{
// Any sigs smaller than 100 bytes? skip?
// Valid?
// Really want to avoid searching for single bytes everywhere.
foreach (var sigSize in signatureSizes)
{
var sigs = sig.Signatures[sigSize];
var newRemainingByteList = SearchLocalFileForSignaturesBasedOnSize(sigs, accessor, remainingByteList, sigSize, fileLength, signaturesToReuse);
remainingByteList = newRemainingByteList;
}
}
}
result.ByteRangesToUpload = remainingByteList;
result.SignaturesToReuse = signaturesToReuse;
return(result);
}
// Uploads differences between existing blob and updated local file.
// Have local file to reference, the search results (indicating which parts need to be uploaded)
// container and blob name.
private List <UploadedBlock> UploadDelta(string localFilePath, SignatureSearchResult searchResults, string containerName, string blobName, bool testMode = false)
{
var allUploadedBlocks = new List <UploadedBlock>();
// loop through each section of the search results.
// create blob from each RemainingBytes instances.
// reuse the blocks already in use.
foreach (var remainingBytes in searchResults.ByteRangesToUpload)
{
var uploadedBlockList = UploadBytesParallel(remainingBytes, localFilePath, containerName, blobName, testMode);
//var uploadedBlockList = UploadBytes(remainingBytes, localFilePath, containerName, blobName, testMode);
allUploadedBlocks.AddRange(uploadedBlockList);
}
// once we're here we should have uploaded ALL new data to Azure Blob Storage.
// We then need to send the "construct" blob message.
// loop through existing blocks and get offset + blockId's.
foreach (var sig in searchResults.SignaturesToReuse)
{
if (sig.MD5Signature != null)
{
var blockId = Convert.ToBase64String(sig.MD5Signature);
allUploadedBlocks.Add(new UploadedBlock()
{
BlockId = blockId, Offset = sig.Offset, Size = sig.Size, Sig = sig, IsNew = false
});
}
}
if (!testMode)
{
// needs to be sorted by offset so the final blob constructed is in correct order.
var res = (from b in allUploadedBlocks orderby b.Offset ascending select b.BlockId);
PutBlockList(res.ToArray(), containerName, blobName);
}
return(allUploadedBlocks);
}
