*/
public File assembleToCache(FileVersion fileVersion) throws Exception {
File reconstructedFileInCache = config.getCache().createTempFile("reconstructedFileVersion");
logger.log(Level.INFO, " - Creating file " + fileVersion.getPath() + " to " + reconstructedFileInCache + " ...");
FileContent fileContent = localDatabase.getFileContent(fileVersion.getChecksum(), true);
if (fileContent == null && memoryDatabase != null) {
fileContent = memoryDatabase.getContent(fileVersion.getChecksum());
}
// Check consistency!
if (fileContent == null && fileVersion.getChecksum() != null) {
throw new Exception("Cannot determine file content for checksum "+fileVersion.getChecksum());
}
// Create empty file
if (fileContent == null) {
FileUtils.touch(reconstructedFileInCache);
return reconstructedFileInCache;
}
// Create non-empty file
Chunker chunker = config.getChunker();
MultiChunker multiChunker = config.getMultiChunker();
FileOutputStream reconstructedFileOutputStream = new FileOutputStream(reconstructedFileInCache);
MessageDigest reconstructedFileChecksum = MessageDigest.getInstance(chunker.getChecksumAlgorithm());
if (fileContent != null) { // File can be empty!
Collection<ChunkChecksum> fileChunks = fileContent.getChunks();
for (ChunkChecksum chunkChecksum : fileChunks) {
MultiChunkId multiChunkIdForChunk = localDatabase.getMultiChunkId(chunkChecksum);
if (multiChunkIdForChunk == null && memoryDatabase != null) {
multiChunkIdForChunk = memoryDatabase.getMultiChunkIdForChunk(chunkChecksum);
}
File decryptedMultiChunkFile = config.getCache().getDecryptedMultiChunkFile(multiChunkIdForChunk);
MultiChunk multiChunk = multiChunker.createMultiChunk(decryptedMultiChunkFile);
InputStream chunkInputStream = multiChunk.getChunkInputStream(chunkChecksum.getBytes());
byte[] buffer = new byte[4096];
int read = 0;
while (-1 != (read = chunkInputStream.read(buffer))) {
reconstructedFileChecksum.update(buffer, 0, read);
reconstructedFileOutputStream.write(buffer, 0, read);
}
chunkInputStream.close();
multiChunk.close();
}
}
reconstructedFileOutputStream.close();
// Validate checksum
byte[] reconstructedFileExpectedChecksum = fileContent.getChecksum().getBytes();
byte[] reconstructedFileActualChecksum = reconstructedFileChecksum.digest();
if (!Arrays.equals(reconstructedFileActualChecksum, reconstructedFileExpectedChecksum)) {
throw new Exception("Checksums do not match: actual " + fileVersion.getChecksum() + " != expected "
+ StringUtil.toHex(reconstructedFileActualChecksum));