Change handling of connections and add support for download

2 files changed, 43 insertions, 38 deletions

diff --git a/src/main/java/org/openslx/imagemaster/crcchecker/CRCChecker.java b/src/main/java/org/openslx/imagemaster/crcchecker/CRCChecker.java
index 1baa994..78ac4c7 100644
--- a/src/main/java/org/openslx/imagemaster/crcchecker/CRCChecker.java
+++ b/src/main/java/org/openslx/imagemaster/crcchecker/CRCChecker.java
@@ -12,68 +12,65 @@ import org.openslx.imagemaster.Globals;
 
 public class CRCChecker
 {
-	
+
 	private static Logger log = Logger.getLogger( CRCChecker.class );
-	
+
 	/**
-	 * Checks the CRC sum of given blocks of a given imageFile against a given crcFile. 
+	 * Checks the CRC sum of given blocks of a given imageFile against a given crcFile.
+	 * The caller needs to make sure that block that are going to be checked are complete!
+	 * 
 	 * @param imageFile The imageFile to check
 	 * @param crcFile The crcFile to check against
 	 * @param blocks The blocks to check
 	 * @return List of blocks where the crc matches, or null if the crc file is corrupted
 	 */
-	public static List<Integer> checkCRC(String imageFile, String crcFile, List<Integer> blocks) throws IOException
+	public static List<Integer> checkCRC( String imageFile, String crcFile, List<Integer> blocks ) throws IOException
 	{
 		List<Integer> result = new LinkedList<>();
-		
+
 		ImageFile image = new ImageFile( imageFile, Globals.blockSize );
 		CRCFile crc = new CRCFile( crcFile );
-		
-		log.debug( "Checking image file: '" + imageFile + "' with crc file: '" + crcFile + "'");
+
+		log.debug( "Checking image file: '" + imageFile + "' with crc file: '" + crcFile + "'" );
 		try {
-			if (!crc.isValid()) return null;
+			if ( !crc.isValid() )
+				return null;
 			// TODO: also return null if the crc file contains the wrong number of checksums (only makes sense if the upload is complete)
-		} catch (IOException e) {
+		} catch ( IOException e ) {
 			throw new IOException( "Could not read CRC file", e );
 		}
-		
-		// file is smaller than one block - no need to check crc yet
-		// TODO: Needs more logic, if the image is complete and < 16MB, we still need to check the block.
-		// The caller should make sure to only check crc of blocks that are finished downloading
-		if (image.length() < Globals.blockSize) {
-			return result;
-		}
+
 		// check all blocks
-		for (Integer blockN : blocks) {
-			byte[] block;
+		byte[] block = new byte[Globals.blockSize];
+		for ( Integer blockN : blocks ) {
 			try {
-				// TODO: For performance improvements maybe prealloc the array outside the loop with a size of Globals.BLOCK_SIZE
-				// and then make getBlock(blockN, block) return the actual size of the block (Should always be BLOCK_SIZE except
-				// for the last block), so you never need to create fresh byte arrays inside the loop
-				block = image.getBlock( blockN );
+				image.getBlock( blockN, block );
 			} catch ( IOException e ) {
 				throw new IOException( "Could not read image file", e );
 			}
-			
-			if (block == null) continue; // some error occured (for example: someone tried to check a block that is not in the file)
-			
+
+			if ( block == null )
+				continue; // some error occured (for example: someone tried to check a block that is not in the file)
+
 			// check this block with CRC32
 			// add this block to result, if check was ok with CRC file
-			
+
 			CRC32 crcCalc = new CRC32();
 			crcCalc.update( block );
-			int crcSum = Integer.reverseBytes( (int) crcCalc.getValue() );
+			int crcSum = Integer.reverseBytes( (int)crcCalc.getValue() );
 			int crcSumFromFile;
 			try {
 				crcSumFromFile = crc.getCRCSum( blockN );
 			} catch ( IOException e ) {
 				throw new IOException( "Could not read CRC file", e );
 			}
-			
-			if (crcSum == crcSumFromFile) result.add( blockN );
-			else log.debug(blockN + " was invalid");
+
+			if ( crcSum == crcSumFromFile )
+				result.add( blockN );
+			else
+				log.debug( blockN + " was invalid" );
 		}
-		
+
 		return result;
 	}
 }
diff --git a/src/main/java/org/openslx/imagemaster/crcchecker/ImageFile.java b/src/main/java/org/openslx/imagemaster/crcchecker/ImageFile.java
index 9e77537..cb8c700 100644
--- a/src/main/java/org/openslx/imagemaster/crcchecker/ImageFile.java
+++ b/src/main/java/org/openslx/imagemaster/crcchecker/ImageFile.java
@@ -23,13 +23,15 @@ public class ImageFile
 	
 	/**
 	 * Get a certain block (uses RandomAccessFile)
+	 * If the last block is not full an array with a smaller size is set
+	 * and the actual number of bytes is returned.
 	 * @param block The number of the block you want to get
-	 * @return The specified block
+	 * @return The actual size of the array or 0 if the block number is < 0 or the block is not in the file
 	 * @throws IOException When file was not found or could not be read
 	 */
-	public byte[] getBlock(int block) throws IOException {
-		if (block < 0) return null;
-		if (block > f.length()/blockSize) return null;
+	public int getBlock(int block, byte[] array) throws IOException {
+		if (block < 0) return 0;
+		if (block > f.length()/blockSize) return 0;
 		
 		if (file == null) {
 			file = new RandomAccessFile( f, "r" );
@@ -37,10 +39,16 @@ public class ImageFile
 		
 		file.seek( (long)block * blockSize );
 		long remaining = length() - (block * blockSize);
-		byte[] result = new byte[ ( blockSize > remaining )? (int) remaining : blockSize ];	// only read available bytes
-		file.read( result );
 		
-		return result;
+		if (blockSize > remaining) {
+			array = new byte[(int)remaining];	// only read available bytes
+			file.read( array );
+			return (int)remaining;					// return actual size of array
+		} else {
+			// size of array is ok, read the full array and return block size
+			file.read( array );
+			return this.blockSize;
+		}
 	}
 	
 	public long length() {