From 02cf890a3935f2ec0c7ce728a065506bfeca4e4a Mon Sep 17 00:00:00 2001 From: "Anosh D. Ullenius" Date: Fri, 18 Nov 2022 22:26:40 +0100 Subject: [PATCH] Refactoring. Increase use of constants. Extract method --- .../java/se/anosh/spctag/dao/Xid6Reader.java | 48 +++++++++++-------- 1 file changed, 28 insertions(+), 20 deletions(-) diff --git a/src/main/java/se/anosh/spctag/dao/Xid6Reader.java b/src/main/java/se/anosh/spctag/dao/Xid6Reader.java index aea9f3d..3805216 100644 --- a/src/main/java/se/anosh/spctag/dao/Xid6Reader.java +++ b/src/main/java/se/anosh/spctag/dao/Xid6Reader.java @@ -23,6 +23,9 @@ final class Xid6Reader { private static final Map mappningar = new HashMap<>(); private static final long XID6_OFFSET = 0x10200L; + + private static final int XID6_HEADER_SIZE = 8; + static { mappningar.put((byte) 0x01, new Id(Xid6Tag.SONG, Type.TEXT)); mappningar.put((byte) 0x02, new Id(Xid6Tag.GAME, Type.TEXT)); @@ -104,33 +107,33 @@ private void setData(Xid6Tag tag, byte b) { private void parseXid6(Path spc) throws IOException { final long fileSize = Files.size(spc); final long xid6Size = fileSize - XID6_OFFSET; - final long xid6SizeMinusHeader = xid6Size - 8; // size of header + final long xid6SizeMinusHeader = xid6Size - XID6_HEADER_SIZE; if (fileSize <= XID6_OFFSET) { throw new IOException("File too small. Does not contain xid6"); } xid6 = new Xid6(); - var fileChannel = FileChannel.open(spc, StandardOpenOption.READ); + final var fileChannel = FileChannel.open(spc, StandardOpenOption.READ); fileChannel.position(XID6_OFFSET); - var buffer = fileChannel.map( + final var buffer = fileChannel.map( FileChannel.MapMode.READ_ONLY, XID6_OFFSET, xid6Size ); buffer.order(ByteOrder.LITTLE_ENDIAN); Logger.debug("Position: {}", buffer.position()); Logger.debug("Limit: {}", buffer.limit()); - byte[] magic = new byte[4]; + final byte[] magic = new byte[4]; buffer.get(magic); - ChunkHeader header = new ChunkHeader(magic, buffer.getInt()); + final ChunkHeader header = new ChunkHeader(magic, buffer.getInt()); // workaround if header is broken and actual filesize is less than chunk size in header final int chunkSize = (header.chunkSize > xid6SizeMinusHeader) ? (int) xid6SizeMinusHeader : header.chunkSize; Logger.debug("Chunk size: {}", chunkSize); Logger.debug("Current pos: {}", buffer.position()); - byte[] subChunkArr = new byte[chunkSize]; // chunkSize exclusive header + final byte[] subChunkArr = new byte[chunkSize]; // chunkSize exclusive header buffer.get(subChunkArr); // contains all sub-chunks, including sub-chunk headers - var subChunks = ByteBuffer.wrap(subChunkArr).order(ByteOrder.LITTLE_ENDIAN); + final var subChunks = ByteBuffer.wrap(subChunkArr).order(ByteOrder.LITTLE_ENDIAN); Logger.debug("Subchunk contents"); Logger.debug("-----------"); @@ -138,13 +141,13 @@ private void parseXid6(Path spc) throws IOException { Logger.debug("Subchunk header"); Logger.debug("Current pos: {}", subChunks.position()); - byte id = subChunks.get(); + final byte id = subChunks.get(); if (!mappningar.containsKey(id)) { break; } - Id mappatId = mappningar.get(id); - Type type = mappatId.type; - boolean dataStoredInHeader = subChunks.get() == 0 || type == Type.DATA; // workaround for broken type byte, always read from header + final Id mappatId = mappningar.get(id); + final Type type = mappatId.type; + final boolean dataStoredInHeader = subChunks.get() == 0 || type == Type.DATA; // workaround for broken type byte, always read from header Logger.debug("Id: 0x{}", toHexString(id)); Logger.debug("Mapped id: {}", mappatId); @@ -159,7 +162,7 @@ private void parseXid6(Path spc) throws IOException { if (size > 2) { throw new IllegalStateException("Data stored in header. Yet size is larger than 2 bytes"); } - byte[] data = new byte[2]; // always allocate 2 bytes + final byte[] data = new byte[2]; // always allocate 2 bytes subChunks.get(data); var func = mappedBehaviourDataStoredInHeader.get(type); @@ -172,20 +175,16 @@ private void parseXid6(Path spc) throws IOException { if ((size-1) % 4 == 0) { final int peekPos = size - 1; final int oldPos = subChunks.position(); - byte peek = subChunks.get(oldPos + peekPos); + final byte peek = subChunks.get(oldPos + peekPos); Logger.debug("Peek byte: {}", peek); if (mappningar.containsKey(peek)) { size--; } } - int bufsize = size; - while (bufsize % 4 != 0) { - bufsize++; - Logger.debug("Increasing bufsize: {}", bufsize); - } - byte[] buf = new byte[bufsize]; + final int bufsize = createBufferSize(size); + final byte[] buf = new byte[bufsize]; subChunks.get(buf); - String text = new String(buf, StandardCharsets.UTF_8).trim(); + final String text = new String(buf, StandardCharsets.UTF_8).trim(); setText(mappatId.tag, text); break; case INTRO: @@ -210,6 +209,15 @@ private void parseXid6(Path spc) throws IOException { fileChannel.close(); } + private int createBufferSize(final int size) { + int bufsize = size; + while (bufsize % 4 != 0) { + bufsize++; + Logger.debug("Increasing bufsize: {}", bufsize); + } + return bufsize; + } + private final IntConsumer setDate = (num) -> xid6.setDate(num); private final IntConsumer setLoopLength = (num) -> xid6.setLoopLength(num); private final IntConsumer setEnd = (num) -> xid6.setEndLength(num);