From 124f869faae3a0f75a3825e6a8e195c17f3c626a Mon Sep 17 00:00:00 2001
From: Andrew Dolgov <noreply@fakecake.org>
Date: Thu, 16 Oct 2014 23:34:20 +0400
Subject: initial for idea

---
 .../com/github/junrar/io/RandomAccessStream.java   | 203 +++++++++++++++++++++
 1 file changed, 203 insertions(+)
 create mode 100644 org.fox.ttcomics/src/main/java/com/github/junrar/io/RandomAccessStream.java

(limited to 'org.fox.ttcomics/src/main/java/com/github/junrar/io/RandomAccessStream.java')

diff --git a/org.fox.ttcomics/src/main/java/com/github/junrar/io/RandomAccessStream.java b/org.fox.ttcomics/src/main/java/com/github/junrar/io/RandomAccessStream.java
new file mode 100644
index 0000000..49442bf
--- /dev/null
+++ b/org.fox.ttcomics/src/main/java/com/github/junrar/io/RandomAccessStream.java
@@ -0,0 +1,203 @@
+/*
+ * public domain as of http://rsbweb.nih.gov/ij/disclaimer.html
+ */
+package com.github.junrar.io;
+
+import java.io.*;
+import java.util.Vector;
+
+/**
+ * This is a class that uses a memory cache to allow seeking within an
+ * InputStream. Based on the JAI MemoryCacheSeekableStream class. Can also be
+ * constructed from a RandomAccessFile, which uses less memory since the memory
+ * cache is not required.
+ */
+@SuppressWarnings("rawtypes")
+public final class RandomAccessStream extends InputStream {
+
+	private static final int BLOCK_SIZE = 512;
+	private static final int BLOCK_MASK = 511;
+	private static final int BLOCK_SHIFT = 9;
+
+	private InputStream src;
+	private RandomAccessFile ras;
+	private long pointer;
+	private Vector data;
+	private int length;
+	private boolean foundEOS;
+
+	/**
+	 * Constructs a RandomAccessStream from an InputStream. Seeking backwards is
+	 * supported using a memory cache.
+	 */
+	public RandomAccessStream(InputStream inputstream) {
+		pointer = 0L;
+		data = new Vector();
+		length = 0;
+		foundEOS = false;
+		src = inputstream;
+	}
+
+	/** Constructs a RandomAccessStream from an RandomAccessFile. */
+	public RandomAccessStream(RandomAccessFile ras) {
+		this.ras = ras;
+	}
+
+	public int getFilePointer() throws IOException {
+		if (ras != null)
+			return (int) ras.getFilePointer();
+		else
+			return (int) pointer;
+	}
+
+	public long getLongFilePointer() throws IOException {
+		if (ras != null)
+			return ras.getFilePointer();
+		else
+			return pointer;
+	}
+
+	public int read() throws IOException {
+		if (ras != null)
+			return ras.read();
+		long l = pointer + 1L;
+		long l1 = readUntil(l);
+		if (l1 >= l) {
+			byte abyte0[] = (byte[]) data
+					.elementAt((int) (pointer >> BLOCK_SHIFT));
+			return abyte0[(int) (pointer++ & BLOCK_MASK)] & 0xff;
+		} else
+			return -1;
+	}
+
+	public int read(byte[] bytes, int off, int len) throws IOException {
+		if (bytes == null)
+			throw new NullPointerException();
+		if (ras != null)
+			return ras.read(bytes, off, len);
+		if (off < 0 || len < 0 || off + len > bytes.length)
+			throw new IndexOutOfBoundsException();
+		if (len == 0)
+			return 0;
+		long l = readUntil(pointer + len);
+		if (l <= pointer)
+			return -1;
+		else {
+			byte abyte1[] = (byte[]) data
+					.elementAt((int) (pointer >> BLOCK_SHIFT));
+			int k = Math.min(len, BLOCK_SIZE - (int) (pointer & BLOCK_MASK));
+			System.arraycopy(abyte1, (int) (pointer & BLOCK_MASK), bytes, off,
+					k);
+			pointer += k;
+			return k;
+		}
+	}
+
+	public final void readFully(byte[] bytes) throws IOException {
+		readFully(bytes, bytes.length);
+	}
+
+	public final void readFully(byte[] bytes, int len) throws IOException {
+		int read = 0;
+		do {
+			int l = read(bytes, read, len - read);
+			if (l < 0)
+				break;
+			read += l;
+		} while (read < len);
+	}
+
+	@SuppressWarnings("unchecked")
+	private long readUntil(long l) throws IOException {
+		if (l < length)
+			return l;
+		if (foundEOS)
+			return length;
+		int i = (int) (l >> BLOCK_SHIFT);
+		int j = length >> BLOCK_SHIFT;
+		for (int k = j; k <= i; k++) {
+			byte abyte0[] = new byte[BLOCK_SIZE];
+			data.addElement(abyte0);
+			int i1 = BLOCK_SIZE;
+			int j1 = 0;
+			while (i1 > 0) {
+				int k1 = src.read(abyte0, j1, i1);
+				if (k1 == -1) {
+					foundEOS = true;
+					return length;
+				}
+				j1 += k1;
+				i1 -= k1;
+				length += k1;
+			}
+
+		}
+
+		return length;
+	}
+
+	public void seek(long loc) throws IOException {
+		if (ras != null) {
+			ras.seek(loc);
+			return;
+		}
+		if (loc < 0L)
+			pointer = 0L;
+		else
+			pointer = loc;
+	}
+
+	public void seek(int loc) throws IOException {
+		long lloc = ((long) loc) & 0xffffffffL;
+		if (ras != null) {
+			ras.seek(lloc);
+			return;
+		}
+		if (lloc < 0L)
+			pointer = 0L;
+		else
+			pointer = lloc;
+	}
+
+	public final int readInt() throws IOException {
+		int i = read();
+		int j = read();
+		int k = read();
+		int l = read();
+		if ((i | j | k | l) < 0)
+			throw new EOFException();
+		else
+			return (i << 24) + (j << 16) + (k << 8) + l;
+	}
+
+	public final long readLong() throws IOException {
+		return ((long) readInt() << 32) + ((long) readInt() & 0xffffffffL);
+	}
+
+	public final double readDouble() throws IOException {
+		return Double.longBitsToDouble(readLong());
+	}
+
+	public final short readShort() throws IOException {
+		int i = read();
+		int j = read();
+		if ((i | j) < 0)
+			throw new EOFException();
+		else
+			return (short) ((i << 8) + j);
+	}
+
+	public final float readFloat() throws IOException {
+		return Float.intBitsToFloat(readInt());
+	}
+
+	public void close() throws IOException {
+		if (ras != null)
+			ras.close();
+		else {
+			data.removeAllElements();
+			src.close();
+		}
+	}
+
+}
\ No newline at end of file
-- 
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