X-Git-Url: https://code.wpia.club/?p=gigi.git;a=blobdiff_plain;f=lib%2Fjtar%2Forg%2Fkamranzafar%2Fjtar%2FTarInputStream.java;fp=lib%2Fjtar%2Forg%2Fkamranzafar%2Fjtar%2FTarInputStream.java;h=cd48ae0334a87ba1c5ea5aefb51f22a0fdf65c11;hp=0000000000000000000000000000000000000000;hb=69e01f194e6183eccb8c7ca6f75fbe1132e0f194;hpb=49b403316469afb4f62c5b60401667640746af37

diff --git a/lib/jtar/org/kamranzafar/jtar/TarInputStream.java b/lib/jtar/org/kamranzafar/jtar/TarInputStream.java
new file mode 100644
index 00000000..cd48ae03
--- /dev/null
+++ b/lib/jtar/org/kamranzafar/jtar/TarInputStream.java
@@ -0,0 +1,249 @@
+/**
+ * Copyright 2012 Kamran Zafar 
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); 
+ * you may not use this file except in compliance with the License. 
+ * You may obtain a copy of the License at 
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0 
+ * 
+ * Unless required by applicable law or agreed to in writing, software 
+ * distributed under the License is distributed on an "AS IS" BASIS, 
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
+ * See the License for the specific language governing permissions and 
+ * limitations under the License. 
+ * 
+ */
+
+package org.kamranzafar.jtar;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * @author Kamran Zafar
+ * 
+ */
+public class TarInputStream extends FilterInputStream {
+
+	private static final int SKIP_BUFFER_SIZE = 2048;
+	private TarEntry currentEntry;
+	private long currentFileSize;
+	private long bytesRead;
+	private boolean defaultSkip = false;
+
+	public TarInputStream(InputStream in) {
+		super(in);
+		currentFileSize = 0;
+		bytesRead = 0;
+	}
+
+	@Override
+	public boolean markSupported() {
+		return false;
+	}
+
+	/**
+	 * Not supported
+	 * 
+	 */
+	@Override
+	public synchronized void mark(int readlimit) {
+	}
+
+	/**
+	 * Not supported
+	 * 
+	 */
+	@Override
+	public synchronized void reset() throws IOException {
+		throw new IOException("mark/reset not supported");
+	}
+
+	/**
+	 * Read a byte
+	 * 
+	 * @see java.io.FilterInputStream#read()
+	 */
+	@Override
+	public int read() throws IOException {
+		byte[] buf = new byte[1];
+
+		int res = this.read(buf, 0, 1);
+
+		if (res != -1) {
+			return 0xFF & buf[0];
+		}
+
+		return res;
+	}
+
+	/**
+	 * Checks if the bytes being read exceed the entry size and adjusts the byte
+	 * array length. Updates the byte counters
+	 * 
+	 * 
+	 * @see java.io.FilterInputStream#read(byte[], int, int)
+	 */
+	@Override
+	public int read(byte[] b, int off, int len) throws IOException {
+		if (currentEntry != null) {
+			if (currentFileSize == currentEntry.getSize()) {
+				return -1;
+			} else if ((currentEntry.getSize() - currentFileSize) < len) {
+				len = (int) (currentEntry.getSize() - currentFileSize);
+			}
+		}
+
+		int br = super.read(b, off, len);
+
+		if (br != -1) {
+			if (currentEntry != null) {
+				currentFileSize += br;
+			}
+
+			bytesRead += br;
+		}
+
+		return br;
+	}
+
+	/**
+	 * Returns the next entry in the tar file
+	 * 
+	 * @return TarEntry
+	 * @throws IOException
+	 */
+	public TarEntry getNextEntry() throws IOException {
+		closeCurrentEntry();
+
+		byte[] header = new byte[TarConstants.HEADER_BLOCK];
+		byte[] theader = new byte[TarConstants.HEADER_BLOCK];
+		int tr = 0;
+
+		// Read full header
+		while (tr < TarConstants.HEADER_BLOCK) {
+			int res = read(theader, 0, TarConstants.HEADER_BLOCK - tr);
+
+			if (res < 0) {
+				break;
+			}
+
+			System.arraycopy(theader, 0, header, tr, res);
+			tr += res;
+		}
+
+		// Check if record is null
+		boolean eof = true;
+		for (byte b : header) {
+			if (b != 0) {
+				eof = false;
+				break;
+			}
+		}
+
+		if (!eof) {
+			currentEntry = new TarEntry(header);
+		}
+
+		return currentEntry;
+	}
+
+	/**
+	 * Returns the current offset (in bytes) from the beginning of the stream. 
+	 * This can be used to find out at which point in a tar file an entry's content begins, for instance. 
+	 */
+	public long getCurrentOffset() {
+		return bytesRead;
+	}
+	
+	/**
+	 * Closes the current tar entry
+	 * 
+	 * @throws IOException
+	 */
+	protected void closeCurrentEntry() throws IOException {
+		if (currentEntry != null) {
+			if (currentEntry.getSize() > currentFileSize) {
+				// Not fully read, skip rest of the bytes
+				long bs = 0;
+				while (bs < currentEntry.getSize() - currentFileSize) {
+					long res = skip(currentEntry.getSize() - currentFileSize - bs);
+
+					if (res == 0 && currentEntry.getSize() - currentFileSize > 0) {
+						// I suspect file corruption
+						throw new IOException("Possible tar file corruption");
+					}
+
+					bs += res;
+				}
+			}
+
+			currentEntry = null;
+			currentFileSize = 0L;
+			skipPad();
+		}
+	}
+
+	/**
+	 * Skips the pad at the end of each tar entry file content
+	 * 
+	 * @throws IOException
+	 */
+	protected void skipPad() throws IOException {
+		if (bytesRead > 0) {
+			int extra = (int) (bytesRead % TarConstants.DATA_BLOCK);
+
+			if (extra > 0) {
+				long bs = 0;
+				while (bs < TarConstants.DATA_BLOCK - extra) {
+					long res = skip(TarConstants.DATA_BLOCK - extra - bs);
+					bs += res;
+				}
+			}
+		}
+	}
+
+	/**
+	 * Skips 'n' bytes on the InputStream<br>
+	 * Overrides default implementation of skip
+	 * 
+	 */
+	@Override
+	public long skip(long n) throws IOException {
+		if (defaultSkip) {
+			// use skip method of parent stream
+			// may not work if skip not implemented by parent
+			long bs = super.skip(n);
+			bytesRead += bs;
+
+			return bs;
+		}
+
+		if (n <= 0) {
+			return 0;
+		}
+
+		long left = n;
+		byte[] sBuff = new byte[SKIP_BUFFER_SIZE];
+
+		while (left > 0) {
+			int res = read(sBuff, 0, (int) (left < SKIP_BUFFER_SIZE ? left : SKIP_BUFFER_SIZE));
+			if (res < 0) {
+				break;
+			}
+			left -= res;
+		}
+
+		return n - left;
+	}
+
+	public boolean isDefaultSkip() {
+		return defaultSkip;
+	}
+
+	public void setDefaultSkip(boolean defaultSkip) {
+		this.defaultSkip = defaultSkip;
+	}
+}