aboutsummaryrefslogtreecommitdiffstats
path: root/lib/src/main/java/com/trilead/ssh2/compression/Zlib.java
diff options
context:
space:
mode:
Diffstat (limited to 'lib/src/main/java/com/trilead/ssh2/compression/Zlib.java')
-rw-r--r--lib/src/main/java/com/trilead/ssh2/compression/Zlib.java121
1 files changed, 121 insertions, 0 deletions
diff --git a/lib/src/main/java/com/trilead/ssh2/compression/Zlib.java b/lib/src/main/java/com/trilead/ssh2/compression/Zlib.java
new file mode 100644
index 0000000..c81a719
--- /dev/null
+++ b/lib/src/main/java/com/trilead/ssh2/compression/Zlib.java
@@ -0,0 +1,121 @@
+/*
+ ConnectBot: simple, powerful, open-source SSH client for Android
+ Copyright (C) 2007-2008 Kenny Root, Jeffrey Sharkey
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.trilead.ssh2.compression;
+
+import com.jcraft.jzlib.JZlib;
+import com.jcraft.jzlib.ZStream;
+
+/**
+ * @author Kenny Root
+ *
+ */
+public class Zlib implements ICompressor {
+ static private final int BUF_SIZE = 4096;
+ static private final int LEVEL = 5;
+
+ private ZStream deflate;
+ private byte[] deflate_tmpbuf = new byte[BUF_SIZE];
+
+ private ZStream inflate;
+ private byte[] inflate_tmpbuf = new byte[BUF_SIZE];
+ private byte[] inflated_buf;
+
+ public Zlib() {
+ deflate = new ZStream();
+ inflate = new ZStream();
+
+ deflate.deflateInit(LEVEL);
+ inflate.inflateInit();
+ inflated_buf = new byte[BUF_SIZE];
+ }
+
+ public int getBufferSize() {
+ return BUF_SIZE;
+ }
+
+ public int compress(byte[] buf, int start, int len, byte[] output) {
+ deflate.next_in = buf;
+ deflate.next_in_index = start;
+ deflate.avail_in = len - start;
+
+ int status;
+ int outputlen = start;
+
+ do {
+ deflate.next_out = deflate_tmpbuf;
+ deflate.next_out_index = 0;
+ deflate.avail_out = BUF_SIZE;
+ status = deflate.deflate(JZlib.Z_PARTIAL_FLUSH);
+ switch (status) {
+ case JZlib.Z_OK:
+ System.arraycopy(deflate_tmpbuf, 0, output, outputlen, BUF_SIZE
+ - deflate.avail_out);
+ outputlen += (BUF_SIZE - deflate.avail_out);
+ break;
+ default:
+ System.err.println("compress: deflate returnd " + status);
+ }
+ } while (deflate.avail_out == 0);
+ return outputlen;
+ }
+
+ public byte[] uncompress(byte[] buffer, int start, int[] length) {
+ int inflated_end = 0;
+
+ inflate.next_in = buffer;
+ inflate.next_in_index = start;
+ inflate.avail_in = length[0];
+
+ while (true) {
+ inflate.next_out = inflate_tmpbuf;
+ inflate.next_out_index = 0;
+ inflate.avail_out = BUF_SIZE;
+ int status = inflate.inflate(JZlib.Z_PARTIAL_FLUSH);
+ switch (status) {
+ case JZlib.Z_OK:
+ if (inflated_buf.length < inflated_end + BUF_SIZE
+ - inflate.avail_out) {
+ byte[] foo = new byte[inflated_end + BUF_SIZE
+ - inflate.avail_out];
+ System.arraycopy(inflated_buf, 0, foo, 0, inflated_end);
+ inflated_buf = foo;
+ }
+ System.arraycopy(inflate_tmpbuf, 0, inflated_buf, inflated_end,
+ BUF_SIZE - inflate.avail_out);
+ inflated_end += (BUF_SIZE - inflate.avail_out);
+ length[0] = inflated_end;
+ break;
+ case JZlib.Z_BUF_ERROR:
+ if (inflated_end > buffer.length - start) {
+ byte[] foo = new byte[inflated_end + start];
+ System.arraycopy(buffer, 0, foo, 0, start);
+ System.arraycopy(inflated_buf, 0, foo, start, inflated_end);
+ buffer = foo;
+ } else {
+ System.arraycopy(inflated_buf, 0, buffer, start,
+ inflated_end);
+ }
+ length[0] = inflated_end;
+ return buffer;
+ default:
+ System.err.println("uncompress: inflate returnd " + status);
+ return null;
+ }
+ }
+ }
+}