Do it. :)
On 6/16/11 3:09 PM, Brian Hinz wrote: > Sure. The decompress function inside rdr/ZlibInStream.java uses a byte > array with a default size of 16K as the output for the inflater, as does > the C version. Since the C-version sets avail_out in the ZStream, zlib > knows how much space is available in the ouput buffer and doesn't > inflate more data than the buffer can hold. The native java inflater > has no equivalent, so a call to inflate can produce enough output data > to exceed the buffer size. I could arbitrarily increase the buffer > size, but this is wasteful and bound to break depending on desktop size > and compression ratio. I could also allocate a buffer large enough by > passing the fbWidth*fbHeight*bytesPerPixel to the ZlibInStream > constructor, but for a large enough desktop (keep in mind that the Tight > encoder allocates 4 streams) this can require enough memory to exceed > the default initial heap size of the Java VM. I haven't seen just how > large of a desktop I can run before the old java client breaks, but > passing 3840x1140@24bpp to the constructor is enough to run out the > initial heap in the new one. > > Also, using JZlib adds a degree of symmetry between the java and C > versions, which I see as a bonus from a maintenance standpoint. > > -brian > > On Thu, Jun 16, 2011 at 3:30 PM, DRC <dcomman...@users.sourceforge.net > <mailto:dcomman...@users.sourceforge.net>> wrote: > > 3-clause BSD is GPL-compatible, so legally there is no problem, but can > you explain further the technical justification? > > > On 6/16/11 2:13 PM, Brian Hinz wrote: > > Assuming that it's OK legally, would anyone object if I were to > import a > > copy of JZlib (http://www.jcraft.com/jzlib/) into the TigerVNC java > > client's tree and revamp ZlibInStream so that it's consistent with > the C > > version? JZlib is released under a BSD-style license > > (http://www.jcraft.com/jzlib/LICENSE.txt): > > > > JZlib 0.0.* were released under the GNU LGPL license. Later, we > have switched > > over to a BSD-style license. > > > > > ------------------------------------------------------------------------------ > > Copyright (c) 2000,2001,2002,2003,2004 ymnk, JCraft,Inc. All rights > reserved. > > > > Redistribution and use in source and binary forms, with or without > > modification, are permitted provided that the following conditions > are met: > > > > 1. Redistributions of source code must retain the above copyright > notice, > > this list of conditions and the following disclaimer. > > > > 2. Redistributions in binary form must reproduce the above copyright > > notice, this list of conditions and the following disclaimer in > > the documentation and/or other materials provided with the > distribution. > > > > 3. The names of the authors may not be used to endorse or promote > products > > derived from this software without specific prior written > permission. > > > > THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED > WARRANTIES, > > INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF > MERCHANTABILITY AND > > FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL > JCRAFT, > > INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, > INDIRECT, > > INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES > (INCLUDING, BUT NOT > > LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF > USE, DATA, > > OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY > THEORY OF > > LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING > > NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS > SOFTWARE, > > EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. > > > > > ------------------------------------------------------------------------------ > > > > This appears to be consistent with the list of GPL-compatible free > software licenses listed on gnu.org <http://gnu.org> > <http://gnu.org>. Also, the JZlib home page notes that JZlib is > used in JmakeTxt, which is released under the GPLv2. I can contact > JCraft to get confirmation. > > > > The reason that I ask is that since adding support for Tight > encoding, I've periodically encountered an exception thrown by the > call to java.util.zip.Inflater.inflate in ZlibInStream. This > because the output buffer for the decompression is a fixed size, and > the native java Infalter class does not provide a means to handle > compressed data whose uncompressed size is unknown prior to > decompression. In the C version, zlib handles this via avail_out, > and in the previous java client the decompression buffer is > allocated based on the required size. The problem with just > allocating bigger decompression buffers is that for large desktops, > this can cause the Java VM to exceed the initial heap size. > > > > When implemented with JZlib, the heap size limitation does not seem > to be an issue, and as far as I can tell, the performance is no > worse (possibly even better). The size of the resulting jar file > only increases by ~30k when all of the JZlib classes are included. > > > > Thanks, > > > > -brian > > > > > > > > > ------------------------------------------------------------------------------ > > EditLive Enterprise is the world's most technically advanced content > > authoring tool. Experience the power of Track Changes, Inline Image > > Editing and ensure content is compliant with Accessibility Checking. > > http://p.sf.net/sfu/ephox-dev2dev > > > > > > > > _______________________________________________ > > Tigervnc-devel mailing list > > Tigervnc-devel@lists.sourceforge.net > <mailto:Tigervnc-devel@lists.sourceforge.net> > > https://lists.sourceforge.net/lists/listinfo/tigervnc-devel > > > ------------------------------------------------------------------------------ > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > _______________________________________________ > Tigervnc-devel mailing list > Tigervnc-devel@lists.sourceforge.net > <mailto:Tigervnc-devel@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/tigervnc-devel > > > > > ------------------------------------------------------------------------------ > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > > > > _______________________________________________ > Tigervnc-devel mailing list > Tigervnc-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/tigervnc-devel ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev _______________________________________________ Tigervnc-devel mailing list Tigervnc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tigervnc-devel
