diff options
Diffstat (limited to 'rdr/ZlibOutStream.cxx')
-rw-r--r-- | rdr/ZlibOutStream.cxx | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/rdr/ZlibOutStream.cxx b/rdr/ZlibOutStream.cxx new file mode 100644 index 0000000..c3a0ca2 --- /dev/null +++ b/rdr/ZlibOutStream.cxx @@ -0,0 +1,140 @@ +// +// Copyright (C) 2002 RealVNC Ltd. All Rights Reserved. +// +// This 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 2 of the License, or +// (at your option) any later version. +// +// This software 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 software; if not, write to the Free Software +// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, +// USA. + +#include <rdr/ZlibOutStream.h> +#include <rdr/Exception.h> +#include <zlib.h> + +using namespace rdr; + +enum { DEFAULT_BUF_SIZE = 16384 }; + +ZlibOutStream::ZlibOutStream(OutStream* os, int bufSize_) + : underlying(os), bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0) +{ + zs = new z_stream; + zs->zalloc = Z_NULL; + zs->zfree = Z_NULL; + zs->opaque = Z_NULL; + if (deflateInit(zs, Z_DEFAULT_COMPRESSION) != Z_OK) { + delete zs; + throw Exception("ZlibOutStream: deflateInit failed"); + } + ptr = start = new U8[bufSize]; + end = start + bufSize; +} + +ZlibOutStream::~ZlibOutStream() +{ + try { + flush(); + } catch (Exception&) { + } + delete [] start; + deflateEnd(zs); + delete zs; +} + +void ZlibOutStream::setUnderlying(OutStream* os) +{ + underlying = os; +} + +int ZlibOutStream::length() +{ + return offset + ptr - start; +} + +void ZlibOutStream::flush() +{ + zs->next_in = start; + zs->avail_in = ptr - start; + +// fprintf(stderr,"zos flush: avail_in %d\n",zs->avail_in); + + while (zs->avail_in != 0) { + + do { + underlying->check(1); + zs->next_out = underlying->getptr(); + zs->avail_out = underlying->getend() - underlying->getptr(); + +// fprintf(stderr,"zos flush: calling deflate, avail_in %d, avail_out %d\n", +// zs->avail_in,zs->avail_out); + int rc = deflate(zs, Z_SYNC_FLUSH); + if (rc != Z_OK) throw Exception("ZlibOutStream: deflate failed"); + +// fprintf(stderr,"zos flush: after deflate: %d bytes\n", +// zs->next_out-underlying->getptr()); + + underlying->setptr(zs->next_out); + } while (zs->avail_out == 0); + } + + offset += ptr - start; + ptr = start; +} + +int ZlibOutStream::overrun(int itemSize, int nItems) +{ +// fprintf(stderr,"ZlibOutStream overrun\n"); + + if (itemSize > bufSize) + throw Exception("ZlibOutStream overrun: max itemSize exceeded"); + + while (end - ptr < itemSize) { + zs->next_in = start; + zs->avail_in = ptr - start; + + do { + underlying->check(1); + zs->next_out = underlying->getptr(); + zs->avail_out = underlying->getend() - underlying->getptr(); + +// fprintf(stderr,"zos overrun: calling deflate, avail_in %d, avail_out %d\n", +// zs->avail_in,zs->avail_out); + + int rc = deflate(zs, 0); + if (rc != Z_OK) throw Exception("ZlibOutStream: deflate failed"); + +// fprintf(stderr,"zos overrun: after deflate: %d bytes\n", +// zs->next_out-underlying->getptr()); + + underlying->setptr(zs->next_out); + } while (zs->avail_out == 0); + + // output buffer not full + + if (zs->avail_in == 0) { + offset += ptr - start; + ptr = start; + } else { + // but didn't consume all the data? try shifting what's left to the + // start of the buffer. + fprintf(stderr,"z out buf not full, but in data not consumed\n"); + memmove(start, zs->next_in, ptr - zs->next_in); + offset += zs->next_in - start; + ptr -= zs->next_in - start; + } + } + + if (itemSize * nItems > end - ptr) + nItems = (end - ptr) / itemSize; + + return nItems; +} |