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-rw-r--r--common/rdr/ZlibOutStream.cxx161
1 files changed, 161 insertions, 0 deletions
diff --git a/common/rdr/ZlibOutStream.cxx b/common/rdr/ZlibOutStream.cxx
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+++ b/common/rdr/ZlibOutStream.cxx
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+/* Copyright (C) 2002-2005 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_, int compressLevel)
+ : underlying(os), compressionLevel(compressLevel), newLevel(compressLevel),
+ 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, compressLevel) != 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;
+}
+
+void ZlibOutStream::setCompressionLevel(int level)
+{
+ if (level < -1 || level > 9)
+ level = -1; // Z_DEFAULT_COMPRESSION
+
+ newLevel = level;
+}
+
+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);
+ checkCompressionLevel();
+ 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);
+
+ checkCompressionLevel();
+ 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;
+}
+
+void ZlibOutStream::checkCompressionLevel()
+{
+ if (newLevel != compressionLevel) {
+ if (deflateParams (zs, newLevel, Z_DEFAULT_STRATEGY) != Z_OK) {
+ throw Exception("ZlibOutStream: deflateParams failed");
+ }
+ compressionLevel = newLevel;
+ }
+}