Implement ozlibstream

4 files changed, 109 insertions, 1 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bed0ca668a..39a3a5759c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,6 +15,7 @@ add_library(nbt++ STATIC
     src/value_initializer.cpp
 
     src/io/izlibstream.cpp
+    src/io/ozlibstream.cpp
     src/io/stream_reader.cpp
     src/io/stream_writer.cpp
 
diff --git a/include/io/ozlibstream.h b/include/io/ozlibstream.h
index 0be792d482..d4ea8c2840 100644
--- a/include/io/ozlibstream.h
+++ b/include/io/ozlibstream.h
@@ -78,7 +78,7 @@ public:
      * @param bufsize the size of the internal buffers
      */
     explicit ozlibstream(std::ostream& output, int level = Z_DEFAULT_COMPRESSION, bool gzip = false, size_t bufsize = 32768):
-        std::ostream(&buf), buf(output, level, bufsize, 15 + (gzip ? 16 : 0))
+        std::ostream(&buf), buf(output, bufsize, level, 15 + (gzip ? 16 : 0))
     {}
 
     ///@return the wrapped ostream
diff --git a/src/io/ozlibstream.cpp b/src/io/ozlibstream.cpp
new file mode 100644
index 0000000000..97702a37e1
--- /dev/null
+++ b/src/io/ozlibstream.cpp
@@ -0,0 +1,87 @@
+/*
+ * libnbt++ - A library for the Minecraft Named Binary Tag format.
+ * Copyright (C) 2013, 2015  ljfa-ag
+ *
+ * This file is part of libnbt++.
+ *
+ * libnbt++ is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libnbt++ 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libnbt++.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "io/ozlibstream.h"
+#include "io/zlib_error.h"
+
+namespace zlib
+{
+
+deflate_streambuf::deflate_streambuf(std::ostream& output, size_t bufsize, int level, int window_bits, int mem_level, int strategy):
+    os(output), in(bufsize), out(bufsize)
+{
+    zstr.zalloc = Z_NULL;
+    zstr.zfree = Z_NULL;
+    zstr.opaque = Z_NULL;
+    int ret = deflateInit2(&zstr, level, Z_DEFLATED, window_bits, mem_level, strategy);
+    if(ret != Z_OK)
+        throw zlib_error(zstr.msg, ret);
+
+    setp(in.data(), in.data() + in.size());
+}
+
+deflate_streambuf::~deflate_streambuf() noexcept
+{
+    try
+    {
+        deflate_chunk(Z_FINISH);
+    }
+    catch(...)
+    {
+        //ignore as we can't do anything about it
+    }
+    deflateEnd(&zstr);
+}
+
+void deflate_streambuf::deflate_chunk(int flush)
+{
+    zstr.next_in = reinterpret_cast<Bytef*>(pbase());
+    zstr.avail_in = pptr() - pbase();
+    do
+    {
+        zstr.next_out = reinterpret_cast<Bytef*>(out.data());
+        zstr.avail_out = out.size();
+        int ret = deflate(&zstr, flush);
+        if(ret != Z_OK && ret != Z_STREAM_END)
+            throw zlib_error(zstr.msg, ret);
+        int have = out.size() - zstr.avail_out;
+        if(!os.write(out.data(), have))
+            throw std::ios_base::failure("Could not write to the output stream");
+    } while(zstr.avail_out == 0);
+    setp(in.data(), in.data() + in.size());
+}
+
+deflate_streambuf::int_type deflate_streambuf::overflow(int_type ch)
+{
+    deflate_chunk();
+    if(ch != traits_type::eof())
+    {
+        *pptr() = ch;
+        pbump(1);
+    }
+    return ch;
+}
+
+int deflate_streambuf::sync()
+{
+    deflate_chunk();
+    return 0;
+}
+
+}
diff --git a/test/zlibstream_test.h b/test/zlibstream_test.h
index 2a94ab7ccb..e0b22c1356 100644
--- a/test/zlibstream_test.h
+++ b/test/zlibstream_test.h
@@ -133,4 +133,24 @@ public:
             TS_ASSERT(igzs.bad());
         }
     }
+
+    void test_deflate_zlib()
+    {
+        //Here we assume that inflating works and has already been tested
+        std::stringstream str;
+        std::stringbuf output;
+        //Small buffer
+        {
+            ozlibstream ozls(str, -1, false, 256);
+            ozls.exceptions(std::ios::failbit | std::ios::badbit);
+            ozls << bigtest;
+            TS_ASSERT(ozls.good());
+        }
+        {
+            izlibstream izls(str);
+            izls >> &output;
+            TS_ASSERT(izls);
+        }
+        TS_ASSERT_EQUALS(output.str(), bigtest);
+    }
 };