4 files changed, 50 insertions, 31 deletions
diff --git a/include/io/izlibstream.h b/include/io/izlibstream.h
index 43d2d2c02e..d3c4faa14e 100644
--- a/include/io/izlibstream.h
+++ b/include/io/izlibstream.h
@@ -20,8 +20,8 @@
 #ifndef IZLIBSTREAM_H_INCLUDED
 #define IZLIBSTREAM_H_INCLUDED
 
+#include "io/zlib_streambuf.h"
 #include <istream>
-#include <vector>
 #include <zlib.h>
 
 namespace zlib
@@ -31,7 +31,7 @@ namespace zlib
  * @brief Stream buffer used by zlib::izlibstream
  * @sa izlibstream
  */
-class inflate_streambuf : public std::streambuf
+class inflate_streambuf : public zlib_streambuf
 {
 public:
     /**
@@ -53,9 +53,6 @@ public:
 
 private:
     std::istream& is;
-    std::vector<char> in;
-    std::vector<char> out;
-    z_stream zstr;
     bool stream_end;
 
     int_type underflow() override;
diff --git a/include/io/ozlibstream.h b/include/io/ozlibstream.h
index bd9faea381..ef93944c94 100644
--- a/include/io/ozlibstream.h
+++ b/include/io/ozlibstream.h
@@ -20,8 +20,8 @@
 #ifndef OZLIBSTREAM_H_INCLUDED
 #define OZLIBSTREAM_H_INCLUDED
 
+#include "io/zlib_streambuf.h"
 #include <ostream>
-#include <vector>
 #include <zlib.h>
 
 namespace zlib
@@ -31,7 +31,7 @@ namespace zlib
  * @brief Stream buffer used by zlib::ozlibstream
  * @sa ozlibstream
  */
-class deflate_streambuf : public std::streambuf
+class deflate_streambuf : public zlib_streambuf
 {
 public:
     /**
@@ -46,15 +46,13 @@ public:
     explicit deflate_streambuf(std::ostream& output, size_t bufsize = 32768, int level = Z_DEFAULT_COMPRESSION, int window_bits = 15, int mem_level = 8, int strategy = Z_DEFAULT_STRATEGY);
     ~deflate_streambuf() noexcept;
 
+    ///@return the wrapped ostream
     std::ostream& get_ostr() const { return os; }
 
     ///Finishes compression and writes all pending data to the output
     void close();
 private:
     std::ostream& os;
-    std::vector<char> in;
-    std::vector<char> out;
-    z_stream zstr;
 
     void deflate_chunk(int flush = Z_NO_FLUSH);
 
diff --git a/include/io/zlib_error.h b/include/io/zlib_error.h
deleted file mode 100644
index 1ecb50e553..0000000000
--- a/include/io/zlib_error.h
+++ /dev/null
@@ -1,21 +0,0 @@
-#ifndef ZLIB_ERROR_H_INCLUDED
-#define ZLIB_ERROR_H_INCLUDED
-
-#include <stdexcept>
-#include <zlib.h>
-
-///Exception thrown in case zlib encounters a problem
-class zlib_error : public std::runtime_error
-{
-public:
-    const int errcode;
-
-    explicit zlib_error(const char* msg, int errcode):
-        std::runtime_error(msg
-                         ? std::string(zError(errcode)) + ": " + msg
-                         : zError(errcode)),
-        errcode(errcode)
-    {}
-};
-
-#endif // ZLIB_ERROR_H_INCLUDED
diff --git a/include/io/zlib_streambuf.h b/include/io/zlib_streambuf.h
new file mode 100644
index 0000000000..36062192b7
--- /dev/null
+++ b/include/io/zlib_streambuf.h
@@ -0,0 +1,45 @@
+#ifndef ZLIB_STREAMBUF_H_INCLUDED
+#define ZLIB_STREAMBUF_H_INCLUDED
+
+#include <stdexcept>
+#include <streambuf>
+#include <vector>
+#include <zlib.h>
+
+namespace zlib
+{
+
+///Exception thrown in case zlib encounters a problem
+class zlib_error : public std::runtime_error
+{
+public:
+    const int errcode;
+
+    explicit zlib_error(const char* msg, int errcode):
+        std::runtime_error(msg
+                         ? std::string(zError(errcode)) + ": " + msg
+                         : zError(errcode)),
+        errcode(errcode)
+    {}
+};
+
+///Base class for deflate_streambuf and inflate_streambuf
+class zlib_streambuf : public std::streambuf
+{
+protected:
+    std::vector<char> in;
+    std::vector<char> out;
+    z_stream zstr;
+
+    explicit zlib_streambuf(size_t bufsize):
+        in(bufsize), out(bufsize)
+    {
+        zstr.zalloc = Z_NULL;
+        zstr.zfree = Z_NULL;
+        zstr.opaque = Z_NULL;
+    }
+};
+
+}
+
+#endif // ZLIB_STREAMBUF_H_INCLUDED