From b0846152c522c859bee2fbce55721d7b79264848 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Fri, 27 Nov 2009 18:17:22 +0200
Subject: Add XML compression example

---
 .../tree/compression/compressed-format-target.hxx  | 96 ++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 examples/cxx/tree/compression/compressed-format-target.hxx

(limited to 'examples/cxx/tree/compression/compressed-format-target.hxx')

diff --git a/examples/cxx/tree/compression/compressed-format-target.hxx b/examples/cxx/tree/compression/compressed-format-target.hxx
new file mode 100644
index 0000000..5d12e81
--- /dev/null
+++ b/examples/cxx/tree/compression/compressed-format-target.hxx
@@ -0,0 +1,96 @@
+// file      : examples/cxx/tree/compression/compressed-format-target.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : not copyrighted - public domain
+
+#ifndef COMPRESSED_FORMAT_TARGET_HXX
+#define COMPRESSED_FORMAT_TARGET_HXX
+
+#include <zlib.h>
+
+#include <iosfwd>
+#include <cstddef>   // std::size_t
+#include <exception>
+
+#include <xercesc/framework/XMLFormatter.hpp>
+
+struct compression_failure: std::exception
+{
+  explicit
+  compression_failure (int code)
+      : code_ (code)
+  {
+  }
+
+  int
+  code () const
+  {
+    return code_;
+  }
+
+  const char*
+  message () const
+  {
+    return zError (code_);
+  }
+
+  virtual const char*
+  what () const throw ();
+
+private:
+  int code_;
+};
+
+// Xerces-C++ XMLFormatTarget interface implementation with on-the-fly,
+// zlib-based compression.
+//
+class compressed_format_target: public xercesc::XMLFormatTarget
+{
+public:
+  enum compression_type
+  {
+    raw,
+    zlib,
+    gzip
+  };
+
+  compressed_format_target (std::ostream&, compression_type);
+
+  virtual
+  ~compressed_format_target ();
+
+  virtual void
+  writeChars (const XMLByte* const buf,
+#if _XERCES_VERSION >= 30000
+              const XMLSize_t size,
+#else
+              const unsigned int size,
+#endif
+              xercesc::XMLFormatter* const);
+
+  virtual void
+  flush ();
+
+  // Close the compressed stream by writing out the zlib or gzip trailer.
+  // This function is automatically called from the destructor but you
+  // may want to call it explicitly to be able to catch any exceptions
+  // that it might throw.
+  //
+  void
+  close ();
+
+private:
+  void
+  write (const char* buf, std::size_t size, bool flush = false);
+
+private:
+  std::ostream& os_;
+  z_stream zs_;
+  bool closed_;
+
+  static const std::size_t buf_size_ = 65536;
+  char in_[buf_size_];
+  char out_[buf_size_];
+  size_t n_;
+};
+
+#endif // COMPRESSED_FORMAT_TARGET_HXX
-- 
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