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-input-source.hxx   | 132 +++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 examples/cxx/tree/compression/compressed-input-source.hxx

(limited to 'examples/cxx/tree/compression/compressed-input-source.hxx')

diff --git a/examples/cxx/tree/compression/compressed-input-source.hxx b/examples/cxx/tree/compression/compressed-input-source.hxx
new file mode 100644
index 0000000..680d39f
--- /dev/null
+++ b/examples/cxx/tree/compression/compressed-input-source.hxx
@@ -0,0 +1,132 @@
+// file      : examples/cxx/tree/compression/compressed-input-source.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : not copyrighted - public domain
+
+#ifndef COMPRESSED_INPUT_SOURCE_HXX
+#define COMPRESSED_INPUT_SOURCE_HXX
+
+#include <zlib.h>
+
+#include <iosfwd>
+#include <string>
+#include <cstddef>   // std::size_t
+#include <exception>
+
+#include <xercesc/sax/InputSource.hpp>
+#include <xercesc/util/BinInputStream.hpp>
+
+struct decompression_failure: std::exception
+{
+  explicit
+  decompression_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++ InputSource interface implementation with on-the-fly, zlib-
+// based decompression.
+//
+class compressed_input_source: public xercesc::InputSource
+{
+public:
+  enum compression_type
+  {
+    raw,
+    zlib,
+    gzip
+  };
+
+  compressed_input_source (std::istream&, compression_type);
+
+  compressed_input_source (std::istream&,
+                           compression_type,
+                           const std::string& system_id);
+
+  compressed_input_source (std::istream&,
+                           compression_type,
+                           const std::string& system_id,
+                           const std::string& public_id);
+
+  struct copy {};
+
+  // Throws the copy exception if this function is called more than once.
+  //
+  virtual xercesc::BinInputStream*
+  makeStream () const;
+
+private:
+  mutable std::istream* is_;
+  compression_type type_;
+};
+
+// Xerces-C++ BinInputStream interface implementation with on-the-fly, zlib-
+// based decompression.
+//
+class compressed_input_stream: public xercesc::BinInputStream
+{
+public:
+  enum compression_type
+  {
+    raw,
+    zlib,
+    gzip
+  };
+
+  compressed_input_stream (std::istream&, compression_type);
+
+  virtual
+  ~compressed_input_stream ();
+
+#if _XERCES_VERSION >= 30000
+  virtual XMLFilePos
+  curPos () const;
+
+  virtual XMLSize_t
+  readBytes (XMLByte* const buf, const XMLSize_t size);
+
+  virtual const XMLCh*
+  getContentType () const;
+
+#else
+
+  virtual unsigned int
+  readBytes (XMLByte* const buf, const unsigned int size);
+
+  virtual unsigned int
+  curPos () const;
+#endif
+
+private:
+  std::size_t
+  read ();
+
+private:
+  std::istream& is_;
+  z_stream zs_;
+  bool end_;
+
+  static const std::size_t buf_size_ = 65536;
+  char in_[buf_size_];
+  std::size_t pos_; // Current decompressed stream position.
+};
+
+#endif // COMPRESSED_INPUT_SOURCE_HXX
-- 
cgit v1.1