comparison src/zlib-1.2.7/contrib/iostream3/zfstream.h @ 4:e13257ea84a4

Add bzip2, zlib, liblo, portaudio sources

+/*
+ * A C++ I/O streams interface to the zlib gz* functions
+ *
+ * by Ludwig Schwardt <[e-mail]>
+ * original version by Kevin Ruland <[e-mail]>
+ *
+ * This version is standard-compliant and compatible with gcc 3.x.
+ */
+
+#ifndef ZFSTREAM_H
+#define ZFSTREAM_H
+
+#include <istream>  // not iostream, since we don't need cin/cout
+#include <ostream>
+#include "zlib.h"
+
+/*****************************************************************************/
+
+/**
+ *  @brief  Gzipped file stream buffer class.
+ *
+ *  This class implements basic_filebuf for gzipped files. It doesn't yet support
+ *  seeking (allowed by zlib but slow/limited), putback and read/write access
+ *  (tricky). Otherwise, it attempts to be a drop-in replacement for the standard
+ *  file streambuf.
+*/
+class gzfilebuf : public std::streambuf
+{
+public:
+  //  Default constructor.
+  gzfilebuf();
+
+  //  Destructor.
+  virtual
+  ~gzfilebuf();
+
+  /**
+   *  @brief  Set compression level and strategy on the fly.
+   *  @param  comp_level  Compression level (see zlib.h for allowed values)
+   *  @param  comp_strategy  Compression strategy (see zlib.h for allowed values)
+   *  @return  Z_OK on success, Z_STREAM_ERROR otherwise.
+   *
+   *  Unfortunately, these parameters cannot be modified separately, as the
+   *  previous zfstream version assumed. Since the strategy is seldom changed,
+   *  it can default and setcompression(level) then becomes like the old
+   *  setcompressionlevel(level).
+  */
+  int
+  setcompression(int comp_level,
+                 int comp_strategy = Z_DEFAULT_STRATEGY);
+
+  /**
+   *  @brief  Check if file is open.
+   *  @return  True if file is open.
+  */
+  bool
+  is_open() const { return (file != NULL); }
+
+  /**
+   *  @brief  Open gzipped file.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags.
+   *  @return  @c this on success, NULL on failure.
+  */
+  gzfilebuf*
+  open(const char* name,
+       std::ios_base::openmode mode);
+
+  /**
+   *  @brief  Attach to already open gzipped file.
+   *  @param  fd  File descriptor.
+   *  @param  mode  Open mode flags.
+   *  @return  @c this on success, NULL on failure.
+  */
+  gzfilebuf*
+  attach(int fd,
+         std::ios_base::openmode mode);
+
+  /**
+   *  @brief  Close gzipped file.
+   *  @return  @c this on success, NULL on failure.
+  */
+  gzfilebuf*
+  close();
+
+protected:
+  /**
+   *  @brief  Convert ios open mode int to mode string used by zlib.
+   *  @return  True if valid mode flag combination.
+  */
+  bool
+  open_mode(std::ios_base::openmode mode,
+            char* c_mode) const;
+
+  /**
+   *  @brief  Number of characters available in stream buffer.
+   *  @return  Number of characters.
+   *
+   *  This indicates number of characters in get area of stream buffer.
+   *  These characters can be read without accessing the gzipped file.
+  */
+  virtual std::streamsize
+  showmanyc();
+
+  /**
+   *  @brief  Fill get area from gzipped file.
+   *  @return  First character in get area on success, EOF on error.
+   *
+   *  This actually reads characters from gzipped file to stream
+   *  buffer. Always buffered.
+  */
+  virtual int_type
+  underflow();
+
+  /**
+   *  @brief  Write put area to gzipped file.
+   *  @param  c  Extra character to add to buffer contents.
+   *  @return  Non-EOF on success, EOF on error.
+   *
+   *  This actually writes characters in stream buffer to
+   *  gzipped file. With unbuffered output this is done one
+   *  character at a time.
+  */
+  virtual int_type
+  overflow(int_type c = traits_type::eof());
+
+  /**
+   *  @brief  Installs external stream buffer.
+   *  @param  p  Pointer to char buffer.
+   *  @param  n  Size of external buffer.
+   *  @return  @c this on success, NULL on failure.
+   *
+   *  Call setbuf(0,0) to enable unbuffered output.
+  */
+  virtual std::streambuf*
+  setbuf(char_type* p,
+         std::streamsize n);
+
+  /**
+   *  @brief  Flush stream buffer to file.
+   *  @return  0 on success, -1 on error.
+   *
+   *  This calls underflow(EOF) to do the job.
+  */
+  virtual int
+  sync();
+
+//
+// Some future enhancements
+//
+//  virtual int_type uflow();
+//  virtual int_type pbackfail(int_type c = traits_type::eof());
+//  virtual pos_type
+//  seekoff(off_type off,
+//          std::ios_base::seekdir way,
+//          std::ios_base::openmode mode = std::ios_base::in|std::ios_base::out);
+//  virtual pos_type
+//  seekpos(pos_type sp,
+//          std::ios_base::openmode mode = std::ios_base::in|std::ios_base::out);
+
+private:
+  /**
+   *  @brief  Allocate internal buffer.
+   *
+   *  This function is safe to call multiple times. It will ensure
+   *  that a proper internal buffer exists if it is required. If the
+   *  buffer already exists or is external, the buffer pointers will be
+   *  reset to their original state.
+  */
+  void
+  enable_buffer();
+
+  /**
+   *  @brief  Destroy internal buffer.
+   *
+   *  This function is safe to call multiple times. It will ensure
+   *  that the internal buffer is deallocated if it exists. In any
+   *  case, it will also reset the buffer pointers.
+  */
+  void
+  disable_buffer();
+
+  /**
+   *  Underlying file pointer.
+  */
+  gzFile file;
+
+  /**
+   *  Mode in which file was opened.
+  */
+  std::ios_base::openmode io_mode;
+
+  /**
+   *  @brief  True if this object owns file descriptor.
+   *
+   *  This makes the class responsible for closing the file
+   *  upon destruction.
+  */
+  bool own_fd;
+
+  /**
+   *  @brief  Stream buffer.
+   *
+   *  For simplicity this remains allocated on the free store for the
+   *  entire life span of the gzfilebuf object, unless replaced by setbuf.
+  */
+  char_type* buffer;
+
+  /**
+   *  @brief  Stream buffer size.
+   *
+   *  Defaults to system default buffer size (typically 8192 bytes).
+   *  Modified by setbuf.
+  */
+  std::streamsize buffer_size;
+
+  /**
+   *  @brief  True if this object owns stream buffer.
+   *
+   *  This makes the class responsible for deleting the buffer
+   *  upon destruction.
+  */
+  bool own_buffer;
+};
+
+/*****************************************************************************/
+
+/**
+ *  @brief  Gzipped file input stream class.
+ *
+ *  This class implements ifstream for gzipped files. Seeking and putback
+ *  is not supported yet.
+*/
+class gzifstream : public std::istream
+{
+public:
+  //  Default constructor
+  gzifstream();
+
+  /**
+   *  @brief  Construct stream on gzipped file to be opened.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags (forced to contain ios::in).
+  */
+  explicit
+  gzifstream(const char* name,
+             std::ios_base::openmode mode = std::ios_base::in);
+
+  /**
+   *  @brief  Construct stream on already open gzipped file.
+   *  @param  fd    File descriptor.
+   *  @param  mode  Open mode flags (forced to contain ios::in).
+  */
+  explicit
+  gzifstream(int fd,
+             std::ios_base::openmode mode = std::ios_base::in);
+
+  /**
+   *  Obtain underlying stream buffer.
+  */
+  gzfilebuf*
+  rdbuf() const
+  { return const_cast<gzfilebuf*>(&sb); }
+
+  /**
+   *  @brief  Check if file is open.
+   *  @return  True if file is open.
+  */
+  bool
+  is_open() { return sb.is_open(); }
+
+  /**
+   *  @brief  Open gzipped file.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags (forced to contain ios::in).
+   *
+   *  Stream will be in state good() if file opens successfully;
+   *  otherwise in state fail(). This differs from the behavior of
+   *  ifstream, which never sets the state to good() and therefore
+   *  won't allow you to reuse the stream for a second file unless
+   *  you manually clear() the state. The choice is a matter of
+   *  convenience.
+  */
+  void
+  open(const char* name,
+       std::ios_base::openmode mode = std::ios_base::in);
+
+  /**
+   *  @brief  Attach to already open gzipped file.
+   *  @param  fd  File descriptor.
+   *  @param  mode  Open mode flags (forced to contain ios::in).
+   *
+   *  Stream will be in state good() if attach succeeded; otherwise
+   *  in state fail().
+  */
+  void
+  attach(int fd,
+         std::ios_base::openmode mode = std::ios_base::in);
+
+  /**
+   *  @brief  Close gzipped file.
+   *
+   *  Stream will be in state fail() if close failed.
+  */
+  void
+  close();
+
+private:
+  /**
+   *  Underlying stream buffer.
+  */
+  gzfilebuf sb;
+};
+
+/*****************************************************************************/
+
+/**
+ *  @brief  Gzipped file output stream class.
+ *
+ *  This class implements ofstream for gzipped files. Seeking and putback
+ *  is not supported yet.
+*/
+class gzofstream : public std::ostream
+{
+public:
+  //  Default constructor
+  gzofstream();
+
+  /**
+   *  @brief  Construct stream on gzipped file to be opened.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags (forced to contain ios::out).
+  */
+  explicit
+  gzofstream(const char* name,
+             std::ios_base::openmode mode = std::ios_base::out);
+
+  /**
+   *  @brief  Construct stream on already open gzipped file.
+   *  @param  fd    File descriptor.
+   *  @param  mode  Open mode flags (forced to contain ios::out).
+  */
+  explicit
+  gzofstream(int fd,
+             std::ios_base::openmode mode = std::ios_base::out);
+
+  /**
+   *  Obtain underlying stream buffer.
+  */
+  gzfilebuf*
+  rdbuf() const
+  { return const_cast<gzfilebuf*>(&sb); }
+
+  /**
+   *  @brief  Check if file is open.
+   *  @return  True if file is open.
+  */
+  bool
+  is_open() { return sb.is_open(); }
+
+  /**
+   *  @brief  Open gzipped file.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags (forced to contain ios::out).
+   *
+   *  Stream will be in state good() if file opens successfully;
+   *  otherwise in state fail(). This differs from the behavior of
+   *  ofstream, which never sets the state to good() and therefore
+   *  won't allow you to reuse the stream for a second file unless
+   *  you manually clear() the state. The choice is a matter of
+   *  convenience.
+  */
+  void
+  open(const char* name,
+       std::ios_base::openmode mode = std::ios_base::out);
+
+  /**
+   *  @brief  Attach to already open gzipped file.
+   *  @param  fd  File descriptor.
+   *  @param  mode  Open mode flags (forced to contain ios::out).
+   *
+   *  Stream will be in state good() if attach succeeded; otherwise
+   *  in state fail().
+  */
+  void
+  attach(int fd,
+         std::ios_base::openmode mode = std::ios_base::out);
+
+  /**
+   *  @brief  Close gzipped file.
+   *
+   *  Stream will be in state fail() if close failed.
+  */
+  void
+  close();
+
+private:
+  /**
+   *  Underlying stream buffer.
+  */
+  gzfilebuf sb;
+};
+
+/*****************************************************************************/
+
+/**
+ *  @brief  Gzipped file output stream manipulator class.
+ *
+ *  This class defines a two-argument manipulator for gzofstream. It is used
+ *  as base for the setcompression(int,int) manipulator.
+*/
+template<typename T1, typename T2>
+  class gzomanip2
+  {
+  public:
+    // Allows insertor to peek at internals
+    template <typename Ta, typename Tb>
+      friend gzofstream&
+      operator<<(gzofstream&,
+                 const gzomanip2<Ta,Tb>&);
+
+    // Constructor
+    gzomanip2(gzofstream& (*f)(gzofstream&, T1, T2),
+              T1 v1,
+              T2 v2);
+  private:
+    // Underlying manipulator function
+    gzofstream&
+    (*func)(gzofstream&, T1, T2);
+
+    // Arguments for manipulator function
+    T1 val1;
+    T2 val2;
+  };
+
+/*****************************************************************************/
+
+// Manipulator function thunks through to stream buffer
+inline gzofstream&
+setcompression(gzofstream &gzs, int l, int s = Z_DEFAULT_STRATEGY)
+{
+  (gzs.rdbuf())->setcompression(l, s);
+  return gzs;
+}
+
+// Manipulator constructor stores arguments
+template<typename T1, typename T2>
+  inline
+  gzomanip2<T1,T2>::gzomanip2(gzofstream &(*f)(gzofstream &, T1, T2),
+                              T1 v1,
+                              T2 v2)
+  : func(f), val1(v1), val2(v2)
+  { }
+
+// Insertor applies underlying manipulator function to stream
+template<typename T1, typename T2>
+  inline gzofstream&
+  operator<<(gzofstream& s, const gzomanip2<T1,T2>& m)
+  { return (*m.func)(s, m.val1, m.val2); }
+
+// Insert this onto stream to simplify setting of compression level
+inline gzomanip2<int,int>
+setcompression(int l, int s = Z_DEFAULT_STRATEGY)
+{ return gzomanip2<int,int>(&setcompression, l, s); }
+
+#endif // ZFSTREAM_H