+++ /dev/null
-/*
- * A C++ I/O streams interface to the zlib gz* functions
- *
- * by Ludwig Schwardt <schwardt@sun.ac.za>
- * original version by Kevin Ruland <kevin@rodin.wustl.edu>
- *
- * 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
git.samba.org / samba.git / blobdiff