/* * * Copyright (c) 1997 * Christian Michelsen Research AS * Advanced Computing * Fantoftvegen 38, 5036 BERGEN, Norway * http://www.cmr.no * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Christian Michelsen Research AS makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. * */ #ifndef ZSTREAM__H #define ZSTREAM__H /* * zstream.h - C++ interface to the 'zlib' general purpose compression library * $Id: zstream.h,v 1.1.1.2 2017/01/10 00:25:30 christos Exp $ */ #include #include #include #include "zlib.h" #if defined(_WIN32) # include # include # define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) #else # define SET_BINARY_MODE(file) #endif class zstringlen { public: zstringlen(class izstream&); zstringlen(class ozstream&, const char*); size_t value() const { return val.word; } private: struct Val { unsigned char byte; size_t word; } val; }; // ----------------------------- izstream ----------------------------- class izstream { public: izstream() : m_fp(0) {} izstream(FILE* fp) : m_fp(0) { open(fp); } izstream(const char* name) : m_fp(0) { open(name); } ~izstream() { close(); } /* Opens a gzip (.gz) file for reading. * open() can be used to read a file which is not in gzip format; * in this case read() will directly read from the file without * decompression. errno can be checked to distinguish two error * cases (if errno is zero, the zlib error is Z_MEM_ERROR). */ void open(const char* name) { if (m_fp) close(); m_fp = ::gzopen(name, "rb"); } void open(FILE* fp) { SET_BINARY_MODE(fp); if (m_fp) close(); m_fp = ::gzdopen(fileno(fp), "rb"); } /* Flushes all pending input if necessary, closes the compressed file * and deallocates all the (de)compression state. The return value is * the zlib error number (see function error() below). */ int close() { int r = ::gzclose(m_fp); m_fp = 0; return r; } /* Binary read the given number of bytes from the compressed file. */ int read(void* buf, size_t len) { return ::gzread(m_fp, buf, len); } /* Returns the error message for the last error which occurred on the * given compressed file. errnum is set to zlib error number. If an * error occurred in the file system and not in the compression library, * errnum is set to Z_ERRNO and the application may consult errno * to get the exact error code. */ const char* error(int* errnum) { return ::gzerror(m_fp, errnum); } gzFile fp() { return m_fp; } private: gzFile m_fp; }; /* * Binary read the given (array of) object(s) from the compressed file. * If the input file was not in gzip format, read() copies the objects number * of bytes into the buffer. * returns the number of uncompressed bytes actually read * (0 for end of file, -1 for error). */ template inline int read(izstream& zs, T* x, Items items) { return ::gzread(zs.fp(), x, items*sizeof(T)); } /* * Binary input with the '>' operator. */ template inline izstream& operator>(izstream& zs, T& x) { ::gzread(zs.fp(), &x, sizeof(T)); return zs; } inline zstringlen::zstringlen(izstream& zs) { zs > val.byte; if (val.byte == 255) zs > val.word; else val.word = val.byte; } /* * Read length of string + the string with the '>' operator. */ inline izstream& operator>(izstream& zs, char* x) { zstringlen len(zs); ::gzread(zs.fp(), x, len.value()); x[len.value()] = '\0'; return zs; } inline char* read_string(izstream& zs) { zstringlen len(zs); char* x = new char[len.value()+1]; ::gzread(zs.fp(), x, len.value()); x[len.value()] = '\0'; return x; } // ----------------------------- ozstream ----------------------------- class ozstream { public: ozstream() : m_fp(0), m_os(0) { } ozstream(FILE* fp, int level = Z_DEFAULT_COMPRESSION) : m_fp(0), m_os(0) { open(fp, level); } ozstream(const char* name, int level = Z_DEFAULT_COMPRESSION) : m_fp(0), m_os(0) { open(name, level); } ~ozstream() { close(); } /* Opens a gzip (.gz) file for writing. * The compression level parameter should be in 0..9 * errno can be checked to distinguish two error cases * (if errno is zero, the zlib error is Z_MEM_ERROR). */ void open(const char* name, int level = Z_DEFAULT_COMPRESSION) { char mode[4] = "wb\0"; if (level != Z_DEFAULT_COMPRESSION) mode[2] = '0'+level; if (m_fp) close(); m_fp = ::gzopen(name, mode); } /* open from a FILE pointer. */ void open(FILE* fp, int level = Z_DEFAULT_COMPRESSION) { SET_BINARY_MODE(fp); char mode[4] = "wb\0"; if (level != Z_DEFAULT_COMPRESSION) mode[2] = '0'+level; if (m_fp) close(); m_fp = ::gzdopen(fileno(fp), mode); } /* Flushes all pending output if necessary, closes the compressed file * and deallocates all the (de)compression state. The return value is * the zlib error number (see function error() below). */ int close() { if (m_os) { ::gzwrite(m_fp, m_os->str(), m_os->pcount()); delete[] m_os->str(); delete m_os; m_os = 0; } int r = ::gzclose(m_fp); m_fp = 0; return r; } /* Binary write the given number of bytes into the compressed file. */ int write(const void* buf, size_t len) { return ::gzwrite(m_fp, (voidp) buf, len); } /* Flushes all pending output into the compressed file. The parameter * _flush is as in the deflate() function. The return value is the zlib * error number (see function gzerror below). flush() returns Z_OK if * the flush_ parameter is Z_FINISH and all output could be flushed. * flush() should be called only when strictly necessary because it can * degrade compression. */ int flush(int _flush) { os_flush(); return ::gzflush(m_fp, _flush); } /* Returns the error message for the last error which occurred on the * given compressed file. errnum is set to zlib error number. If an * error occurred in the file system and not in the compression library, * errnum is set to Z_ERRNO and the application may consult errno * to get the exact error code. */ const char* error(int* errnum) { return ::gzerror(m_fp, errnum); } gzFile fp() { return m_fp; } ostream& os() { if (m_os == 0) m_os = new ostrstream; return *m_os; } void os_flush() { if (m_os && m_os->pcount()>0) { ostrstream* oss = new ostrstream; oss->fill(m_os->fill()); oss->flags(m_os->flags()); oss->precision(m_os->precision()); oss->width(m_os->width()); ::gzwrite(m_fp, m_os->str(), m_os->pcount()); delete[] m_os->str(); delete m_os; m_os = oss; } } private: gzFile m_fp; ostrstream* m_os; }; /* * Binary write the given (array of) object(s) into the compressed file. * returns the number of uncompressed bytes actually written * (0 in case of error). */ template inline int write(ozstream& zs, const T* x, Items items) { return ::gzwrite(zs.fp(), (voidp) x, items*sizeof(T)); } /* * Binary output with the '<' operator. */ template inline ozstream& operator<(ozstream& zs, const T& x) { ::gzwrite(zs.fp(), (voidp) &x, sizeof(T)); return zs; } inline zstringlen::zstringlen(ozstream& zs, const char* x) { val.byte = 255; val.word = ::strlen(x); if (val.word < 255) zs < (val.byte = val.word); else zs < val; } /* * Write length of string + the string with the '<' operator. */ inline ozstream& operator<(ozstream& zs, const char* x) { zstringlen len(zs, x); ::gzwrite(zs.fp(), (voidp) x, len.value()); return zs; } #ifdef _MSC_VER inline ozstream& operator<(ozstream& zs, char* const& x) { return zs < (const char*) x; } #endif /* * Ascii write with the << operator; */ template inline ostream& operator<<(ozstream& zs, const T& x) { zs.os_flush(); return zs.os() << x; } #endif