zstream.h
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上传日期:2007-06-06
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- /*
- *
- * 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 1.1.1.1 2002/10/18 01:43:41 ping Exp $
- */
- #include <strstream.h>
- #include <string.h>
- #include <stdio.h>
- #include "zlib.h"
- #if defined(_WIN32)
- # include <fcntl.h>
- # include <io.h>
- # 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 <class T, class Items>
- inline int read(izstream& zs, T* x, Items items) {
- return ::gzread(zs.fp(), x, items*sizeof(T));
- }
- /*
- * Binary input with the '>' operator.
- */
- template <class T>
- 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()] = ' ';
- 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()] = ' ';
- 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 ";
- 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 ";
- 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 <class T, class Items>
- 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 <class T>
- 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 <class T>
- inline ostream& operator<<(ozstream& zs, const T& x) {
- zs.os_flush();
- return zs.os() << x;
- }
- #endif