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mirror of https://github.com/mariadb-corporation/mariadb-columnstore-engine.git synced 2025-06-01 22:41:43 +03:00
2016-01-06 14:08:59 -06:00

144 lines
3.0 KiB
C++

/* Copyright (C) 2014 InfiniDB, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; version 2 of
the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA. */
/** @file */
/*
* classes isyncstream and osyncstream provide a C++ iostream interface
* for C stdio FILE* streams. The current implementation does not provide
* the necessary methods to support seeking. The I/O buffering of the
* input FILE* is used. The C++ iostream library calls syncbuf::sync()
* for every line, so output buffering is line-by-line.
* */
/*
#include "syncstream.h"
void copyStream(istream& iss, ostream& oss)
{
string line;
getline(iss, line);
while (iss.good())
{
oss << line << endl;
getline(iss, line);
}
}
main()
{
FILE* ifp;
FILE* ofp;
...
isyncstream iss(ifp);
osyncstream oss(ofp);
copyStream(iss, oss);
...
}
*/
#ifndef SYNCSTREAM_H__
#define SYNCSTREAM_H__
#include <iostream>
#include <cstdio>
namespace syncstream
{
/** A streambuf implementation for C stdio FILE* streams.
*
* Adapted from http://www.drdobbs.com/184401305
*/
class syncbuf : public std::streambuf
{
public:
/** ctor */
syncbuf(FILE* f) : std::streambuf(), fptr(f) {}
protected:
/** Write character in the case of overflow */
virtual int overflow(int c = EOF) {
return (c != EOF ? fputc(c, fptr) : EOF);
}
/** Get character in the case of overflow */
virtual int underflow() {
int c = getc(fptr);
if (c != EOF)
ungetc(c, fptr);
return c;
}
/** Get character in the case of overflow and advance get pointer */
virtual int uflow() {
return getc(fptr);
}
/** put character back in the case of backup underflow */
virtual int pbackfail(int c = EOF) {
return (c != EOF ? ungetc(c, fptr) : EOF);
}
/** Synchronize stream buffer */
virtual int sync() {
return fflush(fptr);
}
private:
FILE* fptr;
};
/** An istream adaptor for input FILE* streams */
class isyncstream : public std::istream
{
public:
/** ctor */
isyncstream() : istream(&buf), buf(0) {}
/** ctor */
isyncstream(FILE* fptr) : istream(&buf), buf(fptr) {}
/** const streambuf accessor */
const syncbuf* rdbuf() const {
return &buf;
}
private:
syncbuf buf;
};
/** An ostream adaptor for output FILE* streams */
class osyncstream : public std::ostream
{
public:
/** ctor */
osyncstream() : ostream(&buf), buf(0) {}
/** ctor */
osyncstream(FILE* fptr) : ostream(&buf), buf(fptr) {}
/** const streambuf accessor */
const syncbuf* rdbuf() const {
return &buf;
}
private:
syncbuf buf;
};
}
#endif