diff options
Diffstat (limited to 'src/lib/libast/sfio/sfnew.c')
| -rw-r--r-- | src/lib/libast/sfio/sfnew.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/lib/libast/sfio/sfnew.c b/src/lib/libast/sfio/sfnew.c new file mode 100644 index 0000000..a6feddc --- /dev/null +++ b/src/lib/libast/sfio/sfnew.c @@ -0,0 +1,129 @@ +/*********************************************************************** +* * +* This software is part of the ast package * +* Copyright (c) 1985-2011 AT&T Intellectual Property * +* and is licensed under the * +* Eclipse Public License, Version 1.0 * +* by AT&T Intellectual Property * +* * +* A copy of the License is available at * +* http://www.eclipse.org/org/documents/epl-v10.html * +* (with md5 checksum b35adb5213ca9657e911e9befb180842) * +* * +* Information and Software Systems Research * +* AT&T Research * +* Florham Park NJ * +* * +* Glenn Fowler <gsf@research.att.com> * +* David Korn <dgk@research.att.com> * +* Phong Vo <kpv@research.att.com> * +* * +***********************************************************************/ +#include "sfhdr.h" + +/* Fundamental function to create a new stream. +** The argument flags defines the type of stream and the scheme +** of buffering. +** +** Written by Kiem-Phong Vo. +*/ + +#if __STD_C +Sfio_t* sfnew(Sfio_t* oldf, Void_t* buf, size_t size, int file, int flags) +#else +Sfio_t* sfnew(oldf,buf,size,file,flags) +Sfio_t* oldf; /* old stream to be reused */ +Void_t* buf; /* a buffer to read/write, if NULL, will be allocated */ +size_t size; /* buffer size if buf is given or desired buffer size */ +int file; /* file descriptor to read/write from */ +int flags; /* type of file stream */ +#endif +{ + reg Sfio_t* f; + reg int sflags; + + SFONCE(); /* initialize mutexes */ + + if(!(flags&SF_RDWR)) + return NIL(Sfio_t*); + + sflags = 0; + if((f = oldf) ) + { if(flags&SF_EOF) + { if(f != sfstdin && f != sfstdout && f != sfstderr) + f->mutex = NIL(Vtmutex_t*); + SFCLEAR(f, f->mutex); + oldf = NIL(Sfio_t*); + } + else if(f->mode&SF_AVAIL) + { /* only allow SF_STATIC to be already closed */ + if(!(f->flags&SF_STATIC) ) + return NIL(Sfio_t*); + sflags = f->flags; + oldf = NIL(Sfio_t*); + } + else + { /* reopening an open stream, close it first */ + sflags = f->flags; + + if(((f->mode&SF_RDWR) != f->mode && _sfmode(f,0,0) < 0) || + SFCLOSE(f) < 0 ) + return NIL(Sfio_t*); + + if(f->data && ((flags&SF_STRING) || size != (size_t)SF_UNBOUND) ) + { if(sflags&SF_MALLOC) + free((Void_t*)f->data); + f->data = NIL(uchar*); + } + if(!f->data) + sflags &= ~SF_MALLOC; + } + } + + if(!f) + { /* reuse a standard stream structure if possible */ + if(!(flags&SF_STRING) && file >= 0 && file <= 2) + { f = file == 0 ? sfstdin : file == 1 ? sfstdout : sfstderr; + if(f) + { if(f->mode&SF_AVAIL) + { sflags = f->flags; + SFCLEAR(f, f->mutex); + } + else f = NIL(Sfio_t*); + } + } + + if(!f) + { if(!(f = (Sfio_t*)malloc(sizeof(Sfio_t))) ) + return NIL(Sfio_t*); + SFCLEAR(f, NIL(Vtmutex_t*)); + } + } + + /* create a mutex */ + if(!f->mutex) + f->mutex = vtmtxopen(NIL(Vtmutex_t*), VT_INIT); + + /* stream type */ + f->mode = (flags&SF_READ) ? SF_READ : SF_WRITE; + f->flags = (flags&SF_FLAGS) | (sflags&(SF_MALLOC|SF_STATIC)); + f->bits = (flags&SF_RDWR) == SF_RDWR ? SF_BOTH : 0; + f->file = file; + f->here = f->extent = 0; + f->getr = f->tiny[0] = 0; + + f->mode |= SF_INIT; + if(size != (size_t)SF_UNBOUND) + { f->size = size; + f->data = size <= 0 ? NIL(uchar*) : (uchar*)buf; + } + f->endb = f->endr = f->endw = f->next = f->data; + + if(_Sfnotify) + (*_Sfnotify)(f, SF_NEW, (void*)((long)f->file)); + + if(f->flags&SF_STRING) + (void)_sfmode(f,f->mode&SF_RDWR,0); + + return f; +} |