Imported Upstream version 93u+upstream

1 files changed, 171 insertions, 0 deletions

diff --git a/src/lib/libast/sfio/sfwrite.c b/src/lib/libast/sfio/sfwrite.c
new file mode 100644
index 0000000..170c863
--- /dev/null
+++ b/src/lib/libast/sfio/sfwrite.c
@@ -0,0 +1,171 @@
+/***********************************************************************
+*                                                                      *
+*               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"
+
+/*	Write data out to the file system
+**
+**	Written by Kiem-Phong Vo.
+*/
+
+#if __STD_C
+ssize_t sfwrite(Sfio_t* f, const Void_t* buf, size_t n)
+#else
+ssize_t sfwrite(f,buf,n)
+Sfio_t*		f;	/* write to this stream. 	*/
+Void_t*		buf;	/* buffer to be written.	*/
+size_t		n;	/* number of bytes. 		*/
+#endif
+{
+	reg uchar	*s, *begs, *next;
+	reg ssize_t	w;
+	reg int		local;
+	SFMTXDECL(f);
+
+	SFMTXENTER(f, (ssize_t)(-1));
+
+	GETLOCAL(f,local);
+
+	if(!buf)
+		SFMTXRETURN(f, (ssize_t)(n == 0 ? 0 : -1) );
+
+	/* release peek lock */
+	if(f->mode&SF_PEEK)
+	{	if(!(f->mode&SF_WRITE) && (f->flags&SF_RDWR) != SF_RDWR)
+			SFMTXRETURN(f, (ssize_t)(-1));
+
+		if((uchar*)buf != f->next &&
+		   (!f->rsrv || f->rsrv->data != (uchar*)buf) )
+			SFMTXRETURN(f, (ssize_t)(-1));
+
+		f->mode &= ~SF_PEEK;
+
+		if(f->mode&SF_PKRD)
+		{	/* read past peeked data */
+			char		buf[16];
+			reg ssize_t	r;
+
+			for(w = n; w > 0; )
+			{	if((r = w) > sizeof(buf))
+					r = sizeof(buf);
+				if((r = sysreadf(f->file,buf,r)) <= 0)
+				{	n -= w;
+					break;
+				}
+				else	w -= r;
+			}
+
+			f->mode &= ~SF_PKRD;
+			f->endb = f->data + n;
+			f->here += n;
+		}
+
+		if((f->mode&SF_READ) && f->proc)
+			f->next += n;
+	}
+
+	s = begs = (uchar*)buf;
+	for(;; f->mode &= ~SF_LOCK)
+	{	/* check stream mode */
+		if(SFMODE(f,local) != SF_WRITE && _sfmode(f,SF_WRITE,local) < 0 )
+		{	w = s > begs ? s-begs : -1;
+			SFMTXRETURN(f,w);
+		}
+
+		SFLOCK(f,local);
+
+		w = f->endb - f->next;
+
+		if(s == f->next) /* after sfreserve */
+		{	if(w > (ssize_t)n)
+				w = (ssize_t)n;
+			f->next = (s += w);
+			n -= w;
+			break;
+		}
+
+		/* attempt to create space in buffer */
+		if(w == 0 || ((f->flags&SF_WHOLE) && w < (ssize_t)n) )
+		{	if(f->flags&SF_STRING) /* extend buffer */
+			{	(void)SFWR(f, s, n-w, f->disc);
+				if((w = f->endb - f->next) < (ssize_t)n)
+				{	if(!(f->flags&SF_STRING)) /* maybe sftmp */
+					{	if(f->next > f->data)
+							goto fls_buf;
+					}
+					else if(w == 0)
+						break;
+				}
+			}
+			else if(f->next > f->data)
+			{ fls_buf:
+				(void)SFFLSBUF(f, -1);
+				if((w = f->endb - f->next) < (ssize_t)n &&
+				   (f->flags&SF_WHOLE) && f->next > f->data )
+						break;
+			}
+		}
+
+		if(!(f->flags&SF_STRING) && f->next == f->data &&
+		   (((f->flags&SF_WHOLE) && w <= n) || SFDIRECT(f,n)) )
+		{	/* bypass buffering */
+			if((w = SFWR(f,s,n,f->disc)) <= 0 )
+				break;
+		}
+		else
+		{	if(w > (ssize_t)n)
+				w = (ssize_t)n;
+			if(w <= 0) /* no forward progress possible */
+				break;
+			memmove(f->next, s, w);
+			f->next += w;
+		}
+
+		s += w;
+		if((n -= w) <= 0)
+			break;
+	}
+
+	/* always flush buffer for share streams */
+	if(f->extent < 0 && (f->flags&SF_SHARE) && !(f->flags&SF_PUBLIC) )
+		(void)SFFLSBUF(f,-1);
+
+	/* check to see if buffer should be flushed */
+	else if(n == 0 && (f->flags&SF_LINE) && !(f->flags&SF_STRING))
+	{	if((ssize_t)(n = f->next-f->data) > (w = s-begs))
+			n = w;
+		if(n > 0 && n < HIFORLINE)
+		{	for(next = f->next-1; n > 0; --n, --next)
+			{	if(*next == '\n')
+				{	n = HIFORLINE;
+					break;
+				}
+			}
+		}
+		if(n >= HIFORLINE)
+			(void)SFFLSBUF(f,-1);
+	}
+
+	SFOPEN(f,local);
+
+	w = s-begs;
+	SFMTXRETURN(f,w);
+}