1*b30d1939SAndy Fiddaman /***********************************************************************
2*b30d1939SAndy Fiddaman * *
3*b30d1939SAndy Fiddaman * This software is part of the ast package *
4*b30d1939SAndy Fiddaman * Copyright (c) 1985-2011 AT&T Intellectual Property *
5*b30d1939SAndy Fiddaman * and is licensed under the *
6*b30d1939SAndy Fiddaman * Eclipse Public License, Version 1.0 *
7*b30d1939SAndy Fiddaman * by AT&T Intellectual Property *
8*b30d1939SAndy Fiddaman * *
9*b30d1939SAndy Fiddaman * A copy of the License is available at *
10*b30d1939SAndy Fiddaman * http://www.eclipse.org/org/documents/epl-v10.html *
11*b30d1939SAndy Fiddaman * (with md5 checksum b35adb5213ca9657e911e9befb180842) *
12*b30d1939SAndy Fiddaman * *
13*b30d1939SAndy Fiddaman * Information and Software Systems Research *
14*b30d1939SAndy Fiddaman * AT&T Research *
15*b30d1939SAndy Fiddaman * Florham Park NJ *
16*b30d1939SAndy Fiddaman * *
17*b30d1939SAndy Fiddaman * Glenn Fowler <gsf@research.att.com> *
18*b30d1939SAndy Fiddaman * David Korn <dgk@research.att.com> *
19*b30d1939SAndy Fiddaman * Phong Vo <kpv@research.att.com> *
20*b30d1939SAndy Fiddaman * *
21*b30d1939SAndy Fiddaman ***********************************************************************/
22*b30d1939SAndy Fiddaman #include "sfhdr.h"
23*b30d1939SAndy Fiddaman
24*b30d1939SAndy Fiddaman /* Write data with discipline.
25*b30d1939SAndy Fiddaman ** In the case of a string stream, this is used mainly to extend
26*b30d1939SAndy Fiddaman ** the buffer. However, this is done here so that exception handling
27*b30d1939SAndy Fiddaman ** is done uniformly across all stream types.
28*b30d1939SAndy Fiddaman **
29*b30d1939SAndy Fiddaman ** Written by Kiem-Phong Vo.
30*b30d1939SAndy Fiddaman */
31*b30d1939SAndy Fiddaman
32*b30d1939SAndy Fiddaman /* hole preserving writes */
33*b30d1939SAndy Fiddaman #if __STD_C
sfoutput(Sfio_t * f,char * buf,size_t n)34*b30d1939SAndy Fiddaman static ssize_t sfoutput(Sfio_t* f, char* buf, size_t n)
35*b30d1939SAndy Fiddaman #else
36*b30d1939SAndy Fiddaman static ssize_t sfoutput(f,buf,n)
37*b30d1939SAndy Fiddaman Sfio_t* f;
38*b30d1939SAndy Fiddaman char* buf;
39*b30d1939SAndy Fiddaman size_t n;
40*b30d1939SAndy Fiddaman #endif
41*b30d1939SAndy Fiddaman { reg char *sp, *wbuf, *endbuf;
42*b30d1939SAndy Fiddaman reg ssize_t s, w, wr;
43*b30d1939SAndy Fiddaman
44*b30d1939SAndy Fiddaman s = w = 0;
45*b30d1939SAndy Fiddaman wbuf = buf;
46*b30d1939SAndy Fiddaman endbuf = buf+n;
47*b30d1939SAndy Fiddaman while(n > 0)
48*b30d1939SAndy Fiddaman { if((ssize_t)n < _Sfpage) /* no hole possible */
49*b30d1939SAndy Fiddaman { buf += n;
50*b30d1939SAndy Fiddaman s = n = 0;
51*b30d1939SAndy Fiddaman }
52*b30d1939SAndy Fiddaman else while((ssize_t)n >= _Sfpage)
53*b30d1939SAndy Fiddaman { /* see if a hole of 0's starts here */
54*b30d1939SAndy Fiddaman sp = buf+1;
55*b30d1939SAndy Fiddaman if(buf[0] == 0 && buf[_Sfpage-1] == 0)
56*b30d1939SAndy Fiddaman { /* check byte at a time until int-aligned */
57*b30d1939SAndy Fiddaman while(((ulong)sp)%sizeof(int))
58*b30d1939SAndy Fiddaman { if(*sp != 0)
59*b30d1939SAndy Fiddaman goto chk_hole;
60*b30d1939SAndy Fiddaman sp += 1;
61*b30d1939SAndy Fiddaman }
62*b30d1939SAndy Fiddaman
63*b30d1939SAndy Fiddaman /* check using int to speed up */
64*b30d1939SAndy Fiddaman while(sp < endbuf)
65*b30d1939SAndy Fiddaman { if(*((int*)sp) != 0)
66*b30d1939SAndy Fiddaman goto chk_hole;
67*b30d1939SAndy Fiddaman sp += sizeof(int);
68*b30d1939SAndy Fiddaman }
69*b30d1939SAndy Fiddaman
70*b30d1939SAndy Fiddaman /* check the remaining bytes */
71*b30d1939SAndy Fiddaman if(sp > endbuf)
72*b30d1939SAndy Fiddaman { sp -= sizeof(int);
73*b30d1939SAndy Fiddaman while(sp < endbuf)
74*b30d1939SAndy Fiddaman { if(*sp != 0)
75*b30d1939SAndy Fiddaman goto chk_hole;
76*b30d1939SAndy Fiddaman sp += 1;
77*b30d1939SAndy Fiddaman }
78*b30d1939SAndy Fiddaman }
79*b30d1939SAndy Fiddaman }
80*b30d1939SAndy Fiddaman
81*b30d1939SAndy Fiddaman chk_hole:
82*b30d1939SAndy Fiddaman if((s = sp-buf) >= _Sfpage) /* found a hole */
83*b30d1939SAndy Fiddaman break;
84*b30d1939SAndy Fiddaman
85*b30d1939SAndy Fiddaman /* skip a dirty page */
86*b30d1939SAndy Fiddaman n -= _Sfpage;
87*b30d1939SAndy Fiddaman buf += _Sfpage;
88*b30d1939SAndy Fiddaman }
89*b30d1939SAndy Fiddaman
90*b30d1939SAndy Fiddaman /* write out current dirty pages */
91*b30d1939SAndy Fiddaman if(buf > wbuf)
92*b30d1939SAndy Fiddaman { if((ssize_t)n < _Sfpage)
93*b30d1939SAndy Fiddaman { buf = endbuf;
94*b30d1939SAndy Fiddaman n = s = 0;
95*b30d1939SAndy Fiddaman }
96*b30d1939SAndy Fiddaman if((wr = syswritef(f->file,wbuf,buf-wbuf)) > 0)
97*b30d1939SAndy Fiddaman { w += wr;
98*b30d1939SAndy Fiddaman f->bits &= ~SF_HOLE;
99*b30d1939SAndy Fiddaman }
100*b30d1939SAndy Fiddaman if(wr != (buf-wbuf))
101*b30d1939SAndy Fiddaman break;
102*b30d1939SAndy Fiddaman wbuf = buf;
103*b30d1939SAndy Fiddaman }
104*b30d1939SAndy Fiddaman
105*b30d1939SAndy Fiddaman /* seek to a rounded boundary within the hole */
106*b30d1939SAndy Fiddaman if(s >= _Sfpage)
107*b30d1939SAndy Fiddaman { s = (s/_Sfpage)*_Sfpage;
108*b30d1939SAndy Fiddaman if(SFSK(f,(Sfoff_t)s,SEEK_CUR,NIL(Sfdisc_t*)) < 0)
109*b30d1939SAndy Fiddaman break;
110*b30d1939SAndy Fiddaman w += s;
111*b30d1939SAndy Fiddaman n -= s;
112*b30d1939SAndy Fiddaman wbuf = (buf += s);
113*b30d1939SAndy Fiddaman f->bits |= SF_HOLE;
114*b30d1939SAndy Fiddaman
115*b30d1939SAndy Fiddaman if(n > 0)
116*b30d1939SAndy Fiddaman { /* next page must be dirty */
117*b30d1939SAndy Fiddaman s = (ssize_t)n <= _Sfpage ? 1 : _Sfpage;
118*b30d1939SAndy Fiddaman buf += s;
119*b30d1939SAndy Fiddaman n -= s;
120*b30d1939SAndy Fiddaman }
121*b30d1939SAndy Fiddaman }
122*b30d1939SAndy Fiddaman }
123*b30d1939SAndy Fiddaman
124*b30d1939SAndy Fiddaman return w > 0 ? w : -1;
125*b30d1939SAndy Fiddaman }
126*b30d1939SAndy Fiddaman
127*b30d1939SAndy Fiddaman #if __STD_C
sfwr(Sfio_t * f,const Void_t * buf,size_t n,Sfdisc_t * disc)128*b30d1939SAndy Fiddaman ssize_t sfwr(Sfio_t* f, const Void_t* buf, size_t n, Sfdisc_t* disc)
129*b30d1939SAndy Fiddaman #else
130*b30d1939SAndy Fiddaman ssize_t sfwr(f,buf,n,disc)
131*b30d1939SAndy Fiddaman Sfio_t* f;
132*b30d1939SAndy Fiddaman Void_t* buf;
133*b30d1939SAndy Fiddaman size_t n;
134*b30d1939SAndy Fiddaman Sfdisc_t* disc;
135*b30d1939SAndy Fiddaman #endif
136*b30d1939SAndy Fiddaman {
137*b30d1939SAndy Fiddaman reg ssize_t w;
138*b30d1939SAndy Fiddaman reg Sfdisc_t* dc;
139*b30d1939SAndy Fiddaman reg int local, oerrno;
140*b30d1939SAndy Fiddaman SFMTXDECL(f);
141*b30d1939SAndy Fiddaman
142*b30d1939SAndy Fiddaman SFMTXENTER(f,(ssize_t)(-1));
143*b30d1939SAndy Fiddaman
144*b30d1939SAndy Fiddaman GETLOCAL(f,local);
145*b30d1939SAndy Fiddaman if(!local && !(f->bits&SF_DCDOWN)) /* an external user's call */
146*b30d1939SAndy Fiddaman { if(f->mode != SF_WRITE && _sfmode(f,SF_WRITE,0) < 0 )
147*b30d1939SAndy Fiddaman SFMTXRETURN(f, (ssize_t)(-1));
148*b30d1939SAndy Fiddaman if(f->next > f->data && SFSYNC(f) < 0 )
149*b30d1939SAndy Fiddaman SFMTXRETURN(f, (ssize_t)(-1));
150*b30d1939SAndy Fiddaman }
151*b30d1939SAndy Fiddaman
152*b30d1939SAndy Fiddaman for(;;)
153*b30d1939SAndy Fiddaman { /* stream locked by sfsetfd() */
154*b30d1939SAndy Fiddaman if(!(f->flags&SF_STRING) && f->file < 0)
155*b30d1939SAndy Fiddaman SFMTXRETURN(f,(ssize_t)0);
156*b30d1939SAndy Fiddaman
157*b30d1939SAndy Fiddaman /* clear current error states */
158*b30d1939SAndy Fiddaman f->flags &= ~(SF_EOF|SF_ERROR);
159*b30d1939SAndy Fiddaman
160*b30d1939SAndy Fiddaman dc = disc;
161*b30d1939SAndy Fiddaman if(f->flags&SF_STRING) /* just asking to extend buffer */
162*b30d1939SAndy Fiddaman w = n + (f->next - f->data);
163*b30d1939SAndy Fiddaman else
164*b30d1939SAndy Fiddaman { /* warn that a write is about to happen */
165*b30d1939SAndy Fiddaman SFDISC(f,dc,writef);
166*b30d1939SAndy Fiddaman if(dc && dc->exceptf && (f->flags&SF_IOCHECK) )
167*b30d1939SAndy Fiddaman { reg int rv;
168*b30d1939SAndy Fiddaman if(local)
169*b30d1939SAndy Fiddaman SETLOCAL(f);
170*b30d1939SAndy Fiddaman if((rv = _sfexcept(f,SF_WRITE,n,dc)) > 0)
171*b30d1939SAndy Fiddaman n = rv;
172*b30d1939SAndy Fiddaman else if(rv < 0)
173*b30d1939SAndy Fiddaman { f->flags |= SF_ERROR;
174*b30d1939SAndy Fiddaman SFMTXRETURN(f, rv);
175*b30d1939SAndy Fiddaman }
176*b30d1939SAndy Fiddaman }
177*b30d1939SAndy Fiddaman
178*b30d1939SAndy Fiddaman if(f->extent >= 0)
179*b30d1939SAndy Fiddaman { /* make sure we are at the right place to write */
180*b30d1939SAndy Fiddaman if(f->flags&SF_APPENDWR)
181*b30d1939SAndy Fiddaman { if(f->here != f->extent || (f->flags&SF_SHARE))
182*b30d1939SAndy Fiddaman { f->here = SFSK(f,(Sfoff_t)0,SEEK_END,dc);
183*b30d1939SAndy Fiddaman f->extent = f->here;
184*b30d1939SAndy Fiddaman }
185*b30d1939SAndy Fiddaman }
186*b30d1939SAndy Fiddaman else if((f->flags&SF_SHARE) && !(f->flags&SF_PUBLIC))
187*b30d1939SAndy Fiddaman f->here = SFSK(f,f->here,SEEK_SET,dc);
188*b30d1939SAndy Fiddaman }
189*b30d1939SAndy Fiddaman
190*b30d1939SAndy Fiddaman oerrno = errno;
191*b30d1939SAndy Fiddaman errno = 0;
192*b30d1939SAndy Fiddaman
193*b30d1939SAndy Fiddaman if(dc && dc->writef)
194*b30d1939SAndy Fiddaman { SFDCWR(f,buf,n,dc,w);
195*b30d1939SAndy Fiddaman }
196*b30d1939SAndy Fiddaman else if(SFISNULL(f))
197*b30d1939SAndy Fiddaman w = n;
198*b30d1939SAndy Fiddaman else if(f->flags&SF_WHOLE)
199*b30d1939SAndy Fiddaman goto do_write;
200*b30d1939SAndy Fiddaman else if((ssize_t)n >= _Sfpage &&
201*b30d1939SAndy Fiddaman !(f->flags&(SF_SHARE|SF_APPENDWR)) &&
202*b30d1939SAndy Fiddaman f->here == f->extent && (f->here%_Sfpage) == 0)
203*b30d1939SAndy Fiddaman { if((w = sfoutput(f,(char*)buf,n)) <= 0)
204*b30d1939SAndy Fiddaman goto do_write;
205*b30d1939SAndy Fiddaman }
206*b30d1939SAndy Fiddaman else
207*b30d1939SAndy Fiddaman {
208*b30d1939SAndy Fiddaman do_write:
209*b30d1939SAndy Fiddaman if((w = syswritef(f->file,buf,n)) > 0)
210*b30d1939SAndy Fiddaman f->bits &= ~SF_HOLE;
211*b30d1939SAndy Fiddaman }
212*b30d1939SAndy Fiddaman
213*b30d1939SAndy Fiddaman if(errno == 0)
214*b30d1939SAndy Fiddaman errno = oerrno;
215*b30d1939SAndy Fiddaman
216*b30d1939SAndy Fiddaman if(w > 0)
217*b30d1939SAndy Fiddaman { if(!(f->bits&SF_DCDOWN) )
218*b30d1939SAndy Fiddaman { if((f->flags&(SF_APPENDWR|SF_PUBLIC)) && f->extent >= 0 )
219*b30d1939SAndy Fiddaman f->here = SFSK(f,(Sfoff_t)0,SEEK_CUR,dc);
220*b30d1939SAndy Fiddaman else f->here += w;
221*b30d1939SAndy Fiddaman if(f->extent >= 0 && f->here > f->extent)
222*b30d1939SAndy Fiddaman f->extent = f->here;
223*b30d1939SAndy Fiddaman }
224*b30d1939SAndy Fiddaman
225*b30d1939SAndy Fiddaman SFMTXRETURN(f, (ssize_t)w);
226*b30d1939SAndy Fiddaman }
227*b30d1939SAndy Fiddaman }
228*b30d1939SAndy Fiddaman
229*b30d1939SAndy Fiddaman if(local)
230*b30d1939SAndy Fiddaman SETLOCAL(f);
231*b30d1939SAndy Fiddaman switch(_sfexcept(f,SF_WRITE,w,dc))
232*b30d1939SAndy Fiddaman {
233*b30d1939SAndy Fiddaman case SF_ECONT :
234*b30d1939SAndy Fiddaman goto do_continue;
235*b30d1939SAndy Fiddaman case SF_EDONE :
236*b30d1939SAndy Fiddaman w = local ? 0 : w;
237*b30d1939SAndy Fiddaman SFMTXRETURN(f, (ssize_t)w);
238*b30d1939SAndy Fiddaman case SF_EDISC :
239*b30d1939SAndy Fiddaman if(!local && !(f->flags&SF_STRING))
240*b30d1939SAndy Fiddaman goto do_continue;
241*b30d1939SAndy Fiddaman /* else fall thru */
242*b30d1939SAndy Fiddaman case SF_ESTACK :
243*b30d1939SAndy Fiddaman SFMTXRETURN(f, (ssize_t)(-1));
244*b30d1939SAndy Fiddaman }
245*b30d1939SAndy Fiddaman
246*b30d1939SAndy Fiddaman do_continue:
247*b30d1939SAndy Fiddaman for(dc = f->disc; dc; dc = dc->disc)
248*b30d1939SAndy Fiddaman if(dc == disc)
249*b30d1939SAndy Fiddaman break;
250*b30d1939SAndy Fiddaman disc = dc;
251*b30d1939SAndy Fiddaman }
252*b30d1939SAndy Fiddaman }
253