1da2e3ebdSchin /***********************************************************************
2da2e3ebdSchin * *
3da2e3ebdSchin * This software is part of the ast package *
4*b30d1939SAndy Fiddaman * Copyright (c) 1985-2011 AT&T Intellectual Property *
5da2e3ebdSchin * and is licensed under the *
6*b30d1939SAndy Fiddaman * Eclipse Public License, Version 1.0 *
77c2fbfb3SApril Chin * by AT&T Intellectual Property *
8da2e3ebdSchin * *
9da2e3ebdSchin * 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) *
12da2e3ebdSchin * *
13da2e3ebdSchin * Information and Software Systems Research *
14da2e3ebdSchin * AT&T Research *
15da2e3ebdSchin * Florham Park NJ *
16da2e3ebdSchin * *
17da2e3ebdSchin * Glenn Fowler <gsf@research.att.com> *
18da2e3ebdSchin * David Korn <dgk@research.att.com> *
19da2e3ebdSchin * Phong Vo <kpv@research.att.com> *
20da2e3ebdSchin * *
21da2e3ebdSchin ***********************************************************************/
22da2e3ebdSchin #include "sfhdr.h"
23da2e3ebdSchin
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.
28da2e3ebdSchin **
29da2e3ebdSchin ** Written by Kiem-Phong Vo.
30da2e3ebdSchin */
31da2e3ebdSchin
32da2e3ebdSchin /* hole preserving writes */
33da2e3ebdSchin #if __STD_C
sfoutput(Sfio_t * f,char * buf,size_t n)347c2fbfb3SApril Chin static ssize_t sfoutput(Sfio_t* f, char* buf, size_t n)
35da2e3ebdSchin #else
36da2e3ebdSchin static ssize_t sfoutput(f,buf,n)
37da2e3ebdSchin Sfio_t* f;
387c2fbfb3SApril Chin char* buf;
397c2fbfb3SApril Chin size_t n;
40da2e3ebdSchin #endif
41da2e3ebdSchin { reg char *sp, *wbuf, *endbuf;
42da2e3ebdSchin reg ssize_t s, w, wr;
43da2e3ebdSchin
44da2e3ebdSchin s = w = 0;
45da2e3ebdSchin wbuf = buf;
46da2e3ebdSchin endbuf = buf+n;
47da2e3ebdSchin while(n > 0)
48da2e3ebdSchin { if((ssize_t)n < _Sfpage) /* no hole possible */
49da2e3ebdSchin { buf += n;
50da2e3ebdSchin s = n = 0;
51da2e3ebdSchin }
52da2e3ebdSchin else while((ssize_t)n >= _Sfpage)
53da2e3ebdSchin { /* see if a hole of 0's starts here */
54da2e3ebdSchin sp = buf+1;
55da2e3ebdSchin if(buf[0] == 0 && buf[_Sfpage-1] == 0)
56da2e3ebdSchin { /* check byte at a time until int-aligned */
57da2e3ebdSchin while(((ulong)sp)%sizeof(int))
58da2e3ebdSchin { if(*sp != 0)
59da2e3ebdSchin goto chk_hole;
60da2e3ebdSchin sp += 1;
61da2e3ebdSchin }
62da2e3ebdSchin
63da2e3ebdSchin /* check using int to speed up */
64da2e3ebdSchin while(sp < endbuf)
65da2e3ebdSchin { if(*((int*)sp) != 0)
66da2e3ebdSchin goto chk_hole;
67da2e3ebdSchin sp += sizeof(int);
68da2e3ebdSchin }
69da2e3ebdSchin
70da2e3ebdSchin /* check the remaining bytes */
71da2e3ebdSchin if(sp > endbuf)
72da2e3ebdSchin { sp -= sizeof(int);
73da2e3ebdSchin while(sp < endbuf)
74da2e3ebdSchin { if(*sp != 0)
75da2e3ebdSchin goto chk_hole;
76da2e3ebdSchin sp += 1;
77da2e3ebdSchin }
78da2e3ebdSchin }
79da2e3ebdSchin }
80da2e3ebdSchin
81da2e3ebdSchin chk_hole:
82da2e3ebdSchin if((s = sp-buf) >= _Sfpage) /* found a hole */
83da2e3ebdSchin break;
84da2e3ebdSchin
85da2e3ebdSchin /* skip a dirty page */
86da2e3ebdSchin n -= _Sfpage;
87da2e3ebdSchin buf += _Sfpage;
88da2e3ebdSchin }
89da2e3ebdSchin
90da2e3ebdSchin /* write out current dirty pages */
91da2e3ebdSchin if(buf > wbuf)
92da2e3ebdSchin { if((ssize_t)n < _Sfpage)
93da2e3ebdSchin { buf = endbuf;
94da2e3ebdSchin n = s = 0;
95da2e3ebdSchin }
96da2e3ebdSchin if((wr = syswritef(f->file,wbuf,buf-wbuf)) > 0)
97da2e3ebdSchin { w += wr;
98da2e3ebdSchin f->bits &= ~SF_HOLE;
99da2e3ebdSchin }
100da2e3ebdSchin if(wr != (buf-wbuf))
101da2e3ebdSchin break;
102da2e3ebdSchin wbuf = buf;
103da2e3ebdSchin }
104da2e3ebdSchin
105da2e3ebdSchin /* seek to a rounded boundary within the hole */
106da2e3ebdSchin if(s >= _Sfpage)
107da2e3ebdSchin { s = (s/_Sfpage)*_Sfpage;
108da2e3ebdSchin if(SFSK(f,(Sfoff_t)s,SEEK_CUR,NIL(Sfdisc_t*)) < 0)
109da2e3ebdSchin break;
110da2e3ebdSchin w += s;
111da2e3ebdSchin n -= s;
112da2e3ebdSchin wbuf = (buf += s);
113da2e3ebdSchin f->bits |= SF_HOLE;
114da2e3ebdSchin
115da2e3ebdSchin if(n > 0)
116da2e3ebdSchin { /* next page must be dirty */
117da2e3ebdSchin s = (ssize_t)n <= _Sfpage ? 1 : _Sfpage;
118da2e3ebdSchin buf += s;
119da2e3ebdSchin n -= s;
120da2e3ebdSchin }
121da2e3ebdSchin }
122da2e3ebdSchin }
123da2e3ebdSchin
124da2e3ebdSchin return w > 0 ? w : -1;
125da2e3ebdSchin }
126da2e3ebdSchin
127da2e3ebdSchin #if __STD_C
sfwr(Sfio_t * f,const Void_t * buf,size_t n,Sfdisc_t * disc)1287c2fbfb3SApril Chin ssize_t sfwr(Sfio_t* f, const Void_t* buf, size_t n, Sfdisc_t* disc)
129da2e3ebdSchin #else
130da2e3ebdSchin ssize_t sfwr(f,buf,n,disc)
1317c2fbfb3SApril Chin Sfio_t* f;
1327c2fbfb3SApril Chin Void_t* buf;
1337c2fbfb3SApril Chin size_t n;
1347c2fbfb3SApril Chin Sfdisc_t* disc;
135da2e3ebdSchin #endif
136da2e3ebdSchin {
137da2e3ebdSchin reg ssize_t w;
138da2e3ebdSchin reg Sfdisc_t* dc;
139da2e3ebdSchin reg int local, oerrno;
1407c2fbfb3SApril Chin SFMTXDECL(f);
141da2e3ebdSchin
1427c2fbfb3SApril Chin SFMTXENTER(f,(ssize_t)(-1));
143da2e3ebdSchin
144da2e3ebdSchin GETLOCAL(f,local);
145da2e3ebdSchin if(!local && !(f->bits&SF_DCDOWN)) /* an external user's call */
146da2e3ebdSchin { if(f->mode != SF_WRITE && _sfmode(f,SF_WRITE,0) < 0 )
147da2e3ebdSchin SFMTXRETURN(f, (ssize_t)(-1));
148da2e3ebdSchin if(f->next > f->data && SFSYNC(f) < 0 )
149da2e3ebdSchin SFMTXRETURN(f, (ssize_t)(-1));
150da2e3ebdSchin }
151da2e3ebdSchin
152da2e3ebdSchin for(;;)
153da2e3ebdSchin { /* stream locked by sfsetfd() */
154da2e3ebdSchin if(!(f->flags&SF_STRING) && f->file < 0)
155da2e3ebdSchin SFMTXRETURN(f,(ssize_t)0);
156da2e3ebdSchin
157da2e3ebdSchin /* clear current error states */
158da2e3ebdSchin f->flags &= ~(SF_EOF|SF_ERROR);
159da2e3ebdSchin
160da2e3ebdSchin dc = disc;
161*b30d1939SAndy Fiddaman if(f->flags&SF_STRING) /* just asking to extend buffer */
162da2e3ebdSchin w = n + (f->next - f->data);
163da2e3ebdSchin else
164da2e3ebdSchin { /* warn that a write is about to happen */
165da2e3ebdSchin SFDISC(f,dc,writef);
166da2e3ebdSchin if(dc && dc->exceptf && (f->flags&SF_IOCHECK) )
167da2e3ebdSchin { reg int rv;
168da2e3ebdSchin if(local)
169da2e3ebdSchin SETLOCAL(f);
170da2e3ebdSchin if((rv = _sfexcept(f,SF_WRITE,n,dc)) > 0)
171da2e3ebdSchin n = rv;
172da2e3ebdSchin else if(rv < 0)
173da2e3ebdSchin { f->flags |= SF_ERROR;
174da2e3ebdSchin SFMTXRETURN(f, rv);
175da2e3ebdSchin }
176da2e3ebdSchin }
177da2e3ebdSchin
178da2e3ebdSchin if(f->extent >= 0)
179da2e3ebdSchin { /* make sure we are at the right place to write */
180da2e3ebdSchin if(f->flags&SF_APPENDWR)
181da2e3ebdSchin { if(f->here != f->extent || (f->flags&SF_SHARE))
182da2e3ebdSchin { f->here = SFSK(f,(Sfoff_t)0,SEEK_END,dc);
183da2e3ebdSchin f->extent = f->here;
184da2e3ebdSchin }
185da2e3ebdSchin }
186da2e3ebdSchin else if((f->flags&SF_SHARE) && !(f->flags&SF_PUBLIC))
187da2e3ebdSchin f->here = SFSK(f,f->here,SEEK_SET,dc);
188da2e3ebdSchin }
189da2e3ebdSchin
190da2e3ebdSchin oerrno = errno;
191da2e3ebdSchin errno = 0;
192da2e3ebdSchin
193da2e3ebdSchin if(dc && dc->writef)
194da2e3ebdSchin { SFDCWR(f,buf,n,dc,w);
195da2e3ebdSchin }
196da2e3ebdSchin else if(SFISNULL(f))
197da2e3ebdSchin w = n;
198da2e3ebdSchin else if(f->flags&SF_WHOLE)
199da2e3ebdSchin goto do_write;
200da2e3ebdSchin else if((ssize_t)n >= _Sfpage &&
201da2e3ebdSchin !(f->flags&(SF_SHARE|SF_APPENDWR)) &&
202da2e3ebdSchin f->here == f->extent && (f->here%_Sfpage) == 0)
203da2e3ebdSchin { if((w = sfoutput(f,(char*)buf,n)) <= 0)
204da2e3ebdSchin goto do_write;
205da2e3ebdSchin }
206da2e3ebdSchin else
207da2e3ebdSchin {
208da2e3ebdSchin do_write:
209da2e3ebdSchin if((w = syswritef(f->file,buf,n)) > 0)
210da2e3ebdSchin f->bits &= ~SF_HOLE;
211da2e3ebdSchin }
212da2e3ebdSchin
213da2e3ebdSchin if(errno == 0)
214da2e3ebdSchin errno = oerrno;
215da2e3ebdSchin
216da2e3ebdSchin if(w > 0)
217da2e3ebdSchin { if(!(f->bits&SF_DCDOWN) )
218da2e3ebdSchin { if((f->flags&(SF_APPENDWR|SF_PUBLIC)) && f->extent >= 0 )
219da2e3ebdSchin f->here = SFSK(f,(Sfoff_t)0,SEEK_CUR,dc);
220da2e3ebdSchin else f->here += w;
221da2e3ebdSchin if(f->extent >= 0 && f->here > f->extent)
222da2e3ebdSchin f->extent = f->here;
223da2e3ebdSchin }
224da2e3ebdSchin
225da2e3ebdSchin SFMTXRETURN(f, (ssize_t)w);
226da2e3ebdSchin }
227da2e3ebdSchin }
228da2e3ebdSchin
229da2e3ebdSchin if(local)
230da2e3ebdSchin SETLOCAL(f);
231da2e3ebdSchin switch(_sfexcept(f,SF_WRITE,w,dc))
232da2e3ebdSchin {
233da2e3ebdSchin case SF_ECONT :
234da2e3ebdSchin goto do_continue;
235da2e3ebdSchin case SF_EDONE :
236da2e3ebdSchin w = local ? 0 : w;
237da2e3ebdSchin SFMTXRETURN(f, (ssize_t)w);
238da2e3ebdSchin case SF_EDISC :
239da2e3ebdSchin if(!local && !(f->flags&SF_STRING))
240da2e3ebdSchin goto do_continue;
241da2e3ebdSchin /* else fall thru */
242da2e3ebdSchin case SF_ESTACK :
243da2e3ebdSchin SFMTXRETURN(f, (ssize_t)(-1));
244da2e3ebdSchin }
245da2e3ebdSchin
246da2e3ebdSchin do_continue:
247da2e3ebdSchin for(dc = f->disc; dc; dc = dc->disc)
248da2e3ebdSchin if(dc == disc)
249da2e3ebdSchin break;
250da2e3ebdSchin disc = dc;
251da2e3ebdSchin }
252da2e3ebdSchin }
253