1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * Phong Vo <kpv@research.att.com> * 20 * * 21 ***********************************************************************/ 22 #if defined(__STDPP__directive) && defined(__STDPP__hide) 23 __STDPP__directive pragma pp:hide getpagesize 24 #else 25 #define getpagesize ______getpagesize 26 #endif 27 28 #include "sfhdr.h" 29 30 #if defined(__STDPP__directive) && defined(__STDPP__hide) 31 __STDPP__directive pragma pp:nohide getpagesize 32 #else 33 #undef getpagesize 34 #endif 35 36 #if _lib_getpagesize 37 _BEGIN_EXTERNS_ 38 extern int getpagesize _ARG_((void)); 39 _END_EXTERNS_ 40 #endif 41 42 /* Set a (new) buffer for a stream. 43 ** If size < 0, it is assigned a suitable value depending on the 44 ** kind of stream. The actual buffer size allocated is dependent 45 ** on how much memory is available. 46 ** 47 ** Written by Kiem-Phong Vo. 48 */ 49 50 #if !_sys_stat 51 struct stat 52 { int st_mode; 53 int st_size; 54 }; 55 #undef sysfstatf 56 #define sysfstatf(fd,st) (-1) 57 #endif /*_sys_stat*/ 58 59 static int setlinemode() 60 { char* astsfio; 61 char* endw; 62 63 static int modes = -1; 64 static const char sf_line[] = "SF_LINE"; 65 static const char sf_wcwidth[] = "SF_WCWIDTH"; 66 67 #define ISSEPAR(c) ((c) == ',' || (c) == ' ' || (c) == '\t') 68 if (modes < 0) 69 { modes = 0; 70 if(astsfio = getenv("_AST_SFIO_OPTIONS")) 71 { for(; *astsfio != 0; astsfio = endw) 72 { while(ISSEPAR(*astsfio) ) 73 *astsfio++; 74 for(endw = astsfio; *endw && !ISSEPAR(*endw); ++endw) 75 ; 76 if((endw-astsfio) == (sizeof(sf_line)-1) && 77 strncmp(astsfio,sf_line,endw-astsfio) == 0) 78 { if ((modes |= SF_LINE) == (SF_LINE|SF_WCWIDTH)) 79 break; 80 } 81 else if((endw-astsfio) == (sizeof(sf_wcwidth)-1) && 82 strncmp(astsfio,sf_wcwidth,endw-astsfio) == 0) 83 { if ((modes |= SF_WCWIDTH) == (SF_LINE|SF_WCWIDTH)) 84 break; 85 } 86 } 87 } 88 } 89 return modes; 90 } 91 92 #if __STD_C 93 Void_t* sfsetbuf(reg Sfio_t* f, reg Void_t* buf, reg size_t size) 94 #else 95 Void_t* sfsetbuf(f,buf,size) 96 reg Sfio_t* f; /* stream to be buffered */ 97 reg Void_t* buf; /* new buffer */ 98 reg size_t size; /* buffer size, -1 for default size */ 99 #endif 100 { 101 int sf_malloc, oflags, init, okmmap, local; 102 ssize_t bufsize, blksz; 103 Sfdisc_t* disc; 104 sfstat_t st; 105 uchar* obuf = NIL(uchar*); 106 ssize_t osize = 0; 107 108 SFONCE(); 109 110 SFMTXSTART(f,NIL(Void_t*)); 111 112 GETLOCAL(f,local); 113 114 if(size == 0 && buf) 115 { /* special case to get buffer info */ 116 _Sfi = f->val = (f->bits&SF_MMAP) ? (f->endb-f->data) : f->size; 117 SFMTXRETURN(f, (Void_t*)f->data); 118 } 119 120 /* cleanup actions already done, don't allow write buffering any more */ 121 if(_Sfexiting && !(f->flags&SF_STRING) && (f->mode&SF_WRITE)) 122 { buf = NIL(Void_t*); 123 size = 0; 124 } 125 126 if((init = f->mode&SF_INIT) ) 127 { if(!f->pool && _sfsetpool(f) < 0) 128 SFMTXRETURN(f, NIL(Void_t*)); 129 } 130 else if((f->mode&SF_RDWR) != SFMODE(f,local) && _sfmode(f,0,local) < 0) 131 SFMTXRETURN(f, NIL(Void_t*)); 132 133 if(init) 134 f->mode = (f->mode&SF_RDWR)|SF_LOCK; 135 else 136 { int rv; 137 138 /* make sure there is no hidden read data */ 139 if(f->proc && (f->flags&SF_READ) && (f->mode&SF_WRITE) && 140 _sfmode(f,SF_READ,local) < 0) 141 SFMTXRETURN(f, NIL(Void_t*)); 142 143 /* synchronize first */ 144 SFLOCK(f,local); rv = SFSYNC(f); SFOPEN(f,local); 145 if(rv < 0) 146 SFMTXRETURN(f, NIL(Void_t*)); 147 148 /* turn off the SF_SYNCED bit because buffer is changing */ 149 f->mode &= ~SF_SYNCED; 150 } 151 152 SFLOCK(f,local); 153 154 if((Sfio_t*)buf != f) 155 blksz = -1; 156 else /* setting alignment size only */ 157 { blksz = (ssize_t)size; 158 159 if(!init) /* stream already initialized */ 160 { obuf = f->data; 161 osize = f->size; 162 goto done; 163 } 164 else /* initialize stream as if in the default case */ 165 { buf = NIL(Void_t*); 166 size = (size_t)SF_UNBOUND; 167 } 168 } 169 170 bufsize = 0; 171 oflags = f->flags; 172 173 /* see if memory mapping is possible (see sfwrite for SF_BOTH) */ 174 okmmap = (buf || (f->flags&SF_STRING) || (f->flags&SF_RDWR) == SF_RDWR) ? 0 : 1; 175 176 /* save old buffer info */ 177 #ifdef MAP_TYPE 178 if(f->bits&SF_MMAP) 179 { if(f->data) 180 { SFMUNMAP(f,f->data,f->endb-f->data); 181 f->data = NIL(uchar*); 182 } 183 } else 184 #endif 185 if(f->data == f->tiny) 186 { f->data = NIL(uchar*); 187 f->size = 0; 188 } 189 obuf = f->data; 190 osize = f->size; 191 192 f->flags &= ~SF_MALLOC; 193 f->bits &= ~SF_MMAP; 194 195 /* pure read/string streams must have a valid string */ 196 if((f->flags&(SF_RDWR|SF_STRING)) == SF_RDSTR && 197 (size == (size_t)SF_UNBOUND || !buf)) 198 size = 0; 199 200 /* set disc to the first discipline with a seekf */ 201 for(disc = f->disc; disc; disc = disc->disc) 202 if(disc->seekf) 203 break; 204 205 if((init || local) && !(f->flags&SF_STRING)) 206 { /* ASSERT(f->file >= 0) */ 207 st.st_mode = 0; 208 209 /* if has discipline, set size by discipline if possible */ 210 if(!_sys_stat || disc) 211 { if((f->here = SFSK(f,(Sfoff_t)0,SEEK_CUR,disc)) < 0) 212 goto unseekable; 213 else 214 { Sfoff_t e; 215 if((e = SFSK(f,(Sfoff_t)0,SEEK_END,disc)) >= 0) 216 f->extent = e > f->here ? e : f->here; 217 (void)SFSK(f,f->here,SEEK_SET,disc); 218 goto setbuf; 219 } 220 } 221 222 /* get file descriptor status */ 223 if(sysfstatf((int)f->file,&st) < 0) 224 f->here = -1; 225 else 226 { 227 #if _sys_stat && _stat_blksize /* preferred io block size */ 228 f->blksz = (size_t)st.st_blksize; 229 #endif 230 bufsize = 64 * 1024; 231 if(S_ISDIR(st.st_mode) || (Sfoff_t)st.st_size < (Sfoff_t)SF_GRAIN) 232 okmmap = 0; 233 if(S_ISREG(st.st_mode) || S_ISDIR(st.st_mode)) 234 f->here = SFSK(f,(Sfoff_t)0,SEEK_CUR,f->disc); 235 else f->here = -1; 236 237 #if O_TEXT /* no memory mapping with O_TEXT because read()/write() alter data stream */ 238 if(okmmap && f->here >= 0 && 239 (sysfcntlf((int)f->file,F_GETFL,0) & O_TEXT) ) 240 okmmap = 0; 241 #endif 242 } 243 244 if(init) 245 f->flags |= setlinemode(); 246 247 if(f->here >= 0) 248 { f->extent = (Sfoff_t)st.st_size; 249 250 /* seekable std-devices are share-public by default */ 251 if(f == sfstdin || f == sfstdout || f == sfstderr) 252 f->flags |= SF_SHARE|SF_PUBLIC; 253 } 254 else 255 { 256 unseekable: 257 f->extent = -1; 258 f->here = 0; 259 260 if(init) 261 { if(S_ISCHR(st.st_mode) ) 262 { int oerrno = errno; 263 264 bufsize = SF_GRAIN; 265 266 /* set line mode for terminals */ 267 if(!(f->flags&(SF_LINE|SF_WCWIDTH)) && isatty(f->file)) 268 f->flags |= SF_LINE|SF_WCWIDTH; 269 #if _sys_stat 270 else /* special case /dev/null */ 271 { reg int dev, ino; 272 dev = (int)st.st_dev; 273 ino = (int)st.st_ino; 274 if(sysstatf(DEVNULL,&st) >= 0 && 275 dev == (int)st.st_dev && 276 ino == (int)st.st_ino) 277 SFSETNULL(f); 278 } 279 #endif 280 errno = oerrno; 281 } 282 283 /* initialize side buffer for r+w unseekable streams */ 284 if(!f->proc && (f->bits&SF_BOTH) ) 285 (void)_sfpopen(f,-1,-1,1); 286 } 287 } 288 289 /* set page size, this is also the desired default buffer size */ 290 if(_Sfpage <= 0) 291 { 292 #if _lib_getpagesize 293 if((_Sfpage = (size_t)getpagesize()) <= 0) 294 #endif 295 _Sfpage = SF_PAGE; 296 } 297 } 298 299 #ifdef MAP_TYPE 300 if(okmmap && size && (f->mode&SF_READ) && f->extent >= 0 ) 301 { /* see if we can try memory mapping */ 302 if(!disc) 303 for(disc = f->disc; disc; disc = disc->disc) 304 if(disc->readf) 305 break; 306 if(!disc) 307 { f->bits |= SF_MMAP; 308 if(size == (size_t)SF_UNBOUND) 309 { if(bufsize > _Sfpage) 310 size = bufsize * SF_NMAP; 311 else size = _Sfpage * SF_NMAP; 312 if(size > 256*1024) 313 size = 256*1024; 314 } 315 } 316 } 317 #endif 318 319 /* get buffer space */ 320 setbuf: 321 if(size == (size_t)SF_UNBOUND) 322 { /* define a default size suitable for block transfer */ 323 if(init && osize > 0) 324 size = osize; 325 else if(f == sfstderr && (f->mode&SF_WRITE)) 326 size = 0; 327 else if(f->flags&SF_STRING ) 328 size = SF_GRAIN; 329 else if((f->flags&SF_READ) && !(f->bits&SF_BOTH) && 330 f->extent > 0 && f->extent < (Sfoff_t)_Sfpage ) 331 size = (((size_t)f->extent + SF_GRAIN-1)/SF_GRAIN)*SF_GRAIN; 332 else if((ssize_t)(size = _Sfpage) < bufsize) 333 size = bufsize; 334 335 buf = NIL(Void_t*); 336 } 337 338 sf_malloc = 0; 339 if(size > 0 && !buf && !(f->bits&SF_MMAP)) 340 { /* try to allocate a buffer */ 341 if(obuf && size == (size_t)osize && init) 342 { buf = (Void_t*)obuf; 343 obuf = NIL(uchar*); 344 sf_malloc = (oflags&SF_MALLOC); 345 } 346 if(!buf) 347 { /* do allocation */ 348 while(!buf && size > 0) 349 { if((buf = (Void_t*)malloc(size)) ) 350 break; 351 else size /= 2; 352 } 353 if(size > 0) 354 sf_malloc = SF_MALLOC; 355 } 356 } 357 358 if(size == 0 && !(f->flags&SF_STRING) && !(f->bits&SF_MMAP) && (f->mode&SF_READ)) 359 { /* use the internal buffer */ 360 size = sizeof(f->tiny); 361 buf = (Void_t*)f->tiny; 362 } 363 364 /* set up new buffer */ 365 f->size = size; 366 f->next = f->data = f->endr = f->endw = (uchar*)buf; 367 f->endb = (f->mode&SF_READ) ? f->data : f->data+size; 368 if(f->flags&SF_STRING) 369 { /* these fields are used to test actual size - see sfseek() */ 370 f->extent = (!sf_malloc && 371 ((f->flags&SF_READ) || (f->bits&SF_BOTH)) ) ? size : 0; 372 f->here = 0; 373 374 /* read+string stream should have all data available */ 375 if((f->mode&SF_READ) && !sf_malloc) 376 f->endb = f->data+size; 377 } 378 379 f->flags = (f->flags & ~SF_MALLOC)|sf_malloc; 380 381 if(obuf && obuf != f->data && osize > 0 && (oflags&SF_MALLOC)) 382 { free((Void_t*)obuf); 383 obuf = NIL(uchar*); 384 } 385 386 done: 387 _Sfi = f->val = obuf ? osize : 0; 388 389 /* blksz is used for aligning disk block boundary while reading data to 390 ** optimize data transfer from disk (eg, via direct I/O). blksz can be 391 ** at most f->size/2 so that data movement in buffer can be optimized. 392 ** blksz should also be a power-of-2 for optimal disk seeks. 393 */ 394 if(blksz <= 0 || (blksz & (blksz-1)) != 0 ) 395 blksz = SF_GRAIN; 396 while(blksz > f->size/2) 397 blksz /= 2; 398 f->blksz = blksz; 399 400 SFOPEN(f,local); 401 402 SFMTXRETURN(f, (Void_t*)obuf); 403 } 404