1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789
|
/* $Id: qfits_cache.c,v 1.12 2006/12/04 15:34:48 yjung Exp $
*
* This file is part of the ESO QFITS Library
* Copyright (C) 2001-2004 European Southern Observatory
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* $Author: yjung $
* $Date: 2006/12/04 15:34:48 $
* $Revision: 1.12 $
* $Name: qfits-6_2_0 $
*/
/*-----------------------------------------------------------------------------
Includes
-----------------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "qfits_cache.h"
#include "qfits_card.h"
#include "qfits_std.h"
#include "qfits_memory.h"
/*-----------------------------------------------------------------------------
Defines
-----------------------------------------------------------------------------*/
/* Define this symbol to get debug symbols -- not recommended! */
#define QFITS_CACHE_DEBUG 0
#if QFITS_CACHE_DEBUG
#define qdebug( code ) { code }
#else
#define qdebug( code )
#endif
/*
* Cache size:
* Maximum number of FITS file informations stored in the cache.
*/
#define QFITS_CACHESZ 128
/*
* This static definition declares the maximum possible number of
* extensions in a FITS file. It only has effects in the qfits_cache_add
* function where a table is statically allocated for efficiency reasons.
* If the number of extensions grows over this limit, change the value of
* this constant. If the number of extensions is a priori unknown but can
* grow much larger than a predictable value, the best solution is to
* implement a dynamic memory allocation in qfits_cache_add.
*/
#define QFITS_MAX_EXTS 10192
/*-----------------------------------------------------------------------------
New types
-----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/*
This structure stores all informations about a given FITS file.
It is strictly internal to this module.
*/
/*----------------------------------------------------------------------------*/
typedef struct _qfits_cache_cell_ {
char * name ; /* File name */
ino_t inode ; /* Inode */
time_t mtime; /* Last modification date */
int filesize; /* File size in bytes */
time_t ctime; /* Last modification date */
int exts ; /* # of extensions in file */
int * ohdr ; /* Offsets to headers */
int * shdr ; /* Header sizes */
int * data ; /* Offsets to data */
int * dsiz ; /* Data sizes */
int fsize ; /* File size in blocks (2880 bytes) */
} qfits_cache_cell ;
static qfits_cache_cell qfits_cache[QFITS_CACHESZ] ;
static int qfits_cache_last = -1 ;
static int qfits_cache_entries = 0 ;
static int qfits_cache_init = 0 ;
/*-----------------------------------------------------------------------------
Functions prototypes
-----------------------------------------------------------------------------*/
static void qfits_cache_activate(void);
static int qfits_is_cached(const char * filename);
static int qfits_cache_add(const char * name);
static void qfits_cache_dump(void) ;
/*----------------------------------------------------------------------------*/
/**
* @defgroup qfits_cache FITS caching capabilities
*
* This modules implements a cache for FITS access routines.
* The first time a FITS file is seen by the library, all corresponding
* pointers are cached here. This speeds up multiple accesses to large
* files by magnitudes.
*
*/
/*----------------------------------------------------------------------------*/
/**@{*/
/*-----------------------------------------------------------------------------
Function codes
-----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/**
@brief Purge the qfits cache.
@return void
This function is useful for programs running for a long period,
to clean up the cache. Ideally in a daemon, it should be called
by a timer at regular intervals. Notice that since the cache is
fairly small, you should not need to care too much about this.
*/
/*----------------------------------------------------------------------------*/
void qfits_cache_purge(void)
{
int i ;
qdebug(
printf("qfits: purging cache...\n");
);
for (i=0 ; i<QFITS_CACHESZ; i++) {
if (qfits_cache[i].name!=NULL) {
qfits_free(qfits_cache[i].name);
qfits_cache[i].name = NULL ;
qfits_free(qfits_cache[i].ohdr);
qfits_free(qfits_cache[i].data);
qfits_free(qfits_cache[i].shdr);
qfits_free(qfits_cache[i].dsiz);
qfits_cache_entries -- ;
}
}
if (qfits_cache_entries!=0) {
qdebug(
printf("qfits: internal error in cache consistency\n");
);
exit(-1);
}
qfits_cache_last = -1 ;
return ;
}
/*----------------------------------------------------------------------------*/
/**
@brief Query a FITS file offset from the cache.
@param filename Name of the file to examine.
@param what What should be queried (see below).
@return an integer offset, or -1 if an error occurred.
This function queries the cache for FITS offset information. If the
requested file name has never been seen before, it is completely parsed
to extract all offset informations, which are then stored in the cache.
The next query will get the informations from the cache, avoiding
a complete re-parsing of the file. This is especially useful for large
FITS files with lots of extensions, because querying the extensions
is an expensive operation.
This operation has side-effects: the cache is an automatically
allocated structure in memory, that can only grow. Every request
on a new FITS file will make it grow. The structure is pretty
light-weight in memory, but nonetheless this is an issue for daemon-type
programs which must run over long periods. The solution is to clean
the cache using qfits_cache_purge() at regular intervals. This is left
to the user of this library.
To request information about a FITS file, you must pass an integer
built from the following symbols:
- @c QFITS_QUERY_N_EXT
- @c QFITS_QUERY_HDR_START
- @c QFITS_QUERY_DAT_START
- @c QFITS_QUERY_HDR_SIZE
- @c QFITS_QUERY_DAT_SIZE
Querying the number of extensions present in a file is done
simply with:
@code
next = qfits_query(filename, QFITS_QUERY_N_EXT);
@endcode
Querying the offset to the i-th extension header is done with:
@code
off = qfits_query(filename, QFITS_QUERY_HDR_START | i);
@endcode
i.e. you must OR (|) the extension number with the
@c QFITS_QUERY_HDR_START symbol. Requesting offsets to extension data is
done in the same way:
@code
off = qfits_query(filename, QFITS_QUERY_DAT_START | i);
@endcode
Notice that extension 0 is the main header and main data part
of the FITS file.
*/
/*----------------------------------------------------------------------------*/
int qfits_query(const char * filename, int what)
{
int rank ;
int which ;
int answer ;
qdebug(
printf("qfits: cache req %s\n", filename);
);
if ((rank=qfits_is_cached(filename))==-1) {
rank = qfits_cache_add(filename);
}
if (rank==-1) {
qdebug(
printf("qfits: error adding %s to cache\n", filename);
);
return -1 ;
}
/* See what was requested */
answer=-1 ;
if (what & QFITS_QUERY_N_EXT) {
answer = qfits_cache[rank].exts ;
qdebug(
printf("qfits: query n_exts\n");
printf("qfits: -> %d\n", answer);
);
} else if (what & QFITS_QUERY_HDR_START) {
which = what & (~QFITS_QUERY_HDR_START);
if (which>=0 && which<=qfits_cache[rank].exts) {
answer = qfits_cache[rank].ohdr[which] * FITS_BLOCK_SIZE ;
}
qdebug(
printf("qfits: query offset to header %d\n", which);
printf("qfits: -> %d (%d bytes)\n", answer/2880, answer);
);
} else if (what & QFITS_QUERY_DAT_START) {
which = what & (~QFITS_QUERY_DAT_START);
if (which>=0 && which<=qfits_cache[rank].exts) {
answer = qfits_cache[rank].data[which] * FITS_BLOCK_SIZE ;
}
qdebug(
printf("qfits: query offset to data %d\n", which);
printf("qfits: -> %d (%d bytes)\n", answer/2880, answer);
);
} else if (what & QFITS_QUERY_HDR_SIZE) {
which = what & (~QFITS_QUERY_HDR_SIZE);
if (which>=0 && which<=qfits_cache[rank].exts) {
answer = qfits_cache[rank].shdr[which] * FITS_BLOCK_SIZE ;
}
qdebug(
printf("qfits: query sizeof header %d\n", which);
printf("qfits: -> %d (%d bytes)\n", answer/2880, answer);
);
} else if (what & QFITS_QUERY_DAT_SIZE) {
which = what & (~QFITS_QUERY_DAT_SIZE);
if (which>=0 && which<=qfits_cache[rank].exts) {
answer = qfits_cache[rank].dsiz[which] * FITS_BLOCK_SIZE ;
}
qdebug(
printf("qfits: query sizeof data %d\n", which);
printf("qfits: -> %d (%d bytes)\n", answer/2880, answer);
);
}
return answer ;
}
/**@}*/
/*----------------------------------------------------------------------------*/
/**
@brief Add pointer information about a file into the qfits cache.
@param filename Name of the file to examine.
@return index to the file information in the cache, or -1 if failure.
This function picks a file name, and examines the corresponding FITS file
to deduce all relevant pointers in the file (byte offsets). These byte
offsets are later used to speed up header lookups. Example: requesting
some keyword information in the header of the n-th extension will first
fseek the file to the header start, then search from this position
onwards. This means that the input FITS file is only parsed for extension
positions once.
What this function does is:
- Open the file, read the first FITS block (@c FITS_BLOCK_SIZE bytes)
- Check the file is FITS (must have SIMPLE = at top)
- Register start of first header at offset 0.
- Look for END keyword, register start of first data section
if NAXIS>0.
- If the EXTEND=T line was found, continue looking for extensions.
- For each consecutive extension, register extension header start
and extension data start.
*/
/*----------------------------------------------------------------------------*/
static int qfits_cache_add(const char * filename)
{
FILE * in ;
int off_hdr[QFITS_MAX_EXTS];
int off_dat[QFITS_MAX_EXTS];
char buf[FITS_BLOCK_SIZE] ;
char * buf_c ;
int n_blocks ;
int found_it ;
int xtend ;
int naxis ;
char * read_val ;
int last ;
int end_of_file ;
int data_bytes ;
int skip_blocks ;
struct stat sta ;
int seeked ;
int i ;
qfits_cache_cell * qc ;
/* Initialize cache if not done yet (done only once) */
if (qfits_cache_init==0) {
qfits_cache_init++ ;
qfits_cache_activate();
}
/* Stat file to get its size */
if (stat(filename, &sta)!=0) {
qdebug(
printf("qfits: cannot stat file %s\n", filename);
);
return -1 ;
}
/* Open input file */
if ((in=fopen(filename, "r"))==NULL) {
qdebug(
printf("qfits: cannot open file %s\n", filename);
);
return -1 ;
}
/* Read first block in */
if (fread(buf, 1, FITS_BLOCK_SIZE, in)!=FITS_BLOCK_SIZE) {
qdebug(
printf("qfits: error reading first block from %s\n", filename);
);
fclose(in);
return -1 ;
}
/* Identify FITS magic number */
if (buf[0]!='S' ||
buf[1]!='I' ||
buf[2]!='M' ||
buf[3]!='P' ||
buf[4]!='L' ||
buf[5]!='E' ||
buf[6]!=' ' ||
buf[7]!=' ' ||
buf[8]!='=') {
qdebug(
printf("qfits: file %s is not FITS\n", filename);
);
fclose(in);
return -1 ;
}
/*
* Browse through file to identify primary HDU size and see if there
* might be some extensions. The size of the primary data zone will
* also be estimated from the gathering of the NAXIS?? values and
* BITPIX.
*/
/* Rewind input file, END card might be in first block */
rewind(in);
/* Initialize all counters */
n_blocks = 0 ;
found_it = 0 ;
xtend = 0 ;
naxis = 0 ;
data_bytes = 1 ;
/* Start looking for END card */
while (found_it==0) {
/* Read one FITS block */
if (fread(buf, 1, FITS_BLOCK_SIZE, in)!=FITS_BLOCK_SIZE) {
qdebug(
printf("qfits: error reading file %s\n", filename);
);
fclose(in);
return -1 ;
}
n_blocks ++ ;
/* Browse through current block */
buf_c = buf ;
for (i=0 ; i<FITS_NCARDS ; i++) {
/* Look for BITPIX keyword */
if (buf_c[0]=='B' &&
buf_c[1]=='I' &&
buf_c[2]=='T' &&
buf_c[3]=='P' &&
buf_c[4]=='I' &&
buf_c[5]=='X' &&
buf_c[6]==' ') {
read_val = qfits_getvalue(buf_c);
data_bytes *= (int)atoi(read_val) / 8 ;
if (data_bytes<0) data_bytes *= -1 ;
} else
/* Look for NAXIS keyword */
if (buf_c[0]=='N' &&
buf_c[1]=='A' &&
buf_c[2]=='X' &&
buf_c[3]=='I' &&
buf_c[4]=='S') {
if (buf_c[5]==' ') {
/* NAXIS keyword */
read_val = qfits_getvalue(buf_c);
naxis = (int)atoi(read_val);
} else {
/* NAXIS?? keyword (axis size) */
read_val = qfits_getvalue(buf_c);
data_bytes *= (int)atoi(read_val);
}
} else
/* Look for EXTEND keyword */
if (buf_c[0]=='E' &&
buf_c[1]=='X' &&
buf_c[2]=='T' &&
buf_c[3]=='E' &&
buf_c[4]=='N' &&
buf_c[5]=='D' &&
buf_c[6]==' ') {
/* The EXTEND keyword is present: might be some extensions */
read_val = qfits_getvalue(buf_c);
if (read_val[0]=='T' || read_val[0]=='1') {
xtend=1 ;
}
} else
/* Look for END keyword */
if (buf_c[0] == 'E' &&
buf_c[1] == 'N' &&
buf_c[2] == 'D' &&
buf_c[3] == ' ') {
found_it = 1 ;
}
buf_c += FITS_LINESZ ;
}
}
/*
* Prepare qfits cache for addition of a new entry
*/
qfits_cache_last++ ;
/* Rotate buffer if needed */
if (qfits_cache_last >= QFITS_CACHESZ) {
qfits_cache_last = 0 ;
}
/* Alias to current pointer in cache for easier reading */
qc = &(qfits_cache[qfits_cache_last]);
/* Clean cache cell if needed */
if (qc->name!=NULL) {
qfits_free(qc->name) ;
qc->name = NULL ;
qfits_free(qc->ohdr);
qfits_free(qc->data);
qfits_free(qc->shdr);
qfits_free(qc->dsiz);
qfits_cache_entries -- ;
}
/* Initialize cache cell */
qc->exts=0 ;
qc->name = qfits_strdup(filename);
qc->inode= sta.st_ino ;
/* Set first HDU offsets */
off_hdr[0] = 0 ;
off_dat[0] = n_blocks ;
/* Last is the pointer to the last added extension, plus one. */
last = 1 ;
if (xtend) {
/* Look for extensions */
qdebug(
printf("qfits: searching for extensions in %s\n", filename);
);
/*
* Register all extension offsets
*/
end_of_file = 0 ;
while (end_of_file==0) {
/*
* Skip the previous data section if pixels were declared
*/
if (naxis>0) {
/* Skip as many blocks as there are declared pixels */
skip_blocks = data_bytes/FITS_BLOCK_SIZE ;
if ((data_bytes % FITS_BLOCK_SIZE)!=0) {
skip_blocks ++ ;
}
seeked = fseek(in, skip_blocks*FITS_BLOCK_SIZE, SEEK_CUR);
if (seeked<0) {
qdebug(
printf("qfits: error seeking file %s\n", filename);
);
qfits_free(qc->name);
fclose(in);
return -1 ;
}
/* Increase counter of current seen blocks. */
n_blocks += skip_blocks ;
}
/* Look for extension start */
found_it=0 ;
while ((found_it==0) && (end_of_file==0)) {
if (fread(buf,1,FITS_BLOCK_SIZE,in)!=FITS_BLOCK_SIZE) {
/* Reached end of file */
end_of_file=1 ;
break ;
}
n_blocks ++ ;
/* Search for XTENSION at block top */
if (buf[0]=='X' &&
buf[1]=='T' &&
buf[2]=='E' &&
buf[3]=='N' &&
buf[4]=='S' &&
buf[5]=='I' &&
buf[6]=='O' &&
buf[7]=='N' &&
buf[8]=='=') {
/* Got an extension */
found_it=1 ;
off_hdr[last] = n_blocks-1 ;
}
}
if (end_of_file) break ;
/*
* Look for extension END
* Rewind one block backwards, END might be in same section as
* XTENSION start.
*/
if (fseek(in, -FITS_BLOCK_SIZE, SEEK_CUR)==-1) {
qdebug(
printf("qfits: error fseeking file backwards\n");
) ;
qfits_free(qc->name);
fclose(in);
return -1 ;
}
n_blocks -- ;
found_it=0 ;
data_bytes = 1 ;
naxis = 0 ;
while ((found_it==0) && (end_of_file==0)) {
if (fread(buf,1,FITS_BLOCK_SIZE,in)!=FITS_BLOCK_SIZE) {
qdebug(
printf("qfits: XTENSION without END in %s\n", filename);
);
end_of_file=1;
break ;
}
n_blocks++ ;
/* Browse current block */
buf_c = buf ;
for (i=0 ; i<FITS_NCARDS ; i++) {
/* Look for BITPIX keyword */
if (buf_c[0]=='B' &&
buf_c[1]=='I' &&
buf_c[2]=='T' &&
buf_c[3]=='P' &&
buf_c[4]=='I' &&
buf_c[5]=='X' &&
buf_c[6]==' ') {
read_val = qfits_getvalue(buf_c);
data_bytes *= (int)atoi(read_val) / 8 ;
if (data_bytes<0) data_bytes *= -1 ;
} else
/* Look for NAXIS keyword */
if (buf_c[0]=='N' &&
buf_c[1]=='A' &&
buf_c[2]=='X' &&
buf_c[3]=='I' &&
buf_c[4]=='S') {
if (buf_c[5]==' ') {
/* NAXIS keyword */
read_val = qfits_getvalue(buf_c);
naxis = (int)atoi(read_val);
} else {
/* NAXIS?? keyword (axis size) */
read_val = qfits_getvalue(buf_c);
data_bytes *= (int)atoi(read_val);
}
} else
/* Look for END keyword */
if (buf_c[0]=='E' &&
buf_c[1]=='N' &&
buf_c[2]=='D' &&
buf_c[3]==' ') {
/* Got the END card */
found_it=1 ;
/* Update registered extension list */
off_dat[last] = n_blocks ;
last ++ ;
qc->exts ++ ;
break ;
}
buf_c+=FITS_LINESZ ;
}
}
}
}
/* Close file */
fclose(in);
/* Check last */
if (last >= QFITS_MAX_EXTS) {
return -1 ;
}
/* Allocate buffers in cache */
qc->ohdr = qfits_malloc(last * sizeof(int));
qc->data = qfits_malloc(last * sizeof(int));
qc->shdr = qfits_malloc(last * sizeof(int));
qc->dsiz = qfits_malloc(last * sizeof(int));
/* Store retrieved pointers in the cache */
for (i=0 ; i<last ; i++) {
/* Offsets to start */
qc->ohdr[i] = off_hdr[i];
qc->data[i] = off_dat[i];
/* Sizes */
qc->shdr[i] = off_dat[i] - off_hdr[i] ;
if (i==last-1) {
qc->dsiz[i] = (sta.st_size/FITS_BLOCK_SIZE) - off_dat[i] ;
} else {
qc->dsiz[i] = off_hdr[i+1] - off_dat[i] ;
}
}
qc->fsize = sta.st_size / FITS_BLOCK_SIZE ;
/* Add last modification date */
qc->mtime = sta.st_mtime ;
qc->filesize = sta.st_size ;
qc->ctime = sta.st_ctime ;
qfits_cache_entries ++ ;
qdebug(
qfits_cache_dump();
);
/* Return index of the added file in the cache */
return qfits_cache_last ;
}
static void qfits_cache_dump(void)
{
int i, j ;
printf("qfits: dumping cache...\n");
printf("cache contains %d entries\n", qfits_cache_entries);
for (i=0 ; i<QFITS_CACHESZ ; i++) {
if (qfits_cache[i].name!=NULL) {
printf("qfits: -----> entry: %d\n", i);
printf("qfits: name %s\n", qfits_cache[i].name);
printf("qfits: exts %d\n", qfits_cache[i].exts);
printf("qfits: size %d\n", qfits_cache[i].fsize);
printf("qfits: ohdr %d\n"
"qfits: shdr %d\n"
"qfits: data %d\n"
"qfits: dsiz %d\n",
qfits_cache[i].ohdr[0],
qfits_cache[i].shdr[0],
qfits_cache[i].data[0],
qfits_cache[i].dsiz[0]);
if (qfits_cache[i].exts>0) {
for (j=1 ; j<=qfits_cache[i].exts ; j++) {
printf("qfits: %s [%d]\n", qfits_cache[i].name, j);
printf("qfits: ohdr %d\n"
"qfits: shdr %d\n"
"qfits: data %d\n"
"qfits: dsiz %d\n",
qfits_cache[i].ohdr[j],
qfits_cache[i].shdr[j],
qfits_cache[i].data[j],
qfits_cache[i].dsiz[j]);
}
}
}
}
return ;
}
/*----------------------------------------------------------------------------*/
/**
@brief initialize cache buffer with minimum size
*/
/*----------------------------------------------------------------------------*/
static void qfits_cache_activate(void)
{
int i ;
qdebug(
printf("qfits: activating cache...\n");
);
/* Set all slots to NULL */
for (i=0 ; i<QFITS_CACHESZ ; i++) {
qfits_cache[i].name = NULL ;
}
/* Register purge function with atexit */
atexit(qfits_cache_purge);
return ;
}
/*----------------------------------------------------------------------------*/
/**
@brief Find out if a file is in the cache already
@param filename file name
@return int 1 if in the cache, 0 if not
*/
/*----------------------------------------------------------------------------*/
static int qfits_is_cached(const char * filename)
{
int i, n ;
struct stat sta ;
/* Stat input file */
if (stat(filename, &sta)!=0) {
return -1 ;
}
n=0 ;
/* Loop over all cache entries */
for (i=0 ; i<QFITS_CACHESZ ; i++) {
/* If entry is valid (name is not NULL) */
if (qfits_cache[i].name!=NULL) {
/* One more entry found */
n++ ;
/* If inode is the same */
if ((qfits_cache[i].inode == sta.st_ino) &&
(qfits_cache[i].mtime == sta.st_mtime) &&
(qfits_cache[i].filesize == sta.st_size) &&
(qfits_cache[i].ctime == sta.st_ctime)) {
/* This is the requested file */
return i ;
}
}
/* Early exit: all entries have been browsed */
if (n>=qfits_cache_entries) {
return -1 ;
}
}
return -1 ;
}
|