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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996
|
/**
* @file
*
* Infer as much as possible from the omode + path.
* Rewrite the path to a canonical form.
*
* Copyright 2018 University Corporation for Atmospheric
* Research/Unidata. See COPYRIGHT file for more info.
*/
#include "config.h"
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ncdispatch.h"
#include "ncwinpath.h"
#include "netcdf_mem.h"
#include "fbits.h"
#include "ncbytes.h"
#include "nclist.h"
#include "nclog.h"
#ifdef ENABLE_BYTERANGE
#include "nchttp.h"
#endif
#undef DEBUG
/* If Defined, then use only stdio for all magic number io;
otherwise use stdio or mpio as required.
*/
#undef USE_STDIO
/**
Sort info for open/read/close of
file when searching for magic numbers
*/
struct MagicFile {
const char* path;
struct NCURI* uri;
int omode;
NCmodel* model;
fileoffset_t filelen;
int use_parallel;
void* parameters; /* !NULL if inmemory && !diskless */
FILE* fp;
#ifdef USE_PARALLEL
MPI_File fh;
#endif
#ifdef ENABLE_BYTERANGE
void* curl; /* avoid need to include curl.h */
char* curlurl; /* url to use with CURLOPT_SET_URL */
#endif
};
/** @internal Magic number for HDF5 files. To be consistent with
* H5Fis_hdf5, use the complete HDF5 magic number */
static char HDF5_SIGNATURE[MAGIC_NUMBER_LEN] = "\211HDF\r\n\032\n";
#define modelcomplete(model) ((model)->impl != 0)
#ifdef DEBUG
static void dbgflush(void)
{
fflush(stdout);
fflush(stderr);
}
static void
fail(int err)
{
return;
}
static int
check(int err)
{
if(err != NC_NOERR)
fail(err);
return err;
}
#else
#define check(err) (err)
#endif
/*
Define a table of "mode=" string values
from which the implementation can be inferred.
Note that only cases that can currently
take URLs are included.
*/
static struct FORMATMODES {
const char* tag;
const int impl; /* NC_FORMATX_XXX value */
} formatmodes[] = {
{"dap2",NC_FORMATX_DAP2},
{"dap4",NC_FORMATX_DAP4},
{"netcdf-3",NC_FORMATX_NC3},
{"classic",NC_FORMATX_NC3},
{"netcdf-4",NC_FORMATX_NC4},
{"enhanced",NC_FORMATX_NC4},
{"udf0",NC_FORMATX_UDF0},
{"udf1",NC_FORMATX_UDF1},
{"zarr",NC_FORMATX_ZARR},
{NULL,0},
};
/* Define the legal singleton mode tags;
thse should also appear in the above mode table. */
static const char* modesingles[] = {
"dap2", "dap4", "bytes", "zarr", NULL
};
/* Map FORMATX to readability to get magic number */
static struct Readable {
int impl;
int readable;
} readable[] = {
{NC_FORMATX_NC3,1},
{NC_FORMATX_NC_HDF5,1},
{NC_FORMATX_NC_HDF4,1},
{NC_FORMATX_PNETCDF,1},
{NC_FORMATX_DAP2,0},
{NC_FORMATX_DAP4,0},
{NC_FORMATX_UDF0,0},
{NC_FORMATX_UDF1,0},
{NC_FORMATX_ZARR,0},
{0,0},
};
/* Define the known URL protocols and their interpretation */
static struct NCPROTOCOLLIST {
const char* protocol;
const char* substitute;
const char* mode;
} ncprotolist[] = {
{"http",NULL,NULL},
{"https",NULL,NULL},
{"file",NULL,NULL},
{"dods","http","dap2"},
{"dap4","http","dap4"},
{NULL,NULL,NULL} /* Terminate search */
};
/* Forward */
static int NC_omodeinfer(int useparallel, int omode, NCmodel*);
static int check_file_type(const char *path, int omode, int use_parallel, void *parameters, NCmodel* model, NCURI* uri);
static int parseurlmode(const char* modestr, NClist* list);
static int processuri(const char* path, NCURI** urip, char** newpathp, NClist* modeargs);
static char* list2string(NClist* modelist);
static char* envv2string(NClist* envv);
static int issingleton(const char* tag);;
static void set_default_mode(int* cmodep);
static int openmagic(struct MagicFile* file);
static int readmagic(struct MagicFile* file, long pos, char* magic);
static int closemagic(struct MagicFile* file);
static int NC_interpret_magic_number(char* magic, NCmodel* model);
#ifdef DEBUG
static void printmagic(const char* tag, char* magic,struct MagicFile*);
#endif
static int isreadable(NCmodel*);
/*
If the path looks like a URL, then parse it, reformat it,
and compute the mode= flags. Then return it and the the reformatted path.
*/
static int
processuri(const char* path, NCURI** urip, char** newpathp, NClist* modeargs)
{
int i,j,stat = NC_NOERR;
int found = 0;
const char** fragp = NULL;
NClist* fraglist = NULL;
struct NCPROTOCOLLIST* protolist;
NCURI* uri = NULL;
size_t pathlen = strlen(path);
char* str = NULL;
if(path == NULL || pathlen == 0) {stat = NC_EURL; goto done;}
/* Defaults */
if(newpathp) *newpathp = NULL;
if(urip) *urip = NULL;
if(ncuriparse(path,&uri)) goto done; /* not url */
/* Look up the protocol */
for(found=0,protolist=ncprotolist;protolist->protocol;protolist++) {
if(strcmp(uri->protocol,protolist->protocol) == 0) {
found = 1;
break;
}
}
if(!found)
{stat = NC_EINVAL; goto done;} /* unrecognized URL form */
/* process the corresponding mode arg */
if(protolist->mode != NULL)
nclistpush(modeargs,strdup(protolist->mode));
/* Substitute the protocol in any case */
if(protolist->substitute) ncurisetprotocol(uri,protolist->substitute);
/* Iterate over the url fragment parameters and collect,
but remove mode= proto= and protocol= */
fraglist = nclistnew();
for(fragp=ncurifragmentparams(uri);fragp && *fragp;fragp+=2) {
int elide = 0;
const char* name = fragp[0];
const char* value = fragp[1];
if(strcmp(name,"protocol")==0
|| strcmp(name,"proto")==0) { /* for back compatibility */
nclistpush(modeargs,strdup(value));
elide = 1;
} else if(strcmp(name,"mode")==0) {
/* Capture the list of mode arguments */
if((stat = parseurlmode(value,modeargs))) goto done;
elide = 1;
} else if(issingleton(name) && (value == NULL || strlen(value)==0)) {
nclistpush(modeargs,strdup(name));
elide = 1;
} /*else ignore*/
if(!elide) {
/* Copy over */
nclistpush(fraglist,strdup(name));
if(value == NULL) value = "";
nclistpush(fraglist,strdup(value));
}
}
/* At this point modeargs should contain all mode-like args from the URL */
/* Remove duplicates */
for(i=nclistlength(modeargs)-1;i>=0;i--) {
const char* mode = nclistget(modeargs,i);
for(j=0;j<i;j++) {
const char* other = nclistget(modeargs,i);
if(strcasecmp(mode,other)==0) {
nclistremove(modeargs,i); /* duplicate */
break;
}
}
}
/* Convert the modelist to a new mode= fragment */
if(nclistlength(modeargs) > 0) {
str = list2string(modeargs);
/* Re-insert mode into fraglist */
nclistinsert(fraglist,0,str);
nclistinsert(fraglist,0,strdup("mode"));
}
/* Convert frag list to a string */
str = envv2string(fraglist);
ncurisetfragments(uri,str);
/* Rebuild the path (including fragment)*/
if(newpathp)
*newpathp = ncuribuild(uri,NULL,NULL,NCURIALL);
if(urip) {
*urip = uri;
uri = NULL;
}
#ifdef DEBUG
fprintf(stderr,"newpath=|%s|\n",*newpathp); fflush(stderr);
#endif
done:
nclistfreeall(fraglist);
nullfree(str);
if(uri != NULL) ncurifree(uri);
return check(stat);
}
/* Parse a mode string at the commas */
static int
parseurlmode(const char* modestr, NClist* list)
{
int stat = NC_NOERR;
const char* p = NULL;
const char* endp = NULL;
if(modestr == NULL || *modestr == '\0') goto done;
/* Split modestr at the commas or EOL */
p = modestr;
for(;;) {
char* s;
ptrdiff_t slen;
endp = strchr(p,',');
if(endp == NULL) endp = p + strlen(p);
slen = (endp - p);
if((s = malloc(slen+1)) == NULL) {stat = NC_ENOMEM; goto done;}
memcpy(s,p,slen);
s[slen] = '\0';
nclistpush(list,s);
if(*endp == '\0') break;
p = endp+1;
}
done:
return check(stat);
}
/* Convert an envv into a comma'd string*/
static char*
envv2string(NClist* envv)
{
int i;
NCbytes* buf = NULL;
char* result = NULL;
if(envv == NULL || nclistlength(envv) == 0) return NULL;
buf = ncbytesnew();
for(i=0;i<nclistlength(envv);i+=2) {
const char* key = nclistget(envv,i);
const char* val = nclistget(envv,i+1);
if(key == NULL || strlen(key) == 0) continue;
if(val == NULL) val = "";
if(i > 0) ncbytescat(buf,"&");
ncbytescat(buf,key);
ncbytescat(buf,"=");
ncbytescat(buf,val);
}
result = ncbytesextract(buf);
ncbytesfree(buf);
return result;
}
/* Convert a list into a comma'd string */
static char*
list2string(NClist* modelist)
{
int i;
NCbytes* buf = NULL;
char* result = NULL;
if(modelist == NULL || nclistlength(modelist)==0) return NULL;
buf = ncbytesnew();
for(i=0;i<nclistlength(modelist);i++) {
const char* m = nclistget(modelist,i);
if(m == NULL || strlen(m) == 0) continue;
if(i > 0) ncbytescat(buf,",");
ncbytescat(buf,m);
}
result = ncbytesextract(buf);
ncbytesfree(buf);
return result;
}
/* Given a mode= argument, fill in the impl and possibly mode flags */
static int
processmodearg(const char* arg, NCmodel* model)
{
int stat = NC_NOERR;
struct FORMATMODES* format = formatmodes;
for(;format->tag;format++) {
if(strcmp(format->tag,arg)==0) {
model->impl = format->impl;
}
}
return check(stat);
}
/* Search singleton list */
static int
issingleton(const char* tag)
{
const char** p;
for(p=modesingles;*p;p++) {
if(strcmp(*p,tag)==0) return 1;
}
return 0;
}
/*
Infer from the mode + useparallel
only call if iscreate or file is not easily readable.
*/
static int
NC_omodeinfer(int useparallel, int cmode, NCmodel* model)
{
int stat = NC_NOERR;
/* If no format flags are set, then use default */
if(!fIsSet(cmode,NC_FORMAT_ALL))
set_default_mode(&cmode);
/* Process the cmode; may override some already set flags. The
* user-defined formats must be checked first. They may choose to
* use some of the other flags, like NC_NETCDF4, so we must fist
* check NC_UDF0 and NC_UDF1 before checking for any other
* flag. */
if(fIsSet(cmode,(NC_UDF0|NC_UDF1))) {
model->format = NC_FORMAT_NETCDF4;
if(fIsSet(cmode,NC_UDF0)) {
model->impl = NC_FORMATX_UDF0;
} else {
model->impl = NC_FORMATX_UDF1;
}
goto done;
}
if(fIsSet(cmode,NC_64BIT_OFFSET)) {
model->impl = NC_FORMATX_NC3;
model->format = NC_FORMAT_64BIT_OFFSET;
goto done;
}
if(fIsSet(cmode,NC_64BIT_DATA)) {
model->impl = NC_FORMATX_NC3;
model->format = NC_FORMAT_64BIT_DATA;
goto done;
}
if(fIsSet(cmode,NC_NETCDF4)) {
model->impl = NC_FORMATX_NC4;
if(fIsSet(cmode,NC_CLASSIC_MODEL))
model->format = NC_FORMAT_NETCDF4_CLASSIC;
else
model->format = NC_FORMAT_NETCDF4;
goto done;
}
/* Default to classic model */
model->format = NC_FORMAT_CLASSIC;
model->impl = NC_FORMATX_NC3;
done:
/* Apply parallel flag */
if(useparallel) {
if(model->impl == NC_FORMATX_NC3)
model->impl = NC_FORMATX_PNETCDF;
}
return check(stat);
}
/*
If the mode flags do not necessarily specify the
format, then default it by adding in appropriate flags.
*/
static void
set_default_mode(int* modep)
{
int mode = *modep;
int dfaltformat;
dfaltformat = nc_get_default_format();
switch (dfaltformat) {
case NC_FORMAT_64BIT_OFFSET: mode |= NC_64BIT_OFFSET; break;
case NC_FORMAT_64BIT_DATA: mode |= NC_64BIT_DATA; break;
case NC_FORMAT_NETCDF4: mode |= NC_NETCDF4; break;
case NC_FORMAT_NETCDF4_CLASSIC: mode |= (NC_NETCDF4|NC_CLASSIC_MODEL); break;
case NC_FORMAT_CLASSIC: /* fall thru */
default: break; /* default to classic */
}
*modep = mode; /* final result */
}
/**************************************************/
/*
Infer model for this dataset using some
combination of cmode, path, and reading the dataset.
See the documentation in docs/internal.dox.
@param path
@param omode
@param iscreate
@param useparallel
@param params
@param model
@param newpathp
*/
int
NC_infermodel(const char* path, int* omodep, int iscreate, int useparallel, void* params, NCmodel* model, char** newpathp)
{
int i,stat = NC_NOERR;
char* newpath = NULL;
NCURI* uri = NULL;
int omode = *omodep;
NClist* modeargs = nclistnew();
/* Phase 1: Reformat the uri to canonical form; store canonical form
into newpath. Return the "mode=" list in modeargs */
if((stat = processuri(path, &uri, &newpath, modeargs))) goto done;
if(newpath == NULL) newpath = strdup(path); /* No change */
/* Phase 2: Process the modeargs list to see if we can tell the formatx */
/* Note that if the path was not a URL, then modeargs will be empty list*/
for(i=0;i<nclistlength(modeargs);i++) {
const char* arg = nclistget(modeargs,i);
if((stat=processmodearg(arg,model))) goto done;
}
/* Phase 2.5: Special case: if this is a URL, and there are no mode args
and model.impl is still not defined, default to DAP2 */
if(uri != NULL && nclistlength(modeargs) == 0 && !modelcomplete(model)) {
model->impl = NC_FORMATX_DAP2;
model->format = NC_FORMAT_NC3;
}
/* Phase 3: mode inference from mode flags */
/* The modeargs did not give us a model (probably not a URL).
So look at the combination of mode flags and the useparallel flag */
if(!modelcomplete(model)) {
if((stat = NC_omodeinfer(useparallel,omode,model))) goto done;
}
/* Phase 4: Infer from file content, if possible;
this has highest precedence, so it may override
previous decisions. Note that we do this last
because we need previously determined model info
to guess if this file is readable.
*/
if(!iscreate && isreadable(model)) {
/* Ok, we need to try to read the file */
if((stat = check_file_type(path, omode, useparallel, params, model, uri))) goto done;
}
/* Need a decision */
if(!modelcomplete(model))
{stat = NC_ENOTNC; goto done;}
/* Force flag consistency */
switch (model->impl) {
case NC_FORMATX_NC4:
case NC_FORMATX_NC_HDF4:
case NC_FORMATX_DAP4:
case NC_FORMATX_UDF0:
case NC_FORMATX_UDF1:
omode |= NC_NETCDF4;
if(model->format == NC_FORMAT_NETCDF4_CLASSIC)
omode |= NC_CLASSIC_MODEL;
break;
case NC_FORMATX_NC3:
omode &= ~NC_NETCDF4; /* must be netcdf-3 (CDF-1, CDF-2, CDF-5) */
if(model->format == NC_FORMAT_64BIT_OFFSET) omode |= NC_64BIT_OFFSET;
else if(model->format == NC_FORMAT_64BIT_DATA) omode |= NC_64BIT_DATA;
break;
case NC_FORMATX_PNETCDF:
omode &= ~NC_NETCDF4; /* must be netcdf-3 (CDF-1, CDF-2, CDF-5) */
if(model->format == NC_FORMAT_64BIT_OFFSET) omode |= NC_64BIT_OFFSET;
else if(model->format == NC_FORMAT_64BIT_DATA) omode |= NC_64BIT_DATA;
break;
case NC_FORMATX_DAP2:
omode &= ~(NC_NETCDF4|NC_64BIT_OFFSET|NC_64BIT_DATA|NC_CLASSIC_MODEL);
break;
default:
{stat = NC_ENOTNC; goto done;}
}
done:
if(uri) ncurifree(uri);
nclistfreeall(modeargs);
if(stat == NC_NOERR && newpathp) {*newpathp = newpath; newpath = NULL;}
nullfree(newpath);
*omodep = omode; /* in/out */
return check(stat);
}
static int
isreadable(NCmodel* model)
{
struct Readable* r;
/* Look up the protocol */
for(r=readable;r->impl;r++) {
if(model->impl == r->impl) return r->readable;
}
return 0;
}
/**************************************************/
#if 0
/* return 1 if path looks like a url; 0 otherwise */
int
NC_testurl(const char* path)
{
int isurl = 0;
NCURI* tmpurl = NULL;
if(path == NULL) return 0;
/* Ok, try to parse as a url */
if(ncuriparse(path,&tmpurl)==NCU_OK) {
/* Do some extra testing to make sure this really is a url */
/* Look for a known/accepted protocol */
struct NCPROTOCOLLIST* protolist;
for(protolist=ncprotolist;protolist->protocol;protolist++) {
if(strcmp(tmpurl->protocol,protolist->protocol) == 0) {
isurl=1;
break;
}
}
ncurifree(tmpurl);
return isurl;
}
return 0;
}
#endif
/**************************************************/
/**
* Provide a hidden interface to allow utilities
* to check if a given path name is really a url.
* If not, put null in basenamep, else put basename of the url
* minus any extension into basenamep; caller frees.
* Return 1 if it looks like a url, 0 otherwise.
*/
int
nc__testurl(const char* path, char** basenamep)
{
NCURI* uri;
int ok = 0;
if(!ncuriparse(path,&uri)) {
char* slash = (uri->path == NULL ? NULL : strrchr(uri->path, '/'));
char* dot;
if(slash == NULL) slash = (char*)path; else slash++;
slash = nulldup(slash);
if(slash == NULL)
dot = NULL;
else
dot = strrchr(slash, '.');
if(dot != NULL && dot != slash) *dot = '\0';
if(basenamep)
*basenamep=slash;
else if(slash)
free(slash);
ncurifree(uri);
ok = 1;
}
return ok;
}
/**************************************************/
/**
* @internal Given an existing file, figure out its format and return
* that format value (NC_FORMATX_XXX) in model arg. Assume any path
* conversion was already performed at a higher level.
*
* @param path File name.
* @param flags
* @param use_parallel
* @param parameters
* @param model Pointer that gets the model to use for the dispatch table.
* @param version Pointer that gets version of the file.
*
* @return ::NC_NOERR No error.
* @author Dennis Heimbigner
*/
static int
check_file_type(const char *path, int omode, int use_parallel,
void *parameters, NCmodel* model, NCURI* uri)
{
char magic[NC_MAX_MAGIC_NUMBER_LEN];
int status = NC_NOERR;
struct MagicFile magicinfo;
memset((void*)&magicinfo,0,sizeof(magicinfo));
magicinfo.path = path; /* do not free */
magicinfo.uri = uri; /* do not free */
magicinfo.omode = omode;
magicinfo.model = model; /* do not free */
magicinfo.parameters = parameters; /* do not free */
#ifdef USE_STDIO
magicinfo.use_parallel = 0;
#else
magicinfo.use_parallel = use_parallel;
#endif
if((status = openmagic(&magicinfo))) goto done;
/* Verify we have a large enough file */
if(magicinfo.filelen < MAGIC_NUMBER_LEN)
{status = NC_ENOTNC; goto done;}
if((status = readmagic(&magicinfo,0L,magic)) != NC_NOERR) {
status = NC_ENOTNC;
goto done;
}
/* Look at the magic number */
if(NC_interpret_magic_number(magic,model) == NC_NOERR
&& model->format != 0) {
if (model->format == NC_FORMAT_NC3 && use_parallel)
/* this is called from nc_open_par() and file is classic */
model->impl = NC_FORMATX_PNETCDF;
goto done; /* found something */
}
/* Remaining case when implementation is an HDF5 file;
search forward at starting at 512
and doubling to see if we have HDF5 magic number */
{
long pos = 512L;
for(;;) {
if((pos+MAGIC_NUMBER_LEN) > magicinfo.filelen)
{status = NC_ENOTNC; goto done;}
if((status = readmagic(&magicinfo,pos,magic)) != NC_NOERR)
{status = NC_ENOTNC; goto done; }
NC_interpret_magic_number(magic,model);
if(model->impl == NC_FORMATX_NC4) break;
/* double and try again */
pos = 2*pos;
}
}
done:
closemagic(&magicinfo);
return check(status);
}
/**
\internal
\ingroup datasets
Provide open, read and close for use when searching for magic numbers
*/
static int
openmagic(struct MagicFile* file)
{
int status = NC_NOERR;
if(fIsSet(file->omode,NC_INMEMORY)) {
/* Get its length */
NC_memio* meminfo = (NC_memio*)file->parameters;
assert(meminfo != NULL);
file->filelen = (long long)meminfo->size;
#ifdef ENABLE_BYTERANGE
} else if(file->uri != NULL) {
/* Construct a URL minus any fragment */
file->curlurl = ncuribuild(file->uri,NULL,NULL,NCURISVC);
/* Open the curl handle */
if((status=nc_http_open(file->curlurl,&file->curl,&file->filelen))) goto done;
#endif
} else {
#ifdef USE_PARALLEL
if (file->use_parallel) {
int retval;
MPI_Offset size;
assert(file->parameters != NULL);
if((retval = MPI_File_open(((NC_MPI_INFO*)file->parameters)->comm,
(char*)file->path,MPI_MODE_RDONLY,
((NC_MPI_INFO*)file->parameters)->info,
&file->fh)) != MPI_SUCCESS) {
#ifdef MPI_ERR_NO_SUCH_FILE
int errorclass;
MPI_Error_class(retval, &errorclass);
if (errorclass == MPI_ERR_NO_SUCH_FILE)
#ifdef NC_ENOENT
status = NC_ENOENT;
#else
status = errno;
#endif
else
#endif
status = NC_EPARINIT;
goto done;
}
/* Get its length */
if((retval=MPI_File_get_size(file->fh, &size)) != MPI_SUCCESS)
{status = NC_EPARINIT; goto done;}
file->filelen = (long long)size;
} else
#endif /* USE_PARALLEL */
{
if(file->path == NULL || strlen(file->path)==0)
{status = NC_EINVAL; goto done;}
#ifdef _WIN32
file->fp = NCfopen(file->path, "rb");
#else
file->fp = NCfopen(file->path, "r");
#endif
if(file->fp == NULL)
{status = errno; goto done;}
/* Get its length */
{
int fd = fileno(file->fp);
#ifdef _WIN32
__int64 len64 = _filelengthi64(fd);
if(len64 < 0)
{status = errno; goto done;}
file->filelen = (long long)len64;
#else
off_t size;
size = lseek(fd, 0, SEEK_END);
if(size == -1)
{status = errno; goto done;}
file->filelen = (long long)size;
#endif
}
rewind(file->fp);
}
}
done:
return check(status);
}
static int
readmagic(struct MagicFile* file, long pos, char* magic)
{
int status = NC_NOERR;
memset(magic,0,MAGIC_NUMBER_LEN);
if(fIsSet(file->omode,NC_INMEMORY)) {
char* mempos;
NC_memio* meminfo = (NC_memio*)file->parameters;
if((pos + MAGIC_NUMBER_LEN) > meminfo->size)
{status = NC_EINMEMORY; goto done;}
mempos = ((char*)meminfo->memory) + pos;
memcpy((void*)magic,mempos,MAGIC_NUMBER_LEN);
#ifdef DEBUG
printmagic("XXX: readmagic",magic,file);
#endif
#ifdef ENABLE_BYTERANGE
} else if(file->uri != NULL) {
NCbytes* buf = ncbytesnew();
fileoffset_t start = (size_t)pos;
fileoffset_t count = MAGIC_NUMBER_LEN;
status = nc_http_read(file->curl,file->curlurl,start,count,buf);
if(status == NC_NOERR) {
if(ncbyteslength(buf) != count)
status = NC_EINVAL;
else
memcpy(magic,ncbytescontents(buf),count);
}
ncbytesfree(buf);
#endif
} else {
#ifdef USE_PARALLEL
if (file->use_parallel) {
MPI_Status mstatus;
int retval;
if((retval = MPI_File_read_at_all(file->fh, pos, magic,
MAGIC_NUMBER_LEN, MPI_CHAR, &mstatus)) != MPI_SUCCESS)
{status = NC_EPARINIT; goto done;}
} else
#endif /* USE_PARALLEL */
{
int count;
int i = fseek(file->fp,pos,SEEK_SET);
if(i < 0)
{status = errno; goto done;}
for(i=0;i<MAGIC_NUMBER_LEN;) {/* make sure to read proper # of bytes */
count=fread(&magic[i],1,(size_t)(MAGIC_NUMBER_LEN-i),file->fp);
if(count == 0 || ferror(file->fp))
{status = errno; goto done;}
i += count;
}
}
}
done:
if(file && file->fp) clearerr(file->fp);
return check(status);
}
/**
* Close the file opened to check for magic number.
*
* @param file pointer to the MagicFile struct for this open file.
* @returns NC_NOERR for success
* @returns NC_EPARINIT if there was a problem closing file with MPI
* (parallel builds only).
* @author Dennis Heimbigner
*/
static int
closemagic(struct MagicFile* file)
{
int status = NC_NOERR;
if(fIsSet(file->omode,NC_INMEMORY)) {
/* noop */
#ifdef ENABLE_BYTERANGE
} else if(file->uri != NULL) {
status = nc_http_close(file->curl);
nullfree(file->curlurl);
#endif
} else {
#ifdef USE_PARALLEL
if (file->use_parallel) {
int retval;
if((retval = MPI_File_close(&file->fh)) != MPI_SUCCESS)
{status = NC_EPARINIT; return status;}
} else
#endif
{
if(file->fp) fclose(file->fp);
}
}
return status;
}
/*!
Interpret the magic number found in the header of a netCDF file.
This function interprets the magic number/string contained in the header of a netCDF file and sets the appropriate NC_FORMATX flags.
@param[in] magic Pointer to a character array with the magic number block.
@param[out] model Pointer to an integer to hold the corresponding netCDF type.
@param[out] version Pointer to an integer to hold the corresponding netCDF version.
@returns NC_NOERR if a legitimate file type found
@returns NC_ENOTNC otherwise
\internal
\ingroup datasets
*/
static int
NC_interpret_magic_number(char* magic, NCmodel* model)
{
int status = NC_NOERR;
/* Look at the magic number */
#ifdef USE_NETCDF4
if (strlen(UDF0_magic_number) && !strncmp(UDF0_magic_number, magic,
strlen(UDF0_magic_number)))
{
model->impl = NC_FORMATX_UDF0;
model->format = NC_FORMAT_NETCDF4;
goto done;
}
if (strlen(UDF1_magic_number) && !strncmp(UDF1_magic_number, magic,
strlen(UDF1_magic_number)))
{
model->impl = NC_FORMATX_UDF1;
model->format = NC_FORMAT_NETCDF4;
goto done;
}
#endif /* USE_NETCDF4 */
/* Use the complete magic number string for HDF5 */
if(memcmp(magic,HDF5_SIGNATURE,sizeof(HDF5_SIGNATURE))==0) {
model->impl = NC_FORMATX_NC4;
model->format = NC_FORMAT_NETCDF4;
goto done;
}
if(magic[0] == '\016' && magic[1] == '\003'
&& magic[2] == '\023' && magic[3] == '\001') {
model->impl = NC_FORMATX_NC_HDF4;
model->format = NC_FORMAT_NETCDF4;
goto done;
}
if(magic[0] == 'C' && magic[1] == 'D' && magic[2] == 'F') {
if(magic[3] == '\001') {
model->impl = NC_FORMATX_NC3;
model->format = NC_FORMAT_CLASSIC;
goto done;
}
if(magic[3] == '\002') {
model->impl = NC_FORMATX_NC3;
model->format = NC_FORMAT_64BIT_OFFSET;
goto done;
}
if(magic[3] == '\005') {
model->impl = NC_FORMATX_NC3;
model->format = NC_FORMAT_64BIT_DATA;
goto done;
}
}
/* No match */
status = NC_ENOTNC;
goto done;
done:
return check(status);
}
#ifdef DEBUG
static void
printmagic(const char* tag, char* magic, struct MagicFile* f)
{
int i;
fprintf(stderr,"%s: ispar=%d magic=",tag,f->use_parallel);
for(i=0;i<MAGIC_NUMBER_LEN;i++) {
unsigned int c = (unsigned int)magic[i];
c = c & 0x000000FF;
if(c == '\n')
fprintf(stderr," 0x%0x/'\\n'",c);
else if(c == '\r')
fprintf(stderr," 0x%0x/'\\r'",c);
else if(c < ' ')
fprintf(stderr," 0x%0x/'?'",c);
else
fprintf(stderr," 0x%0x/'%c'",c,c);
}
fprintf(stderr,"\n");
fflush(stderr);
}
#endif
|