netcdf-c/libdispatch/dinfermodel.c
2022-04-07 16:57:35 -06:00

1512 lines
40 KiB
C

/**
* @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 "ncpathmgr.h"
#include "netcdf_mem.h"
#include "fbits.h"
#include "ncbytes.h"
#include "nclist.h"
#include "nclog.h"
#include "ncrc.h"
#ifdef ENABLE_BYTERANGE
#include "nchttp.h"
#ifdef ENABLE_S3_SDK
#include "ncs3sdk.h"
#endif
#endif
#ifndef nulldup
#define nulldup(x) ((x)?strdup(x):(x))
#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;
long long filelen;
int use_parallel;
int iss3;
void* parameters; /* !NULL if inmemory && !diskless */
FILE* fp;
#ifdef USE_PARALLEL
MPI_File fh;
#endif
#ifdef ENABLE_BYTERANGE
char* curlurl; /* url to use with CURLOPT_SET_URL */
NC_HTTP_STATE* state;
#ifdef ENABLE_S3_SDK
NCS3INFO s3;
void* s3client;
char* errmsg;
#endif
#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 */
const int format; /* NC_FORMAT_XXX value */
} formatmodes[] = {
{"dap2",NC_FORMATX_DAP2,NC_FORMAT_CLASSIC},
{"dap4",NC_FORMATX_DAP4,NC_FORMAT_NETCDF4},
{"netcdf-3",NC_FORMATX_NC3,0}, /* Might be e.g. cdf5 */
{"classic",NC_FORMATX_NC3,0}, /* ditto */
{"netcdf-4",NC_FORMATX_NC4,NC_FORMAT_NETCDF4},
{"enhanced",NC_FORMATX_NC4,NC_FORMAT_NETCDF4},
{"udf0",NC_FORMATX_UDF0,NC_FORMAT_NETCDF4},
{"udf1",NC_FORMATX_UDF1,NC_FORMAT_NETCDF4},
{"nczarr",NC_FORMATX_NCZARR,NC_FORMAT_NETCDF4},
{"zarr",NC_FORMATX_NCZARR,NC_FORMAT_NETCDF4},
{"bytes",NC_FORMATX_NC4,NC_FORMAT_NETCDF4}, /* temporary until 3 vs 4 is determined */
{NULL,0},
};
/* Replace top-level name with defkey=defvalue */
static const struct MACRODEF {
char* name;
char* defkey;
char* defvalues[4];
} macrodefs[] = {
{"zarr","mode",{"nczarr","zarr",NULL}},
{"dap2","mode",{"dap2",NULL}},
{"dap4","mode",{"dap4",NULL}},
{"s3","mode",{"s3","nczarr",NULL}},
{"bytes","mode",{"bytes",NULL}},
{"xarray","mode",{"nczarr","zarr","xarray",NULL}},
{"noxarray","mode",{"nczarr","zarr","noxarray",NULL}},
{"zarr","mode",{"nczarr","zarr","xarray",NULL}},
{NULL,NULL,{NULL}}
};
/* Mode inferences: if mode contains key, then add the inference and infer again */
static const struct MODEINFER {
char* key;
char* inference;
} modeinferences[] = {
{"zarr","nczarr"},
{"zarr","xarray"},
{"xarray","zarr"},
{"noxarray","zarr"},
{NULL,NULL}
};
/* Mode negations: if mode contains key, then remove all occurrences of the inference and repeat */
static const struct MODEINFER modenegations[] = {
{"bytes","nczarr"}, /* bytes negates (nc)zarr */
{"bytes","zarr"},
{"noxarray","xarray"},
{NULL,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_NCZARR,0}, /* eventually make readable */
{0,0},
};
/* Define the known URL protocols and their interpretation */
static struct NCPROTOCOLLIST {
const char* protocol;
const char* substitute;
const char* fragments; /* arbitrary fragment arguments */
} ncprotolist[] = {
{"http",NULL,NULL},
{"https",NULL,NULL},
{"file",NULL,NULL},
{"dods","http","mode=dap2"},
{"dap4","http","mode=dap4"},
{"s3","s3","mode=s3"},
{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 processuri(const char* path, NCURI** urip, NClist* fraglist);
static int processmacros(NClist** fraglistp);
static char* envvlist2string(NClist* pairs, const char*);
static void set_default_mode(int* cmodep);
static int parseonchar(const char* s, int ch, NClist* segments);
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*);
static void printlist(NClist* list, const char* tag);
#endif
static int isreadable(NCURI*,NCmodel*);
static char* list2string(NClist*);
static int parsepair(const char* pair, char** keyp, char** valuep);
static NClist* parsemode(const char* modeval);
static const char* getmodekey(const NClist* envv);
static int replacemode(NClist* envv, const char* newval);
static int inferone(const char* mode, NClist* newmodes);
static int negateone(const char* mode, NClist* modes);
/*
If the path looks like a URL, then parse it, reformat it.
*/
static int
processuri(const char* path, NCURI** urip, NClist* fraglenv)
{
int stat = NC_NOERR;
int found = 0;
NClist* tmp = NULL;
struct NCPROTOCOLLIST* protolist;
NCURI* uri = NULL;
size_t pathlen = strlen(path);
char* str = NULL;
const char** ufrags;
const char** p;
if(path == NULL || pathlen == 0) {stat = NC_EURL; goto done;}
/* Defaults */
if(urip) *urip = NULL;
ncuriparse(path,&uri);
if(uri == NULL) 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 fragments for that protocol */
if(protolist->fragments != NULL) {
int i;
tmp = nclistnew();
if((stat = parseonchar(protolist->fragments,'&',tmp))) goto done;
for(i=0;i<nclistlength(tmp);i++) {
char* key=NULL;
char* value=NULL;
if((stat = parsepair(nclistget(tmp,i),&key,&value))) goto done;
if(value == NULL) value = strdup("");
nclistpush(fraglenv,key);
nclistpush(fraglenv,value);
}
nclistfreeall(tmp); tmp = NULL;
}
/* Substitute the protocol in any case */
if(protolist->substitute) ncurisetprotocol(uri,protolist->substitute);
/* capture the fragments of the url */
ufrags = ncurifragmentparams(uri);
if(ufrags != NULL) {
for(p=ufrags;*p;p+=2) {
const char* key = p[0];
const char* value = p[1];
nclistpush(fraglenv,nulldup(key));
value = (value==NULL?"":value);
nclistpush(fraglenv,strdup(value));
}
}
if(urip) {
*urip = uri;
uri = NULL;
}
done:
nclistfreeall(tmp);
nullfree(str);
if(uri != NULL) ncurifree(uri);
return check(stat);
}
/* Split a key=value pair */
static int
parsepair(const char* pair, char** keyp, char** valuep)
{
const char* p;
char* key = NULL;
char* value = NULL;
if(pair == NULL)
return NC_EINVAL; /* empty pair */
if(pair[0] == '\0' || pair[0] == '=')
return NC_EINVAL; /* no key */
p = strchr(pair,'=');
if(p == NULL) {
value = NULL;
key = strdup(pair);
} else {
ptrdiff_t len = (p-pair);
if((key = malloc(len+1))==NULL) return NC_ENOMEM;
memcpy(key,pair,len);
key[len] = '\0';
if(p[1] == '\0')
value = NULL;
else
value = strdup(p+1);
}
if(keyp) {*keyp = key; key = NULL;};
if(valuep) {*valuep = value; value = NULL;};
nullfree(key);
nullfree(value);
return NC_NOERR;
}
#if 0
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);
}
#endif
/* Split a string at a given char */
static int
parseonchar(const char* s, int ch, NClist* segments)
{
int stat = NC_NOERR;
const char* p = NULL;
const char* endp = NULL;
if(s == NULL || *s == '\0') goto done;
p = s;
for(;;) {
char* q;
ptrdiff_t slen;
endp = strchr(p,ch);
if(endp == NULL) endp = p + strlen(p);
slen = (endp - p);
if((q = malloc(slen+1)) == NULL) {stat = NC_ENOMEM; goto done;}
memcpy(q,p,slen);
q[slen] = '\0';
nclistpush(segments,q);
if(*endp == '\0') break;
p = endp+1;
}
done:
return check(stat);
}
/* Convert a key,value envv pairlist into a delimited string*/
static char*
envvlist2string(NClist* envv, const char* delim)
{
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;
assert(val != NULL);
if(i > 0) ncbytescat(buf,"&");
ncbytescat(buf,key);
if(val != NULL && val[0] != '\0') {
ncbytescat(buf,"=");
ncbytescat(buf,val);
}
}
result = ncbytesextract(buf);
ncbytesfree(buf);
return result;
}
/* Convert a list into a comma'd string */
static char*
list2string(NClist* list)
{
int i;
NCbytes* buf = NULL;
char* result = NULL;
if(list == NULL || nclistlength(list)==0) return strdup("");
buf = ncbytesnew();
for(i=0;i<nclistlength(list);i++) {
const char* m = nclistget(list,i);
if(m == NULL || strlen(m) == 0) continue;
if(i > 0) ncbytescat(buf,",");
ncbytescat(buf,m);
}
result = ncbytesextract(buf);
ncbytesfree(buf);
if(result == NULL) result = strdup("");
return result;
}
/* Given a mode= argument, fill in the impl */
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;
if(format->format != 0) model->format = format->format;
}
}
return check(stat);
}
/* Given an envv fragment list, do macro replacement */
static int
processmacros(NClist** fraglenvp)
{
int stat = NC_NOERR;
const struct MACRODEF* macros = NULL;
NClist* fraglenv = NULL;
NClist* expanded = NULL;
if(fraglenvp == NULL || nclistlength(*fraglenvp) == 0) goto done;
fraglenv = *fraglenvp;
expanded = nclistnew();
while(nclistlength(fraglenv) > 0) {
int found = 0;
char* key = NULL;
char* value = NULL;
key = nclistremove(fraglenv,0); /* remove from changing front */
value = nclistremove(fraglenv,0); /* remove from changing front */
if(strlen(value) == 0) { /* must be a singleton */
for(macros=macrodefs;macros->name;macros++) {
if(strcmp(macros->name,key)==0) {
char* const * p;
nclistpush(expanded,strdup(macros->defkey));
for(p=macros->defvalues;*p;p++)
nclistpush(expanded,strdup(*p));
found = 1;
break;
}
}
}
if(!found) {/* pass thru */
nclistpush(expanded,strdup(key));
nclistpush(expanded,strdup(value));
}
nullfree(key);
nullfree(value);
}
*fraglenvp = expanded; expanded = NULL;
done:
nclistfreeall(expanded);
nclistfreeall(fraglenv);
return check(stat);
}
/* Process mode flag inferences */
static int
processinferences(NClist* fraglenv)
{
int stat = NC_NOERR;
const char* modeval = NULL;
NClist* modes = NULL;
NClist* newmodes = nclistnew();
int i,inferred = 0;
char* newmodeval = NULL;
if(fraglenv == NULL || nclistlength(fraglenv) == 0) goto done;
/* Get "mode" entry */
if((modeval = getmodekey(fraglenv))==NULL) goto done;
/* Get the mode as list */
modes = parsemode(modeval);
/* Repeatedly walk the mode list until no more new positive inferences */
do {
for(i=0;i<nclistlength(modes);i++) {
const char* mode = nclistget(modes,i);
inferred = inferone(mode,newmodes);
nclistpush(newmodes,strdup(mode)); /* keep key */
if(!inferred) nclistpush(newmodes,strdup(mode));
}
} while(inferred);
/* Remove negative inferences */
for(i=0;i<nclistlength(modes);i++) {
const char* mode = nclistget(modes,i);
inferred = negateone(mode,newmodes);
}
/* Store new mode value */
if((newmodeval = list2string(newmodes))== NULL)
{stat = NC_ENOMEM; goto done;}
if((stat=replacemode(fraglenv,newmodeval))) goto done;
modeval = NULL;
done:
nullfree(newmodeval);
nclistfreeall(modes);
nclistfreeall(newmodes);
return check(stat);
}
static int
negateone(const char* mode, NClist* newmodes)
{
const struct MODEINFER* tests = modenegations;
int changed = 0;
for(;tests->key;tests++) {
int i;
if(strcasecmp(tests->key,mode)==0) {
/* Find and remove all instances of the inference value */
for(i=nclistlength(newmodes)-1;i>=0;i--) {
char* candidate = nclistget(newmodes,i);
if(strcasecmp(candidate,tests->inference)==0) {
nclistremove(newmodes,i);
nullfree(candidate);
changed = 1;
}
}
}
}
return changed;
}
static int
inferone(const char* mode, NClist* newmodes)
{
const struct MODEINFER* tests = modeinferences;
int changed = 0;
for(;tests->key;tests++) {
if(strcasecmp(tests->key,mode)==0) {
/* Append the inferred mode; dups removed later */
nclistpush(newmodes,strdup(tests->inference));
changed = 1;
}
}
return changed;
}
static int
mergekey(NClist** valuesp)
{
int i,j;
int stat = NC_NOERR;
NClist* values = *valuesp;
NClist* allvalues = nclistnew();
NClist* newvalues = nclistnew();
char* value = NULL;
for(i=0;i<nclistlength(values);i++) {
char* val1 = nclistget(values,i);
/* split on commas and put pieces into allvalues */
if((stat=parseonchar(val1,',',allvalues))) goto done;
}
/* Remove duplicates and "" */
while(nclistlength(allvalues) > 0) {
value = nclistremove(allvalues,0);
if(strlen(value) == 0) {
nullfree(value); value = NULL;
} else {
for(j=0;j<nclistlength(newvalues);j++) {
char* candidate = nclistget(newvalues,j);
if(strcasecmp(candidate,value)==0)
{nullfree(value); value = NULL; break;}
}
}
if(value != NULL) {nclistpush(newvalues,value); value = NULL;}
}
/* Make sure to have at least 1 value */
if(nclistlength(newvalues)==0) nclistpush(newvalues,strdup(""));
*valuesp = values; values = NULL;
done:
nclistfree(allvalues);
nclistfreeall(values);
nclistfreeall(newvalues);
return check(stat);
}
static int
lcontains(NClist* l, const char* key0)
{
int i;
for(i=0;i<nclistlength(l);i++) {
const char* key1 = nclistget(l,i);
if(strcasecmp(key0,key1)==0) return 1;
}
return 0;
}
/* Warning values should not use nclistfreeall */
static void
collectvaluesbykey(NClist* fraglenv, const char* key, NClist* values)
{
int i;
/* collect all the values with the same key (including this one) */
for(i=0;i<nclistlength(fraglenv);i+=2) {
const char* key2 = nclistget(fraglenv,i);
if(strcasecmp(key,key2)==0) {
const char* value2 = nclistget(fraglenv,i+1);
nclistpush(values,value2); value2 = NULL;
}
}
}
/* Warning allkeys should not use nclistfreeall */
static void
collectallkeys(NClist* fraglenv, NClist* allkeys)
{
int i;
/* collect all the distinct keys */
for(i=0;i<nclistlength(fraglenv);i+=2) {
char* key = nclistget(fraglenv,i);
if(!lcontains(allkeys,key)) {
nclistpush(allkeys,key);
}
}
}
/* Given a fragment envv list, coalesce duplicate keys and remove duplicate values*/
static int
cleanfragments(NClist** fraglenvp)
{
int i,stat = NC_NOERR;
NClist* fraglenv = NULL;
NClist* tmp = NULL;
NClist* allkeys = NULL;
NClist* newlist = NULL;
NCbytes* buf = NULL;
char* key = NULL;
char* value = NULL;
if(fraglenvp == NULL || nclistlength(*fraglenvp) == 0) return NC_NOERR;
fraglenv = *fraglenvp; /* take control of this list */
*fraglenvp = NULL;
newlist = nclistnew();
buf = ncbytesnew();
allkeys = nclistnew();
tmp = nclistnew();
/* collect all unique keys */
collectallkeys(fraglenv,allkeys);
/* Collect all values for same key across all fragments */
for(i=0;i<nclistlength(allkeys);i++) {
key = nclistget(allkeys,i);
collectvaluesbykey(fraglenv,key,tmp);
/* merge the key values, remove duplicate */
if((stat=mergekey(&tmp))) goto done;
/* Construct key,value pair and insert into newlist */
key = strdup(key);
nclistpush(newlist,key);
value = list2string(tmp);
nclistpush(newlist,value);
nclistclear(tmp);
}
*fraglenvp = newlist; newlist = NULL;
done:
nclistfree(allkeys);
nclistfree(tmp);
ncbytesfree(buf);
nclistfreeall(fraglenv);
nclistfreeall(newlist);
return check(stat);
}
/* process non-mode fragment keys in case they hold significance; currently not */
static int
processfragmentkeys(const char* key, const char* value, NCmodel* model)
{
return NC_NOERR;
}
/*
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 first
* 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;
NCURI* uri = NULL;
int omode = *omodep;
NClist* fraglenv = nclistnew();
NClist* modeargs = nclistnew();
char* sfrag = NULL;
const char* modeval = NULL;
char* abspath = NULL;
/* Phase 1:
1. convert special protocols to http|https
2. begin collecting fragments
*/
if((stat = processuri(path, &uri, fraglenv))) goto done;
if(uri != NULL) {
#ifdef DEBUG
printlist(fraglenv,"processuri");
#endif
/* Phase 2: Expand macros and add to fraglenv */
if((stat = processmacros(&fraglenv))) goto done;
#ifdef DEBUG
printlist(fraglenv,"processmacros");
#endif
/* Cleanup the fragment list */
if((stat = cleanfragments(&fraglenv))) goto done;
/* Phase 2a: Expand mode inferences and add to fraglenv */
if((stat = processinferences(fraglenv))) goto done;
#ifdef DEBUG
printlist(fraglenv,"processinferences");
#endif
/* Phase 3: coalesce duplicate fragment keys and remove duplicate values */
if((stat = cleanfragments(&fraglenv))) goto done;
#ifdef DEBUG
printlist(fraglenv,"cleanfragments");
#endif
/* Phase 4: Rebuild the url fragment and rebuilt the url */
sfrag = envvlist2string(fraglenv,"&");
nclistfreeall(fraglenv); fraglenv = NULL;
#ifdef DEBUG
fprintf(stderr,"frag final: %s\n",sfrag);
#endif
ncurisetfragments(uri,sfrag);
nullfree(sfrag); sfrag = NULL;
/* If s3, then rebuild the url */
if(NC_iss3(uri)) {
NCURI* newuri = NULL;
if((stat = NC_s3urlrebuild(uri,&newuri,NULL,NULL))) goto done;
ncurifree(uri);
uri = newuri;
} else if(strcmp(uri->protocol,"file")==0) {
/* convert path to absolute */
char* canon = NULL;
abspath = NCpathabsolute(uri->path);
if((stat = NCpathcanonical(abspath,&canon))) goto done;
nullfree(abspath);
abspath = canon; canon = NULL;
if((stat = ncurisetpath(uri,abspath))) goto done;
}
/* rebuild the path */
if(newpathp) {
*newpathp = ncuribuild(uri,NULL,NULL,NCURIALL);
#ifdef DEBUG
fprintf(stderr,"newpath=|%s|\n",*newpathp); fflush(stderr);
#endif
}
/* Phase 5: Process the mode key to see if we can tell the formatx */
modeval = ncurifragmentlookup(uri,"mode");
if(modeval != NULL) {
if((stat = parseonchar(modeval,',',modeargs))) goto done;
for(i=0;i<nclistlength(modeargs);i++) {
const char* arg = nclistget(modeargs,i);
if((stat=processmodearg(arg,model))) goto done;
}
}
/* Phase 6: Process the non-mode keys to see if we can tell the formatx */
if(!modelcomplete(model)) {
const char** p = ncurifragmentparams(uri); /* envv format */
if(p != NULL) {
for(;*p;p++) {
const char* key = p[0];
const char* value = p[1];;
if((stat=processfragmentkeys(key,value,model))) goto done;
}
}
}
/* Phase 7: Special cases: if this is a URL and model.impl is still not defined */
/* Phase7a: Default is DAP2 */
if(!modelcomplete(model)) {
model->impl = NC_FORMATX_DAP2;
model->format = NC_FORMAT_NC3;
}
} else {/* Not URL */
if(*newpathp) *newpathp = NULL;
}
/* Phase 8: 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 9: 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(uri,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:
case NC_FORMATX_NCZARR:
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:
nullfree(sfrag);
nullfree(abspath);
ncurifree(uri);
nclistfreeall(modeargs);
nclistfreeall(fraglenv);
*omodep = omode; /* in/out */
return check(stat);
}
static int
isreadable(NCURI* uri, NCmodel* model)
{
int canread = 0;
struct Readable* r;
/* Step 1: Look up the implementation */
for(r=readable;r->impl;r++) {
if(model->impl == r->impl) {canread = r->readable; break;}
}
/* Step 2: check for bytes mode */
if(!canread && NC_testmode(uri,"bytes") && (model->impl == NC_FORMATX_NC4 || model->impl == NC_FORMATX_NC_HDF5))
canread = 1;
return canread;
}
#if 0
static char*
emptyify(char* s)
{
if(s == NULL) s = strdup("");
return strdup(s);
}
static const char*
nullify(const char* s)
{
if(s != NULL && strlen(s) == 0)
return NULL;
return s;
}
#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 path
* minus any extension into basenamep; caller frees.
* Return 1 if it looks like a url, 0 otherwise.
*/
int
nc__testurl(const char* path0, char** basenamep)
{
NCURI* uri = NULL;
int ok = 0;
char* path = NULL;
if(!ncuriparse(path0,&uri)) {
char* p;
char* q;
path = strdup(uri->path);
if(path == NULL||strlen(path)==0) goto done;
p = strrchr(path, '/');
if(p == NULL) p = path; else p++;
q = strrchr(p,'.');
if(q != NULL) *q = '\0';
if(strlen(p) == 0) goto done;
if(basenamep)
*basenamep = strdup(p);
ok = 1;
}
done:
ncurifree(uri);
nullfree(path);
return ok;
}
/**************************************************/
/* Envv list utilities */
static const char*
getmodekey(const NClist* envv)
{
int i;
/* Get "mode" entry */
for(i=0;i<nclistlength(envv);i+=2) {
char* key = NULL;
key = nclistget(envv,i);
if(strcasecmp(key,"mode")==0)
return nclistget(envv,i+1);
}
return NULL;
}
static int
replacemode(NClist* envv, const char* newval)
{
int i;
/* Get "mode" entry */
for(i=0;i<nclistlength(envv);i+=2) {
char* key = NULL;
char* val = NULL;
key = nclistget(envv,i);
if(strcasecmp(key,"mode")==0) {
val = nclistget(envv,i+1);
nclistset(envv,i+1,strdup(newval));
nullfree(val);
return NC_NOERR;
}
}
return NC_EINVAL;
}
static NClist*
parsemode(const char* modeval)
{
NClist* modes = nclistnew();
if(modeval)
(void)parseonchar(modeval,',',modes);/* split on commas */
return modes;
}
/**************************************************/
/**
* @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;
#ifdef _WIN32
NC* nc = NULL;
#endif
memset((void*)&magicinfo,0,sizeof(magicinfo));
#ifdef _WIN32 /* including MINGW */
/* Windows does not handle well multiple handles to the same file.
So if file is already open/created, then find it and just get the
model from that. */
if((nc = find_in_NCList_by_name(path)) != NULL) {
int format = 0;
/* Get the model from this NC */
if((status = nc_inq_format_extended(nc->ext_ncid,&format,NULL))) goto done;
model->impl = format;
if((status = nc_inq_format(nc->ext_ncid,&format))) goto done;
model->format = format;
goto done;
}
#endif
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 < (unsigned long long)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 (use_parallel && (model->format == NC_FORMAT_NC3 || model->impl == NC_FORMATX_NC3))
/* 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) {
#ifdef ENABLE_S3_SDK
/* If this is an S3 URL, then handle specially */
if(NC_iss3(file->uri)) {
if((status = NC_s3urlprocess(file->uri,&file->s3))) goto done;
if((file->s3client = NC_s3sdkcreateclient(&file->s3))==NULL) {status = NC_EURL; goto done;}
if((status = NC_s3sdkinfo(file->s3client,file->s3.bucket,file->s3.rootkey,&file->filelen,&file->errmsg)))
goto done;
file->iss3 = 1;
} else
#endif
{
/* Construct a URL minus any fragment */
file->curlurl = ncuribuild(file->uri,NULL,NULL,NCURISVC);
/* Open the curl handle */
if((status=nc_http_init(&file->state))) goto done;
if((status=nc_http_size(file->state,file->curlurl,&file->filelen))) goto done;
}
#endif /*BYTERANGE*/
} 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;}
file->fp = NCfopen(file->path, "r");
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;
NCbytes* buf = ncbytesnew();
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) {
fileoffset_t start = (size_t)pos;
fileoffset_t count = MAGIC_NUMBER_LEN;
#ifdef ENABLE_S3_SDK
if(file->iss3) {
if((status = NC_s3sdkread(file->s3client,file->s3.bucket,file->s3.rootkey,start,count,(void*)magic,&file->errmsg)))
{goto done;}
}
else
#endif
{
status = nc_http_read(file->state, file->curlurl, start, count, buf);
if (status == NC_NOERR) {
if (ncbyteslength(buf) != count)
status = NC_EINVAL;
else
memcpy(magic, ncbytescontents(buf), count);
}
}
#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 */
{ /* Ordinary read */
long i;
i = fseek(file->fp, pos, SEEK_SET);
if (i < 0) { status = errno; goto done; }
ncbytessetlength(buf, 0);
if ((status = NC_readfileF(file->fp, buf, MAGIC_NUMBER_LEN))) goto done;
memcpy(magic, ncbytescontents(buf), MAGIC_NUMBER_LEN);
}
}
done:
ncbytesfree(buf);
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) {
#ifdef ENABLE_S3_SDK
if(file->iss3) {
NC_s3sdkclose(file->s3client, &file->s3, 0, &file->errmsg);
NC_s3clear(&file->s3);
nullfree(file->errmsg);
} else
#endif
{
status = nc_http_close(file->state);
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);
}
static void
printlist(NClist* list, const char* tag)
{
int i;
fprintf(stderr,"%s:",tag);
for(i=0;i<nclistlength(list);i++)
fprintf(stderr," %s",(char*)nclistget(list,i));
fprintf(stderr,"\n");
dbgflush();
}
#endif