netcdf-c/libdap4/d4fix.c
Dennis Heimbigner 65414eeaa4 Fix some protocol differences between netcdf-c and the Hyrax server.
re: Partly addresses issue https://github.com/Unidata/netcdf-c/issues/1712.

1. Turn on Hyrax Hack to accept Hyrax style attribute containers.
2. Support Url type as alias for String.
3. Accept the special attribute, "__DAP4_Checksum_CRC32",
   to control per-variable checksums.
4. Make _DAP4_xxx attributes be reserved and only accessible
   by name (ala _SuperBlock attribute).
5. Fix handling of checksums. There is a hack in the code
   that uses an extra flag in the chunk header to indicate
   that all variables have checksums. This violates the spec
   and will be removed once it is possible to regenerate the
   test cases.

Note that checksumming with the Hyrax test server has not
been tested. This, along with some other probable inconsistencies,
needs fixing when OPeNDAP and Unidata can agree on the proper
specification. Testing will be included.
2020-05-30 17:36:25 -06:00

555 lines
14 KiB
C

/*********************************************************************
* Copyright 2018, UCAR/Unidata
* See netcdf/COPYRIGHT file for copying and redistribution conditions.
*********************************************************************/
#include <stdarg.h>
#include <assert.h>
#include "d4includes.h"
#include "ezxml.h"
/*
The primary purpose of this code is to provide node and data walkers
to do a variety of things.
* (topo)
a. topologically sort the set of allnodes in postfix order.
* (delimit)
a. Delimit the top-level vars in the dap4data and also compute checksum
* (move)
a. Walk the (toplevel) var's data to get to the count'th instance.
*/
/**************************************************/
#define COUNTSIZE 8
/**************************************************/
/* Forward */
static int delimitAtomicVar(NCD4meta*, NCD4node* var, void** offsetp);
static int delimitOpaqueVar(NCD4meta*, NCD4node* var, void** offsetp);
static int delimitSeq(NCD4meta*, NCD4node* var, void** offsetp);
static int delimitSeqArray(NCD4meta*, NCD4node* var, void** offsetp);
static int delimitStruct(NCD4meta*, NCD4node* var, void** offsetp);
static int delimitStructArray(NCD4meta*, NCD4node* var, void** offsetp);
static int skipInstance(NCD4meta*, NCD4node* type, void** offsetp);
static int skipAtomicInstance(NCD4meta*, NCD4node* type, void** offsetp);
static int skipStructInstance(NCD4meta*, NCD4node* type, void** offsetp);
static int skipSeqInstance(NCD4meta*, NCD4node* vlentype, void** offsetp);
static void walk(NCD4node* node, NClist* sorted);
#ifdef D4DEBUGDATA
static void
ADDNODE(NClist* list, NCD4node* node)
{
fprintf(stderr,"addnode: %s: %s %s (%llu)\n",
node->name,
NCD4_sortname(node->sort),
NCD4_subsortname(node->subsort),
node);
fflush(stderr);
nclistpush(list,node);
}
#else
#define ADDNODE(list,node) nclistpush((list),(node))
#endif
/**************************************************/
/* Topo sort in postfix order */
int
NCD4_toposort(NCD4meta* compiler)
{
int i, ret=NC_NOERR;
size_t len = nclistlength(compiler->allnodes);
NCD4node** list = (NCD4node**)nclistcontents(compiler->allnodes);
NCD4node** p;
NClist* sorted = nclistnew();
nclistsetalloc(sorted,len);
for(i=0,p=list;i<len;p++,i++) {
NCD4node* node = *p;
switch (node->sort) { /* Collect things known to have no dependencies */
case NCD4_DIM:
node->visited = 1;
ADDNODE(sorted,node);
break;
case NCD4_TYPE:
if(node->subsort <= NC_MAX_ATOMIC_TYPE || node->subsort == NC_OPAQUE) {
node->visited = 1;
ADDNODE(sorted,node);
} else
node->visited = 0;
break;
default:
node->visited = 0;
}
}
walk(compiler->root,sorted);
/* Last step is to add in any remaining unvisited nodes, but report them */
for(i=0,p=list;i<len;p++,i++) {
NCD4node* node = *p;
if(node->visited) continue;
#ifdef D4DEBUGDATA
fprintf(stderr,"unvisited node: %s\n",node->name); fflush(stderr);
#endif
node->visited = 1;
ADDNODE(sorted,node);
}
nclistfree(compiler->allnodes);
compiler->allnodes = sorted;
#ifdef D4DEBUGDATA
{int i;
for(i=0;i<nclistlength(sorted);i++)
fprintf(stderr,"sorted: %s\n",((NCD4node*)nclistget(sorted,i))->name);
fflush(stderr);
}
#endif
return THROW(ret);
}
/*
Do depth first search
*/
static void
walk(NCD4node* node, NClist* sorted)
{
int i;
if(node->visited) return;
node->visited = 1;
switch (node->sort) {
case NCD4_GROUP: /* depends on its elements and attributes and subgroups */
for(i=0;i<nclistlength(node->group.elements);i++) {
NCD4node* elem = (NCD4node*)nclistget(node->group.elements,i);
walk(elem,sorted);
}
break;
case NCD4_TYPE: /* Need to discriminate on the subsort */
switch (node->subsort) {
case NC_SEQ:
/* Depends on its basetype */
walk(node->basetype,sorted);
break;
case NC_STRUCT: /* Depends on its fields */
for(i=0;i<nclistlength(node->vars);i++) {
NCD4node* f = (NCD4node*)nclistget(node->vars,i);
walk(f,sorted);
}
break;
case NC_ENUM: /* Depends on its basetype, but since that is atomic, we can ignore */
/* fall thru */
default: /* Atomic or opaque, so already marked */
break;
}
break;
case NCD4_VAR: /* Depends on: dimensions and basetype and maps */
for(i=0;i<nclistlength(node->dims);i++) {
NCD4node* d = (NCD4node*)nclistget(node->dims,i);
walk(d,sorted);
}
walk(node->basetype,sorted);
for(i=0;i<nclistlength(node->maps);i++) {
NCD4node* m = (NCD4node*)nclistget(node->maps,i);
walk(m,sorted);
}
break;
case NCD4_ATTR: /* Depends on its base type */
walk(node->basetype,sorted);
break;
case NCD4_ATTRSET: /* Depends on its contained attributes, but handled after switch */
/* fall thru */
default: /* depends on nothing else */
break;
}
/* Do Attributes last */
for(i=0;i<nclistlength(node->attributes);i++) {
NCD4node* a = (NCD4node*)nclistget(node->attributes,i);
walk(a,sorted);
}
ADDNODE(sorted,node);
}
/**************************************************/
/* Mark the offset and length of each var/field
inside the raw dapdata.
Assumes it is called before byte swapping, so we
need to do swapping of counts and the final remote checksum.
*/
int
NCD4_delimit(NCD4meta* compiler, NCD4node* topvar, void** offsetp)
{
int ret = NC_NOERR;
void* offset;
offset = *offsetp;
ASSERT((ISTOPLEVEL(topvar)));
topvar->data.dap4data.memory = offset;
if(topvar->sort == NCD4_VAR) {
switch (topvar->subsort) {
case NC_STRUCT:
if((ret=delimitStructArray(compiler,topvar,&offset))) goto done;
break;
case NC_SEQ:
if((ret=delimitSeqArray(compiler,topvar,&offset))) goto done;
break;
default:
if((ret=delimitAtomicVar(compiler,topvar,&offset))) goto done;
break;
}
}
/* Track the variable size (in the dap4 data) but do not include
any checksum */
topvar->data.dap4data.size = (d4size_t)(((char*)offset) - ((char*)*offsetp));
/* extract the dap4 data checksum, if present */
if(topvar->data.remotechecksummed) {
union ATOMICS csum;
memcpy(csum.u8,offset,CHECKSUMSIZE);
topvar->data.remotechecksum = csum.u32[0];
if(compiler->swap) swapinline32(&topvar->data.remotechecksum);
offset = INCR(offset,CHECKSUMSIZE);
}
*offsetp = offset;
done:
return THROW(ret);
}
/* Includes opaque and enum */
static int
delimitAtomicVar(NCD4meta* compiler, NCD4node* var, void** offsetp)
{
int ret = NC_NOERR;
void* offset;
int typesize;
d4size_t i;
d4size_t dimproduct;
nc_type tid;
NCD4node* basetype;
NCD4node* truetype;
assert(var->sort == NCD4_VAR);
dimproduct = NCD4_dimproduct(var);
basetype = var->basetype;
if(basetype->subsort == NC_OPAQUE)
return delimitOpaqueVar(compiler,var,offsetp);
truetype = basetype;
if(truetype->subsort == NC_ENUM)
truetype = basetype->basetype;
offset = *offsetp;
tid = truetype->subsort;
typesize = NCD4_typesize(tid);
if(tid != NC_STRING) {
offset = INCR(offset,(typesize*dimproduct));
} else if(tid == NC_STRING) { /* walk the counts */
unsigned long long count;
for(i=0;i<dimproduct;i++) {
/* Get string count */
count = GETCOUNTER(offset);
SKIPCOUNTER(offset);
if(compiler->swap) swapinline64(&count);
/* skip count bytes */
offset = INCR(offset,count);
}
}
*offsetp = offset;
return THROW(ret);
}
static int
delimitOpaqueVar(NCD4meta* compiler, NCD4node* var, void** offsetp)
{
int ret = NC_NOERR;
void* offset;
d4size_t i;
unsigned long long count;
d4size_t dimproduct = NCD4_dimproduct(var);
offset = *offsetp;
for(i=0;i<dimproduct;i++) {
/* Walk the instances */
count = GETCOUNTER(offset);
SKIPCOUNTER(offset);
if(compiler->swap) swapinline64(&count);
offset = INCR(offset,count);
}
*offsetp = offset;
return THROW(ret);
}
static int
delimitStructArray(NCD4meta* compiler, NCD4node* varortype, void** offsetp)
{
int ret = NC_NOERR;
void* offset;
d4size_t i;
d4size_t dimproduct;
NCD4node* type;
if(varortype->sort == NCD4_VAR) {
dimproduct = NCD4_dimproduct(varortype);
type = varortype->basetype;
} else {
dimproduct = 1;
type = varortype;
}
offset = *offsetp;
for(i=0;i<dimproduct;i++) {
if((ret=delimitStruct(compiler,type,&offset))) goto done;
}
*offsetp = offset;
done:
return THROW(ret);
}
static int
delimitStruct(NCD4meta* compiler, NCD4node* basetype, void** offsetp)
{
int ret = NC_NOERR;
int i;
void* offset;
offset = *offsetp;
/* The fields are associated with the basetype struct */
for(i=0;i<nclistlength(basetype->vars);i++) {
NCD4node* field = (NCD4node*)nclistget(basetype->vars,i);
switch (field->subsort) {
default:
if((ret=delimitAtomicVar(compiler,field,&offset))) goto done;
break;
case NC_STRUCT: /* recurse */
if((ret=delimitStructArray(compiler,field,&offset))) goto done;
break;
case NC_SEQ:
if((ret=delimitSeqArray(compiler,field,&offset))) goto done;
break;
}
}
*offsetp = offset;
done:
return THROW(ret);
}
static int
delimitSeqArray(NCD4meta* compiler, NCD4node* varortype, void** offsetp)
{
int ret = NC_NOERR;
void* offset;
d4size_t i;
d4size_t dimproduct;
NCD4node* type;
if(varortype->sort == NCD4_VAR) {
dimproduct = NCD4_dimproduct(varortype);
type = varortype->basetype;
} else {
dimproduct = 1;
type = varortype;
}
offset = *offsetp;
for(i=0;i<dimproduct;i++) {
if((ret=delimitSeq(compiler,type,&offset))) goto done;
}
*offsetp = offset;
done:
return THROW(ret);
}
static int
delimitSeq(NCD4meta* compiler, NCD4node* vlentype, void** offsetp)
{
int ret = NC_NOERR;
int i;
void* offset;
d4size_t recordcount;
NCD4node* recordtype;
/* The true type of the record is the basetype of the vlen,
where the vlen type is the basetype of the var
*/
assert(vlentype->subsort == NC_VLEN);
recordtype = vlentype->basetype;
offset = *offsetp;
/* Get he record count */
recordcount = GETCOUNTER(offset);
SKIPCOUNTER(offset);
if(compiler->swap) swapinline64(&recordcount);
for(i=0;i<recordcount;i++) {
switch (recordtype->subsort) {
case NC_STRUCT:
if((ret=delimitStructArray(compiler,recordtype,&offset))) goto done;
break;
case NC_SEQ:
if((ret=delimitSeqArray(compiler,recordtype,&offset))) goto done;
break;
default:
if((ret=delimitAtomicVar(compiler,recordtype,&offset))) goto done;
break;
}
}
*offsetp = offset;
done:
return THROW(ret);
}
/**************************************************/
/*
Walk the (toplevel) var's data to get to the count'th instance.
For efficiency, it can be supplied with a previous case.
Assumes it is called after byte swapping and offsetting.
Assumes that var is not fixed size.
*/
int
NCD4_moveto(NCD4meta* compiler, NCD4node* var, d4size_t count, void** offsetp)
{
int ret = NC_NOERR;
void* offset = NULL;
d4size_t startcount = 0;
NCD4node* basetype = NULL;
ASSERT((ISTOPLEVEL(var)));
offset = *offsetp;
startcount = 0;
basetype = var->basetype;
for(;startcount < count;startcount++) {
if((ret=skipInstance(compiler,basetype,&offset)))
goto done;
}
*offsetp = offset;
done:
return THROW(ret);
}
static int
skipInstance(NCD4meta* compiler, NCD4node* type, void** offsetp)
{
int ret = NC_NOERR;
void* offset = NULL;
offset = *offsetp;
switch (type->subsort) {
case NC_STRUCT:
if((ret=skipStructInstance(compiler,type,&offset))) goto done;
break;
case NC_SEQ:
if((ret=skipSeqInstance(compiler,type,&offset))) goto done;
break;
default:
if((ret=skipAtomicInstance(compiler,type,&offset))) goto done;
break;
}
*offsetp = offset;
done:
return THROW(ret);
}
/* Includes opaque and enum */
static int
skipAtomicInstance(NCD4meta* compiler, NCD4node* type, void** offsetp)
{
int ret = NC_NOERR;
void* offset;
d4size_t count;
int typesize;
offset = *offsetp;
switch (type->subsort) {
default: /* fixed size atomic type */
typesize = NCD4_typesize(type->meta.id);
offset = INCR(offset,typesize);
break;
case NC_STRING:
/* Get string count */
count = GETCOUNTER(offset);
SKIPCOUNTER(offset);
/* skip count bytes */
offset = INCR(offset,count);
break;
case NC_OPAQUE:
/* get count */
count = GETCOUNTER(offset);
SKIPCOUNTER(offset);
offset = INCR(offset,count);
break;
case NC_ENUM:
return skipAtomicInstance(compiler,type->basetype,offsetp);
}
*offsetp = offset;
return THROW(ret);
}
static int
skipStructInstance(NCD4meta* compiler, NCD4node* type, void** offsetp)
{
int ret = NC_NOERR;
d4size_t i,j;
void* offset;
offset = *offsetp;
/* Skip each field */
for(i=0;i<nclistlength(type->vars);i++) {
NCD4node* field = (NCD4node*)nclistget(type->vars,i);
NCD4node* ftype = field->basetype;
d4size_t dimproduct = NCD4_dimproduct(field);
for(j=0;j<dimproduct;j++) {
if((ret=skipInstance(compiler,ftype,&offset)))
goto done;
}
}
*offsetp = offset;
done:
return THROW(ret);
}
static int
skipSeqInstance(NCD4meta* compiler, NCD4node* vlentype, void** offsetp)
{
int ret = NC_NOERR;
d4size_t i;
void* offset;
NCD4node* structtype;
d4size_t recordcount;
offset = *offsetp;
structtype = vlentype->basetype;
ASSERT((structtype->subsort == NC_STRUCT));
/* Get record count */
recordcount = GETCOUNTER(offset);
SKIPCOUNTER(offset);
for(i=0;i<recordcount;i++) {
/* Skip a record instance */
if((ret=skipStructInstance(compiler,structtype,&offset)))
goto done;
}
*offsetp = offset;
done:
return THROW(ret);
}