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parseJSON() track modified fields

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This commit is contained in:
Michael Davidsaver
2017-09-07 11:53:54 -05:00
parent 787af8de18
commit 111f7bd15e
3 changed files with 79 additions and 31 deletions
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75
src/json/parseinto.cpp
View File

@@ -10,6 +10,7 @@
#include <pv/pvdVersion.h>
#include <pv/pvData.h>
#include <pv/valueBuilder.h>
#include <pv/bitSet.h>
#if EPICS_VERSION_INT>=VERSION_INT(3,15,0,1)
@@ -22,18 +23,26 @@ struct context {
std::string msg;
typedef std::vector<pvd::PVFieldPtr> stack_t;
struct frame {
pvd::PVFieldPtr fld;
pvd::BitSet *assigned;
frame(const pvd::PVFieldPtr& fld, pvd::BitSet *assigned)
:fld(fld), assigned(assigned)
{}
};
typedef std::vector<frame> stack_t;
stack_t stack;
context(const pvd::PVFieldPtr& root)
context(const pvd::PVFieldPtr& root, pvd::BitSet *assigned)
{
stack.push_back(root);
stack.push_back(frame(root, assigned));
}
};
#define TRY context *self = (context*)ctx; assert(!self->stack.empty()); try
#define CATCH() catch(std::exception& e) { self->msg = e.what(); return 0; }
#define CATCH() catch(std::exception& e) { if(self->msg.empty()) self->msg = e.what(); return 0; }
int jtree_null(void * ctx)
{
@@ -46,18 +55,20 @@ int jtree_null(void * ctx)
template<typename PVScalarT, typename PVArrayT>
void valueAssign(context *self, typename PVScalarT::value_type val)
{
pvd::Type type(self->stack.back()->getField()->getType());
assert(!self->stack.empty());
context::frame& back = self->stack.back();
pvd::Type type(back.fld->getField()->getType());
if(type==pvd::scalar) {
pvd::PVScalar* fld(static_cast<pvd::PVScalar*>(self->stack.back().get()));
pvd::PVScalar* fld(static_cast<pvd::PVScalar*>(back.fld.get()));
fld->putFrom(val);
if(back.assigned)
back.assigned->set(fld->getFieldOffset());
self->stack.pop_back();
// structure back at the top of the stack
// structure at the top of the stack
} else if(type==pvd::scalarArray) {
pvd::PVScalarArray* fld(static_cast<pvd::PVScalarArray*>(self->stack.back().get()));
PVArrayT* arrfld(dynamic_cast<PVArrayT*>(fld));
PVArrayT* arrfld(dynamic_cast<PVArrayT*>(back.fld.get()));
if(!arrfld)
throw std::invalid_argument("wrong type for scalar array");
@@ -73,7 +84,7 @@ void valueAssign(context *self, typename PVScalarT::value_type val)
// leave array field at top of stack
} else if(type==pvd::union_) {
pvd::PVUnion* fld(static_cast<pvd::PVUnion*>(self->stack.back().get()));
pvd::PVUnion* fld(static_cast<pvd::PVUnion*>(back.fld.get()));
pvd::UnionConstPtr utype(fld->getUnion());
if(utype->isVariant()) {
@@ -109,6 +120,8 @@ void valueAssign(context *self, typename PVScalarT::value_type val)
if(!assigned)
throw std::runtime_error("Unable to select union member");
}
if(back.assigned)
back.assigned->set(fld->getFieldOffset());
self->stack.pop_back();
// structure back at the top of the stack
@@ -154,22 +167,24 @@ int jtree_string(void * ctx, const unsigned char * stringVal,
int jtree_start_map(void * ctx)
{
TRY {
pvd::PVFieldPtr& back(self->stack.back());
pvd::Type type = back->getField()->getType();
assert(!self->stack.empty());
context::frame& back = self->stack.back();
pvd::Type type = back.fld->getField()->getType();
if(type==pvd::structure) {
// will fill in
} else if(type==pvd::structureArray) {
// starting new element in structure array
pvd::PVStructureArrayPtr sarr(std::tr1::static_pointer_cast<pvd::PVStructureArray>(back));
pvd::PVStructureArray* sarr(static_cast<pvd::PVStructureArray*>(back.fld.get()));
pvd::PVStructurePtr elem(pvd::getPVDataCreate()->createPVStructure(sarr->getStructureArray()->getStructure()));
self->stack.push_back(elem);
self->stack.push_back(context::frame(elem, 0));
} else {
throw std::runtime_error("Can't map (sub)structure");
}
assert(self->stack.back()->getField()->getType()==pvd::structure);
assert(self->stack.back().fld->getField()->getType()==pvd::structure);
return 1;
}CATCH()
}
@@ -178,13 +193,14 @@ int jtree_map_key(void * ctx, const unsigned char * key,
unsigned int stringLen)
{
TRY {
assert(!self->stack.empty());
std::string name((const char*)key, stringLen);
// start_map() ensures we have a structure at the top of the stack
pvd::PVStructure *fld = static_cast<pvd::PVStructure*>(self->stack.back().get());
pvd::PVStructure *fld = static_cast<pvd::PVStructure*>(self->stack.back().fld.get());
try {
self->stack.push_back(fld->getSubFieldT(name));
self->stack.push_back(context::frame(fld->getSubFieldT(name), self->stack.back().assigned));
}catch(std::runtime_error& e){
std::ostringstream strm;
strm<<"At "<<fld->getFullName()<<" : "<<e.what()<<"\n";
@@ -198,21 +214,22 @@ int jtree_map_key(void * ctx, const unsigned char * key,
int jtree_end_map(void * ctx)
{
TRY {
assert(self->stack.back()->getField()->getType()==pvd::structure);
assert(!self->stack.empty());
assert(self->stack.back().fld->getField()->getType()==pvd::structure);
pvd::PVStructurePtr elem(std::tr1::static_pointer_cast<pvd::PVStructure>(self->stack.back()));
context::frame elem(self->stack.back());
self->stack.pop_back();
if(!self->stack.empty() && self->stack.back()->getField()->getType()==pvd::structureArray) {
if(!self->stack.empty() && self->stack.back().fld->getField()->getType()==pvd::structureArray) {
// append element to struct array
pvd::PVStructureArray *sarr = static_cast<pvd::PVStructureArray*>(self->stack.back().get());
pvd::PVStructureArray *sarr = static_cast<pvd::PVStructureArray*>(self->stack.back().fld.get());
pvd::PVStructureArray::const_svector cval;
sarr->swap(cval);
pvd::PVStructureArray::svector val(pvd::thaw(cval));
val.push_back(elem);
val.push_back(std::tr1::static_pointer_cast<pvd::PVStructure>(elem.fld));
sarr->replace(pvd::freeze(val));
}
@@ -224,7 +241,8 @@ int jtree_end_map(void * ctx)
int jtree_start_array(void * ctx)
{
TRY {
pvd::PVFieldPtr& back(self->stack.back());
assert(!self->stack.empty());
pvd::PVFieldPtr& back(self->stack.back().fld);
pvd::Type type = back->getField()->getType();
if(type!=pvd::structureArray && type!=pvd::scalarArray)
throw std::runtime_error("Can't assign array");
@@ -235,6 +253,10 @@ int jtree_start_array(void * ctx)
int jtree_end_array(void * ctx)
{
TRY {
assert(!self->stack.empty());
if(self->stack.back().assigned)
self->stack.back().assigned->set(self->stack.back().fld->getFieldOffset());
self->stack.pop_back();
return 1;
}CATCH()
@@ -274,14 +296,15 @@ namespace epics{namespace pvData{
epicsShareFunc
void parseJSON(std::istream& strm,
const PVField::shared_pointer& dest)
const PVField::shared_pointer& dest,
BitSet *assigned)
{
yajl_parser_config conf;
memset(&conf, 0, sizeof(conf));
conf.allowComments = 1;
conf.checkUTF8 = 1;
context ctxt(dest);
context ctxt(dest, assigned);
handler handle(yajl_alloc(&jtree_cbs, &conf, NULL, &ctxt));

12
src/json/pv/json.h
View File

@@ -31,6 +31,8 @@
namespace epics{namespace pvData{
class BitSet;
/** @defgroup pvjson JSON print/parse
*
* Printing PVField as JSON and parsing JSON into PVField.
@@ -73,12 +75,18 @@ PVStructure::shared_pointer parseJSON(std::istream& strm);
*
* Restrictions:
*
* - array of union not permitted
* - array of union not supported
* - Only scalar value assigned to union
*
* @param strm Read JSON text from stream
* @param dest Store in fields of this structure
* @param assigned Which fields of _dest_ were assigned. (Optional)
* @throws std::runtime_error on failure. dest and assigned may be modified.
*/
epicsShareFunc
void parseJSON(std::istream& strm,
const PVField::shared_pointer& dest);
const PVField::shared_pointer& dest,
BitSet *assigned=0);
/** Wrapper around yajl_parse()