Files
pvData/src/json/parsehelper.cpp
2019-09-23 10:14:55 -07:00

119 lines
2.9 KiB
C++

/*
* Copyright information and license terms for this software can be
* found in the file LICENSE that is included with the distribution
*/
#include <stdexcept>
#include <sstream>
#define epicsExportSharedSymbols
#include <pv/pvdVersion.h>
#include "pv/json.h"
namespace {
void check_trailing(const std::string& line)
{
size_t idx = line.find_first_not_of(" \t\n\r");
if(idx==line.npos) return;
// TODO: detect the end of potentially multi-line comments...
// for now trailing comments not allowed
throw std::runtime_error("Trailing junk");
}
} // namespace
namespace epics{namespace pvData{
bool yajl_parse_helper(std::istream& src,
yajl_handle handle)
{
unsigned linenum=0;
#ifndef EPICS_YAJL_VERSION
bool done = false;
#endif
std::string line;
while(std::getline(src, line)) {
linenum++;
#ifndef EPICS_YAJL_VERSION
if(done) {
check_trailing(line);
continue;
}
#endif
yajl_status sts = yajl_parse(handle, (const unsigned char*)line.c_str(), line.size());
switch(sts) {
case yajl_status_ok: {
size_t consumed = yajl_get_bytes_consumed(handle);
if(consumed<line.size()) {
check_trailing(line.substr(consumed));
}
#ifndef EPICS_YAJL_VERSION
done = true;
#endif
break;
}
case yajl_status_client_canceled:
return false;
#ifndef EPICS_YAJL_VERSION
case yajl_status_insufficient_data:
// continue with next line
break;
#endif
case yajl_status_error:
{
std::ostringstream msg;
unsigned char *raw = yajl_get_error(handle, 1, (const unsigned char*)line.c_str(), line.size());
if(!raw) {
msg<<"Unknown error on line "<<linenum;
} else {
try {
msg<<"Error on line "<<linenum<<" : "<<(const char*)raw;
}catch(...){
yajl_free_error(handle, raw);
throw;
}
yajl_free_error(handle, raw);
}
throw std::runtime_error(msg.str());
}
}
}
if(!src.eof() || src.bad()) {
std::ostringstream msg;
msg<<"I/O error after line "<<linenum;
throw std::runtime_error(msg.str());
#ifndef EPICS_YAJL_VERSION
} else if(!done) {
switch(yajl_parse_complete(handle)) {
#else
} else {
switch(yajl_complete_parse(handle)) {
#endif
case yajl_status_ok:
break;
case yajl_status_client_canceled:
return false;
#ifndef EPICS_YAJL_VERSION
case yajl_status_insufficient_data:
throw std::runtime_error("unexpected end of input");
#endif
case yajl_status_error:
throw std::runtime_error("Error while completing parsing");
}
}
return true;
}
}} // namespace epics::pvData