ardupilot/libraries/SITL/picojson.cpp

63 lines
1.5 KiB
C++
Raw Normal View History

#include "SIM_Aircraft.h"
#include <AP_Filesystem/AP_Filesystem.h>
#if USE_PICOJSON
#include "picojson.h"
/*
load JSON file, returning a picojson object or nullptr on failure
*/
void *load_json(const char *filename)
{
struct stat st;
if (AP::FS().stat(filename, &st) != 0) {
::printf("No such json file %s\n", filename);
return nullptr;
}
int fd = AP::FS().open(filename, O_RDONLY);
if (fd == -1) {
::printf("failed to open json %s\n", filename);
return nullptr;
}
char buf[st.st_size+1];
memset(buf, '\0', sizeof(buf));
if (AP::FS().read(fd, buf, st.st_size) != st.st_size) {
::printf("failed to read json %s\n", filename);
AP::FS().close(fd);
return nullptr;
}
AP::FS().close(fd);
char *start = strchr(buf, '{');
if (!start) {
::printf("Invalid json %s", filename);
return nullptr;
}
/*
remove comments, as not allowed by the parser
*/
for (char *p = strchr(start,'#'); p; p=strchr(p+1, '#')) {
// clear to end of line
do {
*p++ = ' ';
} while (*p != '\n' && *p != '\r' && *p);
}
picojson::value *obj = new picojson::value;
if (obj == nullptr) {
::printf("Invalid allocate json for %s", filename);
return nullptr;
}
std::string err = picojson::parse(*obj, start);
if (!err.empty()) {
::printf("parse failed for json %s", filename);
delete obj;
return nullptr;
}
return obj;
}
#endif // USE_PICOJSON