Runtime Library

prophys-runtime evaluates exported surrogates without Python. It is a small shared library with a C interface that runs the same network interpreter and tree kernels as the Python package, so an exported surrogate gives the same bits in a control system, a simulator plug in or an edge device as in prophys.

Exporting

A model package of format 1.2 carries every surrogate of the model (SurrogateExport). to_bytes() writes the binary blob the runtime loads. Networks with compiled physics layers export as one program, so the physics runs in the runtime too. A physics layer that did not compile stops the export with NN112 and its reason.

pkg = compiled.export()
exp = pkg.surrogate("power")
open("power.prsb", "wb").write(exp.to_bytes())
exp.verify()          # recompute the parity checksum in Python

Each export records its probe inputs and an FNV 1a checksum of the outputs at those inputs. The runtime recomputes it on demand, which proves that the deployed binary reproduces the exported surrogate exactly.

C interface

typedef struct Surrogate Surrogate;

Surrogate *prophys_runtime_load(const uint8_t *blob, size_t len);
void       prophys_runtime_free(Surrogate *s);
size_t     prophys_runtime_inputs(const Surrogate *s);
size_t     prophys_runtime_outputs(const Surrogate *s);
size_t     prophys_runtime_members(const Surrogate *s);
/* out has members * rows * outputs doubles */
int        prophys_runtime_eval(const Surrogate *s, const double *x, size_t rows, double *out);
int        prophys_runtime_verify(const Surrogate *s);   /* 1 reproduced, 0 not, -1 error */
size_t     prophys_runtime_last_error(char *buf, size_t len);

The runtime is supplied as a prebuilt shared library with this C header for the target platform; contact RhineQC GmbH (see Imprint / Impressum) for the build matching your system. The same free tier as the Python package applies, and a valid license in PROPHYS_LICENSE unlocks larger surrogates.

Blob format

All numbers are little endian. The header holds the magic PRSB, the format version, the kind (1 network, 2 trees), the number of members, the description length, the parameters per member, the inputs, the outputs and the link (1 logistic). The network program or tree spec follows as doubles, then the parameters of every member, the number of probe rows, the probe inputs and the sixteen character checksum.