Replace Python numerical kernels with native C execution

native/runtime/main.c

@@ -0,0 +1,119 @@
+#include "runtime.h"
+#include <sundials/sundials_config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+static void json_string(FILE *f, const char *value) {
+    fputc('"',f);
+    for (const unsigned char *p=(const unsigned char *)value; *p; p++) {
+        if (*p=='"' || *p=='\\') { fputc('\\',f); fputc(*p,f); }
+        else if (*p<32) fprintf(f,"\\u%04x",*p);
+        else fputc(*p,f);
+    }
+    fputc('"',f);
+}
+static void vector(FILE *f, const double *value, int count) {
+    fputc('[',f);
+    for (int i=0;i<count;i++) fprintf(f,"%s%.17g",i?",":"",value[i]);
+    fputc(']',f);
+}
+static int probe(void) {
+    double t, y[NSTATES], dy[NSTATES], w[NOUTPUTS];
+    while (scanf("%lf",&t)==1) {
+        for (int i=0;i<NSTATES;i++) if (scanf("%lf",&y[i])!=1) return 64;
+        int ok=model_eval(t,y,dy,w);
+        printf("{\"success\":%s",ok?"true":"false");
+        if (ok) { printf(",\"rhs\":"); vector(stdout,dy,NSTATES); printf(",\"outputs\":"); vector(stdout,w,NOUTPUTS); }
+        printf("}\n");
+    }
+    return 0;
+}
+static int write_result(NativeRun *r, const char *path) {
+    double dy[NSTATES], final[NOUTPUTS];
+    int final_ok=model_eval(r->final_time,r->final_state,dy,final);
+    size_t length=r->count*NOUTPUTS;
+    if (length>268435456u/sizeof(double)) return 0;
+    double *values=length?malloc(length*sizeof(double)):NULL;
+    if (length && !values) return 0;
+    for (size_t i=0;i<r->count;i++) {
+        if (!model_eval(r->times[i],r->states+i*NSTATES,dy,values+i*NOUTPUTS)) {
+            free(values); return 0;
+        }
+    }
+    FILE *f=fopen(path,"wb"); if (!f) { free(values); return 0; }
+    fprintf(f,"{\"success\":%s,\"status\":",!r->status?"true":"false");
+    json_string(f,r->status==0?"completed":r->status==1?"cancelled":"failed");
+    fprintf(f,",\"message\":"); json_string(f,r->message);
+    fprintf(f,",\"backend\":\"native-c\",\"method\":\"%s\",\"solver\":\"%s\",\"sundialsVersion\":\"%s\","
+              "\"simulatedUntil\":%.17g,\"solveSeconds\":%.17g,\"solveCpuSeconds\":%.17g,"
+              "\"nfev\":%lu,\"acceptedSteps\":%lu,\"rejectedSteps\":%lu,\"stateTransitions\":%lu,"
+              "\"solverStarts\":%lu,\"njev\":%lu,\"nlu\":%lu,\"maxAcceptedStep\":%.17g,\"series\":{",
+            r->options.bdf?"BDF":"RK45",r->options.bdf?"CVODE":"Dormand-Prince 5(4)",SUNDIALS_VERSION,
+            r->final_time,r->solve_seconds,r->solve_cpu_seconds,r->nfev,r->accepted,r->rejected,
+            r->events,r->starts,r->njev,r->nlu,r->max_accepted_step);
+    if (r->count) {
+        fprintf(f,"\"time\":[");
+        for (size_t i=0;i<r->count;i++) fprintf(f,"%s%.17g",i?",":"",r->times[i]);
+        fputc(']',f);
+        for (int j=0;j<NOUTPUTS;j++) {
+            fputc(',',f); json_string(f,model_output_keys[j]); fprintf(f,":[");
+            for (size_t i=0;i<r->count;i++) fprintf(f,"%s%.17g",i?",":"",values[i*NOUTPUTS+j]);
+            fputc(']',f);
+        }
+    }
+    fprintf(f,"},\"final\":{");
+    if (final_ok) for (int j=0;j<NOUTPUTS;j++) {
+        if (j) fputc(',',f);
+        json_string(f,model_output_keys[j]); fprintf(f,":%.17g",final[j]);
+    }
+    fprintf(f,"},\"finalState\":"); vector(f,r->final_state,NSTATES);
+    fprintf(f,"}\n"); int ok=!ferror(f); if (fclose(f)) ok=0;
+    free(values); return ok;
+}
+
+int main(int argc, char **argv) {
+    NativeRun r={0};
+    r.options=(NativeOptions){0,10,.02,.001,1e-6,300,0,1,NULL};
+    const char *output="result.json";
+    for (int i=1;i<argc;i++) {
+        const char *arg=argv[i];
+        if (!strcmp(arg,"--probe")) return probe();
+        if (!strcmp(arg,"--init")) {
+            double y[NSTATES]; if (!model_init(y)) return 2;
+            vector(stdout,y,NSTATES); fputc('\n',stdout); return 0;
+        }
+        if (!strcmp(arg,"--solve-only")) { r.options.record_samples=0; continue; }
+        if (i+1==argc) return 64;
+        const char *value=argv[++i];
+        if (!strcmp(arg,"--output")) output=value;
+        else if (!strcmp(arg,"--cancel-file")) r.options.cancel_path=value;
+        else if (!strcmp(arg,"--method")) {
+            if (strcmp(value,"RK45") && strcmp(value,"BDF")) return 64;
+            r.options.bdf=!strcmp(value,"BDF");
+        } else {
+            char *end; double number=strtod(value,&end);
+            if (*end || !isfinite(number)) return 64;
+            if (!strcmp(arg,"--start")) r.options.start=number;
+            else if (!strcmp(arg,"--stop")) r.options.stop=number;
+            else if (!strcmp(arg,"--sample-step")) r.options.sample_step=number;
+            else if (!strcmp(arg,"--max-step")) r.options.max_step=number;
+            else if (!strcmp(arg,"--rtol")) r.options.rtol=number;
+            else if (!strcmp(arg,"--timeout")) r.options.timeout=number;
+            else return 64;
+        }
+    }
+    if (!(r.options.stop>r.options.start && r.options.sample_step>0 && r.options.max_step>0 &&
+          r.options.rtol>0 && r.options.timeout>0) ||
+        r.options.start+r.options.sample_step==r.options.start ||
+        r.options.start+r.options.max_step==r.options.start ||
+        !isfinite(r.options.stop-r.options.start)) return 64;
+    if (r.options.record_samples &&
+        ((r.options.stop-r.options.start)/r.options.sample_step>1000000 ||
+         ((r.options.stop-r.options.start)/r.options.sample_step+1024)*(NSTATES+NOUTPUTS)*sizeof(double)>268435456)) return 64;
+    native_solve(&r);
+    int saved=write_result(&r,output);
+    int code=saved?(r.status==2?2:0):3;
+    native_run_free(&r); return code;
+}