docs.sheetjs.com/docz/static/hermes/sheetjs-hermesw.cpp

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2023-09-28 17:13:57 +00:00
/* sheetjs-hermesw.cpp Copyright (c) SheetJS LLC. */
#include <iostream>
#include "hermes/hermes.h"
static char *read_file(const char *filename, size_t *sz) {
FILE *f = fopen(filename, "rb");
if(!f) return NULL;
long fsize; { fseek(f, 0, SEEK_END); fsize = ftell(f); fseek(f, 0, SEEK_SET); }
char *buf = (char *)malloc(fsize * sizeof(char));
*sz = fread((void *) buf, 1, fsize, f);
fclose(f);
return buf;
}
/* Hermes-Windows requires the null terminator */
static char *read_file_null(const char *filename, size_t *sz) {
FILE *f = fopen(filename, "rb");
if(!f) return NULL;
long fsize; { fseek(f, 0, SEEK_END); fsize = ftell(f) + 1; fseek(f, 0, SEEK_SET); }
char *buf = (char *)malloc(fsize * sizeof(char));
*sz = fread((void *) buf, 1, fsize, f);
buf[fsize - 1] = 0;
fclose(f);
return buf;
}
/* Unfortunately the library provides no C-friendly Buffer classes */
class CBuffer : public facebook::jsi::Buffer {
public:
CBuffer(const uint8_t *data, size_t size) : buf(data), sz(size) {}
size_t size() const override { return sz; }
const uint8_t *data() const override { return buf; }
private:
const uint8_t *buf;
size_t sz;
};
/* ArrayBuffer constructor expects MutableBuffer*/
class CMutableBuffer : public facebook::jsi::MutableBuffer {
public:
CMutableBuffer(uint8_t *data, size_t size) : buf(data), sz(size) {}
size_t size() const override { return sz; }
uint8_t *data() override { return buf; }
private:
uint8_t *buf;
size_t sz;
};
int main(int argc, char **argv) {
std::unique_ptr<facebook::jsi::Runtime> rt(facebook::hermes::makeHermesRuntime());
/* setup */
try {
auto src = std::make_shared<facebook::jsi::StringBuffer>(
"var global = (function(){ return this; }).call(null);"
"var console = { log: function(x) { print(x); } };"
);
auto js = rt->prepareJavaScript(src, std::string("<eval>"));
rt->evaluatePreparedJavaScript(js);
} catch (const facebook::jsi::JSIException &e) {
std::cerr << "JavaScript terminated via uncaught exception: " << e.what() << '\n';
return 1;
}
/* load SheetJS library */
try {
size_t sz; char *xlsx_full_min_js = read_file_null("xlsx.full.min.js", &sz);
auto src = std::make_shared<CBuffer>(CBuffer((uint8_t *)xlsx_full_min_js, sz));
auto js = rt->prepareJavaScript(src, std::string("xlsx.full.min.js"));
rt->evaluatePreparedJavaScript(js);
} catch (const facebook::jsi::JSIException &e) {
std::cerr << "JavaScript terminated via uncaught exception: " << e.what() << '\n';
return 1;
}
/* print library version */
try {
auto src = std::make_shared<facebook::jsi::StringBuffer>(
"console.log('SheetJS Library Version: ' + XLSX.version)"
);
auto js = rt->prepareJavaScript(src, std::string("<eval>"));
rt->evaluatePreparedJavaScript(js);
} catch (const facebook::jsi::JSIException &e) {
std::cerr << "JavaScript terminated via uncaught exception: " << e.what() << '\n';
return 1;
}
try {
/* load payload as ArrayBuffer */
size_t sz; char *data = read_file(argv[1], &sz);
auto payload = std::make_shared<CMutableBuffer>(CMutableBuffer((uint8_t *)data, sz));
auto ab = facebook::jsi::ArrayBuffer(*rt, payload);
/* define stub function to read and convert first sheet to CSV */
auto src = std::make_shared<facebook::jsi::StringBuffer>(
"(function(buf) {"
"var wb = XLSX.read(buf);"
"return XLSX.utils.sheet_to_csv(wb.Sheets[wb.SheetNames[0]]);"
"})"
);
auto js = rt->prepareJavaScript(src, std::string("<eval>"));
auto func = rt->evaluatePreparedJavaScript(js);
/* call stub function and capture result */
auto csv = func.asObject(*rt).asFunction(*rt).call(*rt, ab);
/* interpret as utf8 and print to stdout */
std::string str = csv.getString(*rt).utf8(*rt);
std::cout << str << std::endl;
} catch (const facebook::jsi::JSIException &e) {
std::cerr << "JavaScript terminated via uncaught exception: " << e.what() << std::endl;
return 1;
}
return 0;
}