swiplite.c converted to C++ API

swiplite.cpp

#include <SWI-cpp2.h>
#include <sqlite3.h>
#include <string.h>

static PL_option_t sqlite3_open_options[] = {
        PL_OPTION("mode", OPT_ATOM),
        PL_OPTION("memory", OPT_BOOL),
        PL_OPTION("mutex", OPT_ATOM),
        PL_OPTIONS_END
};

PREDICATE(pl_sqlite3_open, 3)
{
        auto db_name = A1, opts = A2, db_handle = A3;
        char *file;
        PlEx<bool>(db_name.get_chars(&file,
                        CVT_ATOM | CVT_STRING | CVT_LIST
                        | CVT_EXCEPTION
                        | BUF_STACK
                        | REP_UTF8));

        int flags = SQLITE_OPEN_EXRESCODE;

        PlAtom mode(PlAtom::null);
        int memory = false;
        PlAtom mutex(PlAtom::null);
        PlEx<bool>(PL_scan_options(opts.unwrap(), OPT_ALL,
                                   "sqlite3_open_options", sqlite3_open_options,
                                   mode.unwrap_as_ptr(), &memory, mutex.unwrap_as_ptr()));

        const char *m;

        if (mode.not_null() && (m = Plx_atom_nchars(mode.unwrap(), nullptr))) {
                if (0 == strcmp("read", m)) {
                        flags |= SQLITE_OPEN_READONLY;
                }
                else if (0 == strcmp("write", m)) {
                        flags |= SQLITE_OPEN_READWRITE;
                }
                else if (0 == strcmp("create", m)) {
                        flags |= SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
                }
                else throw PlDomainError("mode(read|write|create)", PlTerm_atom(mode));
        }
        else flags |= SQLITE_OPEN_READONLY;

        if (memory) flags |= SQLITE_OPEN_MEMORY;

        /* reusing m for mode as m for mutex */
        if (mutex.not_null() && (m = Plx_atom_nchars(mutex.unwrap(), nullptr))) {
                if (0 == strcmp("no", m)) {
                        flags |= SQLITE_OPEN_NOMUTEX;
                }
                else if (0 == strcmp("full", m)) {
                        flags |= SQLITE_OPEN_FULLMUTEX;
                }
                else throw PlDomainError("mutex(no|full)", PlTerm_atom(mutex));
        }

        sqlite3 *db;
        if (SQLITE_OK != sqlite3_open_v2(file, &db, flags, NULL)) {
          throw PlPermissionError("open", sqlite3_errmsg(db), db_name);
        }
        else return db_handle.unify_pointer(db);
}

PREDICATE(pl_sqlite3_close, 1)
{
        auto db_handle = A1;
        sqlite3 *db;
        db_handle.get_pointer_ex((void **)&db);

        if (SQLITE_OK != sqlite3_close_v2(db)) {
                throw PlResourceError(sqlite3_errmsg(db));
        }
        return true;
}