Allowing adding many clauses

python/src/pyapproxmc.cpp

@@ -208,6 +208,138 @@ static PyObject* add_clause(Counter *self, PyObject *args, PyObject *kwds)
 
 }
 
+template <typename T>
+static int _add_clauses_from_array(Counter *self, const size_t array_length, const T *array)
+{
+    if (array_length == 0) {
+        return 1;
+    }
+    if (array[array_length - 1] != 0) {
+        PyErr_SetString(PyExc_ValueError, "last clause not terminated by zero");
+        return 0;
+    }
+    size_t k = 0;
+    long val = 0;
+    std::vector<CMSat::Lit>& lits = self->tmp_cl_lits;
+    for (val = (long) array[k]; k < array_length; val = (long) array[++k]) {
+        lits.clear();
+        long int max_var = 0;
+        for (; k < array_length && val != 0; val = (long) array[++k]) {
+            long var;
+            bool sign;
+            if (val > std::numeric_limits<int>::max()/2
+                || val < std::numeric_limits<int>::min()/2
+            ) {
+                PyErr_Format(PyExc_ValueError, "integer %ld is too small or too large", val);
+                return 0;
+            }
+
+            sign = (val < 0);
+            var = std::abs(val) - 1;
+            max_var = std::max(var, max_var);
+
+            lits.push_back(CMSat::Lit(var, sign));
+        }
+        if (!lits.empty()) {
+            if (max_var >= (long int)self->appmc->nVars()) {
+                self->appmc->new_vars(max_var-(long int)self->appmc->nVars()+1);
+            }
+            self->appmc->add_clause(lits);
+        }
+    }
+    return 1;
+}
+
+static int _add_clauses_from_buffer(Counter *self, Py_buffer *view)
+{
+    if (view->ndim != 1) {
+        PyErr_Format(PyExc_ValueError, "invalid clause array: expected 1-D array, got %d-D", view->ndim);
+        return 0;
+    }
+    if (strcmp(view->format, "i") != 0 && strcmp(view->format, "l") != 0 && strcmp(view->format, "q") != 0) {
+        PyErr_Format(PyExc_ValueError, "invalid clause array: invalid format '%s'", view->format);
+        return 0;
+    }
+
+    void * array_address = view->buf;
+    size_t itemsize = view->itemsize;
+    size_t array_length = view->len / itemsize;
+
+    if (itemsize == sizeof(int)) {
+        return _add_clauses_from_array(self, array_length, (const int *) array_address);
+    }
+    if (itemsize == sizeof(long)) {
+        return _add_clauses_from_array(self, array_length, (const long *) array_address);
+    }
+    if (itemsize == sizeof(long long)) {
+        return _add_clauses_from_array(self, array_length, (const long long *) array_address);
+    }
+    PyErr_Format(PyExc_ValueError, "invalid clause array: invalid itemsize '%ld'", itemsize);
+    return 0;
+}
+
+PyDoc_STRVAR(add_clauses_doc,
+"add_clauses(clauses)\n\
+Add iterable of clauses to the solver.\n\
+\n\
+:param clauses: List of clauses. Each clause contains literals (ints)\n\
+    Alternatively, this can be a flat array.array or other contiguous\n\
+    buffer (format 'i', 'l', or 'q') of zero separated and terminated\n\
+    clauses of literals (ints).\n\
+:type clauses: <list> or <array.array>\n\
+:return: None\n\
+:rtype: <None>"
+);
+
+static PyObject* add_clauses(Counter *self, PyObject *args, PyObject *kwds)
+{
+    static char const* kwlist[] = {"clauses", NULL};
+    PyObject *clauses;
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O", const_cast<char**>(kwlist), &clauses)) {
+        return NULL;
+    }
+
+    if (PyObject_CheckBuffer(clauses)) {
+        Py_buffer view;
+        memset(&view, 0, sizeof(view));
+        if (PyObject_GetBuffer(clauses, &view, PyBUF_CONTIG_RO | PyBUF_FORMAT) != 0) {
+            return NULL;
+        }
+
+        int ret = _add_clauses_from_buffer(self, &view);
+        PyBuffer_Release(&view);
+
+        if (ret == 0 || PyErr_Occurred()) {
+            return 0;
+        }
+        Py_INCREF(Py_None);
+        return Py_None;
+    }
+
+    PyObject *iterator = PyObject_GetIter(clauses);
+    if (iterator == NULL) {
+        PyErr_SetString(PyExc_TypeError, "iterable object expected");
+        return NULL;
+    }
+
+    PyObject *clause;
+    while ((clause = PyIter_Next(iterator)) != NULL) {
+        _add_clause(self, clause);
+        /* release reference when done */
+        Py_DECREF(clause);
+    }
+
+    /* release reference when done */
+    Py_DECREF(iterator);
+    if (PyErr_Occurred()) {
+        return NULL;
+    }
+
+    Py_INCREF(Py_None);
+    return Py_None;
+}
+
+
 static void get_cnf_from_arjun(Counter* self)
 {
     const uint32_t orig_num_vars = self->arjun->get_orig_num_vars();
@@ -357,6 +489,7 @@ static PyObject* count(Counter *self, PyObject *args, PyObject *kwds)
 static PyMethodDef Counter_methods[] = {
     {"count",     (PyCFunction) count,       METH_VARARGS | METH_KEYWORDS, count_doc},
     {"add_clause",(PyCFunction) add_clause,  METH_VARARGS | METH_KEYWORDS, add_clause_doc},
+    {"add_clauses", (PyCFunction) add_clauses,  METH_VARARGS | METH_KEYWORDS, add_clauses_doc},
     {NULL, NULL}  // Sentinel
 };