+static QObject *parser_context_pop_token(JSONParserContext *ctxt)
+{
+ QObject *token;
+ g_assert(ctxt->tokens.pos < ctxt->tokens.count);
+ token = ctxt->tokens.buf[ctxt->tokens.pos];
+ ctxt->tokens.pos++;
+ return token;
+}
+
+/* Note: parser_context_{peek|pop}_token do not increment the
+ * token object's refcount. In both cases the references will continue
+ * to be tracked and cleaned up in parser_context_free(), so do not
+ * attempt to free the token object.
+ */
+static QObject *parser_context_peek_token(JSONParserContext *ctxt)
+{
+ QObject *token;
+ g_assert(ctxt->tokens.pos < ctxt->tokens.count);
+ token = ctxt->tokens.buf[ctxt->tokens.pos];
+ return token;
+}
+
+static JSONParserContext parser_context_save(JSONParserContext *ctxt)
+{
+ JSONParserContext saved_ctxt = {0};
+ saved_ctxt.tokens.pos = ctxt->tokens.pos;
+ saved_ctxt.tokens.count = ctxt->tokens.count;
+ saved_ctxt.tokens.buf = ctxt->tokens.buf;
+ return saved_ctxt;
+}
+
+static void parser_context_restore(JSONParserContext *ctxt,
+ JSONParserContext saved_ctxt)
+{
+ ctxt->tokens.pos = saved_ctxt.tokens.pos;
+ ctxt->tokens.count = saved_ctxt.tokens.count;
+ ctxt->tokens.buf = saved_ctxt.tokens.buf;
+}
+
+static void tokens_append_from_iter(QObject *obj, void *opaque)
+{
+ JSONParserContext *ctxt = opaque;
+ g_assert(ctxt->tokens.pos < ctxt->tokens.count);
+ ctxt->tokens.buf[ctxt->tokens.pos++] = obj;
+ qobject_incref(obj);
+}
+
+static JSONParserContext *parser_context_new(QList *tokens)
+{
+ JSONParserContext *ctxt;
+ size_t count;
+
+ if (!tokens) {
+ return NULL;
+ }
+
+ count = qlist_size(tokens);
+ if (count == 0) {
+ return NULL;
+ }
+
+ ctxt = g_malloc0(sizeof(JSONParserContext));
+ ctxt->tokens.pos = 0;
+ ctxt->tokens.count = count;
+ ctxt->tokens.buf = g_malloc(count * sizeof(QObject *));
+ qlist_iter(tokens, tokens_append_from_iter, ctxt);
+ ctxt->tokens.pos = 0;
+
+ return ctxt;
+}
+
+/* to support error propagation, ctxt->err must be freed separately */
+static void parser_context_free(JSONParserContext *ctxt)
+{
+ int i;
+ if (ctxt) {
+ for (i = 0; i < ctxt->tokens.count; i++) {
+ qobject_decref(ctxt->tokens.buf[i]);
+ }
+ g_free(ctxt->tokens.buf);
+ g_free(ctxt);
+ }
+}
+