Am 18.05.2021 um 17:40 hat Paolo Bonzini geschrieben:
> Change the parser to put the values into a QDict and pass them
> to a callback. qemu_config_parse's QemuOpts creation is
> itself turned into a callback function.
>
> This is useful for -readconfig to support keyval-based options;
> getting a QDict from the parser removes a roundtrip from
> QDict to QemuOpts and then back to QDict.
>
> Cc: Kevin Wolf <kw...@redhat.com>
> Cc: Markus Armbruster <arm...@redhat.com>
> Cc: qemu-sta...@nongnu.org
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> diff --git a/util/qemu-config.c b/util/qemu-config.c
> index 34974c4b47..7bca153c6c 100644
> --- a/util/qemu-config.c
> +++ b/util/qemu-config.c
> @@ -351,19 +351,19 @@ void qemu_config_write(FILE *fp)
> }
>
> /* Returns number of config groups on success, -errno on error */
> -int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname,
> Error **errp)
> +static int qemu_config_foreach(FILE *fp, QEMUConfigCB *cb, void *opaque,
> + const char *fname, Error **errp)
> {
> - char line[1024], group[64], id[64], arg[64], value[1024];
> + char line[1024], prev_group[64], group[64], arg[64], value[1024];
> Location loc;
> - QemuOptsList *list = NULL;
> Error *local_err = NULL;
> - QemuOpts *opts = NULL;
> + QDict *qdict = NULL;
> int res = -EINVAL, lno = 0;
> int count = 0;
>
> loc_push_none(&loc);
> while (fgets(line, sizeof(line), fp) != NULL) {
> - loc_set_file(fname, ++lno);
> + ++lno;
> if (line[0] == '\n') {
> /* skip empty lines */
> continue;
> @@ -372,39 +372,39 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists,
> const char *fname, Error *
> /* comment */
> continue;
> }
> - if (sscanf(line, "[%63s \"%63[^\"]\"]", group, id) == 2) {
> - /* group with id */
> - list = find_list(lists, group, &local_err);
> - if (local_err) {
> - error_propagate(errp, local_err);
> - goto out;
> + if (line[0] == '[') {
> + QDict *prev = qdict;
> + if (sscanf(line, "[%63s \"%63[^\"]\"]", group, value) == 2) {
> + qdict = qdict_new();
> + qdict_put_str(qdict, "id", value);
> + count++;
> + } else if (sscanf(line, "[%63[^]]]", group) == 1) {
> + qdict = qdict_new();
> + count++;
> }
> - opts = qemu_opts_create(list, id, 1, NULL);
> - count++;
> - continue;
> - }
> - if (sscanf(line, "[%63[^]]]", group) == 1) {
> - /* group without id */
> - list = find_list(lists, group, &local_err);
> - if (local_err) {
> - error_propagate(errp, local_err);
> - goto out;
> + if (qdict != prev) {
> + if (prev) {
> + cb(prev_group, prev, opaque, &local_err);
> + qobject_unref(prev);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + goto out;
> + }
> + }
> + strcpy(prev_group, group);
> + continue;
> }
> - opts = qemu_opts_create(list, NULL, 0, &error_abort);
> - count++;
> - continue;
> }
> + loc_set_file(fname, lno);
Error reporting is going to suffer quite a bit from this delayed
parsing, reporting the last line of a group for most cases now.
I think it's acceptable for an option that we want to get rid of in the
long term anyway, but worth noting.
> value[0] = '\0';
> if (sscanf(line, " %63s = \"%1023[^\"]\"", arg, value) == 2 ||
> sscanf(line, " %63s = \"\"", arg) == 1) {
> /* arg = value */
> - if (opts == NULL) {
> + if (qdict == NULL) {
> error_setg(errp, "no group defined");
> goto out;
> }
> - if (!qemu_opt_set(opts, arg, value, errp)) {
> - goto out;
> - }
> + qdict_put_str(qdict, arg, value);
> continue;
> }
> error_setg(errp, "parse error");
> @@ -418,10 +418,41 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists,
> const char *fname, Error *
> res = count;
> out:
> loc_pop(&loc);
> + if (qdict) {
> + cb(group, qdict, opaque, errp);
> + qobject_unref(qdict);
> + }
> return res;
> }
>
> -int qemu_read_config_file(const char *filename, Error **errp)
> +void qemu_config_do_parse(const char *group, QDict *qdict, void *opaque,
> Error **errp)
> +{
> + QemuOptsList **lists = opaque;
> + const char *id = qdict_get_try_str(qdict, "id");
> + QemuOptsList *list;
> + QemuOpts *opts;
> +
> + list = find_list(lists, group, errp);
> + if (!list) {
> + return;
> + }
> +
> + opts = qemu_opts_create(list, id, 1, errp);
> + if (!opts) {
> + return;
> + }
> + if (id) {
> + qdict_del(qdict, "id");
> + }
> + qemu_opts_absorb_qdict(opts, qdict, errp);
Shouldn't we check that qdict is empty now and return an error if there
are any options that the QemuOptsList doesn't accept?
Kevin
