This patch introduces a function that merges two keyval-produced (or keyval-like) QDicts. It can be used to emulate the behavior of .merge_lists = true QemuOpts groups, merging -readconfig sections and command-line options in a single QDict, and also to implement -set.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- include/qemu/option.h | 1 + tests/unit/test-keyval.c | 56 ++++++++++++++++++++++++++++++++++++++++ util/keyval.c | 47 +++++++++++++++++++++++++++++++++ 3 files changed, 104 insertions(+) diff --git a/include/qemu/option.h b/include/qemu/option.h index f73e0dc7d9..d89c66145a 100644 --- a/include/qemu/option.h +++ b/include/qemu/option.h @@ -149,5 +149,6 @@ QemuOptsList *qemu_opts_append(QemuOptsList *dst, QemuOptsList *list); QDict *keyval_parse(const char *params, const char *implied_key, bool *help, Error **errp); +void keyval_merge(QDict *old, const QDict *new, Error **errp); #endif diff --git a/tests/unit/test-keyval.c b/tests/unit/test-keyval.c index e20c07cf3e..254b51e98c 100644 --- a/tests/unit/test-keyval.c +++ b/tests/unit/test-keyval.c @@ -747,6 +747,59 @@ static void test_keyval_visit_any(void) visit_free(v); } +static void test_keyval_merge_success(void) +{ + QDict *old = keyval_parse("opt1=abc,opt2.sub1=def,opt2.sub2=ghi,opt3=xyz", + NULL, NULL, &error_abort); + QDict *new = keyval_parse("opt1=ABC,opt2.sub2=GHI,opt2.sub3=JKL", + NULL, NULL, &error_abort); + QDict *combined = keyval_parse("opt1=ABC,opt2.sub1=def,opt2.sub2=GHI,opt2.sub3=JKL,opt3=xyz", + NULL, NULL, &error_abort); + Error *err = NULL; + + keyval_merge(old, new, &err); + g_assert(!err); + g_assert(qobject_is_equal(QOBJECT(combined), QOBJECT(old))); + qobject_unref(old); + qobject_unref(new); + qobject_unref(combined); +} + +static void test_keyval_merge_list(void) +{ + QDict *old = keyval_parse("opt1.0=abc,opt2.0=xyz", + NULL, NULL, &error_abort); + QDict *new = keyval_parse("opt1.0=def", + NULL, NULL, &error_abort); + QDict *combined = keyval_parse("opt1.0=abc,opt1.1=def,opt2.0=xyz", + NULL, NULL, &error_abort); + Error *err = NULL; + + keyval_merge(old, new, &err); + g_assert(!err); + g_assert(qobject_is_equal(QOBJECT(combined), QOBJECT(old))); + qobject_unref(old); + qobject_unref(new); + qobject_unref(combined); +} + +static void test_keyval_merge_conflict(void) +{ + QDict *old = keyval_parse("opt2.sub1=def,opt2.sub2=ghi", + NULL, NULL, &error_abort); + QDict *new = keyval_parse("opt2=ABC", + NULL, NULL, &error_abort); + Error *err = NULL; + + keyval_merge(new, old, &err); + error_free_or_abort(&err); + keyval_merge(old, new, &err); + error_free_or_abort(&err); + + qobject_unref(old); + qobject_unref(new); +} + int main(int argc, char *argv[]) { g_test_init(&argc, &argv, NULL); @@ -760,6 +813,9 @@ int main(int argc, char *argv[]) g_test_add_func("/keyval/visit/optional", test_keyval_visit_optional); g_test_add_func("/keyval/visit/alternate", test_keyval_visit_alternate); g_test_add_func("/keyval/visit/any", test_keyval_visit_any); + g_test_add_func("/keyval/merge/success", test_keyval_merge_success); + g_test_add_func("/keyval/merge/list", test_keyval_merge_list); + g_test_add_func("/keyval/merge/conflict", test_keyval_merge_conflict); g_test_run(); return 0; } diff --git a/util/keyval.c b/util/keyval.c index be34928813..0797f36e1d 100644 --- a/util/keyval.c +++ b/util/keyval.c @@ -310,6 +310,53 @@ static char *reassemble_key(GSList *key) return g_string_free(s, FALSE); } +/* Merge two dictionaries. */ +static void keyval_do_merge(QDict *old, const QDict *new, GString *str, Error **errp) +{ + size_t save_len = str->len; + const QDictEntry *ent; + QObject *old_value; + + for (ent = qdict_first(new); ent; ent = qdict_next(new, ent)) { + old_value = qdict_get(old, ent->key); + if (old_value) { + if (qobject_type(old_value) != qobject_type(ent->value)) { + error_setg(errp, "Parameter '%s%s' used inconsistently", str->str, ent->key); + return; + } else if (qobject_type(ent->value) == QTYPE_QDICT) { + /* Merge sub-dictionaries. */ + g_string_append(str, ent->key); + g_string_append_c(str, '.'); + keyval_do_merge(qobject_to(QDict, old_value), + qobject_to(QDict, ent->value), + str, errp); + g_string_truncate(str, save_len); + continue; + } else if (qobject_type(ent->value) == QTYPE_QLIST) { + /* Append to old list. */ + QList *old = qobject_to(QList, old_value); + QList *new = qobject_to(QList, ent->value); + const QListEntry *item; + QLIST_FOREACH_ENTRY(new, item) { + qobject_ref(item->value); + qlist_append_obj(old, item->value); + } + continue; + } + } + + qobject_ref(ent->value); + qdict_put_obj(old, ent->key, ent->value); + } +} + +void keyval_merge(QDict *old, const QDict *new, Error **errp) +{ + GString *str = g_string_new(""); + keyval_do_merge(old, new, str, errp); + g_string_free(str, TRUE); +} + /* * Listify @cur recursively. * Replace QDicts whose keys are all valid list indexes by QLists. -- 2.31.1