Commit b471d012 authored by Eric Blake's avatar Eric Blake Committed by Markus Armbruster
Browse files

qmp-input: Clean up stack handling 



Management of the top of stack was a bit verbose; creating a
temporary variable and adding some comments makes the existing
code more legible before the next few patches improve things.
No semantic changes other than asserting that we are always
visiting a QObject, and not a NULL value.  In particular, the
check for 'name && qobject_type(qobj) == QTYPE_QDICT)' is a
bit overkill (a dict visit should always have a name); a later
patch revisits that, while this patch is only changing one
layer of indentation due to dropping 'if (qobj)'.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-5-git-send-email-eblake@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent 42a502a7

qapi/qmp-input-visitor.c

+35 −16
Original line number Diff line number Diff line
@@ -25,16 +25,23 @@ 


typedef struct StackObject

{

    QObject *obj;

    const QListEntry *entry;

    GHashTable *h;

    QObject *obj; /* Object being visited */



    GHashTable *h;           /* If obj is dict: unvisited keys */

    const QListEntry *entry; /* If obj is list: unvisited tail */

} StackObject;



struct QmpInputVisitor

{

    Visitor visitor;



    /* Stack of objects being visited.  stack[0] is root of visit,

     * stack[1..] records the nesting of start_struct()/end_struct()

     * and start_list()/end_list() pairs. */

    StackObject stack[QIV_STACK_SIZE];

    int nb_stack;



    /* True to reject parse in visit_end_struct() if unvisited keys remain. */

    bool strict;

};
@@ -47,19 +54,29 @@ static QObject *qmp_input_get_object(QmpInputVisitor *qiv, 
                                     const char *name,

                                     bool consume)

{

    QObject *qobj = qiv->stack[qiv->nb_stack - 1].obj;

    StackObject *tos = &qiv->stack[qiv->nb_stack - 1];

    QObject *qobj = tos->obj;



    assert(qobj);



    if (qobj) {

    /* If we have a name, and we're in a dictionary, then return that

     * value. */

    if (name && qobject_type(qobj) == QTYPE_QDICT) {

            if (qiv->stack[qiv->nb_stack - 1].h && consume) {

                g_hash_table_remove(qiv->stack[qiv->nb_stack - 1].h, name);

        if (tos->h && consume) {

            g_hash_table_remove(tos->h, name);

        }

        return qdict_get(qobject_to_qdict(qobj), name);

        } else if (qiv->stack[qiv->nb_stack - 1].entry) {

            return qlist_entry_obj(qiv->stack[qiv->nb_stack - 1].entry);

    }



    /* If we are in the middle of a list, then return the next element

     * of the list. */

    if (tos->entry) {

        assert(qobject_type(qobj) == QTYPE_QLIST);

        return qlist_entry_obj(tos->entry);

    }



    /* Otherwise, we are at the root of the visit or the start of a

     * list, and return the object as-is. */

    return qobj;

}
@@ -72,20 +89,22 @@ static void qdict_add_key(const char *key, QObject *obj, void *opaque) 
static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj, Error **errp)

{

    GHashTable *h;

    StackObject *tos = &qiv->stack[qiv->nb_stack];



    assert(obj);

    if (qiv->nb_stack >= QIV_STACK_SIZE) {

        error_setg(errp, "An internal buffer overran");

        return;

    }



    qiv->stack[qiv->nb_stack].obj = obj;

    qiv->stack[qiv->nb_stack].entry = NULL;

    qiv->stack[qiv->nb_stack].h = NULL;

    tos->obj = obj;

    tos->entry = NULL;

    tos->h = NULL;



    if (qiv->strict && qobject_type(obj) == QTYPE_QDICT) {

        h = g_hash_table_new(g_str_hash, g_str_equal);

        qdict_iter(qobject_to_qdict(obj), qdict_add_key, h);

        qiv->stack[qiv->nb_stack].h = h;

        tos->h = h;

    }



    qiv->nb_stack++;