aboutsummaryrefslogtreecommitdiff
path: root/qapi/qapi-clone-visitor.c
blob: daab6819b486fa2e37ad55dcd85e390f9b9d4075 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
/*
 * Copy one QAPI object to another
 *
 * Copyright (C) 2016 Red Hat, Inc.
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 *
 */

#include "qemu/osdep.h"
#include "qapi/clone-visitor.h"
#include "qapi/visitor-impl.h"
#include "qapi/error.h"
#include "qapi/qmp/qnull.h"

struct QapiCloneVisitor {
    Visitor visitor;
    size_t depth;
};

static QapiCloneVisitor *to_qcv(Visitor *v)
{
    return container_of(v, QapiCloneVisitor, visitor);
}

static void qapi_clone_start_struct(Visitor *v, const char *name, void **obj,
                                    size_t size, Error **errp)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    if (!obj) {
        assert(qcv->depth);
        /* Only possible when visiting an alternate's object
         * branch. Nothing further to do here, since the earlier
         * visit_start_alternate() already copied memory. */
        return;
    }

    *obj = g_memdup(*obj, size);
    qcv->depth++;
}

static void qapi_clone_end(Visitor *v, void **obj)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    assert(qcv->depth);
    if (obj) {
        qcv->depth--;
    }
}

static void qapi_clone_start_list(Visitor *v, const char *name,
                                  GenericList **listp, size_t size,
                                  Error **errp)
{
    qapi_clone_start_struct(v, name, (void **)listp, size, errp);
}

static GenericList *qapi_clone_next_list(Visitor *v, GenericList *tail,
                                         size_t size)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    assert(qcv->depth);
    /* Unshare the tail of the list cloned by g_memdup() */
    tail->next = g_memdup(tail->next, size);
    return tail->next;
}

static void qapi_clone_start_alternate(Visitor *v, const char *name,
                                       GenericAlternate **obj, size_t size,
                                       Error **errp)
{
    qapi_clone_start_struct(v, name, (void **)obj, size, errp);
}

static void qapi_clone_type_int64(Visitor *v, const char *name, int64_t *obj,
                                   Error **errp)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    assert(qcv->depth);
    /* Value was already cloned by g_memdup() */
}

static void qapi_clone_type_uint64(Visitor *v, const char *name,
                                    uint64_t *obj, Error **errp)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    assert(qcv->depth);
    /* Value was already cloned by g_memdup() */
}

static void qapi_clone_type_bool(Visitor *v, const char *name, bool *obj,
                                  Error **errp)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    assert(qcv->depth);
    /* Value was already cloned by g_memdup() */
}

static void qapi_clone_type_str(Visitor *v, const char *name, char **obj,
                                 Error **errp)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    assert(qcv->depth);
    /*
     * Pointer was already cloned by g_memdup; create fresh copy.
     * Note that as long as qobject-output-visitor accepts NULL instead of
     * "", then we must do likewise. However, we want to obey the
     * input visitor semantics of never producing NULL when the empty
     * string is intended.
     */
    *obj = g_strdup(*obj ?: "");
}

static void qapi_clone_type_number(Visitor *v, const char *name, double *obj,
                                    Error **errp)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    assert(qcv->depth);
    /* Value was already cloned by g_memdup() */
}

static void qapi_clone_type_null(Visitor *v, const char *name, QNull **obj,
                                 Error **errp)
{
    QapiCloneVisitor *qcv = to_qcv(v);

    assert(qcv->depth);
    *obj = qnull();
}

static void qapi_clone_free(Visitor *v)
{
    g_free(v);
}

static Visitor *qapi_clone_visitor_new(void)
{
    QapiCloneVisitor *v;

    v = g_malloc0(sizeof(*v));

    v->visitor.type = VISITOR_CLONE;
    v->visitor.start_struct = qapi_clone_start_struct;
    v->visitor.end_struct = qapi_clone_end;
    v->visitor.start_list = qapi_clone_start_list;
    v->visitor.next_list = qapi_clone_next_list;
    v->visitor.end_list = qapi_clone_end;
    v->visitor.start_alternate = qapi_clone_start_alternate;
    v->visitor.end_alternate = qapi_clone_end;
    v->visitor.type_int64 = qapi_clone_type_int64;
    v->visitor.type_uint64 = qapi_clone_type_uint64;
    v->visitor.type_bool = qapi_clone_type_bool;
    v->visitor.type_str = qapi_clone_type_str;
    v->visitor.type_number = qapi_clone_type_number;
    v->visitor.type_null = qapi_clone_type_null;
    v->visitor.free = qapi_clone_free;

    return &v->visitor;
}

void *qapi_clone(const void *src, void (*visit_type)(Visitor *, const char *,
                                                     void **, Error **))
{
    Visitor *v;
    void *dst = (void *) src; /* Cast away const */

    if (!src) {
        return NULL;
    }

    v = qapi_clone_visitor_new();
    visit_type(v, NULL, &dst, &error_abort);
    visit_free(v);
    return dst;
}

void qapi_clone_members(void *dst, const void *src, size_t sz,
                        void (*visit_type_members)(Visitor *, void *,
                                                   Error **))
{
    Visitor *v;

    v = qapi_clone_visitor_new();
    memcpy(dst, src, sz);
    to_qcv(v)->depth++;
    visit_type_members(v, dst, &error_abort);
    visit_free(v);
}