qemu/qapi/qobject-input-visitor.c
Markus Armbruster 0b2c1beea4 keyval: Support lists
Additionally permit non-negative integers as key components.  A
dictionary's keys must either be all integers or none.  If all keys
are integers, convert the dictionary to a list.  The set of keys must
be [0,N].

Examples:

* list.1=goner,list.0=null,list.1=eins,list.2=zwei
  is equivalent to JSON [ "null", "eins", "zwei" ]

* a.b.c=1,a.b.0=2
  is inconsistent: a.b.c clashes with a.b.0

* list.0=null,list.2=eins,list.2=zwei
  has a hole: list.1 is missing

Similar design flaw as for objects: there is no way to denote an empty
list.  While interpreting "key absent" as empty list seems natural
(removing a list member from the input string works when there are
multiple ones, so why not when there's just one), it doesn't work:
"key absent" already means "optional list absent", which isn't the
same as "empty list present".

Update the keyval object visitor to use this a.0 syntax in error
messages rather than the usual a[0].

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488317230-26248-25-git-send-email-armbru@redhat.com>
[Off-by-one fix squashed in, as per Kevin's review]
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-03-07 16:07:48 +01:00

717 lines
19 KiB
C

/*
* Input Visitor
*
* Copyright (C) 2012-2017 Red Hat, Inc.
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/visitor-impl.h"
#include "qemu/queue.h"
#include "qemu-common.h"
#include "qapi/qmp/qjson.h"
#include "qapi/qmp/types.h"
#include "qapi/qmp/qerror.h"
#include "qemu/cutils.h"
#include "qemu/option.h"
typedef struct StackObject {
const char *name; /* Name of @obj in its parent, if any */
QObject *obj; /* QDict or QList being visited */
void *qapi; /* sanity check that caller uses same pointer */
GHashTable *h; /* If @obj is QDict: unvisited keys */
const QListEntry *entry; /* If @obj is QList: unvisited tail */
unsigned index; /* If @obj is QList: list index of @entry */
QSLIST_ENTRY(StackObject) node; /* parent */
} StackObject;
struct QObjectInputVisitor {
Visitor visitor;
/* Root of visit at visitor creation. */
QObject *root;
bool keyval; /* Assume @root made with keyval_parse() */
/* Stack of objects being visited (all entries will be either
* QDict or QList). */
QSLIST_HEAD(, StackObject) stack;
GString *errname; /* Accumulator for full_name() */
};
static QObjectInputVisitor *to_qiv(Visitor *v)
{
return container_of(v, QObjectInputVisitor, visitor);
}
static const char *full_name_nth(QObjectInputVisitor *qiv, const char *name,
int n)
{
StackObject *so;
char buf[32];
if (qiv->errname) {
g_string_truncate(qiv->errname, 0);
} else {
qiv->errname = g_string_new("");
}
QSLIST_FOREACH(so , &qiv->stack, node) {
if (n) {
n--;
} else if (qobject_type(so->obj) == QTYPE_QDICT) {
g_string_prepend(qiv->errname, name ?: "<anonymous>");
g_string_prepend_c(qiv->errname, '.');
} else {
snprintf(buf, sizeof(buf),
qiv->keyval ? ".%u" : "[%u]",
so->index);
g_string_prepend(qiv->errname, buf);
}
name = so->name;
}
assert(!n);
if (name) {
g_string_prepend(qiv->errname, name);
} else if (qiv->errname->str[0] == '.') {
g_string_erase(qiv->errname, 0, 1);
} else if (!qiv->errname->str[0]) {
return "<anonymous>";
}
return qiv->errname->str;
}
static const char *full_name(QObjectInputVisitor *qiv, const char *name)
{
return full_name_nth(qiv, name, 0);
}
static QObject *qobject_input_try_get_object(QObjectInputVisitor *qiv,
const char *name,
bool consume)
{
StackObject *tos;
QObject *qobj;
QObject *ret;
if (QSLIST_EMPTY(&qiv->stack)) {
/* Starting at root, name is ignored. */
assert(qiv->root);
return qiv->root;
}
/* We are in a container; find the next element. */
tos = QSLIST_FIRST(&qiv->stack);
qobj = tos->obj;
assert(qobj);
if (qobject_type(qobj) == QTYPE_QDICT) {
assert(name);
ret = qdict_get(qobject_to_qdict(qobj), name);
if (tos->h && consume && ret) {
bool removed = g_hash_table_remove(tos->h, name);
assert(removed);
}
} else {
assert(qobject_type(qobj) == QTYPE_QLIST);
assert(!name);
if (tos->entry) {
ret = qlist_entry_obj(tos->entry);
if (consume) {
tos->entry = qlist_next(tos->entry);
}
} else {
ret = NULL;
}
if (consume) {
tos->index++;
}
}
return ret;
}
static QObject *qobject_input_get_object(QObjectInputVisitor *qiv,
const char *name,
bool consume, Error **errp)
{
QObject *obj = qobject_input_try_get_object(qiv, name, consume);
if (!obj) {
error_setg(errp, QERR_MISSING_PARAMETER, full_name(qiv, name));
}
return obj;
}
static const char *qobject_input_get_keyval(QObjectInputVisitor *qiv,
const char *name,
Error **errp)
{
QObject *qobj;
QString *qstr;
qobj = qobject_input_get_object(qiv, name, true, errp);
if (!qobj) {
return NULL;
}
qstr = qobject_to_qstring(qobj);
if (!qstr) {
switch (qobject_type(qobj)) {
case QTYPE_QDICT:
case QTYPE_QLIST:
error_setg(errp, "Parameters '%s.*' are unexpected",
full_name(qiv, name));
return NULL;
default:
/* Non-string scalar (should this be an assertion?) */
error_setg(errp, "Internal error: parameter %s invalid",
full_name(qiv, name));
return NULL;
}
}
return qstring_get_str(qstr);
}
static void qdict_add_key(const char *key, QObject *obj, void *opaque)
{
GHashTable *h = opaque;
g_hash_table_insert(h, (gpointer) key, NULL);
}
static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv,
const char *name,
QObject *obj, void *qapi)
{
GHashTable *h;
StackObject *tos = g_new0(StackObject, 1);
assert(obj);
tos->name = name;
tos->obj = obj;
tos->qapi = qapi;
if (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);
tos->h = h;
} else {
assert(qobject_type(obj) == QTYPE_QLIST);
tos->entry = qlist_first(qobject_to_qlist(obj));
tos->index = -1;
}
QSLIST_INSERT_HEAD(&qiv->stack, tos, node);
return tos->entry;
}
static void qobject_input_check_struct(Visitor *v, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
StackObject *tos = QSLIST_FIRST(&qiv->stack);
GHashTableIter iter;
const char *key;
assert(tos && !tos->entry);
g_hash_table_iter_init(&iter, tos->h);
if (g_hash_table_iter_next(&iter, (void **)&key, NULL)) {
error_setg(errp, "Parameter '%s' is unexpected",
full_name(qiv, key));
}
}
static void qobject_input_stack_object_free(StackObject *tos)
{
if (tos->h) {
g_hash_table_unref(tos->h);
}
g_free(tos);
}
static void qobject_input_pop(Visitor *v, void **obj)
{
QObjectInputVisitor *qiv = to_qiv(v);
StackObject *tos = QSLIST_FIRST(&qiv->stack);
assert(tos && tos->qapi == obj);
QSLIST_REMOVE_HEAD(&qiv->stack, node);
qobject_input_stack_object_free(tos);
}
static void qobject_input_start_struct(Visitor *v, const char *name, void **obj,
size_t size, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
if (obj) {
*obj = NULL;
}
if (!qobj) {
return;
}
if (qobject_type(qobj) != QTYPE_QDICT) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "object");
return;
}
qobject_input_push(qiv, name, qobj, obj);
if (obj) {
*obj = g_malloc0(size);
}
}
static void qobject_input_start_list(Visitor *v, const char *name,
GenericList **list, size_t size,
Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
const QListEntry *entry;
if (list) {
*list = NULL;
}
if (!qobj) {
return;
}
if (qobject_type(qobj) != QTYPE_QLIST) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "array");
return;
}
entry = qobject_input_push(qiv, name, qobj, list);
if (entry && list) {
*list = g_malloc0(size);
}
}
static GenericList *qobject_input_next_list(Visitor *v, GenericList *tail,
size_t size)
{
QObjectInputVisitor *qiv = to_qiv(v);
StackObject *tos = QSLIST_FIRST(&qiv->stack);
assert(tos && tos->obj && qobject_type(tos->obj) == QTYPE_QLIST);
if (!tos->entry) {
return NULL;
}
tail->next = g_malloc0(size);
return tail->next;
}
static void qobject_input_check_list(Visitor *v, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
StackObject *tos = QSLIST_FIRST(&qiv->stack);
assert(tos && tos->obj && qobject_type(tos->obj) == QTYPE_QLIST);
if (tos->entry) {
error_setg(errp, "Only %u list elements expected in %s",
tos->index + 1, full_name_nth(qiv, NULL, 1));
}
}
static void qobject_input_start_alternate(Visitor *v, const char *name,
GenericAlternate **obj, size_t size,
bool promote_int, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, false, errp);
if (!qobj) {
*obj = NULL;
return;
}
*obj = g_malloc0(size);
(*obj)->type = qobject_type(qobj);
if (promote_int && (*obj)->type == QTYPE_QINT) {
(*obj)->type = QTYPE_QFLOAT;
}
}
static void qobject_input_type_int64(Visitor *v, const char *name, int64_t *obj,
Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
QInt *qint;
if (!qobj) {
return;
}
qint = qobject_to_qint(qobj);
if (!qint) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "integer");
return;
}
*obj = qint_get_int(qint);
}
static void qobject_input_type_int64_keyval(Visitor *v, const char *name,
int64_t *obj, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
const char *str = qobject_input_get_keyval(qiv, name, errp);
if (!str) {
return;
}
if (qemu_strtoi64(str, NULL, 0, obj) < 0) {
/* TODO report -ERANGE more nicely */
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
full_name(qiv, name), "integer");
}
}
static void qobject_input_type_uint64(Visitor *v, const char *name,
uint64_t *obj, Error **errp)
{
/* FIXME: qobject_to_qint mishandles values over INT64_MAX */
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
QInt *qint;
if (!qobj) {
return;
}
qint = qobject_to_qint(qobj);
if (!qint) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "integer");
return;
}
*obj = qint_get_int(qint);
}
static void qobject_input_type_uint64_keyval(Visitor *v, const char *name,
uint64_t *obj, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
const char *str = qobject_input_get_keyval(qiv, name, errp);
if (!str) {
return;
}
if (qemu_strtou64(str, NULL, 0, obj) < 0) {
/* TODO report -ERANGE more nicely */
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
full_name(qiv, name), "integer");
}
}
static void qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
QBool *qbool;
if (!qobj) {
return;
}
qbool = qobject_to_qbool(qobj);
if (!qbool) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "boolean");
return;
}
*obj = qbool_get_bool(qbool);
}
static void qobject_input_type_bool_keyval(Visitor *v, const char *name,
bool *obj, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
const char *str = qobject_input_get_keyval(qiv, name, errp);
if (!str) {
return;
}
if (!strcmp(str, "on")) {
*obj = true;
} else if (!strcmp(str, "off")) {
*obj = false;
} else {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
full_name(qiv, name), "'on' or 'off'");
}
}
static void qobject_input_type_str(Visitor *v, const char *name, char **obj,
Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
QString *qstr;
*obj = NULL;
if (!qobj) {
return;
}
qstr = qobject_to_qstring(qobj);
if (!qstr) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "string");
return;
}
*obj = g_strdup(qstring_get_str(qstr));
}
static void qobject_input_type_str_keyval(Visitor *v, const char *name,
char **obj, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
const char *str = qobject_input_get_keyval(qiv, name, errp);
*obj = g_strdup(str);
}
static void qobject_input_type_number(Visitor *v, const char *name, double *obj,
Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
QInt *qint;
QFloat *qfloat;
if (!qobj) {
return;
}
qint = qobject_to_qint(qobj);
if (qint) {
*obj = qint_get_int(qobject_to_qint(qobj));
return;
}
qfloat = qobject_to_qfloat(qobj);
if (qfloat) {
*obj = qfloat_get_double(qobject_to_qfloat(qobj));
return;
}
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "number");
}
static void qobject_input_type_number_keyval(Visitor *v, const char *name,
double *obj, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
const char *str = qobject_input_get_keyval(qiv, name, errp);
char *endp;
if (!str) {
return;
}
errno = 0;
*obj = strtod(str, &endp);
if (errno || endp == str || *endp) {
/* TODO report -ERANGE more nicely */
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "number");
}
}
static void qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
*obj = NULL;
if (!qobj) {
return;
}
qobject_incref(qobj);
*obj = qobj;
}
static void qobject_input_type_null(Visitor *v, const char *name, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
if (!qobj) {
return;
}
if (qobject_type(qobj) != QTYPE_QNULL) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
full_name(qiv, name), "null");
}
}
static void qobject_input_type_size_keyval(Visitor *v, const char *name,
uint64_t *obj, Error **errp)
{
QObjectInputVisitor *qiv = to_qiv(v);
const char *str = qobject_input_get_keyval(qiv, name, errp);
if (!str) {
return;
}
if (qemu_strtosz(str, NULL, obj) < 0) {
/* TODO report -ERANGE more nicely */
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
full_name(qiv, name), "size");
}
}
static void qobject_input_optional(Visitor *v, const char *name, bool *present)
{
QObjectInputVisitor *qiv = to_qiv(v);
QObject *qobj = qobject_input_try_get_object(qiv, name, false);
if (!qobj) {
*present = false;
return;
}
*present = true;
}
static void qobject_input_free(Visitor *v)
{
QObjectInputVisitor *qiv = to_qiv(v);
while (!QSLIST_EMPTY(&qiv->stack)) {
StackObject *tos = QSLIST_FIRST(&qiv->stack);
QSLIST_REMOVE_HEAD(&qiv->stack, node);
qobject_input_stack_object_free(tos);
}
qobject_decref(qiv->root);
if (qiv->errname) {
g_string_free(qiv->errname, TRUE);
}
g_free(qiv);
}
static QObjectInputVisitor *qobject_input_visitor_base_new(QObject *obj)
{
QObjectInputVisitor *v = g_malloc0(sizeof(*v));
assert(obj);
v->visitor.type = VISITOR_INPUT;
v->visitor.start_struct = qobject_input_start_struct;
v->visitor.check_struct = qobject_input_check_struct;
v->visitor.end_struct = qobject_input_pop;
v->visitor.start_list = qobject_input_start_list;
v->visitor.next_list = qobject_input_next_list;
v->visitor.check_list = qobject_input_check_list;
v->visitor.end_list = qobject_input_pop;
v->visitor.start_alternate = qobject_input_start_alternate;
v->visitor.optional = qobject_input_optional;
v->visitor.free = qobject_input_free;
v->root = obj;
qobject_incref(obj);
return v;
}
Visitor *qobject_input_visitor_new(QObject *obj)
{
QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
v->visitor.type_int64 = qobject_input_type_int64;
v->visitor.type_uint64 = qobject_input_type_uint64;
v->visitor.type_bool = qobject_input_type_bool;
v->visitor.type_str = qobject_input_type_str;
v->visitor.type_number = qobject_input_type_number;
v->visitor.type_any = qobject_input_type_any;
v->visitor.type_null = qobject_input_type_null;
return &v->visitor;
}
Visitor *qobject_input_visitor_new_keyval(QObject *obj)
{
QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
v->visitor.type_int64 = qobject_input_type_int64_keyval;
v->visitor.type_uint64 = qobject_input_type_uint64_keyval;
v->visitor.type_bool = qobject_input_type_bool_keyval;
v->visitor.type_str = qobject_input_type_str_keyval;
v->visitor.type_number = qobject_input_type_number_keyval;
v->visitor.type_any = qobject_input_type_any;
v->visitor.type_null = qobject_input_type_null;
v->visitor.type_size = qobject_input_type_size_keyval;
v->keyval = true;
return &v->visitor;
}
Visitor *qobject_input_visitor_new_str(const char *str,
const char *implied_key,
Error **errp)
{
bool is_json = str[0] == '{';
QObject *obj;
QDict *args;
Visitor *v;
if (is_json) {
obj = qobject_from_json(str, errp);
if (!obj) {
/* Work around qobject_from_json() lossage TODO fix that */
if (errp && !*errp) {
error_setg(errp, "JSON parse error");
return NULL;
}
return NULL;
}
args = qobject_to_qdict(obj);
assert(args);
v = qobject_input_visitor_new(QOBJECT(args));
} else {
args = keyval_parse(str, implied_key, errp);
if (!args) {
return NULL;
}
v = qobject_input_visitor_new_keyval(QOBJECT(args));
}
QDECREF(args);
return v;
}