qemu/qapi/string-input-visitor.c
Eric Blake e65d89bf1a qapi: Adjust layout of FooList types
By sticking the next pointer first, we don't need a union with
64-bit padding for smaller types.  On 32-bit platforms, this
can reduce the size of uint8List from 16 bytes (or 12, depending
on whether 64-bit ints can tolerate 4-byte alignment) down to 8.
It has no effect on 64-bit platforms (where alignment still
dictates a 16-byte struct); but fewer anonymous unions is still
a win in my book.

It requires visit_next_list() to gain a size parameter, to know
what size element to allocate; comparable to the size parameter
of visit_start_struct().

I debated about going one step further, to allow for fewer casts,
by doing:
    typedef GenericList GenericList;
    struct GenericList {
        GenericList *next;
    };
    struct FooList {
        GenericList base;
        Foo *value;
    };
so that you convert to 'GenericList *' by '&foolist->base', and
back by 'container_of(generic, GenericList, base)' (as opposed to
the existing '(GenericList *)foolist' and '(FooList *)generic').
But doing that would require hoisting the declaration of
GenericList prior to inclusion of qapi-types.h, rather than its
current spot in visitor.h; it also makes iteration a bit more
verbose through 'foolist->base.next' instead of 'foolist->next'.

Note that for lists of objects, the 'value' payload is still
hidden behind a boxed pointer.  Someday, it would be nice to do:

struct FooList {
    FooList *next;
    Foo value;
};

for one less level of malloc for each list element.  This patch
is a step in that direction (now that 'next' is no longer at a
fixed non-zero offset within the struct, we can store more than
just a pointer's-worth of data as the value payload), but the
actual conversion would be a task for another series, as it will
touch a lot of code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:57 +01:00

366 lines
9.0 KiB
C

/*
* String parsing visitor
*
* Copyright Red Hat, Inc. 2012-2016
*
* Author: Paolo Bonzini <pbonzini@redhat.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 "qemu-common.h"
#include "qapi/string-input-visitor.h"
#include "qapi/visitor-impl.h"
#include "qapi/qmp/qerror.h"
#include "qemu/option.h"
#include "qemu/queue.h"
#include "qemu/range.h"
struct StringInputVisitor
{
Visitor visitor;
bool head;
GList *ranges;
GList *cur_range;
int64_t cur;
const char *string;
};
static StringInputVisitor *to_siv(Visitor *v)
{
return container_of(v, StringInputVisitor, visitor);
}
static void free_range(void *range, void *dummy)
{
g_free(range);
}
static void parse_str(StringInputVisitor *siv, Error **errp)
{
char *str = (char *) siv->string;
long long start, end;
Range *cur;
char *endptr;
if (siv->ranges) {
return;
}
do {
errno = 0;
start = strtoll(str, &endptr, 0);
if (errno == 0 && endptr > str) {
if (*endptr == '\0') {
cur = g_malloc0(sizeof(*cur));
cur->begin = start;
cur->end = start + 1;
siv->ranges = g_list_insert_sorted_merged(siv->ranges, cur,
range_compare);
cur = NULL;
str = NULL;
} else if (*endptr == '-') {
str = endptr + 1;
errno = 0;
end = strtoll(str, &endptr, 0);
if (errno == 0 && endptr > str && start <= end &&
(start > INT64_MAX - 65536 ||
end < start + 65536)) {
if (*endptr == '\0') {
cur = g_malloc0(sizeof(*cur));
cur->begin = start;
cur->end = end + 1;
siv->ranges =
g_list_insert_sorted_merged(siv->ranges,
cur,
range_compare);
cur = NULL;
str = NULL;
} else if (*endptr == ',') {
str = endptr + 1;
cur = g_malloc0(sizeof(*cur));
cur->begin = start;
cur->end = end + 1;
siv->ranges =
g_list_insert_sorted_merged(siv->ranges,
cur,
range_compare);
cur = NULL;
} else {
goto error;
}
} else {
goto error;
}
} else if (*endptr == ',') {
str = endptr + 1;
cur = g_malloc0(sizeof(*cur));
cur->begin = start;
cur->end = start + 1;
siv->ranges = g_list_insert_sorted_merged(siv->ranges,
cur,
range_compare);
cur = NULL;
} else {
goto error;
}
} else {
goto error;
}
} while (str);
return;
error:
g_list_foreach(siv->ranges, free_range, NULL);
g_list_free(siv->ranges);
siv->ranges = NULL;
}
static void
start_list(Visitor *v, const char *name, Error **errp)
{
StringInputVisitor *siv = to_siv(v);
parse_str(siv, errp);
siv->cur_range = g_list_first(siv->ranges);
if (siv->cur_range) {
Range *r = siv->cur_range->data;
if (r) {
siv->cur = r->begin;
}
}
}
static GenericList *next_list(Visitor *v, GenericList **list, size_t size)
{
StringInputVisitor *siv = to_siv(v);
GenericList **link;
Range *r;
if (!siv->ranges || !siv->cur_range) {
return NULL;
}
r = siv->cur_range->data;
if (!r) {
return NULL;
}
if (siv->cur < r->begin || siv->cur >= r->end) {
siv->cur_range = g_list_next(siv->cur_range);
if (!siv->cur_range) {
return NULL;
}
r = siv->cur_range->data;
if (!r) {
return NULL;
}
siv->cur = r->begin;
}
if (siv->head) {
link = list;
siv->head = false;
} else {
link = &(*list)->next;
}
*link = g_malloc0(size);
return *link;
}
static void end_list(Visitor *v)
{
StringInputVisitor *siv = to_siv(v);
siv->head = true;
}
static void parse_type_int64(Visitor *v, const char *name, int64_t *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
if (!siv->string) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"integer");
return;
}
parse_str(siv, errp);
if (!siv->ranges) {
goto error;
}
if (!siv->cur_range) {
Range *r;
siv->cur_range = g_list_first(siv->ranges);
if (!siv->cur_range) {
goto error;
}
r = siv->cur_range->data;
if (!r) {
goto error;
}
siv->cur = r->begin;
}
*obj = siv->cur;
siv->cur++;
return;
error:
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name,
"an int64 value or range");
}
static void parse_type_uint64(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
/* FIXME: parse_type_int64 mishandles values over INT64_MAX */
int64_t i;
Error *err = NULL;
parse_type_int64(v, name, &i, &err);
if (err) {
error_propagate(errp, err);
} else {
*obj = i;
}
}
static void parse_type_size(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
Error *err = NULL;
uint64_t val;
if (siv->string) {
parse_option_size(name, siv->string, &val, &err);
} else {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"size");
return;
}
if (err) {
error_propagate(errp, err);
return;
}
*obj = val;
}
static void parse_type_bool(Visitor *v, const char *name, bool *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
if (siv->string) {
if (!strcasecmp(siv->string, "on") ||
!strcasecmp(siv->string, "yes") ||
!strcasecmp(siv->string, "true")) {
*obj = true;
return;
}
if (!strcasecmp(siv->string, "off") ||
!strcasecmp(siv->string, "no") ||
!strcasecmp(siv->string, "false")) {
*obj = false;
return;
}
}
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"boolean");
}
static void parse_type_str(Visitor *v, const char *name, char **obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
if (siv->string) {
*obj = g_strdup(siv->string);
} else {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"string");
}
}
static void parse_type_number(Visitor *v, const char *name, double *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
char *endp = (char *) siv->string;
double val;
errno = 0;
if (siv->string) {
val = strtod(siv->string, &endp);
}
if (!siv->string || errno || endp == siv->string || *endp) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"number");
return;
}
*obj = val;
}
static void parse_optional(Visitor *v, const char *name, bool *present)
{
StringInputVisitor *siv = to_siv(v);
if (!siv->string) {
*present = false;
return;
}
*present = true;
}
Visitor *string_input_get_visitor(StringInputVisitor *v)
{
return &v->visitor;
}
void string_input_visitor_cleanup(StringInputVisitor *v)
{
g_list_foreach(v->ranges, free_range, NULL);
g_list_free(v->ranges);
g_free(v);
}
StringInputVisitor *string_input_visitor_new(const char *str)
{
StringInputVisitor *v;
v = g_malloc0(sizeof(*v));
v->visitor.type_enum = input_type_enum;
v->visitor.type_int64 = parse_type_int64;
v->visitor.type_uint64 = parse_type_uint64;
v->visitor.type_size = parse_type_size;
v->visitor.type_bool = parse_type_bool;
v->visitor.type_str = parse_type_str;
v->visitor.type_number = parse_type_number;
v->visitor.start_list = start_list;
v->visitor.next_list = next_list;
v->visitor.end_list = end_list;
v->visitor.optional = parse_optional;
v->string = str;
v->head = true;
return v;
}