On 05/22/2014 08:57 PM, Alexander Graf wrote:
>
> On 22.05.14 12:53, Alexey Kardashevskiy wrote:
>> This adds a VMSTATE_HASH_V macro. This implements put/get callbacks for it.
>> This implements a qemu_hash_init() wrapper to save key/value sizes.
>>
>> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
>> ---
>> include/migration/vmstate.h | 10 +++++++++
>> include/qemu-common.h | 13 +++++++++++
>> vmstate.c | 54
>> +++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 77 insertions(+)
>>
>> diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
>> index 7e45048..6af599d 100644
>> --- a/include/migration/vmstate.h
>> +++ b/include/migration/vmstate.h
>> @@ -166,6 +166,7 @@ extern const VMStateInfo vmstate_info_timer;
>> extern const VMStateInfo vmstate_info_buffer;
>> extern const VMStateInfo vmstate_info_unused_buffer;
>> extern const VMStateInfo vmstate_info_bitmap;
>> +static const VMStateInfo vmstate_info_hash;
>> #define type_check_2darray(t1,t2,n,m) ((t1(*)[n][m])0 - (t2*)0)
>> #define type_check_array(t1,t2,n) ((t1(*)[n])0 - (t2*)0)
>> @@ -740,6 +741,15 @@ extern const VMStateInfo vmstate_info_bitmap;
>> #define VMSTATE_BUFFER_UNSAFE(_field, _state, _version, _size) \
>> VMSTATE_BUFFER_UNSAFE_INFO(_field, _state, _version,
>> vmstate_info_buffer, _size)
>> +#define VMSTATE_HASH_V(_field, _state, _version) { \
>> + .name = (stringify(_field)), \
>> + .version_id = (_version), \
>> + .size = sizeof(qemu_hash), \
>> + .info = &vmstate_info_hash, \
>> + .flags = VMS_SINGLE, \
>> + .offset = vmstate_offset_value(_state, _field, qemu_hash), \
>> +}
>> +
>> #define VMSTATE_UNUSED_V(_v, _size) \
>> VMSTATE_UNUSED_BUFFER(NULL, _v, _size)
>> diff --git a/include/qemu-common.h b/include/qemu-common.h
>> index 3f3fd60..ee973e7 100644
>> --- a/include/qemu-common.h
>> +++ b/include/qemu-common.h
>> @@ -462,4 +462,17 @@ int parse_debug_env(const char *name, int max, int
>> initial);
>> const char *qemu_ether_ntoa(const MACAddr *mac);
>> +typedef struct qemu_hash {
>> + GHashTable *hash;
>> + int key_size;
>> + int value_size;
>> +} qemu_hash;
>> +
>> +static inline void qemu_hash_init(qemu_hash *h, int key_size, int
>> value_size)
>> +{
>> + h->key_size = key_size;
>> + h->value_size = value_size;
>> + h->hash = g_hash_table_new_full(g_int_hash, g_int_equal, g_free,
>> g_free);
>> +}
>> +
>> #endif
>> diff --git a/vmstate.c b/vmstate.c
>> index b5882fa..2148e73 100644
>> --- a/vmstate.c
>> +++ b/vmstate.c
>> @@ -667,3 +667,57 @@ const VMStateInfo vmstate_info_bitmap = {
>> .get = get_bitmap,
>> .put = put_bitmap,
>> };
>> +
>> +/* Save restore for qemu_hash which is a wrapper over GHashTable */
>> +static int get_hash(QEMUFile *f, void *pv, size_t size)
>> +{
>> + qemu_hash *h = pv;
>> + uint32_t num = g_hash_table_size(h->hash);
>> + gpointer key, value;
>> +
>> + num = qemu_get_be32(f);
>> +
>> + for ( ; num; --num) {
>> + int i;
>> +
>> + key = g_malloc0(h->key_size);
>> + for (i = 0; i < h->key_size; ++i) {
>> + ((uint8_t *)key)[i] = qemu_get_byte(f);
>> + }
>> + value = g_malloc0(h->value_size);
>> + for (i = 0; i < h->value_size; ++i) {
>> + ((uint8_t *)value)[i] = qemu_get_byte(f);
>> + }
>> + g_hash_table_insert(h->hash, key, value);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static void put_hash(QEMUFile *f, void *pv, size_t size)
>> +{
>> + qemu_hash *h = pv;
>> + uint32_t num = g_hash_table_size(h->hash);
>> + GHashTableIter iter;
>> + gpointer key, value;
>> +
>> + qemu_put_be32(f, num);
>> +
>> + g_hash_table_iter_init(&iter, h->hash);
>> + while (g_hash_table_iter_next (&iter, &key, &value)) {
>> + int i;
>> +
>> + for (i = 0; i < h->key_size; ++i) {
>> + qemu_put_byte(f, ((uint8_t *)key)[i]);
>> + }
>> + for (i = 0; i < h->value_size; ++i) {
>> + qemu_put_byte(f, ((uint8_t *)value)[i]);
>
> I think the only way to do this safely would be to do a recursive
> introspective walk through the hash table's key and value properties. Every
> key and every property can be an object again, right?
>
> We would basically impose a limit onto ourselves that every member of the
> hash table would have to be a GObject again.
This is a bit too much for the task I am trying to solve :)
@key here is uin32_t and there is no point in making it an object...
--
Alexey
