Hi Arman,
On Fri, Dec 19, 2014 at 7:35 PM, Arman Uguray <armansito@xxxxxxxxxxxx> wrote:
> This patch implements the ReadValue method of
> org.bluez.GattCharacteristic1 and exposes the "Value" property based on
> what was cached during the most recent read. The property is hidden if
> the value is unknown.
> ---
> src/gatt-client.c | 217 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 213 insertions(+), 4 deletions(-)
>
> diff --git a/src/gatt-client.c b/src/gatt-client.c
> index bd3711a..1c4ea51 100644
> --- a/src/gatt-client.c
> +++ b/src/gatt-client.c
> @@ -73,6 +73,12 @@ struct characteristic {
> uint8_t props;
> bt_uuid_t uuid;
> char *path;
> +
> + bool in_read;
> + bool value_known;
> + uint8_t *value;
> + size_t value_len;
> +
> struct queue *descs;
> };
>
> @@ -83,6 +89,66 @@ struct descriptor {
> char *path;
> };
>
> +static DBusMessage *gatt_error_read_not_permitted(DBusMessage *msg)
> +{
> + return g_dbus_create_error(msg, ERROR_INTERFACE ".ReadNotPermitted",
> + "Reading of this value is not allowed");
> +}
> +
> +static DBusMessage *gatt_error_write_not_permitted(DBusMessage *msg)
> +{
> + return g_dbus_create_error(msg, ERROR_INTERFACE ".WriteNotPermitted",
> + "Writing of this value is not allowed");
> +}
> +
> +static DBusMessage *gatt_error_invalid_value_len(DBusMessage *msg)
> +{
> + return g_dbus_create_error(msg, ERROR_INTERFACE ".InvalidValueLength",
> + "Invalid value length");
> +}
> +
> +static DBusMessage *gatt_error_invalid_offset(DBusMessage *msg)
> +{
> + return g_dbus_create_error(msg, ERROR_INTERFACE ".InvalidOffset",
> + "Invalid value offset");
> +}
> +
> +static DBusMessage *gatt_error_not_paired(DBusMessage *msg)
> +{
> + return g_dbus_create_error(msg, ERROR_INTERFACE ".NotPaired",
> + "Not Paired");
> +}
> +
> +static DBusMessage *create_gatt_dbus_error(DBusMessage *msg, uint8_t att_ecode)
> +{
> + switch (att_ecode) {
> + case BT_ATT_ERROR_READ_NOT_PERMITTED:
> + return gatt_error_read_not_permitted(msg);
> + case BT_ATT_ERROR_WRITE_NOT_PERMITTED:
> + return gatt_error_write_not_permitted(msg);
> + case BT_ATT_ERROR_AUTHENTICATION:
> + case BT_ATT_ERROR_INSUFFICIENT_ENCRYPTION:
> + case BT_ATT_ERROR_INSUFFICIENT_ENCRYPTION_KEY_SIZE:
> + return gatt_error_not_paired(msg);
> + case BT_ATT_ERROR_INVALID_OFFSET:
> + return gatt_error_invalid_offset(msg);
> + case BT_ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LEN:
> + return gatt_error_invalid_value_len(msg);
> + case BT_ATT_ERROR_AUTHORIZATION:
> + return btd_error_not_authorized(msg);
> + case BT_ATT_ERROR_REQUEST_NOT_SUPPORTED:
> + return btd_error_not_supported(msg);
> + case 0:
> + return btd_error_failed(msg, "Operation failed");
> + default:
> + return g_dbus_create_error(msg, ERROR_INTERFACE,
> + "Operation failed with ATT error: 0x%02x",
> + att_ecode);
> + }
> +
> + return NULL;
> +}
> +
> static gboolean descriptor_property_get_uuid(const GDBusPropertyTable *property,
> DBusMessageIter *iter, void *data)
> {
> @@ -232,17 +298,32 @@ static gboolean characteristic_property_get_value(
> const GDBusPropertyTable *property,
> DBusMessageIter *iter, void *data)
> {
> + struct characteristic *chrc = data;
> DBusMessageIter array;
> + size_t i;
>
> dbus_message_iter_open_container(iter, DBUS_TYPE_ARRAY, "y", &array);
>
> - /* TODO: Implement this once the value is cached */
> + if (chrc->value_known) {
> + for (i = 0; i < chrc->value_len; i++)
> + dbus_message_iter_append_basic(&array, DBUS_TYPE_BYTE,
> + chrc->value + i);
> + }
>
> dbus_message_iter_close_container(iter, &array);
>
> return TRUE;
> }
>
> +static gboolean characteristic_property_value_exists(
> + const GDBusPropertyTable *property,
> + void *data)
> +{
> + struct characteristic *chrc = data;
> +
> + return chrc->value_known ? TRUE : FALSE;
> +}
> +
> static gboolean characteristic_property_get_notifying(
> const GDBusPropertyTable *property,
> DBusMessageIter *iter, void *data)
> @@ -305,11 +386,137 @@ static gboolean characteristic_property_get_flags(
> return TRUE;
> }
>
> +struct chrc_dbus_op {
> + struct characteristic *chrc;
> + DBusMessage *msg;
> +};
> +
> +static void chrc_dbus_op_free(void *data)
> +{
> + struct chrc_dbus_op *op = data;
> +
> + dbus_message_unref(op->msg);
> + free(op);
> +}
> +
> +static bool chrc_resize_value(struct characteristic *chrc, size_t new_size)
> +{
> + uint8_t *ptr;
> +
> + if (chrc->value_len == new_size)
> + return true;
> +
> + if (!new_size) {
> + free(chrc->value);
> + chrc->value = NULL;
> + chrc->value_len = 0;
> +
> + return true;
> + }
> +
> + ptr = realloc(chrc->value, sizeof(uint8_t) * new_size);
> + if (!ptr)
> + return false;
> +
> + chrc->value = ptr;
> + chrc->value_len = new_size;
> +
> + return true;
> +}
> +
> +static void chrc_read_long_cb(bool success, uint8_t att_ecode,
> + const uint8_t *value, uint16_t length,
> + void *user_data)
> +{
> + struct chrc_dbus_op *op = user_data;
> + struct characteristic *chrc = op->chrc;
> + DBusMessageIter iter, array;
> + DBusMessage *reply;
> +
> + op->chrc->in_read = false;
> +
> + if (!success) {
> + reply = create_gatt_dbus_error(op->msg, att_ecode);
> + goto done;
> + }
> +
> + /*
> + * If the value is the same, then only update it if it wasn't previously
> + * known.
> + */
> + if (chrc->value_known && chrc->value_len == length &&
> + !memcmp(chrc->value, value, sizeof(uint8_t) * length))
> + goto reply;
> +
> + if (!chrc_resize_value(chrc, length)) {
> + /*
> + * Failed to resize the buffer. Since we don't want to show a
> + * stale value, if the value was previously known, then free and
> + * hide it.
> + */
> + free(chrc->value);
> + chrc->value = NULL;
> + chrc->value_len = 0;
> + chrc->value_known = false;
> +
> + goto changed_signal;
> + }
> +
> + chrc->value_known = true;
> + memcpy(chrc->value, value, sizeof(uint8_t) * length);
We could store this in the db itself and remember across connections
since this is supposed to be used only when notifications are enabled.
> +changed_signal:
> + g_dbus_emit_property_changed(btd_get_dbus_connection(), chrc->path,
> + GATT_CHARACTERISTIC_IFACE,
> + "Value");
> +
> +reply:
> + reply = g_dbus_create_reply(op->msg, DBUS_TYPE_INVALID);
> + if (!reply) {
> + error("Failed to allocate D-Bus message reply");
> + return;
> + }
> +
> + dbus_message_iter_init_append(reply, &iter);
> + dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "y", &array);
> +
> + for (i = 0; i < length; i++)
> + dbus_message_iter_append_basic(&array, DBUS_TYPE_BYTE,
> + value + i);
> +
> + dbus_message_iter_close_container(&iter, &array);
> +
> +done:
> + g_dbus_send_message(btd_get_dbus_connection(), reply);
> +}
> +
> static DBusMessage *characteristic_read_value(DBusConnection *conn,
> DBusMessage *msg, void *user_data)
> {
> - /* TODO: Implement */
> - return btd_error_failed(msg, "Not implemented");
> + struct characteristic *chrc = user_data;
> + struct bt_gatt_client *gatt = chrc->service->client->gatt;
> + struct chrc_dbus_op *op;
> +
> + if (chrc->in_read)
> + return btd_error_in_progress(msg);
> +
> + op = new0(struct chrc_dbus_op, 1);
> + if (!op)
> + return btd_error_failed(msg, "Failed to initialize request");
> +
> + op->chrc = chrc;
> + op->msg = dbus_message_ref(msg);
> +
> + if (bt_gatt_client_read_long_value(gatt, chrc->value_handle, 0,
> + chrc_read_long_cb, op,
> + chrc_dbus_op_free)) {
> + chrc->in_read = true;
> + return NULL;
> + }
> +
> + chrc_dbus_op_free(op);
> +
> + return btd_error_failed(msg, "Failed to send read request");
> }
>
> static DBusMessage *characteristic_write_value(DBusConnection *conn,
> @@ -361,7 +568,8 @@ static gboolean characteristic_property_get_descriptors(
> static const GDBusPropertyTable characteristic_properties[] = {
> { "UUID", "s", characteristic_property_get_uuid },
> { "Service", "o", characteristic_property_get_service },
> - { "Value", "ay", characteristic_property_get_value },
> + { "Value", "ay", characteristic_property_get_value, NULL,
> + characteristic_property_value_exists },
> { "Notifying", "b", characteristic_property_get_notifying },
> { "Flags", "as", characteristic_property_get_flags },
> { "Descriptors", "ao", characteristic_property_get_descriptors },
> @@ -384,6 +592,7 @@ static void characteristic_free(void *data)
> struct characteristic *chrc = data;
>
> queue_destroy(chrc->descs, NULL); /* List should be empty here */
> + free(chrc->value);
> g_free(chrc->path);
> free(chrc);
> }
> --
> 2.2.0.rc0.207.ga3a616c
>
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--
Luiz Augusto von Dentz
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