Hi Luiz,
On 22 March 2016 at 16:03, Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote:
> Hi Lukasz,
>
> On Fri, Mar 18, 2016 at 3:08 PM, Łukasz Rymanowski
> <lukasz.rymanowski@xxxxxxxxxxx> wrote:
>> With this patch long write and nested long write reliable is supported.
>> GATT server is responsible now to do aggregation of prep write data
>> for long write session.
>> Note: We consider long write as the consequtive prepare writes with
>> continues offsets.
>>
>> E.g. 1
>>
>> prep_write: handle 1, offset 0, value_len 10
>> prep_write: handle 2, offset 0, value_len 10
>> prep_write: handle 1, offset 10, value_len 10
>> prep_write: handle 2, offset 10, value_len 10
>>
>> Will result with following calles to app:
>>
>> exec_write: handle 1: offset 0, value_len 20
>> exec_write: handle 2: offset 0, value_len 20
>
> We should not alter the sequence if the remote is writing in that way
> we should honor it, so the aggregation shall only be done as long as
> the remote don't nest anything in between at that point you should
> stop aggregating and add a new item to the queue.
Fair enough
Perhaps you just
> detect if the prepare was for for the last handle and the offset start
> from the last point then just append otherwise create a new item.
>
Yes, we can peek tail on the prepare queue and check only that one.
Actually with this approach patch 07/09 is most likely not needed.
>>
>> E.g. 2
>>
>> prep_write: handle 1, offset 0, value_len 10
>> prep_write: handle 1, offset 2, value_len 5
>> prep_write: handle 2, offset 0, value_len 10
>> prep_write: handle 2, offset 4, value_len 5
>>
>> Will result with following calles to app:
>>
>> exec_write: handle 1: offset 0, value_len 10
>> exec_write: handle 1: offset 2, value_len 5
>> exec_write: handle 2: offset 0, value_len 10
>> exec_write: handle 2: offset 4, value_len 5
>> ---
>> src/shared/gatt-server.c | 85 ++++++++++++++++++++++++++++++++++++++++--------
>> 1 file changed, 71 insertions(+), 14 deletions(-)
>>
>> diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c
>> index c41273a..0904336 100644
>> --- a/src/shared/gatt-server.c
>> +++ b/src/shared/gatt-server.c
>> @@ -1088,6 +1088,63 @@ error:
>> bt_att_send_error_rsp(server->att, opcode, 0, ecode);
>> }
>>
>> +static bool match_attribute_handle(const void *data, const void *match_data)
>> +{
>> + const struct prep_write_data *prep_data = data;
>> +
>> + return prep_data->handle == PTR_TO_UINT(match_data);
>> +}
>> +
>> +static bool create_and_store_prep_data(struct bt_gatt_server *server,
>> + uint16_t handle, uint16_t offset,
>> + uint16_t length, uint8_t *value)
>> +{
>> + struct prep_write_data *prep_data;
>> +
>> + prep_data = new0(struct prep_write_data, 1);
>> + prep_data->length = length;
>> + if (prep_data->length) {
>> + prep_data->value = malloc(prep_data->length);
>> + if (!prep_data->value) {
>> + return false;
>> + }
>> +
>> + memcpy(prep_data->value, value, prep_data->length);
>> + }
>> +
>> + prep_data->server = server;
>> + prep_data->handle = handle;
>> + prep_data->offset = offset;
>> +
>> + queue_push_tail(server->prep_queue, prep_data);
>> +
>> + return true;
>> +}
>> +
>> +static bool make_aggregation_of_long_write_data(struct bt_gatt_server *server,
>> + struct prep_write_data *prep_data,
>> + uint16_t handle, uint16_t length,
>> + uint8_t *value)
>> +{
>> + uint8_t *buf;
>> + uint16_t new_len;
>> +
>> + new_len = prep_data->length + length;
>> +
>> + buf = malloc(new_len);
>> + if (!buf)
>> + return false;
>> +
>> + memcpy(buf, prep_data->value, prep_data->length);
>> + memcpy(buf + prep_data->length, value, length);
>> +
>> + free(prep_data->value);
>> + prep_data->value = buf;
>> + prep_data->length = new_len;
>> +
>> + return true;
>> +}
>> +
>> static void prep_write_cb(uint8_t opcode, const void *pdu,
>> uint16_t length, void *user_data)
>> {
>> @@ -1097,6 +1154,7 @@ static void prep_write_cb(uint8_t opcode, const void *pdu,
>> uint16_t offset;
>> struct gatt_db_attribute *attr;
>> uint8_t ecode;
>> + bool success;
>>
>> if (length < 4) {
>> ecode = BT_ATT_ERROR_INVALID_PDU;
>> @@ -1126,22 +1184,21 @@ static void prep_write_cb(uint8_t opcode, const void *pdu,
>> if (ecode)
>> goto error;
>>
>> - prep_data = new0(struct prep_write_data, 1);
>> - prep_data->length = length - 4;
>> - if (prep_data->length) {
>> - prep_data->value = malloc(prep_data->length);
>> - if (!prep_data->value) {
>> - ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES;
>> - goto error;
>> - }
>> - }
>> + prep_data = queue_find(server->prep_queue, match_attribute_handle,
>> + UINT_TO_PTR(handle));
>>
>> - prep_data->server = server;
>> - prep_data->handle = handle;
>> - prep_data->offset = offset;
>> - memcpy(prep_data->value, pdu + 4, prep_data->length);
>> + if (prep_data && offset == prep_data->length + prep_data->offset)
>> + success = make_aggregation_of_long_write_data(server, prep_data,
>> + handle, length - 4,
>> + &((uint8_t *) pdu)[4]);
>> + else
>> + success = create_and_store_prep_data(server, handle, offset,
>> + length - 4, &((uint8_t *) pdu)[4]);
>>
>> - queue_push_tail(server->prep_queue, prep_data);
>> + if (!success) {
>> + ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES;
>> + goto error;
>> + }
>>
>> bt_att_send(server->att, BT_ATT_OP_PREP_WRITE_RSP, pdu, length, NULL,
>> NULL, NULL);
>> --
>> 2.5.0
>>
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>
>
>
> --
> Luiz Augusto von Dentz
--
BR / Pozdrawiam
Łukasz
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