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MXS-1149: maxrows should return empty resultset instead of OK

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maxrows returns empty resultset instead of OK.

The response with coulmndefs is sent then an EOF without flags is added.

Limitations: in case of MULTI_RESULT sets only the first one coulmndefs
is sent with EOF
This commit is contained in:
MassimilianoPinto 2017-03-01 14:48:28 +01:00
parent eefa63be33
commit c9592aa05e
1 changed files with 94 additions and 4 deletions
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98
server/modules/filter/maxrows/maxrows.c
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@ -147,6 +147,7 @@ typedef struct maxrows_response_state
size_t n_fields; /**< How many fields we have received, <= n_totalfields. */
size_t n_rows; /**< How many rows we have received. */
size_t offset; /**< Where we are in the response buffer. */
size_t rows_offset; /**< Offset to first row in result set */
} MAXROWS_RESPONSE_STATE;
static void maxrows_response_state_reset(MAXROWS_RESPONSE_STATE *state);
@ -175,6 +176,7 @@ static bool process_params(char **options, MXS_CONFIG_PARAMETER *params, MAXROWS
static int send_upstream(MAXROWS_SESSION_DATA *csdata);
static int send_ok_upstream(MAXROWS_SESSION_DATA *csdata);
static int send_eof_upstream(MAXROWS_SESSION_DATA *csdata, size_t offset);
/* API BEGIN */
@ -438,6 +440,7 @@ static void maxrows_response_state_reset(MAXROWS_RESPONSE_STATE *state)
state->n_fields = 0;
state->n_rows = 0;
state->offset = 0;
state->rows_offset = 0;
}
/**
@ -511,6 +514,15 @@ static int handle_expecting_fields(MAXROWS_SESSION_DATA *csdata)
{
case 0xfe: // EOF, the one after the fields.
csdata->res.offset += packetlen;
/* Now set the offset to the first resultset
* this could be used for empty response handler
*/
if (!csdata->res.rows_offset)
{
csdata->res.rows_offset = csdata->res.offset;
}
csdata->state = MAXROWS_EXPECTING_ROWS;
rv = handle_rows(csdata);
break;
@ -599,7 +611,7 @@ static int handle_expecting_response(MAXROWS_SESSION_DATA *csdata)
if (csdata->discard_resultset)
{
rv = send_ok_upstream(csdata);
rv = send_eof_upstream(csdata, csdata->res.rows_offset);
csdata->state = MAXROWS_EXPECTING_NOTHING;
}
else
@ -746,7 +758,7 @@ static int handle_rows(MAXROWS_SESSION_DATA *csdata)
// Send data in buffer or empty resultset
if (csdata->discard_resultset)
{
rv = send_ok_upstream(csdata);
rv = send_eof_upstream(csdata, csdata->res.rows_offset);
}
else
{
@ -779,7 +791,7 @@ static int handle_rows(MAXROWS_SESSION_DATA *csdata)
if (packetlen < MYSQL_EOF_PACKET_LEN)
{
MXS_ERROR("EOF packet has size of %lu instead of %d", packetlen, MYSQL_EOF_PACKET_LEN);
rv = send_ok_upstream(csdata);
rv = send_eof_upstream(csdata, csdata->res.rows_offset);
csdata->state = MAXROWS_EXPECTING_NOTHING;
break;
}
@ -800,7 +812,7 @@ static int handle_rows(MAXROWS_SESSION_DATA *csdata)
// Discard data or send data
if (csdata->discard_resultset)
{
rv = send_ok_upstream(csdata);
rv = send_eof_upstream(csdata, csdata->res.rows_offset);
}
else
{
@ -907,7 +919,20 @@ static int send_ok_upstream(MAXROWS_SESSION_DATA *csdata)
{
/* Note: sequence id is always 01 (4th byte) */
uint8_t ok[MYSQL_OK_PACKET_MIN_LEN] = {07, 00, 00, 01, 00, 00, 00, 02, 00, 00, 00};
ss_dassert(csdata->res.data != NULL);
GWBUF *packet = gwbuf_alloc(MYSQL_OK_PACKET_MIN_LEN);
if(!packet)
{
/* Abort clienrt connection */
poll_fake_hangup_event(csdata->session->client_dcb);
gwbuf_free(csdata->res.data);
csdata->res.data = NULL;
gwbuf_free(packet);
return 0;
}
uint8_t *ptr = GWBUF_DATA(packet);
memcpy(ptr, &ok, MYSQL_OK_PACKET_MIN_LEN);
@ -919,3 +944,68 @@ static int send_ok_upstream(MAXROWS_SESSION_DATA *csdata)
return rv;
}
/**
* Send upstream the Respnse Buffer up to columns def in response
* including its EOF of the first result set
* An EOF packet for empty result set with no MULTI flags is added
* at the end.
*
* @param csdata Session data
* @param offset The offset to server reply pointing to
* next byte after EOF or column definitions of first result set
*
* @return Whatever the upstream returns.
*/
static int send_eof_upstream(MAXROWS_SESSION_DATA *csdata, size_t offset)
{
int rv = -1;
/* Sequence byte is #3 */
uint8_t eof[MYSQL_EOF_PACKET_LEN] = {05, 00, 00, 01, 0xfe, 00, 00, 02, 00};
GWBUF *new_pkt = NULL;
ss_dassert(csdata->res.data != NULL);
/* Data to send + added EOF */
uint8_t *new_result = MXS_MALLOC(offset + MYSQL_EOF_PACKET_LEN);
if (new_result)
{
/* Get contiguous data from beginning to specified offset */
gwbuf_copy_data(csdata->res.data, 0, offset, new_result);
/* Increment sequence number for the EOF being added for empty resultset:
* last one if found in EOF terminating column def
*/
eof[3] = new_result[offset - (MYSQL_EOF_PACKET_LEN - 3)] + 1;
/* Copy EOF data */
memcpy(new_result + offset, &eof, MYSQL_EOF_PACKET_LEN);
/* Create new packet */
new_pkt = gwbuf_alloc_and_load(offset + MYSQL_EOF_PACKET_LEN, new_result);
/* Free intermediate data */
MXS_FREE(new_result);
if (new_pkt)
{
/* new_pkt will be freed by write routine */
rv = csdata->up.clientReply(csdata->up.instance, csdata->up.session, new_pkt);
}
}
/* Abort client connection */
if (!(new_result && new_pkt))
{
/* Abort client connection */
poll_fake_hangup_event(csdata->session->client_dcb);
rv = 0;
}
/* Free full input buffer */
gwbuf_free(csdata->res.data);
csdata->res.data = NULL;
return rv;
}