1berry/MariaDB-server
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Auto-merge from mysql-5.1-bugteam for bug#42503.

Browse Source
This commit is contained in:
Dmitry Shulga 2010-09-16 17:38:13 +07:00
commit a684f8df20
2 changed files with 65 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
sql/net_serv.cc
View File

@ -164,7 +164,17 @@ my_bool net_realloc(NET *net, size_t length)
DBUG_ENTER("net_realloc");
DBUG_PRINT("enter",("length: %lu", (ulong) length));
if (length >= net->max_packet_size)
/*
When compression is off, net->where_b is always 0.
With compression turned on, net->where_b may indicate
that we still have a piece of the previous logical
packet in the buffer, unprocessed. Take it into account
when checking that max_allowed_packet is not exceeded.
This ensures that the client treats max_allowed_packet
limit identically, regardless of compression being on
or off.
*/
if (length >= (net->max_packet_size + net->where_b))
{
DBUG_PRINT("error", ("Packet too large. Max size: %lu",
net->max_packet_size));

59
sql/sql_cache.cc
View File

@ -1346,6 +1346,55 @@ end:
}
/**
Send a single memory block from the query cache.
Respects the client/server protocol limits for the
size of the network packet, and splits a large block
in pieces to ensure that individual piece doesn't exceed
the maximal allowed size of the network packet (16M).
@param[in] net NET handler
@param[in] packet packet to send
@param[in] len packet length
@return Operation status
@retval FALSE On success
@retval TRUE On error
*/
static bool
send_data_in_chunks(NET *net, const uchar *packet, ulong len)
{
/*
On the client we may require more memory than max_allowed_packet
to keep, both, the truncated last logical packet, and the
compressed next packet. This never (or in practice never)
happens without compression, since without compression it's very
unlikely that a) a truncated logical packet would remain on the
client when it's time to read the next packet b) a subsequent
logical packet that is being read would be so large that
size-of-new-packet + size-of-old-packet-tail >
max_allowed_packet. To remedy this issue, we send data in 1MB
sized packets, that's below the current client default of 16MB
for max_allowed_packet, but large enough to ensure there is no
unnecessary overhead from too many syscalls per result set.
*/
static const ulong MAX_CHUNK_LENGTH= 1024*1024;
while (len > MAX_CHUNK_LENGTH)
{
if (net_real_write(net, packet, MAX_CHUNK_LENGTH))
return TRUE;
packet+= MAX_CHUNK_LENGTH;
len-= MAX_CHUNK_LENGTH;
}
if (len && net_real_write(net, packet, len))
return TRUE;
return FALSE;
}
/*
Check if the query is in the cache. If it was cached, send it
to the user.
@ -1655,11 +1704,11 @@ def_week_frmt: %lu, in_trans: %d, autocommit: %d",
ALIGN_SIZE(sizeof(Query_cache_result)))));
Query_cache_result *result = result_block->result();
if (net_real_write(&thd->net, result->data(),
result_block->used -
result_block->headers_len() -
ALIGN_SIZE(sizeof(Query_cache_result))))
break; // Client aborted
if (send_data_in_chunks(&thd->net, result->data(),
result_block->used -
result_block->headers_len() -
ALIGN_SIZE(sizeof(Query_cache_result))))
break; // Client aborted
result_block = result_block->next;
thd->net.pkt_nr= query->last_pkt_nr; // Keep packet number updated
} while (result_block != first_result_block);