/*
* Do a byte-by-byte comparison between a given plan and a saved one.
*
* Returns true if identical, false otherwise
*
*/
static bool
workfile_mgr_compare_plan(workfile_set *work_set, workfile_set_plan *sf_plan)
{
Assert(NULL != work_set);
Assert(NULL != sf_plan);
ExecWorkFile *plan_file = workfile_mgr_open_fileno(work_set, WORKFILE_NUM_ALL_PLAN);
elog(gp_workfile_caching_loglevel, "Loading and comparing query plan from file %s",
ExecWorkFile_GetFileName(plan_file));
if (plan_file == NULL)
{
elog(gp_workfile_caching_loglevel, "could not open plan file for matching for set %s",
work_set->path);
return false;
}
char buffer[BLCKSZ];
uint64 plan_offset = 0;
bool match = false;
while (true)
{
uint64 size_read = ExecWorkFile_Read(plan_file, buffer, sizeof(buffer));
if (plan_offset + size_read > sf_plan->serialized_plan_len)
{
/* Disk plan is larger than new plan. No match */
break;
}
if (size_read < sizeof(buffer) &&
plan_offset + size_read < sf_plan->serialized_plan_len)
{
/* Disk plan is smaller than new plan. No match */
break;
}
/* We have enough data in memory to compare */
char *plan_pointer = ((char *) sf_plan->serialized_plan ) + plan_offset;
if ( memcmp(buffer, plan_pointer, size_read) != 0)
{
break;
}
/* Reached the end of both streams, with no miss-match */
if (size_read < sizeof(buffer))
{
match = true;
break;
}
plan_offset += size_read;
}
workfile_mgr_close_file(work_set, plan_file);
return match;
}
/*
* Close a logical tape set and release all resources.
*/
void
LogicalTapeSetClose(LogicalTapeSet *lts, workfile_set *workset)
{
Assert(lts != NULL);
workfile_mgr_close_file(workset, lts->pfile);
if(lts->freeBlocks)
pfree(lts->freeBlocks);
pfree(lts);
}
/*
* Save the serialized plan to a file in the workfile set.
* It will be used to do full plan matching before reusing.
*/
static void
workfile_mgr_save_plan(workfile_set *work_set, workfile_set_plan *sf_plan)
{
Assert(work_set);
Assert(sf_plan);
ExecWorkFile *plan_file = workfile_mgr_create_fileno(work_set, WORKFILE_NUM_ALL_PLAN);
insist_log(plan_file != NULL, "Could not create temporary work file: %m");
elog(gp_workfile_caching_loglevel, "Saving query plan to file %s", ExecWorkFile_GetFileName(plan_file));
bool res = ExecWorkFile_Write(plan_file, sf_plan->serialized_plan,
sf_plan->serialized_plan_len);
if(!res)
{
workfile_mgr_report_error();
}
workfile_mgr_close_file(work_set, plan_file);
}
