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/*
This file is part of TALER
Copyright (C) 2022 Taler Systems SA
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file exchangedb/pg_begin_shard.c
* @brief Implementation of the begin_shard function for Postgres
* @author Christian Grothoff
*/
#include "platform.h"
#include "taler_error_codes.h"
#include "taler_dbevents.h"
#include "taler_pq_lib.h"
#include "pg_begin_shard.h"
#include "pg_helper.h"
#include "pg_start.h"
#include "pg_rollback.h"
#include "pg_commit.h"
enum GNUNET_DB_QueryStatus
TEH_PG_begin_shard (void *cls,
const char *job_name,
struct GNUNET_TIME_Relative delay,
uint64_t shard_size,
uint64_t *start_row,
uint64_t *end_row)
{
struct PostgresClosure *pg = cls;
for (unsigned int retries = 0; retries<10; retries++)
{
if (GNUNET_OK !=
TEH_PG_start (pg,
"begin_shard"))
{
GNUNET_break (0);
return GNUNET_DB_STATUS_HARD_ERROR;
}
{
struct GNUNET_TIME_Absolute past;
enum GNUNET_DB_QueryStatus qs;
struct GNUNET_PQ_QueryParam params[] = {
GNUNET_PQ_query_param_string (job_name),
GNUNET_PQ_query_param_absolute_time (&past),
GNUNET_PQ_query_param_end
};
struct GNUNET_PQ_ResultSpec rs[] = {
GNUNET_PQ_result_spec_uint64 ("start_row",
start_row),
GNUNET_PQ_result_spec_uint64 ("end_row",
end_row),
GNUNET_PQ_result_spec_end
};
past = GNUNET_TIME_absolute_get ();
PREPARE (pg,
"get_open_shard",
"SELECT"
" start_row"
",end_row"
" FROM work_shards"
" WHERE job_name=$1"
" AND completed=FALSE"
" AND last_attempt<$2"
" ORDER BY last_attempt ASC"
" LIMIT 1;");
qs = GNUNET_PQ_eval_prepared_singleton_select (pg->conn,
"get_open_shard",
params,
rs);
switch (qs)
{
case GNUNET_DB_STATUS_HARD_ERROR:
GNUNET_break (0);
TEH_PG_rollback (pg);
return qs;
case GNUNET_DB_STATUS_SOFT_ERROR:
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Serialization error on getting open shard\n");
TEH_PG_rollback (pg);
continue;
case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
{
enum GNUNET_DB_QueryStatus qsz;
struct GNUNET_TIME_Absolute now;
struct GNUNET_PQ_QueryParam iparams[] = {
GNUNET_PQ_query_param_string (job_name),
GNUNET_PQ_query_param_absolute_time (&now),
GNUNET_PQ_query_param_uint64 (start_row),
GNUNET_PQ_query_param_uint64 (end_row),
GNUNET_PQ_query_param_end
};
now = GNUNET_TIME_relative_to_absolute (delay);
PREPARE (pg,
"reclaim_shard",
"UPDATE work_shards"
" SET last_attempt=$2"
" WHERE job_name=$1"
" AND start_row=$3"
" AND end_row=$4");
qsz = GNUNET_PQ_eval_prepared_non_select (pg->conn,
"reclaim_shard",
iparams);
switch (qsz)
{
case GNUNET_DB_STATUS_HARD_ERROR:
GNUNET_break (0);
TEH_PG_rollback (pg);
return qsz;
case GNUNET_DB_STATUS_SOFT_ERROR:
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Serialization error on claiming open shard\n");
TEH_PG_rollback (pg);
continue;
case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
goto commit;
case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
GNUNET_break (0); /* logic error, should be impossible */
TEH_PG_rollback (pg);
return GNUNET_DB_STATUS_HARD_ERROR;
}
}
break; /* actually unreachable */
case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
break; /* continued below */
}
} /* get_open_shard */
/* No open shard, find last 'end_row' */
{
enum GNUNET_DB_QueryStatus qs;
struct GNUNET_PQ_QueryParam params[] = {
GNUNET_PQ_query_param_string (job_name),
GNUNET_PQ_query_param_end
};
struct GNUNET_PQ_ResultSpec rs[] = {
GNUNET_PQ_result_spec_uint64 ("end_row",
start_row),
GNUNET_PQ_result_spec_end
};
PREPARE (pg,
"get_last_shard",
"SELECT"
" end_row"
" FROM work_shards"
" WHERE job_name=$1"
" ORDER BY end_row DESC"
" LIMIT 1;");
qs = GNUNET_PQ_eval_prepared_singleton_select (pg->conn,
"get_last_shard",
params,
rs);
switch (qs)
{
case GNUNET_DB_STATUS_HARD_ERROR:
GNUNET_break (0);
TEH_PG_rollback (pg);
return qs;
case GNUNET_DB_STATUS_SOFT_ERROR:
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Serialization error on getting last shard\n");
TEH_PG_rollback (pg);
continue;
case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
break;
case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
*start_row = 0; /* base-case: no shards yet */
break; /* continued below */
}
*end_row = *start_row + shard_size;
} /* get_last_shard */
/* Claim fresh shard */
{
enum GNUNET_DB_QueryStatus qs;
struct GNUNET_TIME_Absolute now;
struct GNUNET_PQ_QueryParam params[] = {
GNUNET_PQ_query_param_string (job_name),
GNUNET_PQ_query_param_absolute_time (&now),
GNUNET_PQ_query_param_uint64 (start_row),
GNUNET_PQ_query_param_uint64 (end_row),
GNUNET_PQ_query_param_end
};
now = GNUNET_TIME_relative_to_absolute (delay);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Trying to claim shard (%llu-%llu]\n",
(unsigned long long) *start_row,
(unsigned long long) *end_row);
PREPARE (pg,
"claim_next_shard",
"INSERT INTO work_shards"
"(job_name"
",last_attempt"
",start_row"
",end_row"
") VALUES "
"($1, $2, $3, $4);");
qs = GNUNET_PQ_eval_prepared_non_select (pg->conn,
"claim_next_shard",
params);
switch (qs)
{
case GNUNET_DB_STATUS_HARD_ERROR:
GNUNET_break (0);
TEH_PG_rollback (pg);
return qs;
case GNUNET_DB_STATUS_SOFT_ERROR:
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Serialization error on claiming next shard\n");
TEH_PG_rollback (pg);
continue;
case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
/* continued below */
break;
case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
/* someone else got this shard already,
try again */
TEH_PG_rollback (pg);
continue;
}
} /* claim_next_shard */
/* commit */
commit:
{
enum GNUNET_DB_QueryStatus qs;
qs = TEH_PG_commit (pg);
switch (qs)
{
case GNUNET_DB_STATUS_HARD_ERROR:
GNUNET_break (0);
TEH_PG_rollback (pg);
return qs;
case GNUNET_DB_STATUS_SOFT_ERROR:
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Serialization error on commit for beginning shard\n");
TEH_PG_rollback (pg);
continue;
case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Claimed new shard\n");
return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
}
}
} /* retry 'for' loop */
return GNUNET_DB_STATUS_SOFT_ERROR;
}
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