// -*- mode: c++; c-file-style: "k&r"; c-basic-offset: 4 -*-
/***********************************************************************
*
* store/tapirstore/shardclient.cc:
* Single shard tapir transactional client.
*
* Copyright 2015 Irene Zhang <iyzhang@cs.washington.edu>
* Naveen Kr. Sharma <naveenks@cs.washington.edu>
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
**********************************************************************/
#include "store/tapirstore/shardclient.h"
namespace tapirstore {
using namespace std;
using namespace proto;
ShardClient::ShardClient(const string &configPath,
Transport *transport, uint64_t client_id, int
shard, int closestReplica)
: client_id(client_id), transport(transport), shard(shard)
{
ifstream configStream(configPath);
if (configStream.fail()) {
Panic("Unable to read configuration file: %s\n", configPath.c_str());
}
transport::Configuration config(configStream);
this->config = &config;
client = new replication::ir::IRClient(config, transport, client_id);
if (closestReplica == -1) {
replica = client_id % config.n;
} else {
replica = closestReplica;
}
Debug("Sending unlogged to replica %i", replica);
waiting = NULL;
blockingBegin = NULL;
}
ShardClient::~ShardClient()
{
delete client;
}
void
ShardClient::Begin(uint64_t id)
{
Debug("[shard %i] BEGIN: %lu", shard, id);
// Wait for any previous pending requests.
if (blockingBegin != NULL) {
blockingBegin->GetReply();
delete blockingBegin;
blockingBegin = NULL;
}
}
void
ShardClient::Get(uint64_t id, const string &key, Promise *promise)
{
// Send the GET operation to appropriate shard.
Debug("[shard %i] Sending GET [%lu : %s]", shard, id, key.c_str());
// create request
string request_str;
Request request;
request.set_op(Request::GET);
request.set_txnid(id);
request.mutable_get()->set_key(key);
request.SerializeToString(&request_str);
// set to 1 second by default
int timeout = (promise != NULL) ? promise->GetTimeout() : 1000;
transport->Timer(0, [=]() {
waiting = promise;
client->InvokeUnlogged(replica,
request_str,
bind(&ShardClient::GetCallback,
this,
placeholders::_1,
placeholders::_2),
bind(&ShardClient::GetTimeout,
this),
timeout); // timeout in ms
});
}
void
ShardClient::Get(uint64_t id, const string &key,
const Timestamp ×tamp, Promise *promise)
{
// Send the GET operation to appropriate shard.
Debug("[shard %i] Sending GET [%lu : %s]", shard, id, key.c_str());
// create request
string request_str;
Request request;
request.set_op(Request::GET);
request.set_txnid(id);
request.mutable_get()->set_key(key);
timestamp.serialize(request.mutable_get()->mutable_timestamp());
request.SerializeToString(&request_str);
// set to 1 second by default
int timeout = (promise != NULL) ? promise->GetTimeout() : 1000;
transport->Timer(0, [=]() {
waiting = promise;
client->InvokeUnlogged(
replica,
request_str,
bind(&ShardClient::GetCallback, this,
placeholders::_1,
placeholders::_2),
bind(&ShardClient::GetTimeout, this),
timeout); // timeout in ms
});
}
void
ShardClient::Put(uint64_t id,
const string &key,
const string &value,
Promise *promise)
{
Panic("Unimplemented PUT");
return;
}
void
ShardClient::Prepare(uint64_t id, const Transaction &txn,
const Timestamp ×tamp, Promise *promise)
{
Debug("[shard %i] Sending PREPARE [%lu]", shard, id);
// create prepare request
string request_str;
Request request;
request.set_op(Request::PREPARE);
request.set_txnid(id);
txn.serialize(request.mutable_prepare()->mutable_txn());
timestamp.serialize(request.mutable_prepare()->mutable_timestamp());
request.SerializeToString(&request_str);
transport->Timer(0, [=]() {
waiting = promise;
client->InvokeConsensus(
request_str,
bind(&ShardClient::TapirDecide, this,
placeholders::_1),
bind(&ShardClient::PrepareCallback, this,
placeholders::_1,
placeholders::_2));
});
}
std::string
ShardClient::TapirDecide(const std::map<std::string, std::size_t> &results)
{
// If a majority say prepare_ok,
int ok_count = 0;
Timestamp ts = 0;
string final_reply_str;
Reply final_reply;
for (const auto& string_and_count : results) {
const std::string &s = string_and_count.first;
const std::size_t count = string_and_count.second;
Reply reply;
reply.ParseFromString(s);
if (reply.status() == REPLY_OK) {
ok_count += count;
} else if (reply.status() == REPLY_FAIL) {
return s;
} else if (reply.status() == REPLY_RETRY) {
Timestamp t(reply.timestamp());
if (t > ts) {
ts = t;
}
}
}
if (ok_count >= config->QuorumSize()) {
final_reply.set_status(REPLY_OK);
} else {
final_reply.set_status(REPLY_RETRY);
ts.serialize(final_reply.mutable_timestamp());
}
final_reply.SerializeToString(&final_reply_str);
return final_reply_str;
}
void
ShardClient::Commit(uint64_t id, const Transaction &txn,
uint64_t timestamp, Promise *promise)
{
Debug("[shard %i] Sending COMMIT [%lu]", shard, id);
// create commit request
string request_str;
Request request;
request.set_op(Request::COMMIT);
request.set_txnid(id);
request.mutable_commit()->set_timestamp(timestamp);
request.SerializeToString(&request_str);
blockingBegin = new Promise(COMMIT_TIMEOUT);
transport->Timer(0, [=]() {
waiting = promise;
client->InvokeInconsistent(
request_str,
bind(&ShardClient::CommitCallback, this,
placeholders::_1,
placeholders::_2));
});
}
void
ShardClient::Abort(uint64_t id, const Transaction &txn, Promise *promise)
{
Debug("[shard %i] Sending ABORT [%lu]", shard, id);
// create abort request
string request_str;
Request request;
request.set_op(Request::ABORT);
request.set_txnid(id);
txn.serialize(request.mutable_abort()->mutable_txn());
request.SerializeToString(&request_str);
blockingBegin = new Promise(ABORT_TIMEOUT);
transport->Timer(0, [=]() {
waiting = promise;
client->InvokeInconsistent(
request_str,
bind(&ShardClient::AbortCallback, this,
placeholders::_1,
placeholders::_2));
});
}
void
ShardClient::GetTimeout()
{
if (waiting != NULL) {
Promise *w = waiting;
waiting = NULL;
w->Reply(REPLY_TIMEOUT);
}
}
/* Callback from a shard replica on get operation completion. */
void
ShardClient::GetCallback(const string &request_str, const string &reply_str)
{
/* Replies back from a shard. */
Reply reply;
reply.ParseFromString(reply_str);
Debug("[shard %lu:%i] GET callback [%d]", client_id, shard, reply.status());
if (waiting != NULL) {
Promise *w = waiting;
waiting = NULL;
if (reply.has_timestamp()) {
w->Reply(reply.status(), Timestamp(reply.timestamp()), reply.value());
} else {
w->Reply(reply.status(), reply.value());
}
}
}
/* Callback from a shard replica on prepare operation completion. */
void
ShardClient::PrepareCallback(const string &request_str, const string &reply_str)
{
Reply reply;
reply.ParseFromString(reply_str);
Debug("[shard %lu:%i] PREPARE callback [%d]", client_id, shard, reply.status());
if (waiting != NULL) {
Promise *w = waiting;
waiting = NULL;
if (reply.has_timestamp()) {
w->Reply(reply.status(), Timestamp(reply.timestamp()));
} else {
w->Reply(reply.status(), Timestamp());
}
}
}
/* Callback from a shard replica on commit operation completion. */
void
ShardClient::CommitCallback(const string &request_str, const string &reply_str)
{
// COMMITs always succeed.
ASSERT(blockingBegin != NULL);
blockingBegin->Reply(0);
if (waiting != NULL) {
waiting = NULL;
}
Debug("[shard %lu:%i] COMMIT callback", client_id, shard);
}
/* Callback from a shard replica on abort operation completion. */
void
ShardClient::AbortCallback(const string &request_str, const string &reply_str)
{
// ABORTs always succeed.
ASSERT(blockingBegin != NULL);
blockingBegin->Reply(0);
if (waiting != NULL) {
waiting = NULL;
}
Debug("[shard %lu:%i] ABORT callback", client_id, shard);
}
} // namespace tapir