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/** NDN-Atmos: Cataloging Service for distributed data originally developed
* for atmospheric science data
* Copyright (C) 2015 Colorado State University
*
* NDN-Atmos 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 of the License, or
* (at your option) any later version.
*
* NDN-Atmos 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 NDN-Atmos. If not, see <http://www.gnu.org/licenses/>.
**/
#ifndef ATMOS_QUERY_QUERY_ADAPTER_HPP
#define ATMOS_QUERY_QUERY_ADAPTER_HPP
#include "util/catalog-adapter.hpp"
#include "util/mysql-util.hpp"
#include "util/config-file.hpp"
#include <thread>
#include <json/reader.h>
#include <json/value.h>
#include <json/writer.h>
#include <ndn-cxx/data.hpp>
#include <ndn-cxx/face.hpp>
#include <ndn-cxx/interest.hpp>
#include <ndn-cxx/interest-filter.hpp>
#include <ndn-cxx/name.hpp>
#include <ndn-cxx/security/key-chain.hpp>
#include <ndn-cxx/util/time.hpp>
#include <ndn-cxx/encoding/encoding-buffer.hpp>
#include <ndn-cxx/util/in-memory-storage-lru.hpp>
#include <ndn-cxx/util/string-helper.hpp>
#include <ChronoSync/socket.hpp>
#include "mysql/mysql.h"
#include <map>
#include <unordered_map>
#include <memory>
#include <mutex>
#include <sstream>
#include <string>
#include <array>
#include <utility>
#include "util/logger.hpp"
namespace atmos {
namespace query {
#ifdef HAVE_LOG4CXX
INIT_LOGGER("QueryAdapter");
#endif
// todo: calculate payload limit by get the size of a signed empty Data packet
static const size_t PAYLOAD_LIMIT = 7000;
/**
* QueryAdapter handles the Query usecases for the catalog
*/
template <typename DatabaseHandler>
class QueryAdapter : public atmos::util::CatalogAdapter {
public:
/**
* Constructor
*
* @param face: Face that will be used for NDN communications
* @param keyChain: KeyChain that will be used for data signing
* @param syncSocket: ChronoSync socket
*/
QueryAdapter(const std::shared_ptr<ndn::Face>& face,
const std::shared_ptr<ndn::KeyChain>& keyChain,
const std::shared_ptr<chronosync::Socket>& syncSocket);
virtual
~QueryAdapter();
/**
* Helper function to specify section handler
*/
void
setConfigFile(util::ConfigFile& config,
const ndn::Name& prefix,
const std::vector<std::string>& nameFields,
const std::string& databaseTable);
protected:
/**
* Helper function for configuration parsing
*/
void
onConfig(const util::ConfigSection& section,
bool isDryDun,
const std::string& fileName,
const ndn::Name& prefix);
/**
* Handles incoming query requests by stripping the filter off the Interest to get the
* actual request out. This removes the need for a 2-step Interest-Data retrieval.
*
* @param filter: InterestFilter that caused this Interest to be routed
* @param interest: Interest that needs to be handled
*/
virtual void
onQueryInterest(const ndn::InterestFilter& filter, const ndn::Interest& interest);
/**
* Handles requests for responses to an existing query
*
* @param filter: InterestFilter that caused this Interest to be routed
* @param interest: Interest that needs to be handled
*/
virtual void
onQueryResultsInterest(const ndn::InterestFilter& filter, const ndn::Interest& interest);
/**
* Handles requests for responses to an filter initialization request
*
* @param filter: InterestFilter that caused this Interest to be routed
* @param interest: Interest that needs to be handled
*/
virtual void
onFiltersInitializationInterest(const ndn::InterestFilter& filter, const ndn::Interest& interest);
/**
* Helper function that generates query results from a Json query carried in the Interest
*
* @param interest: Interest that needs to be handled
*/
void
populateFiltersMenu(std::shared_ptr<const ndn::Interest> interest);
void
getFiltersMenu(Json::Value& value);
/**
* Helper function that makes query-results data
*
* @param segmentPrefix: Name that identifies the Prefix for the Data
* @param value: Json::Value to be sent in the Data
* @param segmentNo: uint64_t the segment for this Data
* @param isFinalBlock: bool to indicate whether this needs to be flagged in the Data as the
* last entry
* @param isAutocomplete: bool to indicate whether this is an autocomplete message
* @param resultCount: the number of records in the query results
* @param viewStart: the start index of the record in the query results payload
* @param viewEnd: the end index of the record in the query results payload
* @param lastComponent: flag to indicate the content contains the last component for
autocompletion query
*/
std::shared_ptr<ndn::Data>
makeReplyData(const ndn::Name& segmentPrefix,
const Json::Value& value,
uint64_t segmentNo,
bool isFinalBlock,
bool isAutocomplete,
uint64_t resultCount,
uint64_t viewStart,
uint64_t viewEnd,
bool lastComponent);
/**
* Helper function that generates query results from a Json query carried in the Interest
*
* @param interest: Interest that needs to be handled
*/
void
runJsonQuery(std::shared_ptr<const ndn::Interest> interest);
/**
* Helper function that makes ACK data
*
* @param interest: Intersts that needs to be handled
* @param version: Version that needs to be in the data name
*/
std::shared_ptr<ndn::Data>
makeAckData(std::shared_ptr<const ndn::Interest> interest,
const ndn::Name::Component& version);
/**
* Helper function that sends NACK
*
* @param dataPrefix: prefix for the data packet
*/
void
sendNack(const ndn::Name& dataPrefix);
/**
* Helper function that generates the sqlQuery string for component-based query
* @param sqlQuery: stringstream to save the sqlQuery string
* @param jsonValue: Json value that contains the query information
*/
bool
json2Sql(std::stringstream& sqlQuery,
Json::Value& jsonValue);
/**
* Helper function that signs the data
*/
void
signData(ndn::Data& data);
/**
* Helper function that publishes query-results data segments
*/
virtual void
prepareSegments(const ndn::Name& segmentPrefix,
const std::string& sqlString,
bool autocomplete,
bool lastComponent);
/**
* Helper function to set the DatabaseHandler
*/
void
setDatabaseHandler(const util::ConnectionDetails& databaseId);
/**
* Helper function that set filters to make the adapter work
*/
void
setFilters();
void
setCatalogId();
/**
* Helper function that generates the sqlQuery string for autocomplete query
* @param sqlQuery: stringstream to save the sqlQuery string
* @param jsonValue: Json value that contains the query information
* @param lastComponent: Flag to mark the last component query
*/
bool
json2AutocompletionSql(std::stringstream& sqlQuery,
Json::Value& jsonValue,
bool& lastComponent);
bool
json2PrefixBasedSearchSql(std::stringstream& sqlQuery,
Json::Value& jsonValue);
ndn::Name
getQueryResultsName(std::shared_ptr<const ndn::Interest> interest,
const ndn::Name::Component& version);
std::string
getChronoSyncDigest();
protected:
typedef std::unordered_map<ndn::Name, const ndn::RegisteredPrefixId*> RegisteredPrefixList;
// Handle to the Catalog's database
std::shared_ptr<DatabaseHandler> m_databaseHandler;
const std::shared_ptr<chronosync::Socket>& m_socket;
// mutex to control critical sections
std::mutex m_mutex;
// @{ needs m_mutex protection
// The Queries we are currently writing to
//std::map<std::string, std::shared_ptr<ndn::Data>> m_activeQueryToFirstResponse;
ndn::util::InMemoryStorageLru m_activeQueryToFirstResponse;
ndn::util::InMemoryStorageLru m_cache;
std::string m_chronosyncDigest;
// @}
RegisteredPrefixList m_registeredPrefixList;
ndn::Name m_catalogId; // should be replaced with the PK digest
std::vector<std::string> m_filterCategoryNames;
};
template <typename DatabaseHandler>
QueryAdapter<DatabaseHandler>::QueryAdapter(const std::shared_ptr<ndn::Face>& face,
const std::shared_ptr<ndn::KeyChain>& keyChain,
const std::shared_ptr<chronosync::Socket>& syncSocket)
: util::CatalogAdapter(face, keyChain)
, m_socket(syncSocket)
, m_activeQueryToFirstResponse(100000)
, m_cache(250000)
, m_chronosyncDigest("0")
, m_catalogId("catalogIdPlaceHolder") // initialize for unitests
{
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::setFilters()
{
ndn::Name queryPrefix = ndn::Name(m_prefix).append("query");
m_registeredPrefixList[queryPrefix] = m_face->setInterestFilter(ndn::InterestFilter(queryPrefix),
bind(&query::QueryAdapter<DatabaseHandler>::onQueryInterest,
this, _1, _2),
bind(&query::QueryAdapter<DatabaseHandler>::onRegisterSuccess,
this, _1),
bind(&query::QueryAdapter<DatabaseHandler>::onRegisterFailure,
this, _1, _2));
ndn::Name queryResultsPrefix = ndn::Name(m_prefix).append("query-results");
m_registeredPrefixList[queryResultsPrefix] =
m_face->setInterestFilter(ndn::InterestFilter(ndn::Name(m_prefix)
.append("query-results").append(m_catalogId)),
bind(&query::QueryAdapter<DatabaseHandler>::onQueryResultsInterest,
this, _1, _2),
bind(&query::QueryAdapter<DatabaseHandler>::onRegisterSuccess,
this, _1),
bind(&query::QueryAdapter<DatabaseHandler>::onRegisterFailure,
this, _1, _2));
ndn::Name filtersInitializationPrefix = ndn::Name(m_prefix).append("filters-initialization");
m_registeredPrefixList[filtersInitializationPrefix] =
m_face->setInterestFilter(ndn::InterestFilter(ndn::Name(m_prefix).append("filters-initialization")),
bind(&query::QueryAdapter<DatabaseHandler>::onFiltersInitializationInterest,
this, _1, _2),
bind(&query::QueryAdapter<DatabaseHandler>::onRegisterSuccess,
this, _1),
bind(&query::QueryAdapter<DatabaseHandler>::onRegisterFailure,
this, _1, _2));
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::setConfigFile(util::ConfigFile& config,
const ndn::Name& prefix,
const std::vector<std::string>& nameFields,
const std::string& databaseTable)
{
m_nameFields = nameFields;
m_databaseTable = databaseTable;
config.addSectionHandler("queryAdapter", bind(&QueryAdapter<DatabaseHandler>::onConfig, this,
_1, _2, _3, prefix));
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::onConfig(const util::ConfigSection& section,
bool isDryRun,
const std::string& filename,
const ndn::Name& prefix)
{
using namespace util;
if (isDryRun) {
return;
}
std::string signingId, dbServer, dbName, dbUser, dbPasswd;
for (auto item = section.begin();
item != section.end();
++item)
{
if (item->first == "signingId") {
signingId = item->second.get_value<std::string>();
if (signingId.empty()) {
throw Error("Empty value for \"signingId\""
" in \"query\" section");
}
}
if (item->first == "filterCategoryNames") {
std::istringstream ss(item->second.get_value<std::string>());
std::string token;
while(std::getline(ss, token, ',')) {
m_filterCategoryNames.push_back(token);
}
}
if (item->first == "database") {
const util::ConfigSection& dataSection = item->second;
for (auto subItem = dataSection.begin();
subItem != dataSection.end();
++subItem)
{
if (subItem->first == "dbServer") {
dbServer = subItem->second.get_value<std::string>();
}
if (subItem->first == "dbName") {
dbName = subItem->second.get_value<std::string>();
}
if (subItem->first == "dbUser") {
dbUser = subItem->second.get_value<std::string>();
}
if (subItem->first == "dbPasswd") {
dbPasswd = subItem->second.get_value<std::string>();
}
}
if (dbServer.empty()){
throw Error("Invalid value for \"dbServer\""
" in \"query\" section");
}
if (dbName.empty()){
throw Error("Invalid value for \"dbName\""
" in \"query\" section");
}
if (dbUser.empty()){
throw Error("Invalid value for \"dbUser\""
" in \"query\" section");
}
if (dbPasswd.empty()){
throw Error("Invalid value for \"dbPasswd\""
" in \"query\" section");
}
}
}
if (m_filterCategoryNames.empty()) {
throw Error("Empty value for \"filterCategoryNames\" in \"query\" section");
}
m_prefix = prefix;
m_signingId = ndn::Name(signingId);
setCatalogId();
util::ConnectionDetails mysqlId(dbServer, dbUser, dbPasswd, dbName);
setDatabaseHandler(mysqlId);
setFilters();
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::setCatalogId()
{
//empty
}
template <>
void
QueryAdapter<MYSQL>::setCatalogId()
{
// use public key digest as the catalog ID
ndn::Name keyId;
if (m_signingId.empty()) {
keyId = m_keyChain->getDefaultKeyNameForIdentity(m_keyChain->getDefaultIdentity());
} else {
keyId = m_keyChain->getDefaultKeyNameForIdentity(m_signingId);
}
std::shared_ptr<ndn::PublicKey> pKey = m_keyChain->getPib().getPublicKey(keyId);
ndn::Block keyDigest = pKey->computeDigest();
m_catalogId.clear();
m_catalogId.append(ndn::toHex(*keyDigest.getBuffer()));
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::setDatabaseHandler(const util::ConnectionDetails& databaseId)
{
//empty
}
template <>
void
QueryAdapter<MYSQL>::setDatabaseHandler(const util::ConnectionDetails& databaseId)
{
std::shared_ptr<MYSQL> conn = atmos::util::MySQLConnectionSetup(databaseId);
m_databaseHandler = conn;
}
template <typename DatabaseHandler>
QueryAdapter<DatabaseHandler>::~QueryAdapter()
{
for (const auto& itr : m_registeredPrefixList) {
if (static_cast<bool>(itr.second))
m_face->unsetInterestFilter(itr.second);
}
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::onQueryInterest(const ndn::InterestFilter& filter,
const ndn::Interest& interest)
{
_LOG_DEBUG(">> QueryAdapter::onQueryInterest");
if (interest.getName().size() != filter.getPrefix().size() + 1) {
// @todo: return a nack
return;
}
std::shared_ptr<const ndn::Interest> interestPtr = interest.shared_from_this();
_LOG_DEBUG("Interest : " << interestPtr->getName());
// @todo: use thread pool
std::thread queryThread(&QueryAdapter<DatabaseHandler>::runJsonQuery,
this,
interestPtr);
queryThread.join();
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::onQueryResultsInterest(const ndn::InterestFilter& filter,
const ndn::Interest& interest)
{
// FIXME Results are currently getting served out of the forwarder's
// CS so we just ignore any retrieval Interests that hit us for
// now. In the future, this should check some form of
// InMemoryStorage.
_LOG_DEBUG(">> QueryAdapter::onQueryResultsInterest");
auto data = m_cache.find(interest.getName());
if (data) {
m_face->put(*data);
}
_LOG_DEBUG("<< QueryAdapter::onQueryResultsInterest");
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::onFiltersInitializationInterest(const ndn::InterestFilter& filter,
const ndn::Interest& interest)
{
_LOG_DEBUG(">> QueryAdapter::onFiltersInitializationInterest");
std::shared_ptr<const ndn::Interest> interestPtr = interest.shared_from_this();
_LOG_DEBUG("Interest : " << interestPtr->getName());
// TODO: save the content in memory, first check the memory, if not exists, start thread to generate it
// Note that if ChronoSync state changes, we need to clear the saved value, and regenerate it
auto data = m_cache.find(interest.getName());
if (data) {
m_face->put(*data);
}
else {
std::thread queryThread(&QueryAdapter<DatabaseHandler>::populateFiltersMenu,
this,
interestPtr);
queryThread.join();
}
_LOG_DEBUG("<< QueryAdapter::onFiltersInitializationInterest");
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::populateFiltersMenu(std::shared_ptr<const ndn::Interest> interest)
{
_LOG_DEBUG(">> QueryAdapter::populateFiltersMenu");
Json::Value filters;
Json::FastWriter fastWriter;
getFiltersMenu(filters);
const std::string filterValue = fastWriter.write(filters);
if (!filters.empty()) {
ndn::Name filterDataName(interest->getName());
filterDataName.append("stateVersion");// TODO: should replace with a state version
const char* payload = filterValue.c_str();
size_t payloadLength = filterValue.size();
size_t startIndex = 0, seqNo = 0;
if (filterValue.length() > PAYLOAD_LIMIT) {
payloadLength = PAYLOAD_LIMIT;
ndn::Name segmentName = ndn::Name(filterDataName).appendSegment(seqNo);
std::shared_ptr<ndn::Data> filterData = std::make_shared<ndn::Data>(segmentName);
filterData->setFreshnessPeriod(ndn::time::milliseconds(10000));
filterData->setContent(reinterpret_cast<const uint8_t*>(payload + startIndex), payloadLength);
signData(*filterData);
_LOG_DEBUG("Populate Filter Data :" << segmentName);
m_mutex.lock();
m_cache.insert(*filterData);
try {
m_face->put(*filterData);
}
catch (std::exception& e) {
_LOG_ERROR(e.what());
}
m_mutex.unlock();
seqNo++;
startIndex = payloadLength * seqNo + 1;
}
payloadLength = filterValue.size() - PAYLOAD_LIMIT * seqNo;
ndn::Name lastSegment = ndn::Name(filterDataName).appendSegment(seqNo);
std::shared_ptr<ndn::Data> filterData = std::make_shared<ndn::Data>(lastSegment);
filterData->setFreshnessPeriod(ndn::time::milliseconds(10000));
filterData->setContent(reinterpret_cast<const uint8_t*>(payload + startIndex), payloadLength);
filterData->setFinalBlockId(ndn::Name::Component::fromSegment(seqNo));
signData(*filterData);
m_mutex.lock();
m_cache.insert(*filterData);
m_face->put(*filterData);
m_mutex.unlock();
}
_LOG_DEBUG("<< QueryAdapter::populateFiltersMenu");
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::getFiltersMenu(Json::Value& value)
{
// empty
}
// get distinct value of each column
template <>
void
QueryAdapter<MYSQL>::getFiltersMenu(Json::Value& value)
{
_LOG_DEBUG(">> QueryAdapter::getFiltersMenu");
Json::Value tmp;
for (size_t i = 0; i < m_filterCategoryNames.size(); i++) {
std::string columnName = m_filterCategoryNames[i];
std::string getFilterSql("SELECT DISTINCT " + columnName +
" FROM " + m_databaseTable + ";");
std::string errMsg;
bool success;
std::shared_ptr<MYSQL_RES> results
= atmos::util::MySQLPerformQuery(m_databaseHandler, getFilterSql,
util::QUERY, success, errMsg);
if (!success) {
_LOG_ERROR(errMsg);
value.clear();
return;
}
while (MYSQL_ROW row = mysql_fetch_row(results.get()))
{
tmp[columnName].append(row[0]);
}
value.append(tmp);
tmp.clear();
}
_LOG_DEBUG("<< QueryAdapter::getFiltersMenu");
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::signData(ndn::Data& data)
{
if (m_signingId.empty())
m_keyChain->sign(data);
else {
ndn::Name keyName = m_keyChain->getDefaultKeyNameForIdentity(m_signingId);
ndn::Name certName = m_keyChain->getDefaultCertificateNameForKey(keyName);
m_keyChain->sign(data, certName);
}
}
template <typename DatabaseHandler>
ndn::Name
QueryAdapter<DatabaseHandler>::getQueryResultsName(std::shared_ptr<const ndn::Interest> interest,
const ndn::Name::Component& version)
{
// the server side should conform: http://redmine.named-data.net/projects/ndn-atmos/wiki/Query
// for now, should be /<prefix>/query-results/<catalog-id>/<query-parameters>/<version>
ndn::Name queryResultName(m_prefix);
queryResultName.append("query-results")
.append(m_catalogId)
.append(interest->getName().get(-1))
.append(version);
return queryResultName;
}
template <typename DatabaseHandler>
std::shared_ptr<ndn::Data>
QueryAdapter<DatabaseHandler>::makeAckData(std::shared_ptr<const ndn::Interest> interest,
const ndn::Name::Component& version)
{
std::string queryResultNameStr(getQueryResultsName(interest, version).toUri());
std::shared_ptr<ndn::Data> ack = std::make_shared<ndn::Data>(interest->getName());
ack->setContent(reinterpret_cast<const uint8_t*>(queryResultNameStr.c_str()),
queryResultNameStr.length());
ack->setFreshnessPeriod(ndn::time::milliseconds(10000));
signData(*ack);
_LOG_DEBUG("Make ACK : " << queryResultNameStr);
return ack;
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::sendNack(const ndn::Name& dataPrefix)
{
uint64_t segmentNo = 0;
std::shared_ptr<ndn::Data> nack =
std::make_shared<ndn::Data>(ndn::Name(dataPrefix).appendSegment(segmentNo));
nack->setFreshnessPeriod(ndn::time::milliseconds(10000));
nack->setFinalBlockId(ndn::Name::Component::fromSegment(segmentNo));
signData(*nack);
_LOG_DEBUG("Send Nack: " << ndn::Name(dataPrefix).appendSegment(segmentNo));
m_mutex.lock();
m_cache.insert(*nack);
m_mutex.unlock();
}
template <typename DatabaseHandler>
bool
QueryAdapter<DatabaseHandler>::json2Sql(std::stringstream& sqlQuery,
Json::Value& jsonValue)
{
_LOG_DEBUG(">> QueryAdapter::json2Sql");
_LOG_DEBUG(jsonValue.toStyledString());
if (jsonValue.type() != Json::objectValue) {
return false;
}
sqlQuery << "SELECT name FROM " << m_databaseTable;
bool input = false;
for (Json::Value::iterator iter = jsonValue.begin(); iter != jsonValue.end(); ++iter)
{
Json::Value key = iter.key();
Json::Value value = (*iter);
if (key == Json::nullValue || value == Json::nullValue) {
_LOG_ERROR("Null key or value in JsonValue");
return false;
}
// cannot convert to string
if (!key.isConvertibleTo(Json::stringValue) || !value.isConvertibleTo(Json::stringValue)) {
_LOG_ERROR("Malformed JsonQuery string");
return false;
}
if (key.asString().compare("?") == 0) {
continue;
}
if (input) {
sqlQuery << " AND";
} else {
sqlQuery << " WHERE";
}
sqlQuery << " " << key.asString() << "='" << value.asString() << "'";
input = true;
}
if (!input) { // Force it to be the empty set
return false;
}
sqlQuery << ";";
return true;
}
template <typename DatabaseHandler>
bool
QueryAdapter<DatabaseHandler>::json2AutocompletionSql(std::stringstream& sqlQuery,
Json::Value& jsonValue,
bool& lastComponent)
{
_LOG_DEBUG(">> QueryAdapter::json2AutocompletionSql");
_LOG_DEBUG(jsonValue.toStyledString());
if (jsonValue.type() != Json::objectValue) {
return false;
}
std::string typedString;
// get the string in the jsonValue
for (Json::Value::iterator iter = jsonValue.begin(); iter != jsonValue.end(); ++iter)
{
Json::Value key = iter.key();
Json::Value value = (*iter);
if (key == Json::nullValue || value == Json::nullValue) {
_LOG_ERROR("Null key or value in JsonValue");
return false;
}
// cannot convert to string
if (!key.isConvertibleTo(Json::stringValue) || !value.isConvertibleTo(Json::stringValue)) {
_LOG_ERROR("Malformed JsonQuery string");
return false;
}
if (key.asString().compare("?") == 0) {
typedString = value.asString();
// since the front end triggers the autocompletion when users typed '/',
// there must be a '/' at the end, and the first char must be '/'
if (typedString.at(typedString.length() - 1) != '/' || typedString.find("/") != 0)
return false;
break;
}
}
// 1. get the expected column number by parsing the typedString, so we can get the filed name
size_t pos = 0;
size_t start = 1; // start from the 1st char which is not '/'
size_t count = 0; // also the name to query for
std::string token;
std::string delimiter = "/";
std::map<std::string, std::string> typedComponents;
while ((pos = typedString.find(delimiter, start)) != std::string::npos) {
token = typedString.substr(start, pos - start);
if (count >= m_nameFields.size() - 1) {
return false;
}
// add column name and value (token) into map
typedComponents.insert(std::pair<std::string, std::string>(m_nameFields[count], token));
count++;
start = pos + 1;
}
// 2. generate the sql string (append what appears in the typed string, like activity='xxx'),
// return true
if (count == m_nameFields.size() - 1)
lastComponent = true; // indicate this query is to query the last component
bool more = false;
sqlQuery << "SELECT DISTINCT " << m_nameFields[count] << " FROM " << m_databaseTable;
for (std::map<std::string, std::string>::iterator it = typedComponents.begin();
it != typedComponents.end(); ++it) {
if (more)
sqlQuery << " AND";
else
sqlQuery << " WHERE";
sqlQuery << " " << it->first << "='" << it->second << "'";
more = true;
}
sqlQuery << ";";
return true;
}
template <typename DatabaseHandler>
bool
QueryAdapter<DatabaseHandler>::json2PrefixBasedSearchSql(std::stringstream& sqlQuery,
Json::Value& jsonValue)
{
_LOG_DEBUG(">> QueryAdapter::json2CompleteSearchSql");
_LOG_DEBUG(jsonValue.toStyledString());
if (jsonValue.type() != Json::objectValue) {
return false;
}
std::string typedString;
// get the string in the jsonValue
for (Json::Value::iterator iter = jsonValue.begin(); iter != jsonValue.end(); ++iter)
{
Json::Value key = iter.key();
Json::Value value = (*iter);
if (key == Json::nullValue || value == Json::nullValue) {
_LOG_ERROR("Null key or value in JsonValue");
return false;
}
// cannot convert to string
if (!key.isConvertibleTo(Json::stringValue) || !value.isConvertibleTo(Json::stringValue)) {
_LOG_ERROR("Malformed JsonQuery string");
return false;
}
if (key.asString().compare("??") == 0) {
typedString = value.asString();
if (typedString.empty() || typedString.find("/") != 0)
return false;
break;
}
}
// 1. get the expected column number by parsing the typedString, so we can get the filed name
size_t pos = 0;
size_t start = 1; // start from the 1st char which is not '/'
size_t count = 0; // also the name to query for
size_t typedStringLen = typedString.length();
std::string token;
std::string delimiter = "/";
std::vector<std::pair<std::string, std::string>> typedComponents;
while ((pos = typedString.find(delimiter, start)) != std::string::npos) {
token = typedString.substr(start, pos - start);
if (count >= m_nameFields.size()) {
return false;
}
// add column name and value (token) into map
typedComponents.push_back(std::make_pair(m_nameFields[count], token));
count++;
start = pos + 1;
}
// we may have a component after the last "/"
if (start < typedStringLen) {
typedComponents.push_back(std::make_pair(m_nameFields[count],
typedString.substr(start, typedStringLen - start)));
}
// 2. generate the sql string (append what appears in the typed string, like activity='xxx'),
// return true
bool more = false;
sqlQuery << "SELECT name FROM " << m_databaseTable;
for (std::vector<std::pair<std::string, std::string>>::iterator it = typedComponents.begin();
it != typedComponents.end(); ++it) {
if (more)
sqlQuery << " AND";
else
sqlQuery << " WHERE";
sqlQuery << " " << it->first << "='" << it->second << "'";
more = true;
}
sqlQuery << ";";
return true;
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::runJsonQuery(std::shared_ptr<const ndn::Interest> interest)
{
_LOG_DEBUG(">> QueryAdapter::runJsonQuery");
// 1) Strip the prefix off the ndn::Interest's ndn::Name
// +1 to grab JSON component after "query" component
ndn::Name::Component jsonStr = interest->getName()[m_prefix.size()+1];
// This one cannot parse the JsonQuery correctly, and should be moved to runJsonQuery
const std::string jsonQuery(reinterpret_cast<const char*>(jsonStr.value()), jsonStr.value_size());
if (jsonQuery.length() <= 0) {
// no JSON query, send Nack?
return;
}
// the version should be replaced with ChronoSync state digest
ndn::name::Component version;
if(m_socket != nullptr) {
const ndn::ConstBufferPtr digestPtr = m_socket->getRootDigest();
std::string digestStr = ndn::toHex(digestPtr->buf(), digestPtr->size());
_LOG_DEBUG("Original digest" << m_chronosyncDigest);
_LOG_DEBUG("New digest : " << digestStr);
// if the m_chronosyncDigest and the rootdigest are not equal
if (digestStr != m_chronosyncDigest) {
// (1) update chronosyncDigest
// (2) clear all staled ACK data
m_mutex.lock();
m_chronosyncDigest = digestStr;
m_activeQueryToFirstResponse.erase(ndn::Name("/"));
m_mutex.unlock();
_LOG_DEBUG("Change digest to " << m_chronosyncDigest);
}
version = ndn::name::Component::fromEscapedString(digestStr);
}
else {
version = ndn::name::Component::fromEscapedString(m_chronosyncDigest);
}
// try to respond with the inMemoryStorage
m_mutex.lock();
{ // !!! BEGIN CRITICAL SECTION !!!
auto data = m_activeQueryToFirstResponse.find(interest->getName());
if (data) {
_LOG_DEBUG("Answer with Data in IMS : " << data->getName());
m_face->put(*data);
m_mutex.unlock();
return;
}
} // !!! END CRITICAL SECTION !!!
m_mutex.unlock();
// 2) From the remainder of the ndn::Interest's ndn::Name, get the JSON out
Json::Value parsedFromString;
Json::Reader reader;
if (!reader.parse(jsonQuery, parsedFromString)) {
// @todo: send NACK?
_LOG_ERROR("Cannot parse the JsonQuery");
return;
}
std::shared_ptr<ndn::Data> ack = makeAckData(interest, version);
m_mutex.lock();
{ // !!! BEGIN CRITICAL SECTION !!!
// An unusual race-condition case, which requires things like PIT aggregation to be off.
auto data = m_activeQueryToFirstResponse.find(interest->getName());
if (data) {
m_face->put(*data);
m_mutex.unlock();
return;
}
// This is where things are expensive so we save them for the lock
// note that we ack the query with the cached ACK messages, but we should remove the ACKs
// that conatin the old version when ChronoSync is updated
m_activeQueryToFirstResponse.insert(*ack);
m_face->put(*ack);
} // !!! END CRITICAL SECTION !!!
m_mutex.unlock();
// 3) Convert the JSON Query into a MySQL one
bool autocomplete = false, lastComponent = false;
std::stringstream sqlQuery;
ndn::Name segmentPrefix(getQueryResultsName(interest, version));
Json::Value tmp;
// expect the autocomplete and the component-based query are separate
// if JSON::Value contains ? as key, is autocompletion
if (parsedFromString.get("?", tmp) != tmp) {
autocomplete = true;
if (!json2AutocompletionSql(sqlQuery, parsedFromString, lastComponent)) {
sendNack(segmentPrefix);
return;
}
}
else if (parsedFromString.get("??", tmp) != tmp) {
if (!json2PrefixBasedSearchSql(sqlQuery, parsedFromString)) {
sendNack(segmentPrefix);
return;
}
}
else {
if (!json2Sql(sqlQuery, parsedFromString)) {
sendNack(segmentPrefix);
return;
}
}
// 4) Run the Query
prepareSegments(segmentPrefix, sqlQuery.str(), autocomplete, lastComponent);
}
template <typename DatabaseHandler>
void
QueryAdapter<DatabaseHandler>::prepareSegments(const ndn::Name& segmentPrefix,
const std::string& sqlString,
bool autocomplete,
bool lastComponent)
{
// empty
}
// prepareSegments specilization function
template<>
void
QueryAdapter<MYSQL>::prepareSegments(const ndn::Name& segmentPrefix,
const std::string& sqlString,
bool autocomplete,
bool lastComponent)
{
_LOG_DEBUG(">> QueryAdapter::prepareSegments");
_LOG_DEBUG(sqlString);
std::string errMsg;
bool success;
// 4) Run the Query
std::shared_ptr<MYSQL_RES> results
= atmos::util::MySQLPerformQuery(m_databaseHandler, sqlString, util::QUERY, success, errMsg);
if (!success)
_LOG_ERROR(errMsg);
if (!results) {
_LOG_ERROR("NULL MYSQL_RES for" << sqlString);
// @todo: throw runtime error or log the error message?
return;
}
uint64_t resultCount = mysql_num_rows(results.get());
_LOG_DEBUG("Query resuls contain " << resultCount << "rows");
MYSQL_ROW row;
uint64_t segmentNo = 0;
Json::Value tmp;
Json::Value resultJson;
Json::FastWriter fastWriter;
uint64_t viewStart = 0, viewEnd = 0;
while ((row = mysql_fetch_row(results.get())))
{
tmp.append(row[0]);
const std::string tmpString = fastWriter.write(tmp);
if (tmpString.length() > PAYLOAD_LIMIT) {
std::shared_ptr<ndn::Data> data
= makeReplyData(segmentPrefix, resultJson, segmentNo, false,
autocomplete, resultCount, viewStart, viewEnd, lastComponent);
m_mutex.lock();
m_cache.insert(*data);
m_mutex.unlock();
tmp.clear();
resultJson.clear();
segmentNo++;
viewStart = viewEnd + 1;
}
resultJson.append(row[0]);
viewEnd++;
}
std::shared_ptr<ndn::Data> data
= makeReplyData(segmentPrefix, resultJson, segmentNo, true,
autocomplete, resultCount, viewStart, viewEnd, lastComponent);
m_mutex.lock();
m_cache.insert(*data);
m_mutex.unlock();
}
template <typename DatabaseHandler>
std::shared_ptr<ndn::Data>
QueryAdapter<DatabaseHandler>::makeReplyData(const ndn::Name& segmentPrefix,
const Json::Value& value,
uint64_t segmentNo,
bool isFinalBlock,
bool isAutocomplete,
uint64_t resultCount,
uint64_t viewStart,
uint64_t viewEnd,
bool lastComponent)
{
Json::Value entry;
Json::FastWriter fastWriter;
entry["resultCount"] = Json::UInt64(resultCount);;
entry["viewStart"] = Json::UInt64(viewStart);
entry["viewEnd"] = Json::UInt64(viewEnd);
if (lastComponent)
entry["lastComponent"] = Json::Value(true);
_LOG_DEBUG("resultCount " << resultCount << ";"
<< "viewStart " << viewStart << ";"
<< "viewEnd " << viewEnd);
if (isAutocomplete) {
entry["next"] = value;
} else {
entry["results"] = value;
}
const std::string jsonMessage = fastWriter.write(entry);
const char* payload = jsonMessage.c_str();
size_t payloadLength = jsonMessage.size() + 1;
ndn::Name segmentName(segmentPrefix);
segmentName.appendSegment(segmentNo);
std::shared_ptr<ndn::Data> data = std::make_shared<ndn::Data>(segmentName);
data->setContent(reinterpret_cast<const uint8_t*>(payload), payloadLength);
data->setFreshnessPeriod(ndn::time::milliseconds(10000));
if (isFinalBlock) {
data->setFinalBlockId(ndn::Name::Component::fromSegment(segmentNo));
}
_LOG_DEBUG(segmentName);
signData(*data);
return data;
}
} // namespace query
} // namespace atmos
#endif //ATMOS_QUERY_QUERY_ADAPTER_HPP