StringDictionaryProxy.cpp

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/*
 * Copyright 2017 MapD Technologies, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "StringDictionaryProxy.h"
#include "../Shared/sqltypes.h"
#include "../Utils/Regexp.h"
#include "../Utils/StringLike.h"
#include "Shared/Logger.h"
#include "Shared/thread_count.h"
#include "StringDictionary.h"

#include <sys/fcntl.h>

#include <thread>

StringDictionaryProxy::StringDictionaryProxy(std::shared_ptr<StringDictionary> sd,
                                             const ssize_t generation)
    : string_dict_(sd), generation_(generation) {}

int32_t truncate_to_generation(const int32_t id, const size_t generation) {
  if (id == StringDictionary::INVALID_STR_ID) {
    return id;
  }
  CHECK_GE(id, 0);
  return static_cast<size_t>(id) >= generation ? StringDictionary::INVALID_STR_ID : id;
}

int32_t StringDictionaryProxy::getOrAddTransient(const std::string& str) {
  mapd_lock_guard<mapd_shared_mutex> write_lock(rw_mutex_);
  CHECK_GE(generation_, 0);
  auto transient_id =
      truncate_to_generation(string_dict_->getIdOfString(str), generation_);
  if (transient_id != StringDictionary::INVALID_STR_ID) {
    return transient_id;
  }
  const auto it = transient_str_to_int_.find(str);
  if (it != transient_str_to_int_.end()) {
    return it->second;
  }
  transient_id =
      -(transient_str_to_int_.size() + 2);  // make sure it's not INVALID_STR_ID
  {
    auto it_ok = transient_str_to_int_.insert(std::make_pair(str, transient_id));
    CHECK(it_ok.second);
  }
  {
    auto it_ok = transient_int_to_str_.insert(std::make_pair(transient_id, str));
    CHECK(it_ok.second);
  }
  return transient_id;
}

int32_t StringDictionaryProxy::getIdOfString(const std::string& str) const {
  mapd_shared_lock<mapd_shared_mutex> read_lock(rw_mutex_);
  CHECK_GE(generation_, 0);
  auto str_id = truncate_to_generation(string_dict_->getIdOfString(str), generation_);
  if (str_id != StringDictionary::INVALID_STR_ID || transient_str_to_int_.empty()) {
    return str_id;
  }
  auto it = transient_str_to_int_.find(str);
  return it != transient_str_to_int_.end() ? it->second
                                           : StringDictionary::INVALID_STR_ID;
}

int32_t StringDictionaryProxy::getIdOfStringNoGeneration(const std::string& str) const {
  mapd_shared_lock<mapd_shared_mutex> read_lock(rw_mutex_);
  auto str_id = string_dict_->getIdOfString(str);
  if (str_id != StringDictionary::INVALID_STR_ID || transient_str_to_int_.empty()) {
    return str_id;
  }
  auto it = transient_str_to_int_.find(str);
  return it != transient_str_to_int_.end() ? it->second
                                           : StringDictionary::INVALID_STR_ID;
}

std::string StringDictionaryProxy::getString(int32_t string_id) const {
  if (inline_int_null_value<int32_t>() == string_id) {
    return "";
  }
  mapd_shared_lock<mapd_shared_mutex> read_lock(rw_mutex_);
  if (string_id >= 0) {
    return string_dict_->getString(string_id);
  }
  CHECK_NE(StringDictionary::INVALID_STR_ID, string_id);
  auto it = transient_int_to_str_.find(string_id);
  CHECK(it != transient_int_to_str_.end());
  return it->second;
}

namespace {

bool is_like(const std::string& str,
             const std::string& pattern,
             const bool icase,
             const bool is_simple,
             const char escape) {
  return icase
             ? (is_simple ? string_ilike_simple(
                                str.c_str(), str.size(), pattern.c_str(), pattern.size())
                          : string_ilike(str.c_str(),
                                         str.size(),
                                         pattern.c_str(),
                                         pattern.size(),
                                         escape))
             : (is_simple ? string_like_simple(
                                str.c_str(), str.size(), pattern.c_str(), pattern.size())
                          : string_like(str.c_str(),
                                        str.size(),
                                        pattern.c_str(),
                                        pattern.size(),
                                        escape));
}

}  // namespace

std::vector<int32_t> StringDictionaryProxy::getLike(const std::string& pattern,
                                                    const bool icase,
                                                    const bool is_simple,
                                                    const char escape) const {
  CHECK_GE(generation_, 0);
  auto result = string_dict_->getLike(pattern, icase, is_simple, escape, generation_);
  for (const auto& kv : transient_int_to_str_) {
    const auto str = getString(kv.first);
    if (is_like(str, pattern, icase, is_simple, escape)) {
      result.push_back(kv.first);
    }
  }
  return result;
}

namespace {

bool do_compare(const std::string& str,
                const std::string& pattern,
                const std::string& comp_operator) {
  int res = str.compare(pattern);
  if (comp_operator == "<") {
    return res < 0;
  } else if (comp_operator == "<=") {
    return res <= 0;
  } else if (comp_operator == "=") {
    return res == 0;
  } else if (comp_operator == ">") {
    return res > 0;
  } else if (comp_operator == ">=") {
    return res >= 0;
  } else if (comp_operator == "<>") {
    return res != 0;
  }
  throw std::runtime_error("unsupported string compare operator");
}

}  // namespace

std::vector<int32_t> StringDictionaryProxy::getCompare(
    const std::string& pattern,
    const std::string& comp_operator) const {
  CHECK_GE(generation_, 0);
  auto result = string_dict_->getCompare(pattern, comp_operator, generation_);
  for (const auto& kv : transient_int_to_str_) {
    const auto str = getString(kv.first);
    if (do_compare(str, pattern, comp_operator)) {
      result.push_back(kv.first);
    }
  }
  return result;
}

namespace {

bool is_regexp_like(const std::string& str,
                    const std::string& pattern,
                    const char escape) {
  return regexp_like(str.c_str(), str.size(), pattern.c_str(), pattern.size(), escape);
}

}  // namespace

std::vector<int32_t> StringDictionaryProxy::getRegexpLike(const std::string& pattern,
                                                          const char escape) const {
  CHECK_GE(generation_, 0);
  auto result = string_dict_->getRegexpLike(pattern, escape, generation_);
  for (const auto& kv : transient_int_to_str_) {
    const auto str = getString(kv.first);
    if (is_regexp_like(str, pattern, escape)) {
      result.push_back(kv.first);
    }
  }
  return result;
}

int32_t StringDictionaryProxy::getOrAdd(const std::string& str) noexcept {
  return string_dict_->getOrAdd(str);
}

std::pair<char*, size_t> StringDictionaryProxy::getStringBytes(int32_t string_id) const
    noexcept {
  return string_dict_.get()->getStringBytes(string_id);
}

size_t StringDictionaryProxy::storageEntryCount() const {
  return string_dict_.get()->storageEntryCount();
}

void StringDictionaryProxy::updateGeneration(const ssize_t generation) noexcept {
  if (generation == -1) {
    return;
  }
  if (generation_ != -1) {
    CHECK_EQ(generation_, generation);
    return;
  }
  generation_ = generation;
}

StringDictionary* StringDictionaryProxy::getDictionary() noexcept {
  return string_dict_.get();
}

ssize_t StringDictionaryProxy::getGeneration() const noexcept {
  return generation_;
}