[redis][refactoring] Adding Redis in server and some code refactoring

CMakeLists.txt

@@ -36,8 +36,10 @@ add_executable(${PROJECT_NAME}
   src/main.cc
   src/server/endpoints/endpoints.cc
   src/server/endpoints/endpoints.h
-  src/database/wrapper.cc
-  src/database/wrapper.h
+  src/database/postgres-wrapper.cc
+  src/database/postgres-wrapper.h
+  src/database/redis-wrapper.cc
+  src/database/redis-wrapper.h
   src/utils/utils.h
   src/utils/logger.h
   src/server/server.cc
@@ -51,4 +53,4 @@ if(APPLE)
 endif()
 
 target_compile_options(${PROJECT_NAME} PRIVATE -Wall -Wextra -Wpedantic -Werror)
-target_link_libraries(${PROJECT_NAME} PRIVATE ${PostgreSQL_LIBRARIES} GTest::gtest_main)
+target_link_libraries(${PROJECT_NAME} PRIVATE ${PostgreSQL_LIBRARIES} GTest::gtest_main -lhiredis)

src/database/wrapper.cc → src/database/postgres-wrapper.cc

@@ -1,4 +1,4 @@
-#include "wrapper.h"
+#include "postgres-wrapper.h"
 
 #include <stdexcept>
 

src/database/redis-wrapper.cc

@@ -0,0 +1,42 @@
+#include "redis-wrapper.h"
+
+#include <stdexcept>
+
+#include "utils/logger.h"
+
+namespace fm {
+
+Redis::Redis(const std::string& host, int32_t port) {
+  context = redisConnect(host.c_str(), port);
+  if (context != nullptr && context->err) {
+    throw std::runtime_error(context->errstr);
+  } else {
+    Logger::Get().Write("Success Redis connection.");
+  }
+}
+
+Redis::~Redis() { redisFree(context); }
+
+redisResponse set(Redis& redis, const std::string& key, const std::string& value) {
+  redisReply* reply;
+  reply = static_cast<redisReply*>(redisCommand(redis.context, "SETEX %s 10 %s", key.c_str(), value.c_str()));
+
+  std::string replyStr(reply->str, reply->len);
+  int8_t status = reply->type;
+
+  freeReplyObject(reply);
+  return {status, replyStr};
+}
+
+redisResponse get(Redis& redis, const std::string& key) {
+  redisReply* reply;
+  reply = static_cast<redisReply*>(redisCommand(redis.context, "GET %s", key.c_str()));
+
+  std::string replyStr(reply->str, reply->len);
+  int8_t status = reply->type;
+
+  freeReplyObject(reply);
+  return {status, replyStr};
+}
+
+}  // namespace fm

src/database/redis-wrapper.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+#include "json.hpp"
+
+using json = nlohmann::json;
+
+#include <hiredis/hiredis.h>
+
+namespace fm {
+
+using redisResponse = std::pair<int8_t, std::string>;  // status code, reply string
+
+class Redis {
+ public:
+  Redis(const std::string& host, int32_t port);
+  ~Redis();
+  Redis(const Redis& other) = delete;
+  Redis(Redis&& other) = delete;
+
+ private:
+  redisContext* context;
+
+  friend redisResponse set(Redis& redis, const std::string& key, const std::string& value);
+  friend redisResponse get(Redis& redis, const std::string& key);
+};
+
+}  // namespace fm

src/server/endpoints/endpoints.cc

@@ -11,41 +11,56 @@ namespace fs = std::filesystem;
 
 namespace fm {
 
-EndPointsHandler::EndPointsHandler() : database(Utils::GetDatabaseConfig(fs::path{".local/database.conf"})) { 
+EndPointsHandler::EndPointsHandler() : database{Utils::GetDatabaseConfig(fs::path{".local/database.conf"})}, redis{"127.0.0.1", 6379} { 
   prepare(database, "add_actor", "INSERT INTO actor (actorname, gender, birthday) VALUES ($1, $2, $3)", 3, nullptr);
   prepare(database, "add_film", "INSERT INTO film (title, description, release_date, rating, actors) VALUES ($1, $2, $3, $4, $5)", 5, nullptr);
 }
 
 response EndPointsHandler::AddActor(const Actor &actor) {
   json response;
   response["message"] = "Successfully adding a new user " + actor.name;
-  const char *paramValues[3] = {actor.name.c_str(), actor.gender.c_str(), actor.date.c_str()};
+  constexpr int32_t paramsCount = 3;
+  const char *paramValues[paramsCount] = {actor.name.c_str(), actor.gender.c_str(), actor.date.c_str()};
 
-  execPrepared(database, "add_actor", 3, paramValues);
+  execPrepared(database, "add_actor", paramsCount, paramValues);
 
   return {200, response.dump(JSON_DUMP)};
 }
 
 response EndPointsHandler::GetActors() {
+  if (auto content = get(redis, "actors"); content.first == REDIS_REPLY_STRING) {
+    return {200, content.second};
+  } else {
   json response = get(database, "SELECT * FROM actor");
-
-  return {200, response.dump(JSON_DUMP)};
+    std::string responseStr =  response.dump(JSON_DUMP);
+    set(redis, "actors", responseStr);
+    return {200, responseStr};  
+  }
+  return {500, "Redis/Postgres error."};
 }
 
 response EndPointsHandler::AddFilm(const Film& film) {
   json response;
   response["message"] = "Successfully adding a new film " + film.title;
-  const char *paramValues[5] = {film.title.c_str(), film.description.c_str(), film.release_date.c_str(), film.rating.c_str(), film.ids.c_str()};
+  constexpr int32_t paramsCount = 5;
+  const char *paramValues[paramsCount] = {film.title.c_str(), film.description.c_str(), film.release_date.c_str(), film.rating.c_str(), film.ids.c_str()};
 
-  execPrepared(database, "add_film", 5, paramValues);
+  execPrepared(database, "add_film", paramsCount, paramValues);
 
   return {200, response.dump(JSON_DUMP)};
 }
 
 response EndPointsHandler::GetFilms() {
-  json response = get(database, "SELECT f.id, f.title, f.description, f.release_date, f.rating, array_agg(a.actorname) AS actors FROM film f LEFT JOIN actor a ON a.id = ANY(f.actors) GROUP BY f.id;");
-
-  return {200, response.dump(JSON_DUMP)};
+  if (auto content = get(redis, "films"); content.first == REDIS_REPLY_STRING) {
+    return {200, content.second};
+  } else {
+    json response = get(database, "SELECT f.id, f.title, f.description, f.release_date, f.rating, array_agg(a.actorname) AS actors FROM film f LEFT JOIN actor a ON a.id = ANY(f.actors) GROUP BY f.id;");
+    std::string responseStr =  response.dump(JSON_DUMP);
+    set(redis, "films", responseStr);
+    return {200, responseStr};  
+  }
+
+  return {500, "Redis/Postgres error."};
 }
 
 }  // namespace fm

src/server/endpoints/endpoints.h

@@ -2,7 +2,8 @@
 
 #include <string>
 #include <vector>
-#include "../../database/wrapper.h"
+#include "database/postgres-wrapper.h"
+#include "database/redis-wrapper.h"
 #include <cstdint>
 
 namespace fm {
@@ -32,6 +33,7 @@ class EndPointsHandler {
   response GetFilms();
  private:
   PGConnection database;
+  Redis redis;
 };
 
 }  // namespace fm