Merge branch 'rolling' into change-document-style-with-linter-warnings

.gitignore

@@ -4,3 +4,4 @@ package-lock.json
 dump.rdb
 .vscode
 megalinter-reports/
+dhat-heap.json

Cargo.toml

@@ -8,9 +8,9 @@ license = "AGPL-3.0"
 
 [dependencies]
 reqwest = {version="0.11.20",features=["json"]}
-tokio = {version="1.32.0",features=["full"]}
+tokio = {version="1.32.0",features=["rt-multi-thread","macros"]}
 serde = {version="1.0.188",features=["derive"]}
-handlebars = { version = "4.3.7", features = ["dir_source"] }
+handlebars = { version = "4.4.0", features = ["dir_source"] }
 scraper = {version="0.17.1"}
 actix-web = {version="4.4.0", features = ["cookies"]}
 actix-files = {version="0.6.2"}
@@ -19,14 +19,20 @@ serde_json = {version="1.0.105"}
 fake-useragent = {version="0.1.3"}
 env_logger = {version="0.10.0"}
 log = {version="0.4.20"}
-rlua = {version="0.19.7"}
-redis = {version="0.23.2"}
+mlua = {version="0.8.10", features=["luajit"]}
+redis = {version="0.23.3", features=["tokio-comp","connection-manager"]}
 md5 = {version="0.7.0"}
 rand={version="0.8.5"}
 once_cell = {version="1.18.0"}
 error-stack = {version="0.4.0"}
 async-trait = {version="0.1.73"}
 regex = {version="1.9.4", features=["perf"]}
+smallvec = {version="1.11.0", features=["union", "serde"]}
+futures = {version="0.3.28"}
+dhat = {version="0.3.2", optional = true}
+mimalloc = { version = "0.1.38", default-features = false }
+async-once-cell = {version="0.5.3"}
+actix-governor = {version="0.4.1"}
 
 [dev-dependencies]
 rusty-hook = "^0.11.2"
@@ -47,13 +53,17 @@ rpath = false
 
 [profile.release]
 opt-level = 3
-debug = false
+debug = false # This should only be commented when testing with dhat profiler
+# debug = 1 # This should only be uncommented when testing with dhat profiler
 split-debuginfo = '...'
 debug-assertions = false
 overflow-checks = false
-lto = 'thin'
+lto = true
 panic = 'abort'
 incremental = false
-codegen-units = 16
+codegen-units = 1
 rpath = false
 strip = "debuginfo"
+
+[features]
+dhat-heap = ["dep:dhat"] 

Dockerfile

@@ -19,7 +19,7 @@ COPY . .
 RUN cargo install --path .
 
 # We do not need the Rust toolchain to run the binary!
-FROM gcr.io/distroless/cc-debian11
+FROM gcr.io/distroless/cc-debian12
 COPY --from=builder /app/public/ /opt/websurfx/public/
 COPY --from=builder /app/websurfx/config.lua /etc/xdg/websurfx/config.lua
 COPY --from=builder /usr/local/cargo/bin/* /usr/local/bin/

README.md

@@ -5,7 +5,7 @@
   <b align="center"><a href="README.md">Readme</a></b> |
   <b><a href="https://discord.gg/SWnda7Mw5u">Discord</a></b> |
   <b><a href="https://github.com/neon-mmd/websurfx">GitHub</a></b> |
-  <b><a href="./docs/README.md">Documentation</a></b>
+  <b><a href="../../tree/HEAD/docs/">Documentation</a></b>
   <br /><br />
   <a href="#">
     <img
@@ -51,7 +51,7 @@
 - **Getting Started**
     - [🔭 Preview](#preview-)
     - [🚀 Features](#features-)
-    - [🛠️ Installation and Testing](#installation-and-testing-)
+    - [🛠️ Installation and Testing](#installation-and-testing-%EF%B8%8F)
     - [🔧 Configuration](#configuration-)
 - **Feature Overview**
     - [🎨 Theming](#theming-)

docs/installation.md

@@ -109,7 +109,7 @@ colorscheme = "catppuccin-mocha" -- the colorscheme name which should be used fo
 theme = "simple" -- the theme name which should be used for the website
 
 -- ### Caching ###
-redis_connection_url = "redis://redis:6379" -- redis connection url address on which the client should connect on.
+redis_url = "redis://redis:6379" -- redis connection url address on which the client should connect on.
 
 -- ### Search Engines ###
 upstream_search_engines = { DuckDuckGo = true, Searx = false } -- select the upstream search engines from which the results should be fetched.

public/static/themes/simple.css

@@ -132,6 +132,35 @@ body {
   width: 1.2rem;
   height: 1.2rem;
 }
+.results .result_disallowed,
+.results .result_filtered {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  gap: 10rem;
+  font-size: 2rem;
+  color: var(--foreground-color);
+  margin: 0rem 7rem;
+}
+
+.results .result_disallowed .user_query,
+.results .result_filtered .user_query {
+  color: var(--background-color);
+  font-weight: 300;
+}
+
+.results .result_disallowed img,
+.results .result_filtered img {
+  width: 30rem;
+}
+
+.results .result_disallowed div,
+.results .result_filtered div {
+  display: flex;
+  flex-direction: column;
+  gap: 1rem;
+  line-break: strict;
+}
 
 /* styles for the footer and header */
 

public/templates/search.html

@@ -13,7 +13,39 @@
                 {{/each}}
             </div>
         </div>
-    {{/each}} {{else}}
+        {{/each}} {{else}} {{#if disallowed}}
+        <div class="result_disallowed">
+            <div class="description">
+                <p>
+                    Your search - <span class="user_query">{{{this.pageQuery}}}</span> -
+                    has been disallowed.
+                </p>
+                <p class="description_paragraph">Dear user,</p>
+                <p class="description_paragraph">
+                    The query - <span class="user_query">{{{this.pageQuery}}}</span> - has
+                    been blacklisted via server configuration and hence disallowed by the
+                    server. Henceforth no results could be displayed for your query.
+                </p>
+            </div>
+            <img src="./images/barricade.png" alt="Image of a Barricade" />
+        </div>
+        {{else}} {{#if filtered}}
+        <div class="result_filtered">
+            <div class="description">
+                <p>
+                    Your search - <span class="user_query">{{{this.pageQuery}}}</span> -
+                    has been filtered.
+                </p>
+                <p class="description_paragraph">Dear user,</p>
+                <p class="description_paragraph">
+                    All the search results contain results that has been configured to be
+                    filtered out via server configuration and henceforth has been
+                    completely filtered out.
+                </p>
+            </div>
+            <img src="./images/filter.png" alt="Image of a paper inside a funnel" />
+        </div>
+        {{else}}
         <div class="result_not_found">
             <p>Your search - {{{this.pageQuery}}} - did not match any documents.</p>
             <p class="suggestions">Suggestions:</p>
@@ -24,7 +56,7 @@
             </ul>
             <img src="./images/no_results.gif" alt="Man fishing gif" />
         </div>
-    {{/if}}
+        {{/if}} {{/if}} {{/if}}
     </div>
     <div class="page_navigation">
         <button type="button" onclick="navigate_backward()">

src/bin/websurfx.rs

@@ -3,9 +3,19 @@
 //! This module contains the main function which handles the logging of the application to the
 //! stdout and handles the command line arguments provided and launches the `websurfx` server.
 
+use mimalloc::MiMalloc;
 use std::net::TcpListener;
 use websurfx::{config::parser::Config, run};
 
+/// A dhat heap memory profiler
+#[cfg(feature = "dhat-heap")]
+#[global_allocator]
+static ALLOC: dhat::Alloc = dhat::Alloc;
+
+#[cfg(not(feature = "dhat-heap"))]
+#[global_allocator]
+static GLOBAL: MiMalloc = MiMalloc;
+
 /// The function that launches the main server and registers all the routes of the website.
 ///
 /// # Error
@@ -14,6 +24,10 @@ use websurfx::{config::parser::Config, run};
 /// available for being used for other applications.
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
+    // A dhat heap profiler initialization.
+    #[cfg(feature = "dhat-heap")]
+    let _profiler = dhat::Profiler::new_heap();
+
     // Initialize the parsed config file.
     let config = Config::parse(false).unwrap();
 

src/cache/cacher.rs

@@ -1,14 +1,24 @@
 //! This module provides the functionality to cache the aggregated results fetched and aggregated
 //! from the upstream search engines in a json format.
 
+use error_stack::Report;
+use futures::future::try_join_all;
 use md5::compute;
-use redis::{Client, Commands, Connection};
+use redis::{aio::ConnectionManager, AsyncCommands, Client, RedisError};
+
+use super::error::PoolError;
 
 /// A named struct which stores the redis Connection url address to which the client will
 /// connect to.
+#[derive(Clone)]
 pub struct RedisCache {
-    /// It stores the redis Connection url address.
-    connection: Connection,
+    /// It stores a pool of connections ready to be used.
+    connection_pool: Vec<ConnectionManager>,
+    /// It stores the size of the connection pool (in other words the number of
+    /// connections that should be stored in the pool).
+    pool_size: u8,
+    /// It stores the index of which connection is being used at the moment.
+    current_connection: u8,
 }
 
 impl RedisCache {
@@ -16,11 +26,25 @@ impl RedisCache {
     ///
     /// # Arguments
     ///
-    /// * `redis_connection_url` - It stores the redis Connection url address.
-    pub fn new(redis_connection_url: String) -> Result<Self, Box<dyn std::error::Error>> {
+    /// * `redis_connection_url` - It takes the redis Connection url address.
+    /// * `pool_size` - It takes the size of the connection pool (in other words the number of
+    /// connections that should be stored in the pool).
+    pub async fn new(
+        redis_connection_url: &str,
+        pool_size: u8,
+    ) -> Result<Self, Box<dyn std::error::Error>> {
         let client = Client::open(redis_connection_url)?;
-        let connection = client.get_connection()?;
-        let redis_cache = RedisCache { connection };
+        let mut tasks: Vec<_> = Vec::new();
+
+        for _ in 0..pool_size {
+            tasks.push(client.get_tokio_connection_manager());
+        }
+
+        let redis_cache = RedisCache {
+            connection_pool: try_join_all(tasks).await?,
+            pool_size,
+            current_connection: Default::default(),
+        };
         Ok(redis_cache)
     }
 
@@ -29,7 +53,7 @@ impl RedisCache {
     /// # Arguments
     ///
     /// * `url` - It takes an url as string.
-    fn hash_url(url: &str) -> String {
+    fn hash_url(&self, url: &str) -> String {
         format!("{:?}", compute(url))
     }
 
@@ -38,9 +62,42 @@ impl RedisCache {
     /// # Arguments
     ///
     /// * `url` - It takes an url as a string.
-    pub fn cached_json(&mut self, url: &str) -> Result<String, Box<dyn std::error::Error>> {
-        let hashed_url_string = Self::hash_url(url);
-        Ok(self.connection.get(hashed_url_string)?)
+    pub async fn cached_json(&mut self, url: &str) -> Result<String, Report<PoolError>> {
+        self.current_connection = Default::default();
+        let hashed_url_string: &str = &self.hash_url(url);
+
+        let mut result: Result<String, RedisError> = self.connection_pool
+            [self.current_connection as usize]
+            .get(hashed_url_string)
+            .await;
+
+        // Code to check whether the current connection being used is dropped with connection error
+        // or not. if it drops with the connection error then the current connection is replaced
+        // with a new connection from the pool which is then used to run the redis command then
+        // that connection is also checked whether it is dropped or not if it is not then the
+        // result is passed as a `Result` or else the same process repeats again and if all of the
+        // connections in the pool result in connection drop error then a custom pool error is
+        // returned.
+        loop {
+            match result {
+                Err(error) => match error.is_connection_dropped() {
+                    true => {
+                        self.current_connection += 1;
+                        if self.current_connection == self.pool_size {
+                            return Err(Report::new(
+                                PoolError::PoolExhaustionWithConnectionDropError,
+                            ));
+                        }
+                        result = self.connection_pool[self.current_connection as usize]
+                            .get(hashed_url_string)
+                            .await;
+                        continue;
+                    }
+                    false => return Err(Report::new(PoolError::RedisError(error))),
+                },
+                Ok(res) => return Ok(res),
+            }
+        }
     }
 
     /// A function which caches the results by using the hashed `url` as the key and
@@ -51,21 +108,45 @@ impl RedisCache {
     ///
     /// * `json_results` - It takes the json results string as an argument.
     /// * `url` - It takes the url as a String.
-    pub fn cache_results(
+    pub async fn cache_results(
         &mut self,
-        json_results: String,
+        json_results: &str,
         url: &str,
-    ) -> Result<(), Box<dyn std::error::Error>> {
-        let hashed_url_string = Self::hash_url(url);
+    ) -> Result<(), Report<PoolError>> {
+        self.current_connection = Default::default();
+        let hashed_url_string: &str = &self.hash_url(url);
 
-        // put results_json into cache
-        self.connection.set(&hashed_url_string, json_results)?;
+        let mut result: Result<(), RedisError> = self.connection_pool
+            [self.current_connection as usize]
+            .set_ex(hashed_url_string, json_results, 60)
+            .await;
 
-        // Set the TTL for the key to 60 seconds
-        self.connection
-            .expire::<String, u32>(hashed_url_string, 60)
-            .unwrap();
-
-        Ok(())
+        // Code to check whether the current connection being used is dropped with connection error
+        // or not. if it drops with the connection error then the current connection is replaced
+        // with a new connection from the pool which is then used to run the redis command then
+        // that connection is also checked whether it is dropped or not if it is not then the
+        // result is passed as a `Result` or else the same process repeats again and if all of the
+        // connections in the pool result in connection drop error then a custom pool error is
+        // returned.
+        loop {
+            match result {
+                Err(error) => match error.is_connection_dropped() {
+                    true => {
+                        self.current_connection += 1;
+                        if self.current_connection == self.pool_size {
+                            return Err(Report::new(
+                                PoolError::PoolExhaustionWithConnectionDropError,
+                            ));
+                        }
+                        result = self.connection_pool[self.current_connection as usize]
+                            .set_ex(hashed_url_string, json_results, 60)
+                            .await;
+                        continue;
+                    }
+                    false => return Err(Report::new(PoolError::RedisError(error))),
+                },
+                Ok(_) => return Ok(()),
+            }
+        }
     }
 }

src/cache/error.rs

@@ -0,0 +1,40 @@
+//! This module provides the error enum to handle different errors associated while requesting data from
+//! the redis server using an async connection pool.
+use std::fmt;
+
+use redis::RedisError;
+
+/// A custom error type used for handling redis async pool associated errors.
+///
+/// This enum provides variants three different categories of errors:
+/// * `RedisError` - This variant handles all errors related to `RedisError`,
+/// * `PoolExhaustionWithConnectionDropError` - This variant handles the error
+/// which occurs when all the connections in the connection pool return a connection
+/// dropped redis error.
+#[derive(Debug)]
+pub enum PoolError {
+    RedisError(RedisError),
+    PoolExhaustionWithConnectionDropError,
+}
+
+impl fmt::Display for PoolError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            PoolError::RedisError(redis_error) => {
+                if let Some(detail) = redis_error.detail() {
+                    write!(f, "{}", detail)
+                } else {
+                    write!(f, "")
+                }
+            }
+            PoolError::PoolExhaustionWithConnectionDropError => {
+                write!(
+                    f,
+                    "Error all connections from the pool dropped with connection error"
+                )
+            }
+        }
+    }
+}
+
+impl error_stack::Context for PoolError {}

src/cache/mod.rs

@@ -2,3 +2,4 @@
 //! results fetched and aggregated from the upstream search engines in a json format.
 
 pub mod cacher;
+pub mod error;

src/config/parser.rs

@@ -3,9 +3,9 @@
 
 use crate::handler::paths::{file_path, FileType};
 
-use super::parser_models::Style;
+use super::parser_models::{AggregatorConfig, RateLimiter, Style};
 use log::LevelFilter;
-use rlua::Lua;
+use mlua::Lua;
 use std::{collections::HashMap, fs, thread::available_parallelism};
 
 /// A named struct which stores the parsed config file options.
@@ -32,14 +32,11 @@ pub struct Config {
     pub request_timeout: u8,
     /// It stores the number of threads which controls the app will use to run.
     pub threads: u8,
-}
-
-/// Configuration options for the aggregator.
-#[derive(Clone)]
-pub struct AggregatorConfig {
-    /// It stores the option to whether enable or disable random delays between
-    /// requests.
-    pub random_delay: bool,
+    /// It stores configuration options for the ratelimiting middleware.
+    pub rate_limiter: RateLimiter,
+    /// It stores the level of safe search to be used for restricting content in the 
+    /// search results.
+    pub safe_search: u8,
 }
 
 impl Config {
@@ -57,17 +54,16 @@ impl Config {
     /// or io error if the config.lua file doesn't exists otherwise it returns a newly constructed
     /// Config struct with all the parsed config options from the parsed config file.
     pub fn parse(logging_initialized: bool) -> Result<Self, Box<dyn std::error::Error>> {
-        Lua::new().context(|context| -> Result<Self, Box<dyn std::error::Error>> {
-            let globals = context.globals();
+        let lua = Lua::new();
+        let globals = lua.globals();
 
-            context
-                .load(&fs::read_to_string(file_path(FileType::Config)?)?)
+        lua.load(&fs::read_to_string(file_path(FileType::Config)?)?)
             .exec()?;
 
         let parsed_threads: u8 = globals.get::<_, u8>("threads")?;
 
         let debug: bool = globals.get::<_, bool>("debug")?;
-            let logging:bool= globals.get::<_, bool>("logging")?;
+        let logging: bool = globals.get::<_, bool>("logging")?;
 
         if !logging_initialized {
             set_logging_level(debug, logging);
@@ -75,13 +71,27 @@ impl Config {
 
         let threads: u8 = if parsed_threads == 0 {
             let total_num_of_threads: usize = available_parallelism()?.get() / 2;
-                log::error!("Config Error: The value of `threads` option should be a non zero positive integer");
+            log::error!(
+                "Config Error: The value of `threads` option should be a non zero positive integer"
+            );
             log::error!("Falling back to using {} threads", total_num_of_threads);
             total_num_of_threads as u8
         } else {
             parsed_threads
         };
 
+        let rate_limiter = globals.get::<_, HashMap<String, u8>>("rate_limiter")?;
+
+        let parsed_safe_search: u8 = globals.get::<_, u8>("safe_search")?;
+        let safe_search: u8 = match parsed_safe_search {
+            0..=4 => parsed_safe_search,
+            _ => {
+                log::error!("Config Error: The value of `safe_search` option should be a non zero positive integer from 0 to 4.");
+                log::error!("Falling back to using the value `1` for the option");
+                1
+            }
+        };
+
         Ok(Config {
             port: globals.get::<_, u16>("port")?,
             binding_ip: globals.get::<_, String>("binding_ip")?,
@@ -103,7 +113,11 @@ impl Config {
                 .collect(),
             request_timeout: globals.get::<_, u8>("request_timeout")?,
             threads,
-            })
+            rate_limiter: RateLimiter {
+                number_of_requests: rate_limiter["number_of_requests"],
+                time_limit: rate_limiter["time_limit"],
+            },
+            safe_search,
         })
     }
 }

src/config/parser_models.rs

@@ -12,7 +12,7 @@ use serde::{Deserialize, Serialize};
 /// order to allow the deserializing the json back to struct in aggregate function in
 /// aggregator.rs and create a new struct out of it and then serialize it back to json and pass
 /// it to the template files.
-#[derive(Serialize, Deserialize, Clone)]
+#[derive(Serialize, Deserialize, Clone, Default)]
 pub struct Style {
     /// It stores the parsed theme option used to set a theme for the website.
     pub theme: String,
@@ -33,3 +33,20 @@ impl Style {
         Style { theme, colorscheme }
     }
 }
+
+/// Configuration options for the aggregator.
+#[derive(Clone)]
+pub struct AggregatorConfig {
+    /// It stores the option to whether enable or disable random delays between
+    /// requests.
+    pub random_delay: bool,
+}
+
+/// Configuration options for the rate limiter middleware.
+#[derive(Clone)]
+pub struct RateLimiter {
+    /// The number of request that are allowed within a provided time limit.
+    pub number_of_requests: u8,
+    /// The time limit in which the quantity of requests that should be accepted.
+    pub time_limit: u8,
+}

src/engines/duckduckgo.rs

@@ -4,14 +4,14 @@
 
 use std::collections::HashMap;
 
-use reqwest::header::{HeaderMap, CONTENT_TYPE, COOKIE, REFERER, USER_AGENT};
+use reqwest::header::HeaderMap;
 use scraper::{Html, Selector};
 
 use crate::results::aggregation_models::SearchResult;
 
 use super::engine_models::{EngineError, SearchEngine};
 
-use error_stack::{IntoReport, Report, Result, ResultExt};
+use error_stack::{Report, Result, ResultExt};
 
 /// A new DuckDuckGo engine type defined in-order to implement the `SearchEngine` trait which allows to
 /// reduce code duplication as well as allows to create vector of different search engines easily.
@@ -21,10 +21,11 @@ pub struct DuckDuckGo;
 impl SearchEngine for DuckDuckGo {
     async fn results(
         &self,
-        query: String,
+        query: &str,
         page: u32,
-        user_agent: String,
+        user_agent: &str,
         request_timeout: u8,
+        _safe_search: u8,
     ) -> Result<HashMap<String, SearchResult>, EngineError> {
         // Page number can be missing or empty string and so appropriate handling is required
         // so that upstream server recieves valid page number.
@@ -43,38 +44,19 @@ impl SearchEngine for DuckDuckGo {
         };
 
         // initializing HeaderMap and adding appropriate headers.
-        let mut header_map = HeaderMap::new();
-        header_map.insert(
-            USER_AGENT,
-            user_agent
-                .parse()
-                .into_report()
-                .change_context(EngineError::UnexpectedError)?,
-        );
-        header_map.insert(
-            REFERER,
-            "https://google.com/"
-                .parse()
-                .into_report()
-                .change_context(EngineError::UnexpectedError)?,
-        );
-        header_map.insert(
-            CONTENT_TYPE,
-            "application/x-www-form-urlencoded"
-                .parse()
-                .into_report()
-                .change_context(EngineError::UnexpectedError)?,
-        );
-        header_map.insert(
-            COOKIE,
-            "kl=wt-wt"
-                .parse()
-                .into_report()
-                .change_context(EngineError::UnexpectedError)?,
-        );
+        let header_map = HeaderMap::try_from(&HashMap::from([
+            ("USER_AGENT".to_string(), user_agent.to_string()),
+            ("REFERER".to_string(), "https://google.com/".to_string()),
+            (
+                "CONTENT_TYPE".to_string(),
+                "application/x-www-form-urlencoded".to_string(),
+            ),
+            ("COOKIE".to_string(), "kl=wt-wt".to_string()),
+        ]))
+        .change_context(EngineError::UnexpectedError)?;
 
         let document: Html = Html::parse_document(
-            &DuckDuckGo::fetch_html_from_upstream(self, url, header_map, request_timeout).await?,
+            &DuckDuckGo::fetch_html_from_upstream(self, &url, header_map, request_timeout).await?,
         );
 
         let no_result: Selector = Selector::parse(".no-results")
@@ -108,8 +90,7 @@ impl SearchEngine for DuckDuckGo {
                         .next()
                         .unwrap()
                         .inner_html()
-                        .trim()
-                        .to_string(),
+                        .trim(),
                     format!(
                         "https://{}",
                         result
@@ -118,15 +99,15 @@ impl SearchEngine for DuckDuckGo {
                             .unwrap()
                             .inner_html()
                             .trim()
-                    ),
+                    )
+                    .as_str(),
                     result
                         .select(&result_desc)
                         .next()
                         .unwrap()
                         .inner_html()
-                        .trim()
-                        .to_string(),
-                    vec!["duckduckgo".to_string()],
+                        .trim(),
+                    &["duckduckgo"],
                 )
             })
             .map(|search_result| (search_result.url.clone(), search_result))

src/engines/engine_models.rs

@@ -2,7 +2,7 @@
 //! the upstream search engines with the search query provided by the user.
 
 use crate::results::aggregation_models::SearchResult;
-use error_stack::{IntoReport, Result, ResultExt};
+use error_stack::{Result, ResultExt};
 use std::{collections::HashMap, fmt, time::Duration};
 
 /// A custom error type used for handle engine associated errors.
@@ -64,7 +64,7 @@ pub trait SearchEngine: Sync + Send {
     /// otherwise it returns a custom `EngineError`.
     async fn fetch_html_from_upstream(
         &self,
-        url: String,
+        url: &str,
         header_map: reqwest::header::HeaderMap,
         request_timeout: u8,
     ) -> Result<String, EngineError> {
@@ -75,11 +75,9 @@ pub trait SearchEngine: Sync + Send {
             .headers(header_map) // add spoofed headers to emulate human behavior
             .send()
             .await
-            .into_report()
             .change_context(EngineError::RequestError)?
             .text()
             .await
-            .into_report()
             .change_context(EngineError::RequestError)?)
     }
 
@@ -103,10 +101,11 @@ pub trait SearchEngine: Sync + Send {
     /// or HeaderMap fails to initialize.
     async fn results(
         &self,
-        query: String,
+        query: &str,
         page: u32,
-        user_agent: String,
+        user_agent: &str,
         request_timeout: u8,
+        safe_search: u8,
     ) -> Result<HashMap<String, SearchResult>, EngineError>;
 }
 

src/engines/searx.rs

@@ -2,14 +2,14 @@
 //! by querying the upstream searx search engine instance with user provided query and with a page
 //! number if provided.
 
-use reqwest::header::{HeaderMap, CONTENT_TYPE, COOKIE, REFERER, USER_AGENT};
+use reqwest::header::HeaderMap;
 use scraper::{Html, Selector};
 use std::collections::HashMap;
 
 use crate::results::aggregation_models::SearchResult;
 
 use super::engine_models::{EngineError, SearchEngine};
-use error_stack::{IntoReport, Report, Result, ResultExt};
+use error_stack::{Report, Result, ResultExt};
 
 /// A new Searx engine type defined in-order to implement the `SearchEngine` trait which allows to
 /// reduce code duplication as well as allows to create vector of different search engines easily.
@@ -19,45 +19,38 @@ pub struct Searx;
 impl SearchEngine for Searx {
     async fn results(
         &self,
-        query: String,
+        query: &str,
         page: u32,
-        user_agent: String,
+        user_agent: &str,
         request_timeout: u8,
+        mut safe_search: u8,
     ) -> Result<HashMap<String, SearchResult>, EngineError> {
         // Page number can be missing or empty string and so appropriate handling is required
         // so that upstream server recieves valid page number.
+        if safe_search == 3 {
+            safe_search = 2;
+        };
+
         let url: String = match page {
-            0 | 1 => format!("https://searx.work/search?q={query}&pageno=1"),
-            _ => format!("https://searx.work/search?q={query}&pageno={page}"),
+            0 | 1 => {
+                format!("https://searx.work/search?q={query}&pageno=1&safesearch={safe_search}")
+            }
+            _ => format!(
+                "https://searx.work/search?q={query}&pageno={page}&safesearch={safe_search}"
+            ),
         };
 
         // initializing headers and adding appropriate headers.
-        let mut header_map = HeaderMap::new();
-        header_map.insert(
-            USER_AGENT,
-            user_agent
-                .parse()
-                .into_report()
-                .change_context(EngineError::UnexpectedError)?,
-        );
-        header_map.insert(
-            REFERER,
-            "https://google.com/"
-                .parse()
-                .into_report()
-                .change_context(EngineError::UnexpectedError)?,
-        );
-        header_map.insert(
-            CONTENT_TYPE,
-            "application/x-www-form-urlencoded"
-                .parse()
-                .into_report()
-                .change_context(EngineError::UnexpectedError)?,
-        );
-        header_map.insert(COOKIE, "categories=general; language=auto; locale=en; autocomplete=duckduckgo; image_proxy=1; method=POST; safesearch=2; theme=simple; results_on_new_tab=1; doi_resolver=oadoi.org; simple_style=auto; center_alignment=1; query_in_title=1; infinite_scroll=0; disabled_engines=; enabled_engines=\"archive is__general\\054yep__general\\054curlie__general\\054currency__general\\054ddg definitions__general\\054wikidata__general\\054duckduckgo__general\\054tineye__general\\054lingva__general\\054startpage__general\\054yahoo__general\\054wiby__general\\054marginalia__general\\054alexandria__general\\054wikibooks__general\\054wikiquote__general\\054wikisource__general\\054wikiversity__general\\054wikivoyage__general\\054dictzone__general\\054seznam__general\\054mojeek__general\\054naver__general\\054wikimini__general\\054brave__general\\054petalsearch__general\\054goo__general\"; disabled_plugins=; enabled_plugins=\"searx.plugins.hostname_replace\\054searx.plugins.oa_doi_rewrite\\054searx.plugins.vim_hotkeys\"; tokens=; maintab=on; enginetab=on".parse().into_report().change_context(EngineError::UnexpectedError)?);
+        let header_map = HeaderMap::try_from(&HashMap::from([
+            ("USER_AGENT".to_string(), user_agent.to_string()),
+            ("REFERER".to_string(), "https://google.com/".to_string()),
+            ("CONTENT_TYPE".to_string(), "application/x-www-form-urlencoded".to_string()),
+            ("COOKIE".to_string(), "categories=general; language=auto; locale=en; autocomplete=duckduckgo; image_proxy=1; method=POST; safesearch=2; theme=simple; results_on_new_tab=1; doi_resolver=oadoi.org; simple_style=auto; center_alignment=1; query_in_title=1; infinite_scroll=0; disabled_engines=; enabled_engines=\"archive is__general\\054yep__general\\054curlie__general\\054currency__general\\054ddg definitions__general\\054wikidata__general\\054duckduckgo__general\\054tineye__general\\054lingva__general\\054startpage__general\\054yahoo__general\\054wiby__general\\054marginalia__general\\054alexandria__general\\054wikibooks__general\\054wikiquote__general\\054wikisource__general\\054wikiversity__general\\054wikivoyage__general\\054dictzone__general\\054seznam__general\\054mojeek__general\\054naver__general\\054wikimini__general\\054brave__general\\054petalsearch__general\\054goo__general\"; disabled_plugins=; enabled_plugins=\"searx.plugins.hostname_replace\\054searx.plugins.oa_doi_rewrite\\054searx.plugins.vim_hotkeys\"; tokens=; maintab=on; enginetab=on".to_string())
+        ]))
+        .change_context(EngineError::UnexpectedError)?;
 
         let document: Html = Html::parse_document(
-            &Searx::fetch_html_from_upstream(self, url, header_map, request_timeout).await?,
+            &Searx::fetch_html_from_upstream(self, &url, header_map, request_timeout).await?,
         );
 
         let no_result: Selector = Selector::parse("#urls>.dialog-error>p")
@@ -98,24 +91,21 @@ impl SearchEngine for Searx {
                         .next()
                         .unwrap()
                         .inner_html()
-                        .trim()
-                        .to_string(),
+                        .trim(),
                     result
                         .select(&result_url)
                         .next()
                         .unwrap()
                         .value()
                         .attr("href")
-                        .unwrap()
-                        .to_string(),
+                        .unwrap(),
                     result
                         .select(&result_desc)
                         .next()
                         .unwrap()
                         .inner_html()
-                        .trim()
-                        .to_string(),
-                    vec!["searx".to_string()],
+                        .trim(),
+                    &["searx"],
                 )
             })
             .map(|search_result| (search_result.url.clone(), search_result))

src/handler/paths.rs

@@ -4,6 +4,7 @@
 use std::collections::HashMap;
 use std::io::Error;
 use std::path::Path;
+use std::sync::OnceLock;
 
 // ------- Constants --------
 /// The constant holding the name of the theme folder.
@@ -31,8 +32,27 @@ pub enum FileType {
 }
 
 /// A static variable which stores the different filesystem paths for various file/folder types.
-static FILE_PATHS_FOR_DIFF_FILE_TYPES: once_cell::sync::Lazy<HashMap<FileType, Vec<String>>> =
-    once_cell::sync::Lazy::new(|| {
+static FILE_PATHS_FOR_DIFF_FILE_TYPES: OnceLock<HashMap<FileType, Vec<String>>> = OnceLock::new();
+
+/// A function which returns an appropriate path for thr provided file type by checking if the path
+/// for the given file type exists on that path.
+///
+/// # Error
+///
+/// Returns a `<File Name> folder/file not found!!` error if the give file_type folder/file is not
+/// present on the path on which it is being tested.
+///
+/// # Example
+///
+/// If this function is give the file_type of Theme variant then the theme folder is checked by the
+/// following steps:
+///
+/// 1. `/opt/websurfx` if it not present here then it fallbacks to the next one (2)
+/// 2. Under project folder ( or codebase in other words) if it is not present
+///    here then it returns an error as mentioned above.
+pub fn file_path(file_type: FileType) -> Result<&'static str, Error> {
+    let file_path: &Vec<String> = FILE_PATHS_FOR_DIFF_FILE_TYPES
+        .get_or_init(|| {
             HashMap::from([
                 (
                     FileType::Config,
@@ -81,29 +101,13 @@ static FILE_PATHS_FOR_DIFF_FILE_TYPES: once_cell::sync::Lazy<HashMap<FileType, V
                     ],
                 ),
             ])
-    });
+        })
+        .get(&file_type)
+        .unwrap();
 
-/// A function which returns an appropriate path for thr provided file type by checking if the path
-/// for the given file type exists on that path.
-///
-/// # Error
-///
-/// Returns a `<File Name> folder/file not found!!` error if the give file_type folder/file is not
-/// present on the path on which it is being tested.
-///
-/// # Example
-///
-/// If this function is give the file_type of Theme variant then the theme folder is checked by the
-/// following steps:
-///
-/// 1. `/opt/websurfx` if it not present here then it fallbacks to the next one (2)
-/// 2. Under project folder ( or codebase in other words) if it is not present
-///    here then it returns an error as mentioned above.
-pub fn file_path(file_type: FileType) -> Result<String, Error> {
-    let file_path = FILE_PATHS_FOR_DIFF_FILE_TYPES.get(&file_type).unwrap();
     for (idx, _) in file_path.iter().enumerate() {
         if Path::new(file_path[idx].as_str()).exists() {
-            return Ok(file_path[idx].clone());
+            return Ok(std::mem::take(&mut &*file_path[idx]));
         }
     }
 

src/lib.rs

@@ -18,6 +18,7 @@ use crate::server::routes;
 
 use actix_cors::Cors;
 use actix_files as fs;
+use actix_governor::{Governor, GovernorConfigBuilder};
 use actix_web::{dev::Server, http::header, middleware::Logger, web, App, HttpServer};
 use config::parser::Config;
 use handlebars::Handlebars;
@@ -46,7 +47,7 @@ use handler::paths::{file_path, FileType};
 pub fn run(listener: TcpListener, config: Config) -> std::io::Result<Server> {
     let mut handlebars: Handlebars<'_> = Handlebars::new();
 
-    let public_folder_path: String = file_path(FileType::Theme)?;
+    let public_folder_path: &str = file_path(FileType::Theme)?;
 
     handlebars
         .register_templates_directory(".html", format!("{}/templates", public_folder_path))
@@ -68,10 +69,17 @@ pub fn run(listener: TcpListener, config: Config) -> std::io::Result<Server> {
             ]);
 
         App::new()
+            .wrap(Logger::default()) // added logging middleware for logging.
             .app_data(handlebars_ref.clone())
             .app_data(web::Data::new(config.clone()))
             .wrap(cors)
-            .wrap(Logger::default()) // added logging middleware for logging.
+            .wrap(Governor::new(
+                &GovernorConfigBuilder::default()
+                    .per_second(config.rate_limiter.time_limit as u64)
+                    .burst_size(config.rate_limiter.number_of_requests as u32)
+                    .finish()
+                    .unwrap(),
+            ))
             // Serve images and static files (css and js files).
             .service(
                 fs::Files::new("/static", format!("{}/static", public_folder_path))

src/results/aggregation_models.rs

@@ -2,6 +2,7 @@
 //! data scraped from the upstream search engines.
 
 use serde::{Deserialize, Serialize};
+use smallvec::SmallVec;
 
 use crate::{config::parser_models::Style, engines::engine_models::EngineError};
 
@@ -19,7 +20,7 @@ pub struct SearchResult {
     /// The description of the search result.
     pub description: String,
     /// The names of the upstream engines from which this results were provided.
-    pub engine: Vec<String>,
+    pub engine: SmallVec<[String; 0]>,
 }
 
 impl SearchResult {
@@ -32,12 +33,12 @@ impl SearchResult {
     /// (href url in html in simple words).
     /// * `description` - The description of the search result.
     /// * `engine` - The names of the upstream engines from which this results were provided.
-    pub fn new(title: String, url: String, description: String, engine: Vec<String>) -> Self {
+    pub fn new(title: &str, url: &str, description: &str, engine: &[&str]) -> Self {
         SearchResult {
-            title,
-            url,
-            description,
-            engine,
+            title: title.to_owned(),
+            url: url.to_owned(),
+            description: description.to_owned(),
+            engine: engine.iter().map(|name| name.to_string()).collect(),
         }
     }
 
@@ -46,8 +47,8 @@ impl SearchResult {
     /// # Arguments
     ///
     /// * `engine` - Takes an engine name provided as a String.
-    pub fn add_engines(&mut self, engine: String) {
-        self.engine.push(engine)
+    pub fn add_engines(&mut self, engine: &str) {
+        self.engine.push(engine.to_owned())
     }
 
     /// A function which returns the engine name stored from the struct as a string.
@@ -55,13 +56,13 @@ impl SearchResult {
     /// # Returns
     ///
     /// An engine name stored as a string from the struct.
-    pub fn engine(self) -> String {
-        self.engine.get(0).unwrap().to_string()
+    pub fn engine(&mut self) -> String {
+        std::mem::take(&mut self.engine[0])
     }
 }
 
 /// A named struct that stores the error info related to the upstream search engines.
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Clone)]
 pub struct EngineErrorInfo {
     /// It stores the error type which occured while fetching the result from a particular search
     /// engine.
@@ -81,18 +82,18 @@ impl EngineErrorInfo {
     /// * `error` - It takes the error type which occured while fetching the result from a particular
     /// search engine.
     /// * `engine` - It takes the name of the engine that failed to provide the requested search results.
-    pub fn new(error: &EngineError, engine: String) -> Self {
+    pub fn new(error: &EngineError, engine: &str) -> Self {
         Self {
             error: match error {
-                EngineError::RequestError => String::from("RequestError"),
-                EngineError::EmptyResultSet => String::from("EmptyResultSet"),
-                EngineError::UnexpectedError => String::from("UnexpectedError"),
+                EngineError::RequestError => "RequestError".to_owned(),
+                EngineError::EmptyResultSet => "EmptyResultSet".to_owned(),
+                EngineError::UnexpectedError => "UnexpectedError".to_owned(),
             },
-            engine,
+            engine: engine.to_owned(),
             severity_color: match error {
-                EngineError::RequestError => String::from("green"),
-                EngineError::EmptyResultSet => String::from("blue"),
-                EngineError::UnexpectedError => String::from("red"),
+                EngineError::RequestError => "green".to_owned(),
+                EngineError::EmptyResultSet => "blue".to_owned(),
+                EngineError::UnexpectedError => "red".to_owned(),
             },
         }
     }
@@ -101,7 +102,7 @@ impl EngineErrorInfo {
 /// A named struct to store, serialize, deserialize the all the search results scraped and
 /// aggregated from the upstream search engines.
 /// `SearchResult` structs.
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Default)]
 #[serde(rename_all = "camelCase")]
 pub struct SearchResults {
     /// Stores the individual serializable `SearchResult` struct into a vector of
@@ -113,6 +114,14 @@ pub struct SearchResults {
     /// Stores the information on which engines failed with their engine name
     /// and the type of error that caused it.
     pub engine_errors_info: Vec<EngineErrorInfo>,
+    /// Stores the flag option which holds the check value that the following 
+    /// search query was disallowed when the safe search level set to 4 and it 
+    /// was present in the `Blocklist` file.
+    pub disallowed: bool,
+    /// Stores the flag option which holds the check value that the following 
+    /// search query was filtered when the safe search level set to 3 and it 
+    /// was present in the `Blocklist` file.
+    pub filtered: bool,
 }
 
 impl SearchResults {
@@ -126,21 +135,48 @@ impl SearchResults {
     /// the search url.
     /// * `empty_result_set` - Takes a boolean which indicates that no engines gave a result for the
     /// given search query.
+    /// * ``
     pub fn new(
         results: Vec<SearchResult>,
-        page_query: String,
-        engine_errors_info: Vec<EngineErrorInfo>,
+        page_query: &str,
+        engine_errors_info: &[EngineErrorInfo],
     ) -> Self {
-        SearchResults {
+        Self {
             results,
-            page_query,
-            style: Style::new("".to_string(), "".to_string()),
-            engine_errors_info,
+            page_query: page_query.to_owned(),
+            style: Style::default(),
+            engine_errors_info: engine_errors_info.to_owned(),
+            disallowed: Default::default(),
+            filtered: Default::default(),
         }
     }
 
     /// A setter function to add website style to the return search results.
-    pub fn add_style(&mut self, style: Style) {
-        self.style = style;
+    pub fn add_style(&mut self, style: &Style) {
+        self.style = style.clone();
+    }
+
+    /// A setter function that sets disallowed to true.
+    pub fn set_disallowed(&mut self) {
+        self.disallowed = true;
+    }
+
+    /// A setter function to set the current page search query.
+    pub fn set_page_query(&mut self, page: &str) {
+        self.page_query = page.to_owned();
+    }
+
+    /// A setter function that sets the filtered to true.
+    pub fn set_filtered(&mut self) {
+        self.filtered = true;
+    }
+
+    /// A getter function that gets the value of `engine_errors_info`.
+    pub fn engine_errors_info(&mut self) -> Vec<EngineErrorInfo> {
+        std::mem::take(&mut self.engine_errors_info)
+    }
+    /// A getter function that gets the value of `results`.
+    pub fn results(&mut self) -> Vec<SearchResult> {
+        self.results.clone()
     }
 }

src/results/aggregator.rs

@@ -64,14 +64,15 @@ type FutureVec = Vec<JoinHandle<Result<HashMap<String, SearchResult>, Report<Eng
 /// function in either `searx` or `duckduckgo` or both otherwise returns a `SearchResults struct`
 /// containing appropriate values.
 pub async fn aggregate(
-    query: String,
+    query: &str,
     page: u32,
     random_delay: bool,
     debug: bool,
-    upstream_search_engines: Vec<EngineHandler>,
+    upstream_search_engines: &[EngineHandler],
     request_timeout: u8,
+    safe_search: u8,
 ) -> Result<SearchResults, Box<dyn std::error::Error>> {
-    let user_agent: String = random_user_agent();
+    let user_agent: &str = random_user_agent();
 
     // Add a random delay before making the request.
     if random_delay || !debug {
@@ -80,19 +81,24 @@ pub async fn aggregate(
         tokio::time::sleep(Duration::from_secs(delay_secs)).await;
     }
 
-    let mut names: Vec<&str> = vec![];
+    let mut names: Vec<&str> = Vec::with_capacity(0);
 
     // create tasks for upstream result fetching
     let mut tasks: FutureVec = FutureVec::new();
 
     for engine_handler in upstream_search_engines {
-        let (name, search_engine) = engine_handler.into_name_engine();
+        let (name, search_engine) = engine_handler.to_owned().into_name_engine();
         names.push(name);
-        let query: String = query.clone();
-        let user_agent: String = user_agent.clone();
+        let query: String = query.to_owned();
         tasks.push(tokio::spawn(async move {
             search_engine
-                .results(query, page, user_agent.clone(), request_timeout)
+                .results(
+                    &query,
+                    page,
+                    user_agent.clone(),
+                    request_timeout,
+                    safe_search,
+                )
                 .await
         }));
     }
@@ -110,7 +116,7 @@ pub async fn aggregate(
     let mut result_map: HashMap<String, SearchResult> = HashMap::new();
     let mut engine_errors_info: Vec<EngineErrorInfo> = Vec::new();
 
-    let mut handle_error = |error: Report<EngineError>, engine_name: String| {
+    let mut handle_error = |error: &Report<EngineError>, engine_name: &'static str| {
         log::error!("Engine Error: {:?}", error);
         engine_errors_info.push(EngineErrorInfo::new(
             error.downcast_ref::<EngineError>().unwrap(),
@@ -120,7 +126,7 @@ pub async fn aggregate(
 
     for _ in 0..responses.len() {
         let response = responses.pop().unwrap();
-        let engine = names.pop().unwrap().to_string();
+        let engine = names.pop().unwrap();
 
         if result_map.is_empty() {
             match response {
@@ -128,7 +134,7 @@ pub async fn aggregate(
                     result_map = results.clone();
                 }
                 Err(error) => {
-                    handle_error(error, engine);
+                    handle_error(&error, engine);
                 }
             }
             continue;
@@ -140,39 +146,37 @@ pub async fn aggregate(
                     result_map
                         .entry(key)
                         .and_modify(|result| {
-                            result.add_engines(engine.clone());
+                            result.add_engines(engine);
                         })
                         .or_insert_with(|| -> SearchResult { value });
                 });
             }
             Err(error) => {
-                handle_error(error, engine);
+                handle_error(&error, engine);
             }
         }
     }
 
+    if safe_search >= 3 {
         let mut blacklist_map: HashMap<String, SearchResult> = HashMap::new();
         filter_with_lists(
             &mut result_map,
             &mut blacklist_map,
-        &file_path(FileType::BlockList)?,
+            file_path(FileType::BlockList)?,
         )?;
 
         filter_with_lists(
             &mut blacklist_map,
             &mut result_map,
-        &file_path(FileType::AllowList)?,
+            file_path(FileType::AllowList)?,
         )?;
 
         drop(blacklist_map);
+    }
 
     let results: Vec<SearchResult> = result_map.into_values().collect();
 
-    Ok(SearchResults::new(
-        results,
-        query.to_string(),
-        engine_errors_info,
-    ))
+    Ok(SearchResults::new(results, query, &engine_errors_info))
 }
 
 /// Filters a map of search results using a list of regex patterns.
@@ -194,7 +198,7 @@ pub fn filter_with_lists(
     let mut reader = BufReader::new(File::open(file_path)?);
 
     for line in reader.by_ref().lines() {
-        let re = Regex::new(&line?)?;
+        let re = Regex::new(line?.trim())?;
 
         // Iterate over each search result in the map and check if it matches the regex pattern
         for (url, search_result) in map_to_be_filtered.clone().into_iter() {
@@ -203,7 +207,10 @@ pub fn filter_with_lists(
                 || re.is_match(&search_result.description.to_lowercase())
             {
                 // If the search result matches the regex pattern, move it from the original map to the resultant map
-                resultant_map.insert(url.clone(), map_to_be_filtered.remove(&url).unwrap());
+                resultant_map.insert(
+                    url.to_owned(),
+                    map_to_be_filtered.remove(&url.to_owned()).unwrap(),
+                );
             }
         }
     }
@@ -214,6 +221,7 @@ pub fn filter_with_lists(
 #[cfg(test)]
 mod tests {
     use super::*;
+    use smallvec::smallvec;
     use std::collections::HashMap;
     use std::io::Write;
     use tempfile::NamedTempFile;
@@ -223,22 +231,22 @@ mod tests {
         // Create a map of search results to filter
         let mut map_to_be_filtered = HashMap::new();
         map_to_be_filtered.insert(
-            "https://www.example.com".to_string(),
+            "https://www.example.com".to_owned(),
             SearchResult {
-                title: "Example Domain".to_string(),
-                url: "https://www.example.com".to_string(),
+                title: "Example Domain".to_owned(),
+                url: "https://www.example.com".to_owned(),
                 description: "This domain is for use in illustrative examples in documents."
-                    .to_string(),
-                engine: vec!["Google".to_string(), "Bing".to_string()],
+                    .to_owned(),
+                engine: smallvec!["Google".to_owned(), "Bing".to_owned()],
             },
         );
         map_to_be_filtered.insert(
-            "https://www.rust-lang.org/".to_string(),
+            "https://www.rust-lang.org/".to_owned(),
             SearchResult {
-                title: "Rust Programming Language".to_string(),
-                url: "https://www.rust-lang.org/".to_string(),
-                description: "A systems programming language that runs blazingly fast, prevents segfaults, and guarantees thread safety.".to_string(),
-                engine: vec!["Google".to_string(), "DuckDuckGo".to_string()],
+                title: "Rust Programming Language".to_owned(),
+                url: "https://www.rust-lang.org/".to_owned(),
+                description: "A systems programming language that runs blazingly fast, prevents segfaults, and guarantees thread safety.".to_owned(),
+                engine: smallvec!["Google".to_owned(), "DuckDuckGo".to_owned()],
             },
         );
 
@@ -267,22 +275,22 @@ mod tests {
     fn test_filter_with_lists_wildcard() -> Result<(), Box<dyn std::error::Error>> {
         let mut map_to_be_filtered = HashMap::new();
         map_to_be_filtered.insert(
-            "https://www.example.com".to_string(),
+            "https://www.example.com".to_owned(),
             SearchResult {
-                title: "Example Domain".to_string(),
-                url: "https://www.example.com".to_string(),
+                title: "Example Domain".to_owned(),
+                url: "https://www.example.com".to_owned(),
                 description: "This domain is for use in illustrative examples in documents."
-                    .to_string(),
-                engine: vec!["Google".to_string(), "Bing".to_string()],
+                    .to_owned(),
+                engine: smallvec!["Google".to_owned(), "Bing".to_owned()],
             },
         );
         map_to_be_filtered.insert(
-            "https://www.rust-lang.org/".to_string(),
+            "https://www.rust-lang.org/".to_owned(),
             SearchResult {
-                title: "Rust Programming Language".to_string(),
-                url: "https://www.rust-lang.org/".to_string(),
-                description: "A systems programming language that runs blazingly fast, prevents segfaults, and guarantees thread safety.".to_string(),
-                engine: vec!["Google".to_string(), "DuckDuckGo".to_string()],
+                title: "Rust Programming Language".to_owned(),
+                url: "https://www.rust-lang.org/".to_owned(),
+                description: "A systems programming language that runs blazingly fast, prevents segfaults, and guarantees thread safety.".to_owned(),
+                engine: smallvec!["Google".to_owned(), "DuckDuckGo".to_owned()],
             },
         );
 
@@ -327,13 +335,13 @@ mod tests {
     fn test_filter_with_lists_invalid_regex() {
         let mut map_to_be_filtered = HashMap::new();
         map_to_be_filtered.insert(
-            "https://www.example.com".to_string(),
+            "https://www.example.com".to_owned(),
             SearchResult {
-                title: "Example Domain".to_string(),
-                url: "https://www.example.com".to_string(),
+                title: "Example Domain".to_owned(),
+                url: "https://www.example.com".to_owned(),
                 description: "This domain is for use in illustrative examples in documents."
-                    .to_string(),
-                engine: vec!["Google".to_string(), "Bing".to_string()],
+                    .to_owned(),
+                engine: smallvec!["Google".to_owned(), "Bing".to_owned()],
             },
         );
 

src/results/user_agent.rs

@@ -1,10 +1,21 @@
 //! This module provides the functionality to generate random user agent string.
 
+use std::sync::OnceLock;
+
 use fake_useragent::{Browsers, UserAgents, UserAgentsBuilder};
 
 /// A static variable which stores the initially build `UserAgents` struct. So as it can be resused
 /// again and again without the need of reinitializing the `UserAgents` struct.
-static USER_AGENTS: once_cell::sync::Lazy<UserAgents> = once_cell::sync::Lazy::new(|| {
+static USER_AGENTS: OnceLock<UserAgents> = OnceLock::new();
+
+/// A function to generate random user agent to improve privacy of the user.
+///
+/// # Returns
+///
+/// A randomly generated user agent string.
+pub fn random_user_agent() -> &'static str {
+    USER_AGENTS
+        .get_or_init(|| {
             UserAgentsBuilder::new()
                 .cache(false)
                 .dir("/tmp")
@@ -18,13 +29,6 @@ static USER_AGENTS: once_cell::sync::Lazy<UserAgents> = once_cell::sync::Lazy::n
                         .set_mozilla(),
                 )
                 .build()
-});
-
-/// A function to generate random user agent to improve privacy of the user.
-///
-/// # Returns
-///
-/// A randomly generated user agent string.
-pub fn random_user_agent() -> String {
-    USER_AGENTS.random().to_string()
+        })
+        .random()
 }

src/server/routes.rs

@@ -2,7 +2,10 @@
 //! meta search engine website and provide appropriate response to each route/page
 //! when requested.
 
-use std::fs::read_to_string;
+use std::{
+    fs::{read_to_string, File},
+    io::{BufRead, BufReader, Read},
+};
 
 use crate::{
     cache::cacher::RedisCache,
@@ -13,9 +16,14 @@ use crate::{
 };
 use actix_web::{get, web, HttpRequest, HttpResponse};
 use handlebars::Handlebars;
+use regex::Regex;
 use serde::Deserialize;
 use tokio::join;
 
+// ---- Constants ----
+/// Initialize redis cache connection once and store it on the heap.
+static REDIS_CACHE: async_once_cell::OnceCell<RedisCache> = async_once_cell::OnceCell::new();
+
 /// A named struct which deserializes all the user provided search parameters and stores them.
 #[derive(Deserialize)]
 struct SearchParams {
@@ -25,6 +33,7 @@ struct SearchParams {
     /// It stores the search parameter `page` (or pageno in simple words)
     /// of the search url.
     page: Option<u32>,
+    safesearch: Option<u8>,
 }
 
 /// Handles the route of index page or main page of the `websurfx` meta search engine website.
@@ -53,13 +62,13 @@ pub async fn not_found(
 /// A named struct which is used to deserialize the cookies fetched from the client side.
 #[allow(dead_code)]
 #[derive(Deserialize)]
-struct Cookie {
+struct Cookie<'a> {
     /// It stores the theme name used in the website.
-    theme: String,
+    theme: &'a str,
     /// It stores the colorscheme name used for the website theme.
-    colorscheme: String,
+    colorscheme: &'a str,
     /// It stores the user selected upstream search engines selected from the UI.
-    engines: Vec<String>,
+    engines: Vec<&'a str>,
 }
 
 /// Handles the route of search page of the `websurfx` meta search engine website and it takes
@@ -95,42 +104,58 @@ pub async fn search(
                 None => 1,
             };
 
+            let safe_search: u8 = match config.safe_search {
+                3..=4 => config.safe_search,
+                _ => match &params.safesearch {
+                    Some(safesearch) => match safesearch {
+                        0..=2 => *safesearch,
+                        _ => 1,
+                    },
+                    None => config.safe_search,
+                },
+            };
+
             let (_, results, _) = join!(
                 results(
                     format!(
-                        "http://{}:{}/search?q={}&page={}",
+                        "http://{}:{}/search?q={}&page={}&safesearch={}",
                         config.binding_ip,
                         config.port,
                         query,
-                        page - 1
+                        page - 1,
+                        safe_search
                     ),
                     &config,
-                    query.to_string(),
+                    query,
                     page - 1,
                     req.clone(),
+                    safe_search
                 ),
                 results(
                     format!(
-                        "http://{}:{}/search?q={}&page={}",
-                        config.binding_ip, config.port, query, page
+                        "http://{}:{}/search?q={}&page={}&safesearch={}",
+                        config.binding_ip, config.port, query, page, safe_search
                     ),
                     &config,
-                    query.to_string(),
+                    query,
                     page,
                     req.clone(),
+                    safe_search
                 ),
                 results(
                     format!(
-                        "http://{}:{}/search?q={}&page={}",
+                        "http://{}:{}/search?q={}&page={}&safesearch={}",
                         config.binding_ip,
                         config.port,
                         query,
-                        page + 1
+                        page + 1,
+                        safe_search
                     ),
                     &config,
-                    query.to_string(),
+                    query,
                     page + 1,
                     req.clone(),
+                    safe_search
                 )
             );
 
@@ -161,30 +186,53 @@ pub async fn search(
 async fn results(
     url: String,
     config: &Config,
-    query: String,
+    query: &str,
     page: u32,
     req: HttpRequest,
+    safe_search: u8,
 ) -> Result<SearchResults, Box<dyn std::error::Error>> {
     // Initialize redis cache connection struct
-    let mut redis_cache = RedisCache::new(config.redis_url.clone())?;
+    let mut redis_cache: RedisCache = REDIS_CACHE
+        .get_or_init(async {
+            // Initialize redis cache connection pool only one and store it in the heap.
+            RedisCache::new(&config.redis_url, 5).await.unwrap()
+        })
+        .await
+        .clone();
     // fetch the cached results json.
-    let cached_results_json = redis_cache.cached_json(&url);
+    let cached_results_json: Result<String, error_stack::Report<crate::cache::error::PoolError>> =
+        redis_cache.clone().cached_json(&url).await;
     // check if fetched cache results was indeed fetched or it was an error and if so
     // handle the data accordingly.
     match cached_results_json {
-        Ok(results) => Ok(serde_json::from_str::<SearchResults>(&results).unwrap()),
+        Ok(results) => Ok(serde_json::from_str::<SearchResults>(&results)?),
         Err(_) => {
+            if safe_search == 4 {
+                let mut results: SearchResults = SearchResults::default();
+                let mut _flag: bool =
+                    is_match_from_filter_list(file_path(FileType::BlockList)?, query)?;
+                _flag = !is_match_from_filter_list(file_path(FileType::AllowList)?, query)?;
+
+                if _flag {
+                    results.set_disallowed();
+                    results.add_style(&config.style);
+                    results.set_page_query(query);
+                    redis_cache
+                        .cache_results(&serde_json::to_string(&results)?, &url)
+                        .await?;
+                    return Ok(results);
+                }
+            }
+
             // check if the cookie value is empty or not if it is empty then use the
             // default selected upstream search engines from the config file otherwise
             // parse the non-empty cookie and grab the user selected engines from the
             // UI and use that.
-            let mut results: crate::results::aggregation_models::SearchResults = match req
-                .cookie("appCookie")
-            {
+            let mut results: SearchResults = match req.cookie("appCookie") {
                 Some(cookie_value) => {
                     let cookie_value: Cookie = serde_json::from_str(cookie_value.name_value().1)?;
 
-                    let engines = cookie_value
+                    let engines: Vec<EngineHandler> = cookie_value
                         .engines
                         .iter()
                         .filter_map(|name| EngineHandler::new(name))
@@ -195,8 +243,9 @@ async fn results(
                         page,
                         config.aggregator.random_delay,
                         config.debug,
-                        engines,
+                        &engines,
                         config.request_timeout,
+                        safe_search,
                     )
                     .await?
                 }
@@ -206,19 +255,41 @@ async fn results(
                         page,
                         config.aggregator.random_delay,
                         config.debug,
-                        config.upstream_search_engines.clone(),
+                        &config.upstream_search_engines,
                         config.request_timeout,
+                        safe_search,
                     )
                     .await?
                 }
             };
-            results.add_style(config.style.clone());
-            redis_cache.cache_results(serde_json::to_string(&results)?, &url)?;
+            if results.engine_errors_info().is_empty() && results.results().is_empty() {
+                results.set_filtered();
+            }
+            results.add_style(&config.style);
+            redis_cache
+                .cache_results(&serde_json::to_string(&results)?, &url)
+                .await?;
             Ok(results)
         }
     }
 }
 
+fn is_match_from_filter_list(
+    file_path: &str,
+    query: &str,
+) -> Result<bool, Box<dyn std::error::Error>> {
+    let mut flag = false;
+    let mut reader = BufReader::new(File::open(file_path)?);
+    for line in reader.by_ref().lines() {
+        let re = Regex::new(&line?)?;
+        if re.is_match(query) {
+            flag = true;
+            break;
+        }
+    }
+    Ok(flag)
+}
+
 /// Handles the route of robots.txt page of the `websurfx` meta search engine website.
 #[get("/robots.txt")]
 pub async fn robots_data(_req: HttpRequest) -> Result<HttpResponse, Box<dyn std::error::Error>> {

websurfx/config.lua

@@ -10,6 +10,21 @@ production_use = false -- whether to use production mode or not (in other words
 -- if production_use is set to true
 -- There will be a random delay before sending the request to the search engines, this is to prevent DDoSing the upstream search engines from a large number of simultaneous requests.
 request_timeout = 30 -- timeout for the search requests sent to the upstream search engines to be fetched (value in seconds).
+rate_limiter = {
+	number_of_requests = 20, -- The number of request that are allowed within a provided time limit.
+	time_limit = 3, -- The time limit in which the quantity of requests that should be accepted.
+}
+
+-- ### Search ###
+-- Filter results based on different levels. The levels provided are:
+-- {{
+-- 0 - None
+-- 1 - Low
+-- 2 - Moderate
+-- 3 - High
+-- 4 - Aggressive
+-- }}
+safe_search = 2
 
 -- ### Website ###
 -- The different colorschemes provided are:
@@ -34,4 +49,7 @@ theme = "simple" -- the theme name which should be used for the website
 redis_url = "redis://127.0.0.1:8082" -- redis connection url address on which the client should connect on.
 
 -- ### Search Engines ###
-upstream_search_engines = { DuckDuckGo = true, Searx = false } -- select the upstream search engines from which the results should be fetched.
+upstream_search_engines = {
+	DuckDuckGo = true,
+	Searx = false,
+} -- select the upstream search engines from which the results should be fetched.