⚙️ refactor: add several optimizations to the engine code (#180)(#178)

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.
@@ -39,9 +39,9 @@ impl SearchEngine for DuckDuckGo {
     /// or HeaderMap fails to initialize.
     async fn results(
         &self,
-        query: String,
+        query: &str,
         page: u32,
-        user_agent: String,
+        user_agent: &str,
         request_timeout: u8,
     ) -> Result<HashMap<String, SearchResult>, EngineError> {
         // Page number can be missing or empty string and so appropriate handling is required
@@ -61,38 +61,19 @@ 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")
@@ -126,8 +107,7 @@ impl SearchEngine for DuckDuckGo {
                         .next()
                         .unwrap()
                         .inner_html()
-                        .trim()
-                        .to_string(),
+                        .trim(),
                     format!(
                         "https://{}",
                         result
@@ -136,15 +116,15 @@ 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/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.
@@ -38,9 +38,9 @@ impl SearchEngine for Searx {
 
     async fn results(
         &self,
-        query: String,
+        query: &str,
         page: u32,
-        user_agent: String,
+        user_agent: &str,
         request_timeout: u8,
     ) -> Result<HashMap<String, SearchResult>, EngineError> {
         // Page number can be missing or empty string and so appropriate handling is required
@@ -51,32 +51,16 @@ impl SearchEngine for Searx {
         };
 
         // 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")
@@ -117,24 +101,21 @@ 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))