Replace HashMap<String, String> with HashMap<&str, &str> to reduce allocation

src/http/mod.rs

@@ -20,8 +20,8 @@ pub use self::reqwest::ReqwestClient as HTTPClient;
 pub use self::ureq::UreqClient as HTTPClient;
 
 pub type Headers = HashMap<String, String>;
-pub type Query = HashMap<String, String>;
-pub type Form = HashMap<String, String>;
+pub type Query<'a> = HashMap<&'a str, &'a str>;
+pub type Form<'a> = HashMap<&'a str, &'a str>;
 
 pub mod headers {
     use crate::oauth2::Token;
@@ -86,11 +86,11 @@ pub trait BaseHttpClient: Default + Clone + fmt::Debug {
         payload: &Value,
     ) -> ClientResult<String>;
 
-    async fn post_form(
+    async fn post_form<'a>(
         &self,
         url: &str,
         headers: Option<&Headers>,
-        payload: &Form,
+        payload: &Form<'a>,
     ) -> ClientResult<String>;
 
     async fn put(
@@ -148,7 +148,7 @@ impl Spotify {
         &self,
         url: &str,
         headers: Option<&Headers>,
-        payload: &Query,
+        payload: &Query<'_>,
     ) -> ClientResult<String> {
         let url = self.endpoint_url(url);
         self.http.get(&url, headers, payload).await
@@ -172,7 +172,7 @@ impl Spotify {
         &self,
         url: &str,
         headers: Option<&Headers>,
-        payload: &Form,
+        payload: &Form<'_>,
     ) -> ClientResult<String> {
         let url = self.endpoint_url(url);
         self.http.post_form(&url, headers, payload).await
@@ -206,7 +206,11 @@ impl Spotify {
     /// autentication.
     #[inline]
     #[maybe_async]
-    pub(crate) async fn endpoint_get(&self, url: &str, payload: &Query) -> ClientResult<String> {
+    pub(crate) async fn endpoint_get(
+        &self,
+        url: &str,
+        payload: &Query<'_>,
+    ) -> ClientResult<String> {
         let headers = self.auth_headers()?;
         self.get(url, Some(&headers), payload).await
     }

src/http/reqwest.rs

@@ -118,11 +118,11 @@ impl BaseHttpClient for ReqwestClient {
     }
 
     #[inline]
-    async fn post_form(
+    async fn post_form<'a>(
         &self,
         url: &str,
         headers: Option<&Headers>,
-        payload: &Form,
+        payload: &Form<'a>,
     ) -> ClientResult<String> {
         self.request(Method::POST, url, headers, |req| req.form(payload))
             .await

src/http/ureq.rs

@@ -75,17 +75,17 @@ impl BaseHttpClient for UreqClient {
     }
 
     #[inline]
-    fn post_form(
+    fn post_form<'a>(
         &self,
         url: &str,
         headers: Option<&Headers>,
-        payload: &Form,
+        payload: &Form<'a>,
     ) -> ClientResult<String> {
         let request = ureq::post(url);
         let sender = |req: Request| {
             let payload = payload
                 .iter()
-                .map(|(key, val)| (key.as_str(), val.as_str()))
+                .map(|(key, val)| (*key, *val))
                 .collect::<Vec<_>>();
 
             req.send_form(&payload)

src/model/enums/country.rs

@@ -1,11 +1,11 @@
 use serde::{Deserialize, Serialize};
-use strum::ToString;
+use strum::AsRefStr;
 
 /// ISO 3166-1 alpha-2 country code, from
 /// [country-list](https://datahub.io/core/country-list)
 ///
 /// [Reference](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 pub enum Country {
     #[strum(serialize = "AF")]
     #[serde(rename = "AF")]

src/model/enums/misc.rs

@@ -1,5 +1,5 @@
 use serde::{Deserialize, Serialize};
-use strum::ToString;
+use strum::AsRefStr;
 
 use super::Country;
 
@@ -8,7 +8,7 @@ use super::Country;
 /// `toggling_shuffle`, `toggling_repeat_track`, `transferring_playback`.
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/object-model/#disallows-object)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, Hash, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, Hash, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum DisallowKey {
@@ -27,7 +27,7 @@ pub enum DisallowKey {
 /// Time range: `long-term`, `medium-term`, `short-term`.
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/personalization/get-users-top-artists-and-tracks/)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum TimeRange {
@@ -39,7 +39,7 @@ pub enum TimeRange {
 /// Repeat state: `track`, `context` or `off`.
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/player/set-repeat-mode-on-users-playback/)
-#[derive(Clone, Debug, Copy, Serialize, Deserialize, PartialEq, Eq, ToString)]
+#[derive(Clone, Debug, Copy, Serialize, Deserialize, PartialEq, Eq, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum RepeatState {
@@ -51,7 +51,7 @@ pub enum RepeatState {
 /// Type for include_external: `audio`.
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/search/search/)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum IncludeExternal {
@@ -61,7 +61,7 @@ pub enum IncludeExternal {
 /// Date precision: `year`, `month`, `day`.
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/object-model/):
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum DatePrecision {
@@ -73,7 +73,7 @@ pub enum DatePrecision {
 /// The reason for the restriction: `market`, `product`, `explicit`
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/object-model/#track-restriction-object)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum RestrictionReason {
@@ -87,7 +87,7 @@ pub enum RestrictionReason {
 /// a -1 for `no result`
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/tracks/get-audio-analysis/#section-object)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 pub enum Modality {
     Minor = 0,
     Major = 1,
@@ -102,12 +102,15 @@ pub enum Market {
     Country(Country),
     FromToken,
 }
+pub trait AsRefStr {
+    fn as_ref(&self) -> &str;
+}
 
-impl ToString for Market {
-    fn to_string(&self) -> String {
+impl AsRefStr for Market {
+    fn as_ref(&self) -> &str {
         match self {
-            Market::Country(c) => c.to_string(),
-            Market::FromToken => "from_token".to_string(),
+            Market::Country(country) => country.as_ref(),
+            Market::FromToken => "from_token",
         }
     }
 }

src/model/enums/types.rs

@@ -1,11 +1,11 @@
 use serde::{Deserialize, Serialize};
-use strum::{Display, EnumString, ToString};
+use strum::{AsRefStr, Display, EnumString};
 
 /// Copyright type: `C` = the copyright, `P` = the sound recording (performance)
 /// copyright.
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/object-model/#copyright-object)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 pub enum CopyrightType {
     #[strum(serialize = "P")]
     #[serde(rename = "P")]
@@ -18,7 +18,7 @@ pub enum CopyrightType {
 /// Album type: `album`, `single`, `appears_on`, `compilation`
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/object-model/#album-object-full)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum AlbumType {
@@ -29,7 +29,9 @@ pub enum AlbumType {
 }
 
 /// Type: `artist`, `album`, `track`, `playlist`, `show` or `episode`
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, Display, EnumString)]
+#[derive(
+    Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, Display, EnumString, AsRefStr,
+)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum Type {
@@ -45,7 +47,7 @@ pub enum Type {
 /// Additional typs: `track`, `episode`
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/player/get-information-about-the-users-current-playback/)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum AdditionalType {
@@ -56,7 +58,7 @@ pub enum AdditionalType {
 /// Currently playing type: `track`, `episode`, `ad`, `unknown`
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/player/get-the-users-currently-playing-track/)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum CurrentlyPlayingType {
@@ -71,7 +73,7 @@ pub enum CurrentlyPlayingType {
 /// Type for search: `artist`, `album`, `track`, `playlist`, `show`, `episode`
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/#category-search)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum SearchType {
@@ -88,7 +90,7 @@ pub enum SearchType {
 /// (The subscription level "open" can be considered the same as "free".)
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/users-profile/get-current-users-profile/)
-#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, ToString)]
+#[derive(Clone, Serialize, Deserialize, Copy, PartialEq, Eq, Debug, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum SubscriptionLevel {
@@ -100,7 +102,7 @@ pub enum SubscriptionLevel {
 /// Device Type: `computer`, `smartphone`, `speaker`, `TV`
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/player/get-a-users-available-devices/#device-types)
-#[derive(Clone, Debug, Serialize, Deserialize, ToString, PartialEq, Eq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, AsRefStr)]
 #[strum(serialize_all = "snake_case")]
 pub enum DeviceType {
     Computer,
@@ -121,7 +123,7 @@ pub enum DeviceType {
 /// Recommendations seed type
 ///
 /// [Reference](https://developer.spotify.com/documentation/web-api/reference/object-model/#recommendations-seed-object)
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, AsRefStr)]
 #[serde(rename_all = "snake_case")]
 pub enum RecommendationsSeedType {
     Artist,

src/oauth2.rs

@@ -246,7 +246,7 @@ impl Spotify {
 
     /// Sends a request to Spotify for an access token.
     #[maybe_async]
-    async fn fetch_access_token(&self, payload: &Form) -> ClientResult<Token> {
+    async fn fetch_access_token(&self, payload: &Form<'_>) -> ClientResult<Token> {
         // This request uses a specific content type, and the client ID/secret
         // as the authentication, since the access token isn't available yet.
         let mut head = Headers::new();
@@ -272,11 +272,8 @@ impl Spotify {
         refresh_token: &str,
     ) -> ClientResult<()> {
         let mut data = Form::new();
-        data.insert(headers::REFRESH_TOKEN.to_owned(), refresh_token.to_owned());
-        data.insert(
-            headers::GRANT_TYPE.to_owned(),
-            headers::GRANT_REFRESH_TOKEN.to_owned(),
-        );
+        data.insert(headers::REFRESH_TOKEN, refresh_token);
+        data.insert(headers::GRANT_TYPE, headers::GRANT_REFRESH_TOKEN);
 
         let mut tok = self.fetch_access_token(&data).await?;
         tok.refresh_token = Some(refresh_token.to_string());
@@ -299,10 +296,7 @@ impl Spotify {
     #[maybe_async]
     pub async fn request_client_token_without_cache(&mut self) -> ClientResult<()> {
         let mut data = Form::new();
-        data.insert(
-            headers::GRANT_TYPE.to_owned(),
-            headers::GRANT_CLIENT_CREDS.to_owned(),
-        );
+        data.insert(headers::GRANT_TYPE, headers::GRANT_CLIENT_CREDS);
 
         self.token = Some(self.fetch_access_token(&data).await?);
 
@@ -338,22 +332,17 @@ impl Spotify {
     pub async fn request_user_token_without_cache(&mut self, code: &str) -> ClientResult<()> {
         let oauth = self.get_oauth()?;
         let mut data = Form::new();
-        data.insert(
-            headers::GRANT_TYPE.to_owned(),
-            headers::GRANT_AUTH_CODE.to_owned(),
-        );
-        data.insert(headers::REDIRECT_URI.to_owned(), oauth.redirect_uri.clone());
-        data.insert(headers::CODE.to_owned(), code.to_owned());
-        data.insert(
-            headers::SCOPE.to_owned(),
-            oauth
-                .scope
-                .clone()
-                .into_iter()
-                .collect::<Vec<_>>()
-                .join(" "),
-        );
-        data.insert(headers::STATE.to_owned(), oauth.state.clone());
+        let scopes = oauth
+            .scope
+            .clone()
+            .into_iter()
+            .collect::<Vec<_>>()
+            .join(" ");
+        data.insert(headers::GRANT_TYPE, headers::GRANT_AUTH_CODE);
+        data.insert(headers::REDIRECT_URI, oauth.redirect_uri.as_ref());
+        data.insert(headers::CODE, code);
+        data.insert(headers::SCOPE, scopes.as_ref());
+        data.insert(headers::STATE, oauth.state.as_ref());
 
         self.token = Some(self.fetch_access_token(&data).await?);