Reduce core dependencies

Cargo.toml

@@ -17,7 +17,7 @@ failure = "0.1"
 lazy_static = "1.0"
 log = "0.4"
 percent-encoding = "1.0.1"
-rand = "0.6.5"
+getrandom = "0.1"
 reqwest = { version = "0.10", features = ["json", "socks"], default-features = false }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"

src/blocking/util.rs

@@ -1,7 +1,5 @@
 //! Utils function
 use chrono::prelude::*;
-use rand::distributions::Alphanumeric;
-use rand::{self, Rng};
 use webbrowser;
 
 use std::collections::HashMap;
@@ -12,17 +10,24 @@ use std::string::ToString;
 
 use super::oauth2::{SpotifyOAuth, TokenInfo};
 
+use getrandom::getrandom;
+
+static ALPHANUM: &[u8] =
+    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".as_bytes();
 /// Convert datetime to unix timestampe
 pub fn datetime_to_timestamp(elapsed: u32) -> i64 {
     let utc: DateTime<Utc> = Utc::now();
     utc.timestamp() + i64::from(elapsed)
 }
 /// Generate `length` random chars
 pub fn generate_random_string(length: usize) -> String {
-    rand::thread_rng()
-        .sample_iter(&Alphanumeric)
-        .take(length)
-        .collect()
+    let mut buf = vec![0u8; length];
+    getrandom(&mut buf).unwrap();
+    let range = ALPHANUM.len();
+    return buf
+        .iter()
+        .map(|byte| ALPHANUM[*byte as usize % range] as char)
+        .collect();
 }
 
 /// Convert map to `query_string`, for example:

src/util.rs

@@ -1,7 +1,5 @@
 //! utils function
 use chrono::prelude::*;
-use rand::distributions::Alphanumeric;
-use rand::{self, Rng};
 
 use std::collections::HashMap;
 use std::fmt::Debug;
@@ -10,6 +8,10 @@ use std::io;
 use std::string::ToString;
 
 use super::oauth2::{SpotifyOAuth, TokenInfo};
+use getrandom::getrandom;
+
+static ALPHANUM: &[u8] =
+    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".as_bytes();
 
 /// convert datetime to unix timestampe
 pub fn datetime_to_timestamp(elapsed: u32) -> i64 {
@@ -18,10 +20,13 @@ pub fn datetime_to_timestamp(elapsed: u32) -> i64 {
 }
 /// generate `length` random chars
 pub fn generate_random_string(length: usize) -> String {
-    rand::thread_rng()
-        .sample_iter(&Alphanumeric)
-        .take(length)
-        .collect()
+    let mut buf = vec![0u8; length];
+    getrandom(&mut buf).unwrap();
+    let range = ALPHANUM.len();
+    return buf
+        .iter()
+        .map(|byte| ALPHANUM[*byte as usize % range] as char)
+        .collect();
 }
 
 /// convert map to `query_string`, for example: