core API: move spotify_id to lib.rs

core/src/spotify_id.rs

@@ -0,0 +1,104 @@
+use byteorder::{BigEndian, ByteOrder};
+use std;
+use std::fmt;
+use util::u128;
+// Unneeded since 1.21
+#[allow(unused_imports)]
+use std::ascii::AsciiExt;
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub struct SpotifyId(u128);
+
+const BASE62_DIGITS: &'static [u8] = b"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+const BASE16_DIGITS: &'static [u8] = b"0123456789abcdef";
+
+impl SpotifyId {
+    pub fn from_base16(id: &str) -> SpotifyId {
+        assert!(id.is_ascii());
+        let data = id.as_bytes();
+
+        let mut n: u128 = u128::zero();
+        for c in data {
+            let d = BASE16_DIGITS.iter().position(|e| e == c).unwrap() as u8;
+            n = n * u128::from(16);
+            n = n + u128::from(d);
+        }
+
+        SpotifyId(n)
+    }
+
+    pub fn from_base62(id: &str) -> SpotifyId {
+        assert!(id.is_ascii());
+        let data = id.as_bytes();
+
+        let mut n: u128 = u128::zero();
+        for c in data {
+            let d = BASE62_DIGITS.iter().position(|e| e == c).unwrap() as u8;
+            n = n * u128::from(62);
+            n = n + u128::from(d);
+        }
+
+        SpotifyId(n)
+    }
+
+    pub fn from_raw(data: &[u8]) -> SpotifyId {
+        assert_eq!(data.len(), 16);
+
+        let high = BigEndian::read_u64(&data[0..8]);
+        let low = BigEndian::read_u64(&data[8..16]);
+
+        SpotifyId(u128::from_parts(high, low))
+    }
+
+    pub fn to_base16(&self) -> String {
+        let &SpotifyId(ref n) = self;
+        let (high, low) = n.parts();
+
+        let mut data = [0u8; 32];
+        for i in 0..16 {
+            data[31 - i] = BASE16_DIGITS[(low.wrapping_shr(4 * i as u32) & 0xF) as usize];
+        }
+        for i in 0..16 {
+            data[15 - i] = BASE16_DIGITS[(high.wrapping_shr(4 * i as u32) & 0xF) as usize];
+        }
+
+        std::str::from_utf8(&data).unwrap().to_owned()
+    }
+
+    pub fn to_raw(&self) -> [u8; 16] {
+        let &SpotifyId(ref n) = self;
+        let (high, low) = n.parts();
+
+        let mut data = [0u8; 16];
+
+        BigEndian::write_u64(&mut data[0..8], high);
+        BigEndian::write_u64(&mut data[8..16], low);
+
+        data
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct FileId(pub [u8; 20]);
+
+impl FileId {
+    pub fn to_base16(&self) -> String {
+        self.0
+            .iter()
+            .map(|b| format!("{:02x}", b))
+            .collect::<Vec<String>>()
+            .concat()
+    }
+}
+
+impl fmt::Debug for FileId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("FileId").field(&self.to_base16()).finish()
+    }
+}
+
+impl fmt::Display for FileId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&self.to_base16())
+    }
+}