refactor: reduce smallvec dep from git-date

Signed-off-by: tison <wander4096@gmail.com>

Author: tisonkun

Cargo.lock

@@ -24,9 +24,6 @@ bstr = { version = "1.12.0", default-features = false, features = ["std"] }
 serde = { version = "1.0.114", optional = true, default-features = false, features = ["derive"] }
 itoa = "1.0.17"
 jiff = "0.2.24"
-# TODO: used for quick and easy `TimeBacking: std::io::Write` implementation, but could make that `Copy`
-#       and remove this dep with custom impl
-smallvec = { version = "1.15.1", features = ["write"] }
 
 document-features = { version = "0.2.0", optional = true }
 

gix-date/Cargo.toml

@@ -1,13 +1,29 @@
+use std::io;
 use std::str::FromStr;
 
 use crate::{Error, Time};
-use smallvec::SmallVec;
 
 /// A container for just enough bytes to hold the largest-possible [`time`](Time) instance.
-/// It's used in conjunction with
 #[derive(Default, Clone)]
 pub struct TimeBuf {
-    buf: SmallVec<[u8; Time::MAX.size()]>,
+    idx: usize,
+    buf: [u8; Time::MAX.size()],
+}
+
+impl io::Write for TimeBuf {
+    fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
+        let end_idx = self.idx + buf.len();
+        if end_idx > Time::MAX.size() {
+            return Err(io::Error::from(io::ErrorKind::StorageFull));
+        }
+        self.buf[self.idx..end_idx].copy_from_slice(buf);
+        self.idx = end_idx;
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
 }
 
 impl TimeBuf {
@@ -21,7 +37,7 @@ impl TimeBuf {
 
     /// Clear the previous content.
     fn clear(&mut self) {
-        self.buf.clear();
+        self.idx = 0;
     }
 }
 
@@ -30,7 +46,7 @@ impl Time {
     /// and return `buf` as `&str` for easy consumption.
     pub fn to_str<'a>(&self, buf: &'a mut TimeBuf) -> &'a str {
         buf.clear();
-        self.write_to(&mut buf.buf)
+        self.write_to(buf)
             .expect("write to memory of just the right size cannot fail");
         buf.as_str()
     }