1 files changed, 84 insertions, 0 deletions
diff --git a/vendor/gix-object/src/encode.rs b/vendor/gix-object/src/encode.rs
new file mode 100644
index 000000000..6d291c92a
--- /dev/null
+++ b/vendor/gix-object/src/encode.rs
@@ -0,0 +1,84 @@
+//! Encoding utilities
+use std::io::{self, Write};
+
+use bstr::{BString, ByteSlice};
+
+/// An error returned when object encoding fails.
+#[derive(Debug, thiserror::Error)]
+#[allow(missing_docs)]
+pub enum Error {
+    #[error("Newlines are not allowed in header values: {value:?}")]
+    NewlineInHeaderValue { value: BString },
+    #[error("Header values must not be empty")]
+    EmptyValue,
+}
+
+macro_rules! check {
+    ($e: expr) => {
+        $e.expect("Writing to a Vec should never fail.")
+    };
+}
+/// Generates a loose header buffer
+pub fn loose_header(kind: crate::Kind, size: usize) -> smallvec::SmallVec<[u8; 28]> {
+    let mut v = smallvec::SmallVec::new();
+    check!(v.write_all(kind.as_bytes()));
+    check!(v.write_all(SPACE));
+    check!(v.write_all(itoa::Buffer::new().format(size).as_bytes()));
+    check!(v.write_all(b"\0"));
+    v
+}
+
+impl From<Error> for io::Error {
+    fn from(other: Error) -> io::Error {
+        io::Error::new(io::ErrorKind::Other, other)
+    }
+}
+
+pub(crate) fn header_field_multi_line(name: &[u8], value: &[u8], mut out: impl io::Write) -> io::Result<()> {
+    let mut lines = value.as_bstr().split_str(b"\n");
+    trusted_header_field(name, lines.next().ok_or(Error::EmptyValue)?, &mut out)?;
+    for line in lines {
+        out.write_all(SPACE)?;
+        out.write_all(line)?;
+        out.write_all(NL)?;
+    }
+    Ok(())
+}
+
+pub(crate) fn trusted_header_field(name: &[u8], value: &[u8], mut out: impl io::Write) -> io::Result<()> {
+    out.write_all(name)?;
+    out.write_all(SPACE)?;
+    out.write_all(value)?;
+    out.write_all(NL)
+}
+
+pub(crate) fn trusted_header_signature(
+    name: &[u8],
+    value: &gix_actor::SignatureRef<'_>,
+    mut out: impl io::Write,
+) -> io::Result<()> {
+    out.write_all(name)?;
+    out.write_all(SPACE)?;
+    value.write_to(&mut out)?;
+    out.write_all(NL)
+}
+
+pub(crate) fn trusted_header_id(name: &[u8], value: &gix_hash::ObjectId, mut out: impl io::Write) -> io::Result<()> {
+    out.write_all(name)?;
+    out.write_all(SPACE)?;
+    value.write_hex_to(&mut out)?;
+    out.write_all(NL)
+}
+
+pub(crate) fn header_field(name: &[u8], value: &[u8], out: impl io::Write) -> io::Result<()> {
+    if value.is_empty() {
+        return Err(Error::EmptyValue.into());
+    }
+    if value.find(NL).is_some() {
+        return Err(Error::NewlineInHeaderValue { value: value.into() }.into());
+    }
+    trusted_header_field(name, value, out)
+}
+
+pub(crate) const NL: &[u8; 1] = b"\n";
+pub(crate) const SPACE: &[u8; 1] = b" ";