Change ParseTree::write_one_entry to use a Write instead of a Vec

src/cinnabar/manifest.rs

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use std::io::{self, Write};
+
 use either::Either;
 
 use crate::git::{git_oid_type, CommitId, MalformedTree, TreeId, TreeIsh};
@@ -85,7 +87,7 @@ impl ParseTree for GitManifestTree {
         ))
     }
 
-    fn write_one_entry(_entry: &WithPath<Self::Inner>, _buf: &mut Vec<u8>) {
+    fn write_one_entry<W: Write>(_entry: &WithPath<Self::Inner>, _w: W) -> io::Result<()> {
         todo!()
     }
 }

src/git/tree.rs

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use std::io::{self, Write};
+
 use digest::OutputSizeUser;
 use either::Either;
 
@@ -86,7 +88,7 @@ impl ParseTree for RawTree {
         .ok_or(MalformedTree)
     }
 
-    fn write_one_entry(_entry: &WithPath<Self::Inner>, _buf: &mut Vec<u8>) {
+    fn write_one_entry<W: Write>(_entry: &WithPath<Self::Inner>, _w: W) -> io::Result<()> {
         todo!()
     }
 }

src/hg/manifest.rs

@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use std::io::Write;
+use std::io::{self, Write};
 
 use bstr::{BStr, ByteSlice};
 
@@ -109,12 +109,13 @@ impl ParseTree for RawHgManifest {
         .ok_or(MalformedManifest)
     }
 
-    fn write_one_entry(entry: &WithPath<Self::Inner>, buf: &mut Vec<u8>) {
-        buf.extend_from_slice(entry.path());
-        buf.push(b'\0');
-        write!(buf, "{}", entry.inner().fid).unwrap();
-        buf.extend_from_slice(entry.inner().attr.as_bstr());
-        buf.push(b'\n');
+    fn write_one_entry<W: Write>(entry: &WithPath<Self::Inner>, mut w: W) -> io::Result<()> {
+        w.write_all(entry.path())?;
+        w.write_all(b"\0")?;
+        write!(w, "{}", entry.inner().fid)?;
+        w.write_all(entry.inner().attr.as_bstr())?;
+        w.write_all(b"\n")?;
+        Ok(())
     }
 }
 

src/main.rs

@@ -1585,7 +1585,7 @@ fn create_root_changeset(cid: CommitId) -> HgChangesetId {
             attr: item.mode.try_into().unwrap(),
         })
     {
-        RawHgManifest::write_one_entry(&entry, &mut manifest);
+        RawHgManifest::write_one_entry(&entry, &mut manifest).unwrap();
         paths.extend_from_slice(entry.path());
         paths.push(b'\0');
     }
@@ -1657,7 +1657,7 @@ fn create_simple_manifest(cid: CommitId, parent: CommitId) -> (HgManifestId, Opt
     {
         let (fid, mode) = match either_or_both {
             EitherOrBoth::Left(info) => {
-                RawHgManifest::write_one_entry(&WithPath::new(path, info), &mut manifest);
+                RawHgManifest::write_one_entry(&WithPath::new(path, info), &mut manifest).unwrap();
                 continue;
             }
             EitherOrBoth::Both(_, DiffTreeItem::Deleted { .. }) => {
@@ -1701,7 +1701,7 @@ fn create_simple_manifest(cid: CommitId, parent: CommitId) -> (HgManifestId, Opt
                 attr: mode.try_into().unwrap(),
             },
         );
-        RawHgManifest::write_one_entry(&entry, &mut manifest);
+        RawHgManifest::write_one_entry(&entry, &mut manifest).unwrap();
         paths.extend_from_slice(entry.path());
         paths.push(b'\0');
     }
@@ -1874,7 +1874,7 @@ fn create_merge_changeset(
                     attr: l.mode.try_into().unwrap(),
                 },
             );
-            RawHgManifest::write_one_entry(&line, &mut manifest);
+            RawHgManifest::write_one_entry(&line, &mut manifest).unwrap();
             if !unchanged
                 || p1_attr
                     .map(|attr| attr != line.inner().attr)

src/store.rs

@@ -609,7 +609,8 @@ impl RawHgManifest {
                                 inner.right().unwrap()
                             }),
                             &mut manifest,
-                        ),
+                        )
+                        .unwrap(),
                         // There was an entry in the last manifest, but the file was modified or removed
                         Both(_, diff) => {
                             if let Some(new_entry) = diff
@@ -624,7 +625,7 @@ impl RawHgManifest {
                                 })
                                 .transpose()
                             {
-                                RawHgManifest::write_one_entry(&new_entry, &mut manifest);
+                                RawHgManifest::write_one_entry(&new_entry, &mut manifest).unwrap();
                             }
                         }
                     };
@@ -635,7 +636,7 @@ impl RawHgManifest {
                     .into_iter()
                     .recurse()
                 {
-                    RawHgManifest::write_one_entry(&entry, &mut manifest);
+                    RawHgManifest::write_one_entry(&entry, &mut manifest).unwrap();
                 }
             }
             let content = Rc::<[u8]>::from(manifest.as_ref());

src/tree_util.rs

@@ -7,6 +7,7 @@
 //! Helpers related to trees.
 
 use std::cmp::Ordering;
+use std::io::{self, Write};
 use std::iter::{zip, Peekable};
 
 use bstr::{BStr, BString, ByteSlice};
@@ -297,7 +298,7 @@ pub trait ParseTree: AsRef<[u8]> {
     fn parse_one_entry(buf: &mut &[u8]) -> Result<WithPath<Self::Inner>, Self::Error>;
 
     /// Write one entry into the given buffer.
-    fn write_one_entry(entry: &WithPath<Self::Inner>, buf: &mut Vec<u8>);
+    fn write_one_entry<W: Write>(entry: &WithPath<Self::Inner>, w: W) -> io::Result<()>;
 
     /// Iterates the tree
     fn iter(&self) -> TreeIter<&Self> {
@@ -313,8 +314,8 @@ impl<T: ParseTree + ?Sized> ParseTree for &T {
         T::parse_one_entry(buf)
     }
 
-    fn write_one_entry(entry: &WithPath<Self::Inner>, buf: &mut Vec<u8>) {
-        T::write_one_entry(entry, buf);
+    fn write_one_entry<W: Write>(entry: &WithPath<Self::Inner>, w: W) -> io::Result<()> {
+        T::write_one_entry(entry, w)
     }
 }