Less copying during dist installation

Per #904 copying the contents of dists out of the extracted staging
directory and then later deleting that same staging directory consumes
60s out of a total of 200s on Windows.

Wall clock testing shows this patch reduces
`rustup toolchain install nightly` from 3m45 to 2m23 for me - including
download times etc.

I'm sure there is more that can be done, thus I'm not marking this as
a closing merge for #904.

Author: rbtcollins

src/dist/component/components.rs

@@ -109,7 +109,16 @@ impl<'a> ComponentBuilder<'a> {
             .push(ComponentPart("dir".to_owned(), path.clone()));
         self.tx.copy_dir(&self.name, path, src)
     }
-
+    pub fn move_file(&mut self, path: PathBuf, src: &Path) -> Result<()> {
+        self.parts
+            .push(ComponentPart("file".to_owned(), path.clone()));
+        self.tx.move_file(&self.name, path, src)
+    }
+    pub fn move_dir(&mut self, path: PathBuf, src: &Path) -> Result<()> {
+        self.parts
+            .push(ComponentPart("dir".to_owned(), path.clone()));
+        self.tx.move_dir(&self.name, path, src)
+    }
     pub fn finish(mut self) -> Result<Transaction<'a>> {
         // Write component manifest
         let path = self.components.rel_component_manifest(&self.name);

src/dist/component/package.rs

@@ -35,17 +35,19 @@ pub trait Package: fmt::Debug {
 pub struct DirectoryPackage {
     path: PathBuf,
     components: HashSet<String>,
+    copy: bool,
 }
 
 impl DirectoryPackage {
-    pub fn new(path: PathBuf) -> Result<Self> {
+    pub fn new(path: PathBuf, copy: bool) -> Result<Self> {
         validate_installer_version(&path)?;
 
         let content = utils::read_file("package components", &path.join("components"))?;
         let components = content.lines().map(|l| l.to_owned()).collect();
         Ok(DirectoryPackage {
             path: path,
             components: components,
+            copy: copy,
         })
     }
 }
@@ -97,8 +99,14 @@ impl Package for DirectoryPackage {
             let src_path = root.join(&path);
 
             match &*part.0 {
-                "file" => builder.copy_file(path.clone(), &src_path)?,
-                "dir" => builder.copy_dir(path.clone(), &src_path)?,
+                "file" => {
+                    if self.copy { builder.copy_file(path.clone(), &src_path)? }
+                    else { builder.move_file(path.clone(), &src_path)? }
+                }
+                "dir" => {
+                    if self.copy { builder.copy_dir(path.clone(), &src_path)? }
+                    else { builder.move_dir(path.clone(), &src_path)? }
+                }
                 _ => return Err(ErrorKind::CorruptComponent(name.to_owned()).into()),
             }
 
@@ -187,7 +195,7 @@ impl<'a> TarPackage<'a> {
         unpack_without_first_dir(&mut archive, &*temp_dir)?;
 
         Ok(TarPackage(
-            DirectoryPackage::new(temp_dir.to_owned())?,
+            DirectoryPackage::new(temp_dir.to_owned(), false)?,
             temp_dir,
         ))
     }

src/dist/component/transaction.rs

@@ -133,6 +133,22 @@ impl<'a> Transaction<'a> {
         Ok(())
     }
 
+    /// Move a file to a relative path of the install prefix.
+    pub fn move_file(&mut self, component: &str, relpath: PathBuf, src: &Path) -> Result<()> {
+        assert!(relpath.is_relative());
+        let item = ChangedItem::move_file(&self.prefix, component, relpath, src)?;
+        self.change(item);
+        Ok(())
+    }
+
+    /// Recursively move a directory to a relative path of the install prefix.
+    pub fn move_dir(&mut self, component: &str, relpath: PathBuf, src: &Path) -> Result<()> {
+        assert!(relpath.is_relative());
+        let item = ChangedItem::move_dir(&self.prefix, component, relpath, src)?;
+        self.change(item);
+        Ok(())
+    }
+
     pub fn temp(&self) -> &'a temp::Cfg {
         self.temp_cfg
     }
@@ -195,8 +211,8 @@ impl<'a> ChangedItem<'a> {
         }
         Ok(())
     }
-    fn add_file(prefix: &InstallPrefix, component: &str, relpath: PathBuf) -> Result<(Self, File)> {
-        let abs_path = prefix.abs_path(&relpath);
+    fn dest_abs_path(prefix: &InstallPrefix, component: &str, relpath: &PathBuf) -> Result<PathBuf> {
+        let abs_path = prefix.abs_path(relpath);
         if utils::path_exists(&abs_path) {
             Err(ErrorKind::ComponentConflict {
                 name: component.to_owned(),
@@ -207,53 +223,34 @@ impl<'a> ChangedItem<'a> {
             if let Some(p) = abs_path.parent() {
                 utils::ensure_dir_exists("component", p, &|_| ())?;
             }
-            let file = File::create(&abs_path)
-                .chain_err(|| format!("error creating file '{}'", abs_path.display()))?;
-
-            Ok((ChangedItem::AddedFile(relpath), file))
+            Ok(abs_path)
         }
     }
+    fn add_file(prefix: &InstallPrefix, component: &str, relpath: PathBuf) -> Result<(Self, File)> {
+        let abs_path = ChangedItem::dest_abs_path(prefix, component, &relpath)?;
+        let file = File::create(&abs_path)
+            .chain_err(|| format!("error creating file '{}'", abs_path.display()))?;
+        Ok((ChangedItem::AddedFile(relpath), file))
+    }
     fn copy_file(
         prefix: &InstallPrefix,
         component: &str,
         relpath: PathBuf,
         src: &Path,
     ) -> Result<Self> {
-        let abs_path = prefix.abs_path(&relpath);
-        if utils::path_exists(&abs_path) {
-            Err(ErrorKind::ComponentConflict {
-                name: component.to_owned(),
-                path: relpath.clone(),
-            }
-            .into())
-        } else {
-            if let Some(p) = abs_path.parent() {
-                utils::ensure_dir_exists("component", p, &|_| ())?;
-            }
-            utils::copy_file(src, &abs_path)?;
-            Ok(ChangedItem::AddedFile(relpath))
-        }
+        let abs_path = ChangedItem::dest_abs_path(prefix, component, &relpath)?;
+        utils::copy_file(src, &abs_path)?;
+        Ok(ChangedItem::AddedFile(relpath))
     }
     fn copy_dir(
         prefix: &InstallPrefix,
         component: &str,
         relpath: PathBuf,
         src: &Path,
     ) -> Result<Self> {
-        let abs_path = prefix.abs_path(&relpath);
-        if utils::path_exists(&abs_path) {
-            Err(ErrorKind::ComponentConflict {
-                name: component.to_owned(),
-                path: relpath.clone(),
-            }
-            .into())
-        } else {
-            if let Some(p) = abs_path.parent() {
-                utils::ensure_dir_exists("component", p, &|_| ())?;
-            }
-            utils::copy_dir(src, &abs_path, &|_| ())?;
-            Ok(ChangedItem::AddedDir(relpath))
-        }
+        let abs_path = ChangedItem::dest_abs_path(prefix, component, &relpath)?;
+        utils::copy_dir(src, &abs_path, &|_| ())?;
+        Ok(ChangedItem::AddedDir(relpath))
     }
     fn remove_file(
         prefix: &InstallPrefix,
@@ -311,4 +308,25 @@ impl<'a> ChangedItem<'a> {
             Ok(ChangedItem::ModifiedFile(relpath, None))
         }
     }
+    fn move_file(
+        prefix: &InstallPrefix,
+        component: &str,
+        relpath: PathBuf,
+        src: &Path,
+    ) -> Result<Self> {
+        let abs_path = ChangedItem::dest_abs_path(prefix, component, &relpath)?;
+        utils::rename_file("component", src, &abs_path)?;
+        Ok(ChangedItem::AddedFile(relpath))
+    }
+    fn move_dir(
+        prefix: &InstallPrefix,
+        component: &str,
+        relpath: PathBuf,
+        src: &Path,
+    ) -> Result<Self> {
+        let abs_path = ChangedItem::dest_abs_path(prefix, component, &relpath)?;
+        utils::rename_dir("component", src, &abs_path)?;
+        Ok(ChangedItem::AddedDir(relpath))
+    }
+
 }

tests/dist_install.rs

@@ -67,7 +67,7 @@ fn package_contains() {
 
     mock.build(tempdir.path());
 
-    let package = DirectoryPackage::new(tempdir.path().to_owned()).unwrap();
+    let package = DirectoryPackage::new(tempdir.path().to_owned(), true).unwrap();
     assert!(package.contains("mycomponent", None));
     assert!(package.contains("mycomponent2", None));
 }
@@ -88,7 +88,7 @@ fn package_bad_version() {
     let mut ver = File::create(tempdir.path().join("rust-installer-version")).unwrap();
     writeln!(ver, "100").unwrap();
 
-    assert!(DirectoryPackage::new(tempdir.path().to_owned()).is_err());
+    assert!(DirectoryPackage::new(tempdir.path().to_owned(), true).is_err());
 }
 
 #[test]
@@ -122,7 +122,7 @@ fn basic_install() {
 
     let components = Components::open(prefix.clone()).unwrap();
 
-    let pkg = DirectoryPackage::new(pkgdir.path().to_owned()).unwrap();
+    let pkg = DirectoryPackage::new(pkgdir.path().to_owned(), true).unwrap();
 
     let tx = pkg.install(&components, "mycomponent", None, tx).unwrap();
     tx.commit();
@@ -168,7 +168,7 @@ fn multiple_component_install() {
 
     let components = Components::open(prefix.clone()).unwrap();
 
-    let pkg = DirectoryPackage::new(pkgdir.path().to_owned()).unwrap();
+    let pkg = DirectoryPackage::new(pkgdir.path().to_owned(), true).unwrap();
 
     let tx = pkg.install(&components, "mycomponent", None, tx).unwrap();
     let tx = pkg.install(&components, "mycomponent2", None, tx).unwrap();
@@ -218,7 +218,7 @@ fn uninstall() {
 
     let components = Components::open(prefix.clone()).unwrap();
 
-    let pkg = DirectoryPackage::new(pkgdir.path().to_owned()).unwrap();
+    let pkg = DirectoryPackage::new(pkgdir.path().to_owned(), true).unwrap();
 
     let tx = pkg.install(&components, "mycomponent", None, tx).unwrap();
     let tx = pkg.install(&components, "mycomponent2", None, tx).unwrap();
@@ -275,7 +275,7 @@ fn component_bad_version() {
 
     let components = Components::open(prefix.clone()).unwrap();
 
-    let pkg = DirectoryPackage::new(pkgdir.path().to_owned()).unwrap();
+    let pkg = DirectoryPackage::new(pkgdir.path().to_owned(), true).unwrap();
 
     let tx = pkg.install(&components, "mycomponent", None, tx).unwrap();
     tx.commit();
@@ -336,7 +336,7 @@ fn unix_permissions() {
 
     let components = Components::open(prefix.clone()).unwrap();
 
-    let pkg = DirectoryPackage::new(pkgdir.path().to_owned()).unwrap();
+    let pkg = DirectoryPackage::new(pkgdir.path().to_owned(), true).unwrap();
 
     let tx = pkg.install(&components, "mycomponent", None, tx).unwrap();
     tx.commit();
@@ -421,7 +421,7 @@ fn install_to_prefix_that_does_not_exist() {
 
     let components = Components::open(prefix.clone()).unwrap();
 
-    let pkg = DirectoryPackage::new(pkgdir.path().to_owned()).unwrap();
+    let pkg = DirectoryPackage::new(pkgdir.path().to_owned(), true).unwrap();
 
     let tx = pkg.install(&components, "mycomponent", None, tx).unwrap();
     tx.commit();