perf(installation-manager): fan out package downloads via Loop::wait

InstallationManager::downloadAndExecuteBatch now matches PHP: every
update/install operation's installer->download() promise is collected
and driven concurrently through waitOnPromises()/Loop::wait instead of
being awaited one package at a time. Concurrency caps stay where PHP
puts them (HttpDownloader 12, ProcessExecutor 10 via their semaphores).
Error semantics follow PHP too: all downloads settle before the first
rejection is rethrown, rather than aborting on the first failure.

To let the collected futures and the cleanup closures own their
installer beyond the loop iteration that created them, the installer
registry becomes Vec<Rc<dyn InstallerInterface>> and get_installer
hands out clones (PHP closures capture $installer the same way), with
InstallerInterface methods taking &self across the six implementors —
the only genuinely mutable state was LibraryInstaller.vendor_dir
(canonicalized in place), now behind a RefCell.
as_plugin_installer_mut/as_binary_presence_interface lose their &mut.

The cleanup_promises entries are now the real thing: the PHP closure
including the getInstallationSource() guard and the
installer->cleanup($opType, $package, $initialPackage) call, replacing
the no-op futures (drops one TODO(phase-b) and two TODO(phase-c)).

Verified against the real network: create-project laravel/laravel
produces a vendor tree byte-identical to real Composer's (diff -rq
clean across all 109 packages including vendor/composer).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 26 insertions, 22 deletions

diff --git a/crates/shirabe/src/installer/library_installer.rs b/crates/shirabe/src/installer/library_installer.rs
index c3ebad16..5baffc15 100644
--- a/crates/shirabe/src/installer/library_installer.rs
+++ b/crates/shirabe/src/installer/library_installer.rs
@@ -22,7 +22,9 @@ use shirabe_php_shim::{
 #[derive(Debug)]
 pub struct LibraryInstaller {
     pub(crate) composer: PartialComposerWeakHandle,
-    pub(crate) vendor_dir: String,
+    /// Behind a RefCell so initialize_vendor_dir can canonicalize it through `&self` (the
+    /// installer instance is shared between concurrent package operations).
+    pub(crate) vendor_dir: std::cell::RefCell<String>,
     pub(crate) download_manager:
         Option<std::rc::Rc<std::cell::RefCell<dyn DownloadManagerInterface>>>,
     pub(crate) io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
@@ -93,7 +95,7 @@ impl LibraryInstaller {
             io,
             r#type,
             filesystem,
-            vendor_dir,
+            vendor_dir: std::cell::RefCell::new(vendor_dir),
             binary_installer,
         }
     }
@@ -108,7 +110,7 @@ impl LibraryInstaller {
     }
 
     /// Make sure binaries are installed for a given package.
-    pub fn ensure_binaries_presence(&mut self, package: PackageInterfaceHandle) {
+    pub fn ensure_binaries_presence(&self, package: PackageInterfaceHandle) {
         let install_path = self.get_install_path(package.clone()).unwrap();
         self.binary_installer
             .borrow_mut()
@@ -119,7 +121,7 @@ impl LibraryInstaller {
     ///
     /// It is used for BC as getInstallPath tends to be overridden by
     /// installer plugins but not getPackageBasePath
-    pub(crate) fn get_package_base_path(&mut self, package: PackageInterfaceHandle) -> String {
+    pub(crate) fn get_package_base_path(&self, package: PackageInterfaceHandle) -> String {
         let install_path = self.get_install_path(package.clone()).unwrap();
         let target_dir = package.get_target_dir();
 
@@ -143,7 +145,7 @@ impl LibraryInstaller {
     /// @return PromiseInterface|null
     /// @phpstan-return PromiseInterface<void|null>|null
     pub(crate) async fn install_code(
-        &mut self,
+        &self,
         package: PackageInterfaceHandle,
     ) -> anyhow::Result<Option<PhpMixed>> {
         let download_path = self.get_install_path(package.clone()).unwrap();
@@ -157,7 +159,7 @@ impl LibraryInstaller {
     /// @return PromiseInterface|null
     /// @phpstan-return PromiseInterface<void|null>|null
     pub(crate) async fn update_code(
-        &mut self,
+        &self,
         initial: PackageInterfaceHandle,
         target: PackageInterfaceHandle,
     ) -> anyhow::Result<Option<PhpMixed>> {
@@ -188,7 +190,7 @@ impl LibraryInstaller {
     /// @return PromiseInterface|null
     /// @phpstan-return PromiseInterface<void|null>|null
     pub(crate) async fn remove_code(
-        &mut self,
+        &self,
         package: PackageInterfaceHandle,
     ) -> anyhow::Result<Option<PhpMixed>> {
         let download_path = self.get_package_base_path(package.clone());
@@ -199,11 +201,12 @@ impl LibraryInstaller {
             .await
     }
 
-    pub(crate) fn initialize_vendor_dir(&mut self) {
+    pub(crate) fn initialize_vendor_dir(&self) {
         self.filesystem
             .borrow_mut()
-            .ensure_directory_exists(&self.vendor_dir);
-        self.vendor_dir = realpath(&self.vendor_dir).unwrap_or_default();
+            .ensure_directory_exists(&self.vendor_dir.borrow());
+        let realpath = realpath(&self.vendor_dir.borrow()).unwrap_or_default();
+        *self.vendor_dir.borrow_mut() = realpath;
     }
 
     pub(crate) fn get_download_manager(
@@ -237,7 +240,7 @@ impl InstallerInterface for LibraryInstaller {
     }
 
     fn is_installed(
-        &mut self,
+        &self,
         repo: &dyn InstalledRepositoryInterface,
         package: PackageInterfaceHandle,
     ) -> bool {
@@ -267,7 +270,7 @@ impl InstallerInterface for LibraryInstaller {
     }
 
     async fn download(
-        &mut self,
+        &self,
         package: PackageInterfaceHandle,
         prev_package: Option<PackageInterfaceHandle>,
     ) -> anyhow::Result<Option<PhpMixed>> {
@@ -281,7 +284,7 @@ impl InstallerInterface for LibraryInstaller {
     }
 
     async fn prepare(
-        &mut self,
+        &self,
         r#type: &str,
         package: PackageInterfaceHandle,
         prev_package: Option<PackageInterfaceHandle>,
@@ -296,7 +299,7 @@ impl InstallerInterface for LibraryInstaller {
     }
 
     async fn cleanup(
-        &mut self,
+        &self,
         r#type: &str,
         package: PackageInterfaceHandle,
         prev_package: Option<PackageInterfaceHandle>,
@@ -311,7 +314,7 @@ impl InstallerInterface for LibraryInstaller {
     }
 
     async fn install(
-        &mut self,
+        &self,
         repo: &mut dyn InstalledRepositoryInterface,
         package: PackageInterfaceHandle,
     ) -> anyhow::Result<Option<PhpMixed>> {
@@ -339,7 +342,7 @@ impl InstallerInterface for LibraryInstaller {
     }
 
     async fn update(
-        &mut self,
+        &self,
         repo: &mut dyn InstalledRepositoryInterface,
         initial: PackageInterfaceHandle,
         target: PackageInterfaceHandle,
@@ -372,7 +375,7 @@ impl InstallerInterface for LibraryInstaller {
     }
 
     async fn uninstall(
-        &mut self,
+        &self,
         repo: &mut dyn InstalledRepositoryInterface,
         package: PackageInterfaceHandle,
     ) -> anyhow::Result<Option<PhpMixed>> {
@@ -407,13 +410,14 @@ impl InstallerInterface for LibraryInstaller {
         Ok(None)
     }
 
-    fn get_install_path(&mut self, package: PackageInterfaceHandle) -> Option<String> {
+    fn get_install_path(&self, package: PackageInterfaceHandle) -> Option<String> {
         self.initialize_vendor_dir();
 
+        let vendor_dir = self.vendor_dir.borrow();
         let base_path = format!(
             "{}{}",
-            if !self.vendor_dir.is_empty() {
-                format!("{}/", self.vendor_dir)
+            if !vendor_dir.is_empty() {
+                format!("{}/", vendor_dir)
             } else {
                 String::new()
             },
@@ -432,13 +436,13 @@ impl InstallerInterface for LibraryInstaller {
         })
     }
 
-    fn as_binary_presence_interface(&mut self) -> Option<&mut dyn BinaryPresenceInterface> {
+    fn as_binary_presence_interface(&self) -> Option<&dyn BinaryPresenceInterface> {
         Some(self)
     }
 }
 
 impl BinaryPresenceInterface for LibraryInstaller {
-    fn ensure_binaries_presence(&mut self, package: PackageInterfaceHandle) {
+    fn ensure_binaries_presence(&self, package: PackageInterfaceHandle) {
         LibraryInstaller::ensure_binaries_presence(self, package);
     }
 }