Optimize show -a by loading only the requested package (#11659)

Fixes #11648

src/Composer/DependencyResolver/PoolBuilder.php

@@ -102,11 +102,21 @@ class PoolBuilder
      * @var BasePackage[]
      */
     private $unacceptableFixedOrLockedPackages = [];
-    /** @var string[] */
+    /** @var array<string> */
     private $updateAllowList = [];
     /** @var array<string, array<PackageInterface>> */
     private $skippedLoad = [];
 
+    /**
+     * If provided, only these package names are loaded
+     *
+     * This is a special-use functionality of the Request class to optimize the pool creation process
+     * when only a minimal subset of packages is needed and we do not need their dependencies.
+     *
+     * @var array<string, int>|null
+     */
+    private $restrictedPackagesList = null;
+
     /**
      * Keeps a list of dependencies which are locked but were auto-unlocked as they are path repositories
      *
@@ -165,6 +175,8 @@ class PoolBuilder
      */
     public function buildPool(array $repositories, Request $request): Pool
     {
+        $this->restrictedPackagesList = $request->getRestrictedPackages() !== null ? array_flip($request->getRestrictedPackages()) : null;
+
         if ($request->getUpdateAllowList()) {
             $this->updateAllowList = $request->getUpdateAllowList();
             $this->warnAboutNonMatchingUpdateAllowList($request);
@@ -366,6 +378,10 @@ class PoolBuilder
     private function loadPackagesMarkedForLoading(Request $request, array $repositories): void
     {
         foreach ($this->packagesToLoad as $name => $constraint) {
+            if ($this->restrictedPackagesList !== null && !isset($this->restrictedPackagesList[$name])) {
+                unset($this->packagesToLoad[$name]);
+                continue;
+            }
             $this->loadedPackages[$name] = $constraint;
         }
 
@@ -559,7 +575,7 @@ class PoolBuilder
      */
     private function isUpdateAllowed(BasePackage $package): bool
     {
-        foreach ($this->updateAllowList as $pattern => $void) {
+        foreach ($this->updateAllowList as $pattern) {
             $patternRegexp = BasePackage::packageNameToRegexp($pattern);
             if (Preg::isMatch($patternRegexp, $package->getName())) {
                 return true;
@@ -571,7 +587,7 @@ class PoolBuilder
 
     private function warnAboutNonMatchingUpdateAllowList(Request $request): void
     {
-        foreach ($this->updateAllowList as $pattern => $void) {
+        foreach ($this->updateAllowList as $pattern) {
             $patternRegexp = BasePackage::packageNameToRegexp($pattern);
             // update pattern matches a locked package? => all good
             foreach ($request->getLockedRepository()->getPackages() as $package) {

src/Composer/DependencyResolver/Request.php

@@ -50,10 +50,12 @@ class Request
     protected $lockedPackages = [];
     /** @var array<string, BasePackage> */
     protected $fixedLockedPackages = [];
-    /** @var string[] */
+    /** @var array<string> */
     protected $updateAllowList = [];
     /** @var false|self::UPDATE_* */
     protected $updateAllowTransitiveDependencies = false;
+    /** @var non-empty-list<string>|null */
+    private $restrictedPackages = null;
 
     public function __construct(?LockArrayRepository $lockedRepository = null)
     {
@@ -118,7 +120,7 @@ class Request
     }
 
     /**
-     * @param string[] $updateAllowList
+     * @param array<string> $updateAllowList
      * @param false|self::UPDATE_* $updateAllowTransitiveDependencies
      */
     public function setUpdateAllowList(array $updateAllowList, $updateAllowTransitiveDependencies): void
@@ -128,7 +130,7 @@ class Request
     }
 
     /**
-     * @return string[]
+     * @return array<string>
      */
     public function getUpdateAllowList(): array
     {
@@ -233,4 +235,22 @@ class Request
     {
         return $this->lockedRepository;
     }
+
+    /**
+     * Restricts the pool builder from loading other packages than those listed here
+     *
+     * @param non-empty-list<string> $names
+     */
+    public function restrictPackages(array $names): void
+    {
+        $this->restrictedPackages = $names;
+    }
+
+    /**
+     * @return list<string>
+     */
+    public function getRestrictedPackages(): ?array
+    {
+        return $this->restrictedPackages;
+    }
 }

src/Composer/Installer.php

@@ -180,7 +180,7 @@ class Installer
     /**
      * Array of package names/globs flagged for update
      *
-     * @var string[]|null
+     * @var non-empty-list<string>|null
      */
     protected $updateAllowList = null;
     /** @var Request::UPDATE_* */
@@ -242,7 +242,7 @@ class Installer
         gc_collect_cycles();
         gc_disable();
 
-        if ($this->updateAllowList && $this->updateMirrors) {
+        if ($this->updateAllowList !== null && $this->updateMirrors) {
             throw new \RuntimeException("The installer options updateMirrors and updateAllowList are mutually exclusive.");
         }
 
@@ -436,7 +436,7 @@ class Installer
                 $lockedRepository = $this->locker->getLockedRepository(true);
             }
         } catch (\Seld\JsonLint\ParsingException $e) {
-            if ($this->updateAllowList || $this->updateMirrors) {
+            if ($this->updateAllowList !== null || $this->updateMirrors) {
                 // in case we are doing a partial update or updating mirrors, the lock file is needed so we error
                 throw $e;
             }
@@ -444,7 +444,7 @@ class Installer
             // doing a full update
         }
 
-        if (($this->updateAllowList || $this->updateMirrors) && !$lockedRepository) {
+        if (($this->updateAllowList !== null || $this->updateMirrors) && !$lockedRepository) {
             $this->io->writeError('<error>Cannot update ' . ($this->updateMirrors ? 'lock file information' : 'only a partial set of packages') . ' without a lock file present. Run `composer update` to generate a lock file.</error>', true, IOInterface::QUIET);
 
             return self::ERROR_NO_LOCK_FILE_FOR_PARTIAL_UPDATE;
@@ -467,7 +467,7 @@ class Installer
         $this->requirePackagesForUpdate($request, $lockedRepository, true);
 
         // pass the allow list into the request, so the pool builder can apply it
-        if ($this->updateAllowList) {
+        if ($this->updateAllowList !== null) {
             $request->setUpdateAllowList($this->updateAllowList, $this->updateAllowTransitiveDependencies);
         }
 
@@ -1337,7 +1337,11 @@ class Installer
      */
     public function setUpdateAllowList(array $packages): self
     {
-        $this->updateAllowList = array_flip(array_map('strtolower', $packages));
+        if (count($packages) === 0) {
+            $this->updateAllowList = null;
+        } else {
+            $this->updateAllowList = array_values(array_unique(array_map('strtolower', $packages)));
+        }
 
         return $this;
     }

src/Composer/Repository/RepositorySet.php

@@ -367,12 +367,18 @@ class RepositorySet
     {
         $request = new Request($lockedRepo);
 
+        $allowedPackages = [];
         foreach ($packageNames as $packageName) {
             if (PlatformRepository::isPlatformPackage($packageName)) {
                 throw new \LogicException('createPoolForPackage(s) can not be used for platform packages, as they are never loaded by the PoolBuilder which expects them to be fixed. Use createPoolWithAllPackages or pass in a proper request with the platform packages you need fixed in it.');
             }
 
             $request->requireName($packageName);
+            $allowedPackages[] = strtolower($packageName);
+        }
+
+        if (count($allowedPackages) > 0) {
+            $request->restrictPackages($allowedPackages);
         }
 
         return $this->createPool($request, new NullIO());

tests/Composer/Test/DependencyResolver/PoolBuilderTest.php

@@ -126,7 +126,7 @@ class PoolBuilderTest extends TestCase
             if (isset($requestData['allowTransitiveDeps']) && $requestData['allowTransitiveDeps']) {
                 $transitiveDeps = Request::UPDATE_LISTED_WITH_TRANSITIVE_DEPS;
             }
-            $request->setUpdateAllowList(array_flip($requestData['allowList']), $transitiveDeps);
+            $request->setUpdateAllowList($requestData['allowList'], $transitiveDeps);
         }
 
         foreach ($fixed as $fixedPackage) {