Optimize solving by removing packages that are excluded by the root package requires

src/Composer/DependencyResolver/Pool.php

@@ -18,6 +18,7 @@ use Composer\Package\Version\VersionParser;
 use Composer\Package\Link;
 use Composer\Package\LinkConstraint\LinkConstraintInterface;
 use Composer\Package\LinkConstraint\VersionConstraint;
+use Composer\Package\LinkConstraint\EmptyConstraint;
 use Composer\Repository\RepositoryInterface;
 use Composer\Repository\CompositeRepository;
 use Composer\Repository\ComposerRepository;
@@ -38,6 +39,7 @@ class Pool
     const MATCH = 1;
     const MATCH_PROVIDE = 2;
     const MATCH_REPLACE = 3;
+    const MATCH_FILTERED = 4;
 
     protected $repositories = array();
     protected $providerRepos = array();
@@ -47,9 +49,10 @@ class Pool
     protected $stabilityFlags;
     protected $versionParser;
     protected $providerCache = array();
+    protected $filterRequires;
     protected $id = 1;
 
-    public function __construct($minimumStability = 'stable', array $stabilityFlags = array())
+    public function __construct($minimumStability = 'stable', array $stabilityFlags = array(), array $filterRequires = array())
     {
         $stabilities = BasePackage::$stabilities;
         $this->versionParser = new VersionParser;
@@ -60,6 +63,7 @@ class Pool
             }
         }
         $this->stabilityFlags = $stabilityFlags;
+        $this->filterRequires = $filterRequires;
     }
 
     /**
@@ -109,6 +113,7 @@ class Pool
 
                     if ($exempt || $this->isPackageAcceptable($names, $stability)) {
                         $package['id'] = $this->id++;
+                        $package['stability'] = $stability;
                         $this->packages[] = $package;
 
                         foreach ($names as $provided) {
@@ -275,6 +280,9 @@ class Pool
                     $matches[] = $this->ensurePackageIsLoaded($candidate);
                     break;
 
+                case self::MATCH_FILTERED:
+                    break;
+
                 default:
                     throw new \UnexpectedValueException('Unexpected match type');
             }
@@ -367,18 +375,30 @@ class Pool
         if (is_array($candidate)) {
             $candidateName = $candidate['name'];
             $candidateVersion = $candidate['version'];
+            $isDev = $candidate['stability'] === 'dev';
+            $isAlias = isset($candidate['alias_of']);
         } else {
             // handle object packages
             $candidateName = $candidate->getName();
             $candidateVersion = $candidate->getVersion();
+            $isDev = $candidate->getStability() === 'dev';
+            $isAlias = $candidate instanceof AliasPackage;
+        }
+
+        if (!$isDev && !$isAlias && isset($this->filterRequires[$name])) {
+            $requireFilter = $this->filterRequires[$name];
+        } else {
+            $requireFilter = new EmptyConstraint;
         }
 
         if ($candidateName === $name) {
-            if ($constraint === null) {
+            $pkgConstraint = new VersionConstraint('==', $candidateVersion);
-                return self::MATCH;
+
+            if ($constraint === null || $constraint->matches($pkgConstraint)) {
+                return $requireFilter->matches($pkgConstraint) ? self::MATCH : self::MATCH_FILTERED;
             }
 
-            return $constraint->matches(new VersionConstraint('==', $candidateVersion)) ? self::MATCH : self::MATCH_NAME;
+            return self::MATCH_NAME;
         }
 
         if (is_array($candidate)) {
@@ -393,17 +413,17 @@ class Pool
             $replaces = $candidate->getReplaces();
         }
 
-        // aliases create multiple replaces/provides for one target so they can not use the shortcut
+        // aliases create multiple replaces/provides for one target so they can not use the shortcut below
         if (isset($replaces[0]) || isset($provides[0])) {
             foreach ($provides as $link) {
                 if ($link->getTarget() === $name && ($constraint === null || $constraint->matches($link->getConstraint()))) {
-                    return self::MATCH_PROVIDE;
+                    return $requireFilter->matches($link->getConstraint()) ? self::MATCH_PROVIDE : self::MATCH_FILTERED;
                 }
             }
 
             foreach ($replaces as $link) {
                 if ($link->getTarget() === $name && ($constraint === null || $constraint->matches($link->getConstraint()))) {
-                    return self::MATCH_REPLACE;
+                    return $requireFilter->matches($link->getConstraint()) ? self::MATCH_REPLACE : self::MATCH_FILTERED;
                 }
             }
 
@@ -411,11 +431,11 @@ class Pool
         }
 
         if (isset($provides[$name]) && ($constraint === null || $constraint->matches($provides[$name]->getConstraint()))) {
-            return self::MATCH_PROVIDE;
+            return $requireFilter->matches($provides[$name]->getConstraint()) ? self::MATCH_PROVIDE : self::MATCH_FILTERED;
         }
 
         if (isset($replaces[$name]) && ($constraint === null || $constraint->matches($replaces[$name]->getConstraint()))) {
-            return self::MATCH_REPLACE;
+            return $requireFilter->matches($replaces[$name]->getConstraint()) ? self::MATCH_REPLACE : self::MATCH_FILTERED;
         }
 
         return self::MATCH_NONE;

src/Composer/Installer.php

@@ -242,7 +242,7 @@ class Installer
                 // split dev and non-dev requirements by checking what would be removed if we update without the dev requirements
                 if ($this->devMode && $this->package->getDevRequires()) {
                     $policy = $this->createPolicy();
-                    $pool = $this->createPool();
+                    $pool = $this->createPool(true);
                     $pool->addRepository($installedRepo, $aliases);
 
                     // creating requirements request
@@ -325,7 +325,7 @@ class Installer
 
         // creating repository pool
         $policy = $this->createPolicy();
-        $pool = $this->createPool();
+        $pool = $this->createPool($withDevReqs);
         $pool->addRepository($installedRepo, $aliases);
         if ($installFromLock) {
             $pool->addRepository($lockedRepository, $aliases);
@@ -573,7 +573,7 @@ class Installer
         return array_merge($installerOps, $operations);
     }
 
-    private function createPool()
+    private function createPool($withDevReqs)
     {
         $minimumStability = $this->package->getMinimumStability();
         $stabilityFlags = $this->package->getStabilityFlags();
@@ -583,7 +583,16 @@ class Installer
             $stabilityFlags = $this->locker->getStabilityFlags();
         }
 
-        return new Pool($minimumStability, $stabilityFlags);
+        $requires = $this->package->getRequires();
+        if ($withDevReqs) {
+            $requires = array_merge($requires, $this->package->getDevRequires());
+        }
+        $rootConstraints = array();
+        foreach ($requires as $req => $constraint) {
+            $rootConstraints[$req] = $constraint->getConstraint();
+        }
+
+        return new Pool($minimumStability, $stabilityFlags, $rootConstraints);
     }
 
     private function createPolicy()