Introduce CPUCoreFinders (#14)

Extract each find logic in its own isolated finder. This will make it easier to later:

- Add test
- Re-order the find logic

src/CpuCoreCounter.php

@@ -13,15 +13,7 @@
 
 namespace Fidry\CpuCounter;
 
-use function count;
-use function fgets;
-use function file_get_contents;
 use function function_exists;
-use function is_file;
-use function is_resource;
-use function pclose;
-use function popen;
-use function preg_match_all;
 use const DIRECTORY_SEPARATOR;
 
 final class CpuCoreCounter
@@ -50,41 +42,25 @@ private static function findCount(): int
             return 1;
         }
 
-        // from brianium/paratest
-        if (is_file('/proc/cpuinfo')) {
-            // Linux (and potentially Windows with linux sub systems)
-            $cpuinfo = file_get_contents('/proc/cpuinfo');
+        /** @var list<class-string<CpuCoreFinder>> $finders */
+        $finders = [
+            CpuInfoFinder::class,
+        ];
 
-            if (false !== $cpuinfo) {
-                preg_match_all('/^processor/m', $cpuinfo, $matches);
-
-                return count($matches[0]);
-            }
+        if (DIRECTORY_SEPARATOR === '\\') {
+            $finders[] = WindowsWmicFinder::class;
         }
 
-        if (DIRECTORY_SEPARATOR === '\\') {
-            // Windows
-            $process = popen('wmic cpu get NumberOfLogicalProcessors', 'rb');
+        $finders[] = HwFinder::class;
 
-            if (is_resource($process)) {
-                fgets($process);
-                $cores = (int) fgets($process);
-                pclose($process);
+        foreach ($finders as $finder) {
+            $cores = $finder::find();
 
+            if (null !== $cores) {
                 return $cores;
             }
         }
 
-        $process = popen('sysctl -n hw.ncpu', 'rb');
-
-        if (is_resource($process)) {
-            // *nix (Linux, BSD and Mac)
-            $cores = (int) fgets($process);
-            pclose($process);
-
-            return $cores;
-        }
-
         return 2;
     }
 }

src/CpuCoreFinder.php

@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of the Fidry CPUCounter Config package.
+ *
+ * (c) Théo FIDRY <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Fidry\CpuCounter;
+
+interface CpuCoreFinder
+{
+    /**
+     * @return positive-int|null
+     */
+    public static function find(): ?int;
+}

src/CpuInfoFinder.php

@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of the Fidry CPUCounter Config package.
+ *
+ * (c) Théo FIDRY <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Fidry\CpuCounter;
+
+use function count;
+use function file_get_contents;
+use function is_file;
+use function preg_match_all;
+
+/**
+ * Find the number of CPU cores looking up at the cpuinfo file which is available
+ * on Linux systems and Windows systems with a Linux sub-system.
+ *
+ * @see https://github.com/paratestphp/paratest/blob/c163539818fd96308ca8dc60f46088461e366ed4/src/Runners/PHPUnit/Options.php#L903-L909
+ * @see https://unix.stackexchange.com/questions/146051/number-of-processors-in-proc-cpuinfo
+ */
+final class CpuInfoFinder implements CpuCoreFinder
+{
+    private function __construct()
+    {
+    }
+
+    /**
+     * @return positive-int|null
+     */
+    public static function find(): ?int
+    {
+        // from brianium/paratest
+        if (is_file('/proc/cpuinfo')) {
+            // Linux (and potentially Windows with linux sub systems)
+            $cpuinfo = file_get_contents('/proc/cpuinfo');
+
+            if (false !== $cpuinfo) {
+                preg_match_all('/^processor/m', $cpuinfo, $matches);
+
+                return count($matches[0]);
+            }
+        }
+
+        return null;
+    }
+}

src/HwFinder.php

@@ -0,0 +1,50 @@
+<?php
+
+/*
+ * This file is part of the Fidry CPUCounter Config package.
+ *
+ * (c) Théo FIDRY <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Fidry\CpuCounter;
+
+use function fgets;
+use function is_resource;
+use function pclose;
+use function popen;
+
+/**
+ * Find the number of CPU cores for Linux, BSD and OSX.
+ *
+ * @see https://github.com/paratestphp/paratest/blob/c163539818fd96308ca8dc60f46088461e366ed4/src/Runners/PHPUnit/Options.php#L903-L909
+ * @see https://opensource.apple.com/source/xnu/xnu-792.2.4/libkern/libkern/sysctl.h.auto.html
+ */
+final class HwFinder implements CpuCoreFinder
+{
+    private function __construct()
+    {
+    }
+
+    /**
+     * @return positive-int|null
+     */
+    public static function find(): ?int
+    {
+        $process = popen('sysctl -n hw.ncpu', 'rb');
+
+        if (is_resource($process)) {
+            // *nix (Linux, BSD and Mac)
+            $cores = (int) fgets($process);
+            pclose($process);
+
+            return $cores;
+        }
+
+        return null;
+    }
+}

src/WindowsWmicFinder.php

@@ -0,0 +1,50 @@
+<?php
+
+/*
+ * This file is part of the Fidry CPUCounter Config package.
+ *
+ * (c) Théo FIDRY <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Fidry\CpuCounter;
+
+use function fgets;
+use function is_resource;
+use function pclose;
+use function popen;
+
+/**
+ * Find the number of CPU cores for Windows.
+ *
+ * @see https://github.com/paratestphp/paratest/blob/c163539818fd96308ca8dc60f46088461e366ed4/src/Runners/PHPUnit/Options.php#L912-L916
+ */
+final class WindowsWmicFinder implements CpuCoreFinder
+{
+    private function __construct()
+    {
+    }
+
+    /**
+     * @return positive-int|null
+     */
+    public static function find(): ?int
+    {
+        // Windows
+        $process = popen('wmic cpu get NumberOfLogicalProcessors', 'rb');
+
+        if (is_resource($process)) {
+            fgets($process);
+            $cores = (int) fgets($process);
+            pclose($process);
+
+            return $cores;
+        }
+
+        return null;
+    }
+}