The var cache is a utility to help store variables that are compiled.

Author: markrandall

src/Build/VarCache.php

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+<?php
+
+namespace phpweb\Build;
+
+use RuntimeException;
+use stdClass;
+use function dirname;
+use function is_dir;
+use function is_readable;
+
+/**
+ * Pregenerated Data Helper for storing and retrieving data from the compiled cache
+ *
+ * This utility is used by various build steps.
+ *
+ * At present these steps must be performed, and the cache committed to the GIT repository.
+ * It is hoped that in the long-term this can be performed as part of CI/CD.
+ */
+final class VarCache
+{
+    private static function makePathForKey(string $key, bool $create = false): string
+    {
+        $path = __DIR__ . "/../../var/cache/{$key}.inc";
+
+        if ($create) {
+            $basePath = dirname($path);
+            is_dir($basePath) || mkdir($basePath, recursive:true);
+        }
+
+        return $path;
+    }
+
+    public static function ReadVar(string $key): mixed
+    {
+        static $dummy = null;
+        $dummy ??= new stdClass();
+        $value = self::ReadVarWithDefault($key, $dummy);
+
+        if ($value === $dummy) {
+            throw new VarUnavailableException('Unable to read var cache value for ' . $key);
+        }
+
+        return $value;
+    }
+
+    public static function ReadVarWithDefault(string $key, mixed $default): mixed
+    {
+        $path = self::makePathForKey($key);
+        if (is_readable($path)) {
+            return require $path;
+        }
+
+        return $default;
+    }
+
+    public static function WriteVar(string $key, mixed $value): void
+    {
+        $path = self::makePathForKey($key, create: true);
+        $result = file_put_contents(
+            $path,
+            "<?php\n\n/* this file is automatically generated. Do not edit. */\nreturn " . var_export($value, true) . ';',
+        );
+
+        if ($result === false) {
+            throw new RuntimeException('Unable to write var cache value for ' . $key);
+        }
+    }
+}

src/Build/VarUnavailableException.php

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+<?php
+
+namespace phpweb\Build;
+
+/**
+ * Thrown when a read to VarCache cannot locate the file
+ */
+class VarUnavailableException extends \Exception
+{
+
+}