text: /*
     +----------------------------------------------------------------------+
     | HipHop for PHP                                                       |
     +----------------------------------------------------------------------+
     | Copyright (c) 2010-2015 Facebook, Inc. (http://www.facebook.com)     |
     +----------------------------------------------------------------------+
     | This source file is subject to version 3.01 of the PHP license,      |
     | that is bundled with this package in the file LICENSE, and is        |
     | available through the world-wide-web at the following url:           |
     | http://www.php.net/license/3_01.txt                                  |
     | If you did not receive a copy of the PHP license and are unable to   |
     | obtain it through the world-wide-web, please send a note to          |
     | license@php.net so we can mail you a copy immediately.               |
     +----------------------------------------------------------------------+
  */
  
  #ifndef incl_HPHP_APC_STRING_H_
  #define incl_HPHP_APC_STRING_H_
  
  #include "hphp/runtime/base/types.h"
  #include "hphp/runtime/base/apc-handle.h"
  #include "hphp/runtime/base/apc-typed-value.h"
  
  namespace HPHP {
  ///////////////////////////////////////////////////////////////////////////////
  
  /*
   * APCString holds the data to create a PHP string from APC.
   * This object only covers KindOfString. KindOfStaticString are handled
   * via APCTypedValue.
   */
  struct APCString {
    // Entry point to create an APCString
    static APCHandle::Pair MakeSharedString(DataType type, StringData* s);
  
    // Return the PHP string from the APC one
    static Variant MakeString(const APCHandle* handle) {
      assert(handle->type() == KindOfString);
      if (handle->isUncounted()) {
        return Variant{APCTypedValue::fromHandle(handle)->getStringData()};
      }
      return Variant::attach(StringData::Make(APCString::fromHandle(handle)));
    }
  
    static APCString* fromHandle(APCHandle* handle) {
      static_assert(
        offsetof(APCString, m_handle) == 0,
        "m_handle must appear first in APCString"
      );
      return reinterpret_cast<APCString*>(handle);
    }
  
    static const APCString* fromHandle(const APCHandle* handle) {
      static_assert(
        offsetof(APCString, m_handle) == 0,
        "m_handle must appear first in APCString"
      );
      return reinterpret_cast<const APCString*>(handle);
    }
  
    const APCHandle* getHandle() const {
      return &m_handle;
    }
  
    APCHandle* getHandle() {
      return &m_handle;
    }
  
    StringData* getStringData() {
      return &m_str;
    }
  
    const StringData* getStringData() const {
      return &m_str;
    }
  
  private:
    APCString(const APCString&) = delete;
    APCString& operator=(const APCString&) = delete;
  
    explicit APCString(DataType type) : m_handle(type) {}
    ~APCString() {}
  
    void *operator new(size_t sz, int size) {
      assert(sz == sizeof(APCString));
      return malloc(sizeof(APCString) + size);
    }
    void operator delete(void* ptr) { free(ptr); }
    // just to keep the compiler happy; used if the constructor throws
    void operator delete(void* ptr, int size) { free(ptr); }
  
    friend struct APCHandle;
    friend struct APCArray;
    friend struct APCObject;
  
  private:
    APCHandle m_handle;
    union {
      StringData m_str;
      uintptr_t dummy[sizeof(StringData) / sizeof(uintptr_t)];
    };
  };
  
  ///////////////////////////////////////////////////////////////////////////////
  }
  
  #endif /* incl_HPHP_APC_TYPED_VALUE_H_ */
  