hphp/runtime/base/apc-object.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #ifndef incl_HPHP_APC_OBJECT_H_
  18 #define incl_HPHP_APC_OBJECT_H_
  19
  20 #include <cinttypes>
  21
  22 #include "hphp/util/either.h"
  23 #include "hphp/runtime/base/apc-string.h"
  24 #include "hphp/runtime/base/type-string.h"
  25
  26 namespace HPHP {
  27
  28 //////////////////////////////////////////////////////////////////////
  29
  30 struct ObjectData;
  31
  32 //////////////////////////////////////////////////////////////////////
  33
  34 /*
  35  * Representation of an object stored in APC.
  36  *
  37  * It may also have a serialized form in which case it will be represented by
  38  * an APCString instance with type KindOfObject.
  39  *
  40  * MakeObject and Delete take care of isolating callers from that detail.
  41  */
  42 struct APCObject {
  43   using ClassOrName = Either<const Class*,const StringData*>;
  44
  45   /*
  46    * Create an APCObject from an ObjectData*; returns its APCHandle.
  47    */
  48   static APCHandle::Pair Construct(ObjectData* data);
  49
  50   // Return an APCObject instance from a serialized version of the
  51   // object.  May return null.
  52   static APCHandle::Pair MakeAPCObject(APCHandle* obj, const Variant& value);
  53
  54   // Return an instance of a PHP object from the given object handle
  55   static Variant MakeLocalObject(const APCHandle* handle);
  56
  57   static void Delete(APCHandle* handle);
  58
  59   static APCObject* fromHandle(APCHandle* handle) {
  60     assert(handle->checkInvariants() &&
  61            handle->kind() == APCKind::SharedObject);
  62     static_assert(offsetof(APCObject, m_handle) == 0, "");
  63     return reinterpret_cast<APCObject*>(handle);
  64   }
  65
  66   static const APCObject* fromHandle(const APCHandle* handle) {
  67     assert(handle->checkInvariants() &&
  68            handle->kind() == APCKind::SharedObject);
  69     static_assert(offsetof(APCObject, m_handle) == 0, "");
  70     return reinterpret_cast<const APCObject*>(handle);
  71   }
  72
  73   APCHandle* getHandle() { return &m_handle; }
  74   const APCHandle* getHandle() const { return &m_handle; }
  75
  76   bool isPersistent() const { return m_persistent; }
  77
  78 private:
  79   struct Prop {
  80     StringData* name;
  81     APCHandle* val;
  82     Either<const Class*,const StringData*> ctx;
  83   };
  84
  85 private:
  86   explicit APCObject(ClassOrName cls, uint32_t propCount);
  87   ~APCObject();
  88   APCObject(const APCObject&) = delete;
  89   APCObject& operator=(const APCObject&) = delete;
  90
  91 private:
  92   static APCHandle::Pair ConstructSlow(ObjectData* data, ClassOrName name);
  93
  94   friend size_t getMemSize(const APCObject*);
  95   Object createObject() const;
  96   Object createObjectSlow() const;
  97
  98   Prop* props() { return reinterpret_cast<Prop*>(this + 1); }
  99   const Prop* props() const {
 100     return const_cast<APCObject*>(this)->props();
 101   }
 102
 103   APCHandle** persistentProps() {
 104     return reinterpret_cast<APCHandle**>(this + 1);
 105   }
 106   const APCHandle* const * persistentProps() const {
 107     return const_cast<APCObject*>(this)->persistentProps();
 108   }
 109
 110 private:
 111   APCHandle m_handle;
 112   ClassOrName m_cls;
 113   uint32_t m_propCount;
 114   uint8_t m_persistent:1;
 115   uint8_t m_no_wakeup:1;
 116   uint8_t m_fast_init:1;
 117 };
 118
 119 //////////////////////////////////////////////////////////////////////
 120
 121 }
 122
 123 #endif