caps/SharedJSONHandler.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_SharedJSONHandler_h
   7 #define mozilla_SharedJSONHandler_h
   8
   9 #include "js/JSON.h"  // JS::JSONParseHandler
  10
  11 #include "mozilla/RefPtr.h"  // RefPtr
  12
  13 #include "BasePrincipal.h"  // BasePrincipal
  14
  15 namespace mozilla {
  16
  17 // Base class of all principal JSON parse handlers.
  18 class PrincipalJSONHandlerShared : public JS::JSONParseHandler {
  19  public:
  20   // Common handlers for inner objects.
  21
  22   // NOTE: propertyName and stringValue are partial overloads.
  23   //       Subclasses should put the following:
  24   //         * `using PrincipalJSONHandlerShared::propertyName`
  25   //         * `using PrincipalJSONHandlerShared::stringValue`
  26   virtual bool propertyName(const char16_t* name, size_t length) override {
  27     NS_WARNING("Principal JSON shouldn't use non-ASCII");
  28     SetErrorState();
  29     return false;
  30   };
  31
  32   virtual bool stringValue(const char16_t* str, size_t length) override {
  33     NS_WARNING("Principal JSON shouldn't use non-ASCII");
  34     SetErrorState();
  35     return true;
  36   }
  37
  38   virtual bool numberValue(double d) override {
  39     NS_WARNING("Unexpected number value");
  40     SetErrorState();
  41     return false;
  42   }
  43
  44   virtual bool booleanValue(bool v) override {
  45     NS_WARNING("Unexpected boolean value");
  46     SetErrorState();
  47     return false;
  48   }
  49
  50   virtual bool nullValue() override {
  51     NS_WARNING("Unexpected null value");
  52     SetErrorState();
  53     return false;
  54   }
  55
  56   virtual void error(const char* msg, uint32_t line, uint32_t column) override {
  57     // Unused.
  58   }
  59
  60  protected:
  61   // Set to the error state for the above handlers.
  62   virtual void SetErrorState() = 0;
  63
  64  public:
  65   RefPtr<BasePrincipal> mPrincipal;
  66 };
  67
  68 // Base class shared between PrincipalJSONHandler and
  69 // SubsumedPrincipalJSONHandler.
  70 // This implements the common code for them, absorbing the difference about
  71 // whether it can contain ExpandedPrincipal or not.
  72 template <typename HandlerTypesT>
  73 class ContainerPrincipalJSONHandler : public PrincipalJSONHandlerShared {
  74   using State = typename HandlerTypesT::State;
  75   using InnerHandlerT = typename HandlerTypesT::InnerHandlerT;
  76   static constexpr bool CanContainExpandedPrincipal =
  77       HandlerTypesT::CanContainExpandedPrincipal;
  78
  79  public:
  80   // Common handlers.
  81
  82   virtual bool startObject() override;
  83
  84   using PrincipalJSONHandlerShared::propertyName;
  85   virtual bool propertyName(const JS::Latin1Char* name, size_t length) override;
  86   virtual bool endObject() override;
  87
  88   virtual bool startArray() override;
  89
  90   virtual bool endArray() override;
  91
  92   using PrincipalJSONHandlerShared::stringValue;
  93   virtual bool stringValue(const JS::Latin1Char* str, size_t length) override;
  94
  95  private:
  96   bool ProcessInnerResult(bool aResult);
  97
  98   template <class Func>
  99   bool CallOnInner(Func&& aFunc) {
 100     return mInnerHandler->match([&](auto& aInner) {
 101       bool result = aFunc(aInner);
 102       return ProcessInnerResult(result);
 103     });
 104   }
 105
 106  protected:
 107   State mState = State::Init;
 108
 109   InnerHandlerT mInnerHandler;
 110 };
 111
 112 }  // namespace mozilla
 113
 114 #endif  // mozilla_SharedJSONHandler_h