src/third_party/mozjs-45/js/src/vm/JSONParser.h - cobalt - Git at Google

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: set ts=8 sts=4 et sw=4 tw=99:
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #ifndef vm_JSONParser_h
 #define vm_JSONParser_h

 #include "mozilla/Attributes.h"
 #include "mozilla/Range.h"

 #include "jspubtd.h"

 #include "ds/IdValuePair.h"
 #include "vm/String.h"

 namespace js {

 // JSONParser base class. JSONParser is templatized to work on either Latin1
 // or TwoByte input strings, JSONParserBase holds all state and methods that
 // can be shared between the two encodings.
 class MOZ_STACK_CLASS JSONParserBase
 {
   public:
     enum ErrorHandling { RaiseError, NoError };

   private:
     /* Data members */
     Value v;

   protected:
     JSContext * const cx;

     const ErrorHandling errorHandling;

     enum Token { String, Number, True, False, Null,
                  ArrayOpen, ArrayClose,
                  ObjectOpen, ObjectClose,
                  Colon, Comma,
                  OOM, Error };

     // State related to the parser's current position. At all points in the
     // parse this keeps track of the stack of arrays and objects which have
     // been started but not finished yet. The actual JS object is not
     // allocated until the literal is closed, so that the result can be sized
     // according to its contents and have its type and shape filled in using
     // caches.

     // State for an array that is currently being parsed. This includes all
     // elements that have been seen so far.
     typedef Vector<Value, 20> ElementVector;

     // State for an object that is currently being parsed. This includes all
     // the key/value pairs that have been seen so far.
     typedef Vector<IdValuePair, 10> PropertyVector;

     // Possible states the parser can be in between values.
     enum ParserState {
         // An array element has just being parsed.
         FinishArrayElement,

         // An object property has just been parsed.
         FinishObjectMember,

         // At the start of the parse, before any values have been processed.
         JSONValue
     };

     // Stack element for an in progress array or object.
     struct StackEntry {
         ElementVector& elements() {
             MOZ_ASSERT(state == FinishArrayElement);
             return * static_cast<ElementVector*>(vector);
         }

         PropertyVector& properties() {
             MOZ_ASSERT(state == FinishObjectMember);
             return * static_cast<PropertyVector*>(vector);
         }

         explicit StackEntry(ElementVector* elements)
           : state(FinishArrayElement), vector(elements)
         {}

         explicit StackEntry(PropertyVector* properties)
           : state(FinishObjectMember), vector(properties)
         {}

         ParserState state;

       private:
         void* vector;
     };

     // All in progress arrays and objects being parsed, in order from outermost
     // to innermost.
     Vector<StackEntry, 10> stack;

     // Unused element and property vectors for previous in progress arrays and
     // objects. These vectors are not freed until the end of the parse to avoid
     // unnecessary freeing and allocation.
     Vector<ElementVector*, 5> freeElements;
     Vector<PropertyVector*, 5> freeProperties;

 #ifdef DEBUG
     Token lastToken;
 #endif

     JSONParserBase(JSContext* cx, ErrorHandling errorHandling)
       : cx(cx),
         errorHandling(errorHandling),
         stack(cx),
         freeElements(cx),
         freeProperties(cx)
 #ifdef DEBUG
       , lastToken(Error)
 #endif
     {}
     ~JSONParserBase();

     // Allow move construction for use with Rooted.
     JSONParserBase(JSONParserBase&& other)
       : v(other.v),
         cx(other.cx),
         errorHandling(other.errorHandling),
         stack(mozilla::Move(other.stack)),
         freeElements(mozilla::Move(other.freeElements)),
         freeProperties(mozilla::Move(other.freeProperties))
 #ifdef DEBUG
       , lastToken(mozilla::Move(other.lastToken))
 #endif
     {}


     Value numberValue() const {
         MOZ_ASSERT(lastToken == Number);
         MOZ_ASSERT(v.isNumber());
         return v;
     }

     Value stringValue() const {
         MOZ_ASSERT(lastToken == String);
         MOZ_ASSERT(v.isString());
         return v;
     }

     JSAtom* atomValue() const {
         Value strval = stringValue();
         return &strval.toString()->asAtom();
     }

     Token token(Token t) {
         MOZ_ASSERT(t != String);
         MOZ_ASSERT(t != Number);
 #ifdef DEBUG
         lastToken = t;
 #endif
         return t;
     }

     Token stringToken(JSString* str) {
         this->v = StringValue(str);
 #ifdef DEBUG
         lastToken = String;
 #endif
         return String;
     }

     Token numberToken(double d) {
         this->v = NumberValue(d);
 #ifdef DEBUG
         lastToken = Number;
 #endif
         return Number;
     }

     enum StringType { PropertyName, LiteralValue };

     bool errorReturn();

     bool finishObject(MutableHandleValue vp, PropertyVector& properties);
     bool finishArray(MutableHandleValue vp, ElementVector& elements);

     void trace(JSTracer* trc);

   private:
     JSONParserBase(const JSONParserBase& other) = delete;
     void operator=(const JSONParserBase& other) = delete;
 };

 template <typename CharT>
 class MOZ_STACK_CLASS JSONParser : public JSONParserBase,
                                    public JS::Traceable
 {
   private:
     typedef mozilla::RangedPtr<const CharT> CharPtr;

     CharPtr current;
     const CharPtr begin, end;

   public:
     /* Public API */

     /* Create a parser for the provided JSON data. */
     JSONParser(JSContext* cx, mozilla::Range<const CharT> data,
                ErrorHandling errorHandling = RaiseError)
       : JSONParserBase(cx, errorHandling),
         current(data.start()),
         begin(current),
         end(data.end())
     {
         MOZ_ASSERT(current <= end);
     }

     /* Allow move construction for use with Rooted. */
     JSONParser(JSONParser&& other)
       : JSONParserBase(mozilla::Forward<JSONParser>(other)),
         current(other.current),
         begin(other.begin),
         end(other.end)
     {}

     /*
      * Parse the JSON data specified at construction time.  If it parses
      * successfully, store the prescribed value in *vp and return true.  If an
      * internal error (e.g. OOM) occurs during parsing, return false.
      * Otherwise, if invalid input was specifed but no internal error occurred,
      * behavior depends upon the error handling specified at construction: if
      * error handling is RaiseError then throw a SyntaxError and return false,
      * otherwise return true and set *vp to |undefined|.  (JSON syntax can't
      * represent |undefined|, so the JSON data couldn't have specified it.)
      */
     bool parse(MutableHandleValue vp);

     static void trace(JSONParser<CharT>* parser, JSTracer* trc) { parser->trace(trc); }
     void trace(JSTracer* trc) { JSONParserBase::trace(trc); }

   private:
     template<StringType ST> Token readString();

     Token readNumber();

     Token advance();
     Token advancePropertyName();
     Token advancePropertyColon();
     Token advanceAfterProperty();
     Token advanceAfterObjectOpen();
     Token advanceAfterArrayElement();

     void error(const char* msg);

     void getTextPosition(uint32_t* column, uint32_t* line);

   private:
     JSONParser(const JSONParser& other) = delete;
     void operator=(const JSONParser& other) = delete;
 };

 template <typename CharT>
 struct RootedBase<JSONParser<CharT>> {
     bool parse(MutableHandleValue vp) {
         return static_cast<Rooted<JSONParser<CharT>>*>(this)->get().parse(vp);
     }
 };

 } /* namespace js */

 #endif /* vm_JSONParser_h */
	/* -- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 --
	* vim: set ts=8 sts=4 et sw=4 tw=99:
	* This Source Code Form is subject to the terms of the Mozilla Public
	* License, v. 2.0. If a copy of the MPL was not distributed with this
	* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

	#ifndef vm_JSONParser_h
	#define vm_JSONParser_h

	#include "mozilla/Attributes.h"
	#include "mozilla/Range.h"

	#include "jspubtd.h"

	#include "ds/IdValuePair.h"
	#include "vm/String.h"

	namespace js {

	// JSONParser base class. JSONParser is templatized to work on either Latin1
	// or TwoByte input strings, JSONParserBase holds all state and methods that
	// can be shared between the two encodings.
	class MOZ_STACK_CLASS JSONParserBase
	{
	public:
	enum ErrorHandling { RaiseError, NoError };

	private:
	/* Data members */
	Value v;

	protected:
	JSContext * const cx;

	const ErrorHandling errorHandling;

	enum Token { String, Number, True, False, Null,
	ArrayOpen, ArrayClose,
	ObjectOpen, ObjectClose,
	Colon, Comma,
	OOM, Error };

	// State related to the parser's current position. At all points in the
	// parse this keeps track of the stack of arrays and objects which have
	// been started but not finished yet. The actual JS object is not
	// allocated until the literal is closed, so that the result can be sized
	// according to its contents and have its type and shape filled in using
	// caches.

	// State for an array that is currently being parsed. This includes all
	// elements that have been seen so far.
	typedef Vector<Value, 20> ElementVector;

	// State for an object that is currently being parsed. This includes all
	// the key/value pairs that have been seen so far.
	typedef Vector<IdValuePair, 10> PropertyVector;

	// Possible states the parser can be in between values.
	enum ParserState {
	// An array element has just being parsed.
	FinishArrayElement,

	// An object property has just been parsed.
	FinishObjectMember,

	// At the start of the parse, before any values have been processed.
	JSONValue
	};

	// Stack element for an in progress array or object.
	struct StackEntry {
	ElementVector& elements() {
	MOZ_ASSERT(state == FinishArrayElement);
	return * static_cast<ElementVector*>(vector);
	}

	PropertyVector& properties() {
	MOZ_ASSERT(state == FinishObjectMember);
	return * static_cast<PropertyVector*>(vector);
	}

	explicit StackEntry(ElementVector* elements)
	: state(FinishArrayElement), vector(elements)
	{}

	explicit StackEntry(PropertyVector* properties)
	: state(FinishObjectMember), vector(properties)
	{}

	ParserState state;

	private:
	void* vector;
	};

	// All in progress arrays and objects being parsed, in order from outermost
	// to innermost.
	Vector<StackEntry, 10> stack;

	// Unused element and property vectors for previous in progress arrays and
	// objects. These vectors are not freed until the end of the parse to avoid
	// unnecessary freeing and allocation.
	Vector<ElementVector*, 5> freeElements;
	Vector<PropertyVector*, 5> freeProperties;

	#ifdef DEBUG
	Token lastToken;
	#endif

	JSONParserBase(JSContext* cx, ErrorHandling errorHandling)
	: cx(cx),
	errorHandling(errorHandling),
	stack(cx),
	freeElements(cx),
	freeProperties(cx)
	#ifdef DEBUG
	, lastToken(Error)
	#endif
	{}
	~JSONParserBase();

	// Allow move construction for use with Rooted.
	JSONParserBase(JSONParserBase&& other)
	: v(other.v),
	cx(other.cx),
	errorHandling(other.errorHandling),
	stack(mozilla::Move(other.stack)),
	freeElements(mozilla::Move(other.freeElements)),
	freeProperties(mozilla::Move(other.freeProperties))
	#ifdef DEBUG
	, lastToken(mozilla::Move(other.lastToken))
	#endif
	{}


	Value numberValue() const {
	MOZ_ASSERT(lastToken == Number);
	MOZ_ASSERT(v.isNumber());
	return v;
	}

	Value stringValue() const {
	MOZ_ASSERT(lastToken == String);
	MOZ_ASSERT(v.isString());
	return v;
	}

	JSAtom* atomValue() const {
	Value strval = stringValue();
	return &strval.toString()->asAtom();
	}

	Token token(Token t) {
	MOZ_ASSERT(t != String);
	MOZ_ASSERT(t != Number);
	#ifdef DEBUG
	lastToken = t;
	#endif
	return t;
	}

	Token stringToken(JSString* str) {
	this->v = StringValue(str);
	#ifdef DEBUG
	lastToken = String;
	#endif
	return String;
	}

	Token numberToken(double d) {
	this->v = NumberValue(d);
	#ifdef DEBUG
	lastToken = Number;
	#endif
	return Number;
	}

	enum StringType { PropertyName, LiteralValue };

	bool errorReturn();

	bool finishObject(MutableHandleValue vp, PropertyVector& properties);
	bool finishArray(MutableHandleValue vp, ElementVector& elements);

	void trace(JSTracer* trc);

	private:
	JSONParserBase(const JSONParserBase& other) = delete;
	void operator=(const JSONParserBase& other) = delete;
	};

	template <typename CharT>
	class MOZ_STACK_CLASS JSONParser : public JSONParserBase,
	public JS::Traceable
	{
	private:
	typedef mozilla::RangedPtr<const CharT> CharPtr;

	CharPtr current;
	const CharPtr begin, end;

	public:
	/* Public API */

	/* Create a parser for the provided JSON data. */
	JSONParser(JSContext* cx, mozilla::Range<const CharT> data,
	ErrorHandling errorHandling = RaiseError)
	: JSONParserBase(cx, errorHandling),
	current(data.start()),
	begin(current),
	end(data.end())
	{
	MOZ_ASSERT(current <= end);
	}

	/* Allow move construction for use with Rooted. */
	JSONParser(JSONParser&& other)
	: JSONParserBase(mozilla::Forward<JSONParser>(other)),
	current(other.current),
	begin(other.begin),
	end(other.end)
	{}

	/*
	* Parse the JSON data specified at construction time. If it parses
	* successfully, store the prescribed value in *vp and return true. If an
	* internal error (e.g. OOM) occurs during parsing, return false.
	* Otherwise, if invalid input was specifed but no internal error occurred,
	* behavior depends upon the error handling specified at construction: if
	* error handling is RaiseError then throw a SyntaxError and return false,
	* otherwise return true and set *vp to \|undefined\|. (JSON syntax can't
	* represent \|undefined\|, so the JSON data couldn't have specified it.)
	*/
	bool parse(MutableHandleValue vp);

	static void trace(JSONParser<CharT>* parser, JSTracer* trc) { parser->trace(trc); }
	void trace(JSTracer* trc) { JSONParserBase::trace(trc); }

	private:
	template<StringType ST> Token readString();

	Token readNumber();

	Token advance();
	Token advancePropertyName();
	Token advancePropertyColon();
	Token advanceAfterProperty();
	Token advanceAfterObjectOpen();
	Token advanceAfterArrayElement();

	void error(const char* msg);

	void getTextPosition(uint32_t* column, uint32_t* line);

	private:
	JSONParser(const JSONParser& other) = delete;
	void operator=(const JSONParser& other) = delete;
	};

	template <typename CharT>
	struct RootedBase<JSONParser<CharT>> {
	bool parse(MutableHandleValue vp) {
	return static_cast<Rooted<JSONParser<CharT>>*>(this)->get().parse(vp);
	}
	};

	} /* namespace js */

	#endif /* vm_JSONParser_h */