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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef PPAPI_SHARED_IMPL_VAR_H_
#define PPAPI_SHARED_IMPL_VAR_H_
#include <string>
#include "base/compiler_specific.h"
#include "base/memory/ref_counted.h"
#include "ppapi/c/pp_var.h"
#include "ppapi/shared_impl/ppapi_shared_export.h"
namespace ppapi {
class ArrayBufferVar;
class NPObjectVar;
class ProxyObjectVar;
class StringVar;
class VarTracker;
// Var -------------------------------------------------------------------------
// Represents a non-POD var.
class PPAPI_SHARED_EXPORT Var : public base::RefCounted<Var> {
public:
virtual ~Var();
// Returns a string representing the given var for logging purposes.
static std::string PPVarToLogString(PP_Var var);
virtual StringVar* AsStringVar();
virtual ArrayBufferVar* AsArrayBufferVar();
virtual NPObjectVar* AsNPObjectVar();
virtual ProxyObjectVar* AsProxyObjectVar();
// Creates a PP_Var corresponding to this object. The return value will have
// one reference addrefed on behalf of the caller.
PP_Var GetPPVar();
// Returns the type of this var.
virtual PP_VarType GetType() const = 0;
// Returns the ID corresponing to the string or object if it exists already,
// or 0 if an ID hasn't been generated for this object (the plugin is holding
// no refs).
//
// Contrast to GetOrCreateVarID which creates the ID and a ref on behalf of
// the plugin.
int32 GetExistingVarID() const;
protected:
friend class VarTracker;
Var();
// Returns the unique ID associated with this string or object, creating it
// if necessary. The return value will be 0 if the string or object is
// invalid.
//
// This function will take a reference to the var that will be passed to the
// caller.
int32 GetOrCreateVarID();
// Sets the internal object ID. This assumes that the ID hasn't been set
// before. This is used in cases where the ID is generated externally.
void AssignVarID(int32 id);
// Reset the assigned object ID.
void ResetVarID() { var_id_ = 0; }
private:
// This will be 0 if no ID has been assigned (this happens lazily).
int32 var_id_;
DISALLOW_COPY_AND_ASSIGN(Var);
};
// StringVar -------------------------------------------------------------------
// Represents a string-based Var.
//
// Returning a given string as a PP_Var:
// return StringVar::StringToPPVar(my_string);
//
// Converting a PP_Var to a string:
// StringVar* string = StringVar::FromPPVar(var);
// if (!string)
// return false; // Not a string or an invalid var.
// DoSomethingWithTheString(string->value());
class PPAPI_SHARED_EXPORT StringVar : public Var {
public:
explicit StringVar(const std::string& str);
StringVar(const char* str, uint32 len);
virtual ~StringVar();
const std::string& value() const { return value_; }
// Return a pointer to the internal string. This allows other objects to
// temporarily store a weak pointer to our internal string. Use with care; the
// pointer *will* become invalid if this StringVar is removed from the
// tracker. (All of this applies to value(), but this one's even easier to use
// dangerously).
const std::string* ptr() const { return &value_; }
// Var override.
virtual StringVar* AsStringVar() OVERRIDE;
virtual PP_VarType GetType() const OVERRIDE;
// Helper function to create a PP_Var of type string that contains a copy of
// the given string. The input data must be valid UTF-8 encoded text, if it
// is not valid UTF-8, a NULL var will be returned.
//
// The return value will have a reference count of 1. Internally, this will
// create a StringVar and return the reference to it in the var.
static PP_Var StringToPPVar(const std::string& str);
static PP_Var StringToPPVar(const char* str, uint32 len);
// Same as StringToPPVar but avoids a copy by destructively swapping the
// given string into the newly created StringVar. The string must already be
// valid UTF-8. After the call, *src will be empty.
static PP_Var SwapValidatedUTF8StringIntoPPVar(std::string* src);
// Helper function that converts a PP_Var to a string. This will return NULL
// if the PP_Var is not of string type or the string is invalid.
static StringVar* FromPPVar(PP_Var var);
private:
StringVar(); // Makes an empty string.
std::string value_;
DISALLOW_COPY_AND_ASSIGN(StringVar);
};
// ArrayBufferVar --------------------------------------------------------------
// Represents an array buffer Var.
//
// Note this is an abstract class. To create an appropriate concrete one, you
// need to use the VarTracker:
// VarArrayBuffer* buf =
// PpapiGlobals::Get()->GetVarTracker()->CreateArrayBuffer(size);
//
// Converting a PP_Var to an ArrayBufferVar:
// ArrayBufferVar* array = ArrayBufferVar::FromPPVar(var);
// if (!array)
// return false; // Not an ArrayBuffer or an invalid var.
// DoSomethingWithTheBuffer(array);
class PPAPI_SHARED_EXPORT ArrayBufferVar : public Var {
public:
ArrayBufferVar();
virtual ~ArrayBufferVar();
virtual void* Map() = 0;
virtual void Unmap() = 0;
virtual uint32 ByteLength() = 0;
// Var override.
virtual ArrayBufferVar* AsArrayBufferVar() OVERRIDE;
virtual PP_VarType GetType() const OVERRIDE;
// Helper function that converts a PP_Var to an ArrayBufferVar. This will
// return NULL if the PP_Var is not of ArrayBuffer type.
static ArrayBufferVar* FromPPVar(PP_Var var);
private:
DISALLOW_COPY_AND_ASSIGN(ArrayBufferVar);
};
} // namespace ppapi
#endif // PPAPI_SHARED_IMPL_VAR_H_