BinaryStream.h

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Author : Corentin Wallez
Date : 2017-11-08 14:00:32
Hash : f0e89be6
Message : Use packed enums for the texture types and targets, part 1 In OpenGL there are two enum "sets" used by the API that are very similar: texture types (or bind point) and texture targets. They only differ in that texture types have GL_TEXTURE_CUBEMAP and target have GL_TEXTURE_CUBEMAP_[POSITIVE|NEGATIVE]_[X|Y|Z]. This is a problem because in ANGLE we use GLenum to pass around both types of data, making it difficult to know which of type and target a variable is. In addition these enums are placed somewhat randomly in the space of OpenGL enums, making it slow to have a mapping from texture types to some data. Such a mapping is in hot-code with gl::State::mTextures. This commit stack makes the texture types and target enums be translated to internal packed enums right at the OpenGL entry point and used throughout ANGLE to have type safety and performance gains. This is the first of two commit which does the refactor for all of the validation and stops inside gl::Context. This was the best place to split patches without having many conversions from packed enums to GL enums. BUG=angleproject:2169 Change-Id: Ib43da7e71c253bd9fe210fb0ec0de61bc286e6d3 Reviewed-on: https://chromium-review.googlesource.com/758835 Commit-Queue: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>

src/libANGLE/BinaryStream.h

//
// Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

// BinaryStream.h: Provides binary serialization of simple types.

#ifndef LIBANGLE_BINARYSTREAM_H_
#define LIBANGLE_BINARYSTREAM_H_

#include <cstddef>
#include <string>
#include <vector>
#include <stdint.h>

#include "common/angleutils.h"
#include "common/mathutil.h"

namespace gl
{

class BinaryInputStream : angle::NonCopyable
{
  public:
    BinaryInputStream(const void *data, size_t length)
    {
        mError = false;
        mOffset = 0;
        mData = static_cast<const uint8_t*>(data);
        mLength = length;
    }

    // readInt will generate an error for bool types
    template <class IntT>
    IntT readInt()
    {
        int value = 0;
        read(&value);
        return static_cast<IntT>(value);
    }

    template <class IntT>
    void readInt(IntT *outValue)
    {
        *outValue = readInt<IntT>();
    }

    template <class IntT, class VectorElementT>
    void readIntVector(std::vector<VectorElementT> *param)
    {
        unsigned int size = readInt<unsigned int>();
        for (unsigned int index = 0; index < size; ++index)
        {
            param->push_back(readInt<IntT>());
        }
    }

    template <class EnumT>
    EnumT readEnum()
    {
        using UnderlyingType = typename std::underlying_type<EnumT>::type;
        return static_cast<EnumT>(readInt<UnderlyingType>());
    }

    template <class EnumT>
    void readEnum(EnumT *outValue)
    {
        *outValue = readEnum<EnumT>();
    }

    bool readBool()
    {
        int value = 0;
        read(&value);
        return (value > 0);
    }

    void readBool(bool *outValue)
    {
        *outValue = readBool();
    }

    void readBytes(unsigned char outArray[], size_t count)
    {
        read<unsigned char>(outArray, count);
    }

    std::string readString()
    {
        std::string outString;
        readString(&outString);
        return outString;
    }

    void readString(std::string *v)
    {
        size_t length;
        readInt(&length);

        if (mError)
        {
            return;
        }

        angle::CheckedNumeric<size_t> checkedOffset(mOffset);
        checkedOffset += length;

        if (!checkedOffset.IsValid() || mOffset + length > mLength)
        {
            mError = true;
            return;
        }

        v->assign(reinterpret_cast<const char *>(mData) + mOffset, length);
        mOffset = checkedOffset.ValueOrDie();
    }

    void skip(size_t length)
    {
        angle::CheckedNumeric<size_t> checkedOffset(mOffset);
        checkedOffset += length;

        if (!checkedOffset.IsValid() || mOffset + length > mLength)
        {
            mError = true;
            return;
        }

        mOffset = checkedOffset.ValueOrDie();
    }

    size_t offset() const
    {
        return mOffset;
    }

    bool error() const
    {
        return mError;
    }

    bool endOfStream() const
    {
        return mOffset == mLength;
    }

    const uint8_t *data()
    {
        return mData;
    }

  private:
    bool mError;
    size_t mOffset;
    const uint8_t *mData;
    size_t mLength;

    template <typename T>
    void read(T *v, size_t num)
    {
        static_assert(std::is_fundamental<T>::value, "T must be a fundamental type.");

        angle::CheckedNumeric<size_t> checkedLength(num);
        checkedLength *= sizeof(T);
        if (!checkedLength.IsValid())
        {
            mError = true;
            return;
        }

        angle::CheckedNumeric<size_t> checkedOffset(mOffset);
        checkedOffset += checkedLength;

        if (!checkedOffset.IsValid() || checkedOffset.ValueOrDie() > mLength)
        {
            mError = true;
            return;
        }

        memcpy(v, mData + mOffset, checkedLength.ValueOrDie());
        mOffset = checkedOffset.ValueOrDie();
    }

    template <typename T>
    void read(T *v)
    {
        read(v, 1);
    }

};

class BinaryOutputStream : angle::NonCopyable
{
  public:
    BinaryOutputStream();
    ~BinaryOutputStream();

    // writeInt also handles bool types
    template <class IntT>
    void writeInt(IntT param)
    {
        ASSERT(angle::IsValueInRangeForNumericType<int>(param));
        int intValue = static_cast<int>(param);
        write(&intValue, 1);
    }

    // Specialized writeInt for values that can also be exactly -1.
    template <class UintT>
    void writeIntOrNegOne(UintT param)
    {
        if (param == static_cast<UintT>(-1))
        {
            writeInt(-1);
        }
        else
        {
            writeInt(param);
        }
    }

    template <class IntT>
    void writeIntVector(std::vector<IntT> param)
    {
        writeInt(param.size());
        for (IntT element : param)
        {
            writeIntOrNegOne(element);
        }
    }

    template <class EnumT>
    void writeEnum(EnumT param)
    {
        using UnderlyingType = typename std::underlying_type<EnumT>::type;
        writeInt<UnderlyingType>(static_cast<UnderlyingType>(param));
    }

    void writeString(const std::string &v)
    {
        writeInt(v.length());
        write(v.c_str(), v.length());
    }

    void writeBytes(const unsigned char *bytes, size_t count)
    {
        write(bytes, count);
    }

    size_t length() const
    {
        return mData.size();
    }

    const void* data() const
    {
        return mData.size() ? &mData[0] : nullptr;
    }

  private:
    std::vector<char> mData;

    template <typename T>
    void write(const T *v, size_t num)
    {
        static_assert(std::is_fundamental<T>::value, "T must be a fundamental type.");
        const char *asBytes = reinterpret_cast<const char*>(v);
        mData.insert(mData.end(), asBytes, asBytes + num * sizeof(T));
    }

};

inline BinaryOutputStream::BinaryOutputStream()
{
}

inline BinaryOutputStream::~BinaryOutputStream() = default;

}  // namespace gl

#endif  // LIBANGLE_BINARYSTREAM_H_

kc3-lang/angle/src/libANGLE/BinaryStream.h

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kc3-lang/angle /src/libANGLE/BinaryStream.h