src/dawn/wire/ChunkedCommandSerializer.cpp

// Copyright 2020 The Dawn & Tint Authors
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#include "src/dawn/wire/ChunkedCommandSerializer.h"

#include "src/utils/assert.h"
#include "src/utils/compiler.h"

namespace dawn::wire {

ChunkedCommandSerializer::ChunkedCommandSerializer(CommandSerializer* serializer)
    : mSerializer(serializer), mMaxAllocationSize(serializer->GetMaximumAllocationSize()) {
    DAWN_ASSERT(mMaxAllocationSize > 0);
}

void ChunkedCommandSerializer::SetCommandSerializerForDisconnect(CommandSerializer* serializer) {
    mSerializer = serializer;
    mMaxAllocationSize = serializer->GetMaximumAllocationSize();
    DAWN_ASSERT(mMaxAllocationSize > 0);
}

void ChunkedCommandSerializer::Flush() {
    mSerializer->Flush();
}

void ChunkedCommandSerializer::SerializeChunkedCommand(Span<const std::byte> allocatedBuffer) {
    // Constant regarding the size of the WireChunkedCommandCmd that can be computed once.
    static size_t kWireChunkedCmdPrefixSize = ChunkedCommandCmd{0, 0, {}}.GetRequiredSize();

    uint64_t commandId = mNextChunkedCommandId++;
    size_t totalSize = allocatedBuffer.size();

    while (!allocatedBuffer.empty()) {
        size_t chunkSize =
            std::min(allocatedBuffer.size(), mMaxAllocationSize - kWireChunkedCmdPrefixSize);

        ChunkedCommandCmd cmd;
        cmd.id = commandId;
        cmd.size = totalSize;
        cmd.chunkData = allocatedBuffer.TakeFirst(chunkSize);
        DAWN_ASSERT(cmd.GetRequiredSize() <= mMaxAllocationSize);

        SerializeCommand(std::move(cmd));
    }
}

}  // namespace dawn::wire