thehub/libs/utils/streaming/ProtoBuilder.cpp

/*
 * This file is part of the Flowee project
 * Copyright (C) 2016,2018-2019 Tom Zander <tom@flowee.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "ProtoBuilder.h"
#include "ProtoParser.h"
#include "BufferPool.h"

namespace {
int serializeProto(char *data, uint64_t value)
{
    int pos = 0;
    while (true) {
        data[pos] = (value & 0x7F) | (value >= 0x80 ? 0x80 : 0x00);
        if (value <= 0x7F)
            break;
        value = value >> 7;
        pos++;
    }

    return pos + 1;
}

int write(char *data, uint32_t tag, Streaming::ProtoParser::WireType type) {
    assert(tag < 32);
    uint8_t byte = tag;
    byte = byte << 3;
    byte += type;
    data[0] = byte;
    return 1;
}
}

Streaming::ProtoBuilder::ProtoBuilder(Streaming::BufferPool &pool)
    : m_buffer(&pool)
{
}

void Streaming::ProtoBuilder::add(uint32_t tag, uint64_t value)
{
    handleNestedBuilder();
    int tagSize = write(m_buffer->data(), tag, Streaming::ProtoParser::VarInt);
    m_buffer->markUsed(tagSize);
    tagSize = ::serializeProto(m_buffer->data(), value);
    m_buffer->markUsed(tagSize);
}

void Streaming::ProtoBuilder::add(uint32_t tag, const std::string &value)
{
    handleNestedBuilder();
    int tagSize = write(m_buffer->data(), tag, Streaming::ProtoParser::Data);
    const unsigned int size = value.size();
    tagSize += ::serializeProto(m_buffer->data() + tagSize, size);
    m_buffer->markUsed(tagSize);
    memcpy(m_buffer->data(), value.c_str(), value.size());
    m_buffer->markUsed(value.size());
}

void Streaming::ProtoBuilder::add(uint32_t tag, const std::vector<char> &data)
{
    addByteArray(tag, data.data(), data.size());
}

void Streaming::ProtoBuilder::addByteArray(uint32_t tag, const void *data, int bytes)
{
    handleNestedBuilder();
    int tagSize = write(m_buffer->data(), tag, Streaming::ProtoParser::Data);
    tagSize += ::serializeProto(m_buffer->data() + tagSize, bytes);
    m_buffer->markUsed(tagSize);
    memcpy(m_buffer->data(), data, bytes);
    m_buffer->markUsed(bytes);
}

void Streaming::ProtoBuilder::add(uint32_t tag, const Streaming::ConstBuffer &data)
{
    handleNestedBuilder();
    int tagSize = write(m_buffer->data(), tag, Streaming::ProtoParser::Data);
    tagSize += ::serializeProto(m_buffer->data() + tagSize, data.size());
    m_buffer->markUsed(tagSize);
    memcpy(m_buffer->data(), data.begin(), data.size());
    m_buffer->markUsed(data.size());
}

void Streaming::ProtoBuilder::add(uint32_t tag, bool value)
{
    return add(tag, (int32_t) (value ? 1 : 0));
}

void Streaming::ProtoBuilder::add(uint32_t tag, int32_t value)
{
    handleNestedBuilder();
    int tagSize = write(m_buffer->data(), tag, Streaming::ProtoParser::VarInt);
    m_buffer->markUsed(tagSize);
    tagSize = ::serializeProto(m_buffer->data(), value);
    m_buffer->markUsed(tagSize);
}

Streaming::ProtoBuilder *Streaming::ProtoBuilder::addNestedMessage(uint32_t tag)
{
    handleNestedBuilder();
    write(m_buffer->data(), tag, Streaming::ProtoParser::Data);
    m_buffer->markUsed(1);
    m_nestedBufferPool = new BufferPool();
    m_nestedBuilder = new Streaming::ProtoBuilder(*m_nestedBufferPool);
    return m_nestedBuilder;
}

void Streaming::ProtoBuilder::add(uint32_t tag, const unsigned char *data, unsigned int length)
{
    handleNestedBuilder();
    int tagSize = write(m_buffer->data(), tag, Streaming::ProtoParser::Data);
    tagSize += ::serializeProto(m_buffer->data() + tagSize, length);
    m_buffer->markUsed(tagSize);
    memcpy(m_buffer->data(), data, length);
    m_buffer->markUsed(length);
}

void Streaming::ProtoBuilder::handleNestedBuilder()
{
    if (m_nestedBuilder == nullptr)
        return;

    delete m_nestedBuilder;
    m_nestedBuilder = nullptr;
    auto blob = m_nestedBufferPool->commit();
    delete m_nestedBufferPool;
    m_nestedBufferPool = nullptr;
    auto tagSize = ::serializeProto(m_buffer->data(), blob.size());
    m_buffer->markUsed(tagSize);
    memcpy(m_buffer->data(), blob.begin(), blob.size());
    m_buffer->markUsed(blob.size());
}

Streaming::ConstBuffer Streaming::ProtoBuilder::buffer()
{
    handleNestedBuilder();
    return m_buffer->commit();
}