Advertisement.cxx

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#include "ble/Advertisement.hxx"
 
namespace ble
{
 
//
// Advertisement::concat_service_data_128()
//
std::basic_string<uint8_t> Advertisement::concat_service_data_128(
    const uint8_t uuid[16], const void *buf, size_t size)
{
    const uint8_t *data = static_cast<const uint8_t*>(buf);
    std::basic_string<uint8_t> result(uuid, uuid + 16);
    result.append(data, size);
    return result;
}
 
//
// Advertisement::prepend()
//
int Advertisement::prepend(
    Field field, Defs::AdvType type, const void *buf, size_t size, bool clip)
{
    const uint8_t *data = static_cast<const uint8_t*>(buf);
    std::basic_string<uint8_t> *d;
    size_t max;
 
    switch (field)
    {
        default:
        case Field::DATA:
            d = &data_;
            max = extended_ ?
                MAX_EXT_DATA_PAYLOAD_SIZE : MAX_SCAN_DATA_PAYLOAD_SIZE;
            break;
        case Field::SCAN_DATA:
            HASSERT(!extended_);
            d = &scanData_;
            max = MAX_DATA_PAYLOAD_SIZE;
            break;
    }
 
    size_t space = std::min((size + 2), (max - d->size()));
    if (space < (size + 2) && clip == false)
    {
        // Data doesn't fit and clipping is not allowed.
        return -1;
    }
    d->insert(0, 1, space - 1);
    d->insert(1, 1, static_cast<uint8_t>(type));
    d->insert(2, data, space - 2);
    return space;
}
 
//
// Advertisement::append()
//
int Advertisement::append(
    Field field, Defs::AdvType type, const void *buf, size_t size, bool clip)
{
    const uint8_t *data = static_cast<const uint8_t*>(buf);
    std::basic_string<uint8_t> *d;
    size_t max;
 
    switch (field)
    {
        default:
        case Field::DATA:
            d = &data_;
            max = extended_ ?
                MAX_EXT_DATA_PAYLOAD_SIZE : MAX_SCAN_DATA_PAYLOAD_SIZE;
            break;
        case Field::SCAN_DATA:
            HASSERT(!extended_);
            d = &scanData_;
            max = MAX_DATA_PAYLOAD_SIZE;
            break;
    }
 
    size_t space = std::min((size + 2), (max - d->size()));
    if (space < (size + 2) && clip == false)
    {
        // Data doesn't fit and clipping is not allowed.
        return -1;
    }
    d->push_back(space - 1);
    d->push_back(static_cast<uint8_t>(type));
    d->append(data, space - 2);
    return space;
}
 
//
// Advertisement::update()
//
int Advertisement::update(Field field, Defs::AdvType type, const void *buf,
                          size_t size, unsigned instance, bool exact_size,
                          bool clip)
{
    const uint8_t *data = static_cast<const uint8_t*>(buf);
    std::basic_string<uint8_t> *d;
    size_t max;
 
    switch (field)
    {
        default:
        case Field::DATA:
            d = &data_;
            max = extended_ ?
                MAX_EXT_DATA_PAYLOAD_SIZE : MAX_SCAN_DATA_PAYLOAD_SIZE;
            break;
        case Field::SCAN_DATA:
            HASSERT(!extended_);
            d = &scanData_;
            max = MAX_DATA_PAYLOAD_SIZE;
            break;
    }
 
    uint8_t len;
    ssize_t pos = Defs::adv_find_data(*d, type, &len, instance);
    if (pos < 0)
    {
        // No matching advertising data found.
        return -1;
    }
    if (exact_size && len != size)
    {
        // Found the data, but it is the wrong size.
        return -1;
    }
    size_t space = std::min((size + 2), (max - d->size()) + (len + 2));
    if (space < size && clip == false)
    {
        // Data doesn't fit and clipping is not allowed.
        return -1;
    }
    d->at(pos) = space - 1;
    d->replace(pos + 2, len, data, space - 2);
    return space;
}
 
} // namespace ble