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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#include "string_sort_blob_writer.h"
#include <vespa/searchcommon/common/iblobconverter.h>
#include <vespa/vespalib/util/arrayref.h>
#include <algorithm>
#include <cstring>
namespace search::attribute {
StringSortBlobWriter::StringSortBlobWriter(void* serialize_to, size_t available, const BlobConverter* bc, bool asc) noexcept
: _best_size(),
_serialize_to(static_cast<unsigned char*>(serialize_to)),
_available(available),
_bc(bc),
_asc(asc)
{
}
StringSortBlobWriter::~StringSortBlobWriter() noexcept = default;
bool
StringSortBlobWriter::candidate(const char* val)
{
size_t size = std::strlen(val) + 1;
vespalib::ConstBufferRef buf(val, size);
if (_bc != nullptr) {
buf = _bc->convert(buf);
}
if (_best_size.has_value()) {
auto common_size = std::min(_best_size.value(), buf.size());
auto cmpres = std::memcmp(_serialize_to + 1, buf.data(), common_size);
if (_asc) {
if (cmpres < 0 || (cmpres == 0 && _best_size.value() < buf.size())) {
return true;
}
} else {
if (cmpres > 0 || (cmpres == 0 && _best_size.value() > buf.size())) {
return true;
}
}
}
if (_available < buf.size() + 1) {
return false;
}
_serialize_to[0] = has_value;
memcpy(_serialize_to + 1, buf.data(), buf.size());
_best_size = buf.size();
return true;
}
long
StringSortBlobWriter::write()
{
if (_best_size.has_value()) {
if (!_asc) {
vespalib::ArrayRef<unsigned char> buf(_serialize_to + 1, _best_size.value());
for (auto& c : buf) {
c = 0xff - c;
}
}
return 1 + _best_size.value();
} else {
if (_available < 1) {
return -1;
}
_serialize_to[0] = missing_value;
return 1;
}
}
}
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