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// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "components/zucchini/encoded_view.h"
#include <algorithm>
#include <utility>
#include "base/check_op.h"
namespace zucchini {
EncodedView::EncodedView(const ImageIndex& image_index)
: image_index_(image_index), pool_infos_(image_index.PoolCount()) {}
EncodedView::~EncodedView() = default;
EncodedView::value_type EncodedView::Projection(offset_t location) const {
DCHECK_LT(location, image_index_->size());
// Find out what lies at |location|.
TypeTag type = image_index_->LookupType(location);
// |location| points into raw data.
if (type == kNoTypeTag) {
// The projection is the identity function on raw content.
return image_index_->GetRawValue(location);
}
// |location| points into a Reference.
const ReferenceSet& ref_set = image_index_->refs(type);
Reference ref = ref_set.at(location);
DCHECK_GE(location, ref.location);
DCHECK_LT(location, ref.location + ref_set.width());
// |location| is not the first byte of the reference.
if (location != ref.location) {
// Trailing bytes of a reference are all projected to the same value.
return kReferencePaddingProjection;
}
PoolTag pool_tag = ref_set.pool_tag();
const auto& target_pool = ref_set.target_pool();
// Targets with an associated Label will use its Label index in projection.
DCHECK_EQ(target_pool.size(), pool_infos_[pool_tag.value()].labels.size());
uint32_t label = pool_infos_[pool_tag.value()]
.labels[target_pool.KeyForOffset(ref.target)];
// Projection is done on (|target|, |type|), shifted by
// kBaseReferenceProjection to avoid collisions with raw content.
value_type projection = label;
projection *= image_index_->TypeCount();
projection += type.value();
return projection + kBaseReferenceProjection;
}
size_t EncodedView::Cardinality() const {
size_t max_width = 0;
for (const auto& pool_info : pool_infos_)
max_width = std::max(max_width, pool_info.bound);
return max_width * image_index_->TypeCount() + kBaseReferenceProjection;
}
void EncodedView::SetLabels(PoolTag pool,
std::vector<uint32_t>&& labels,
size_t bound) {
DCHECK_EQ(labels.size(), image_index_->pool(pool).size());
DCHECK(labels.empty() || *max_element(labels.begin(), labels.end()) < bound);
pool_infos_[pool.value()].labels = std::move(labels);
pool_infos_[pool.value()].bound = bound;
}
EncodedView::PoolInfo::PoolInfo() = default;
EncodedView::PoolInfo::PoolInfo(PoolInfo&&) = default;
EncodedView::PoolInfo::~PoolInfo() = default;
} // namespace zucchini
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