resourceholder.cc

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#include "ion/gfx/resourceholder.h"

#include <algorithm>

namespace ion {
namespace gfx {

ResourceHolder::ResourceHolder()
    : resources_(*this),
      resource_count_(0),
      fields_(*this),
      label_(kLabelChanged, std::string(), this) {}

ResourceHolder::~ResourceHolder() {
  for (const auto& group : resources_)
    for (const auto& entry : group)
      entry.second->holder_ = nullptr;

  for (const auto& group : resources_)
    for (const auto& entry : group)
      entry.second->OnDestroyed();
}

void ResourceHolder::SetResource(size_t index, ResourceKey key,
                                 ResourceBase* resource) const {
  if (resource) {
    DCHECK_EQ(resource->GetKey(), key);
    DCHECK(resource->holder_ == nullptr || resource->holder_ == this);
    const size_t num_fields = fields_.size();
    for (size_t i = 0; i < num_fields; ++i)
      resource->OnChanged(fields_[i]->GetBit());
  }

  ResourceBase* old_resource = nullptr;
  base::WriteLock write_lock(&lock_);
  base::WriteGuard guard(&write_lock);

  if (index >= resources_.size()) {
    if (resource) {
      resources_.resize(index + 1U, ResourceGroup(*this));
    } else {
      return;
    }
  }

  auto found = resources_[index].find(key);
  old_resource = (found == resources_[index].end() ? nullptr : found->second);

  if (resource) {
    resource->holder_ = this;
    if (old_resource) {
      old_resource->holder_ = nullptr;
      found->second = resource;
    } else {
      resources_[index].emplace(key, resource);
    }
  } else if (old_resource) {
    old_resource->holder_ = nullptr;
    resources_[index].erase(found);
    if (index + 1 == resources_.size()) {
      auto first_nonempty = std::find_if(resources_.rbegin(), resources_.rend(),
          [](const ResourceGroup& group) { return !group.empty(); });
      resources_.resize(std::distance(first_nonempty, resources_.rend()),
                        ResourceGroup(*this));
    }
  }

  if (resource && !old_resource)
    ++resource_count_;
  else if (!resource && old_resource)
    --resource_count_;

  DCHECK(resources_.empty() || !resources_.back().empty());
}

ResourceBase* ResourceHolder::GetResource(size_t index, ResourceKey key) const {
  const size_t count = resources_.size();
  if (index >= count) return nullptr;
  auto found = resources_[index].find(key);
  return found == resources_[index].end() ? nullptr : found->second;
}

ResourceHolder::FieldBase::~FieldBase() {}

}  // namespace gfx
}  // namespace ion