Add a Model to the download component.

components/download/internal/model_impl.cc

Index: components/download/internal/model_impl.cc
diff --git a/components/download/internal/model_impl.cc b/components/download/internal/model_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f061b5de07d4e6325450faf15124f2be323021d1
--- /dev/null
+++ b/components/download/internal/model_impl.cc
@@ -0,0 +1,130 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/download/internal/model_impl.h"
+
+#include "base/bind.h"
+#include "base/memory/ptr_util.h"
+#include "components/download/internal/entry.h"
+
+namespace download {
+
+ModelImpl::ModelImpl(Client* client, std::unique_ptr<Store> store)
+    : client_(client), store_(std::move(store)), weak_ptr_factory_(this) {
+  DCHECK(client_);
+  DCHECK(store_);
+}
+
+ModelImpl::~ModelImpl() = default;
+
+void ModelImpl::Initialize() {
+  DCHECK(!store_->IsInitialized());
+  store_->Initialize(base::Bind(&ModelImpl::OnInitializedFinished,
+                                weak_ptr_factory_.GetWeakPtr()));
+}
+
+void ModelImpl::Destroy() {
+  store_->Destroy(base::Bind(&ModelImpl::OnDestroyFinished,
+                             weak_ptr_factory_.GetWeakPtr()));
+}
+
+void ModelImpl::Add(const Entry& entry) {
+  DCHECK(store_->IsInitialized());
+  DCHECK(entries_.find(entry.guid) == entries_.end());
+
+  entries_.emplace(entry.guid, base::MakeUnique<Entry>(entry));
+
+  store_->Update(entry, base::Bind(&ModelImpl::OnAddFinished,
+                                   weak_ptr_factory_.GetWeakPtr(), entry.client,
+                                   entry.guid));
+}
+
+void ModelImpl::Update(const Entry& entry) {
+  DCHECK(store_->IsInitialized());
+  DCHECK(entries_.find(entry.guid) != entries_.end());
+
+  entries_[entry.guid] = base::MakeUnique<Entry>(entry);
+  store_->Update(entry, base::Bind(&ModelImpl::OnUpdateFinished,
+                                   weak_ptr_factory_.GetWeakPtr(), entry.client,
+                                   entry.guid));
+}
+
+void ModelImpl::Remove(const std::string& guid) {
+  DCHECK(store_->IsInitialized());
+
+  const auto& it = entries_.find(guid);
+  DCHECK(it != entries_.end());
+
+  DownloadClient client = it->second->client;
+  entries_.erase(it);
+  store_->Remove(guid,
+                 base::Bind(&ModelImpl::OnRemoveFinished,
+                            weak_ptr_factory_.GetWeakPtr(), client, guid));
+}
+
+Entry* ModelImpl::Get(const std::string& guid) {
+  const auto& it = entries_.find(guid);
+  return it == entries_.end() ? nullptr : it->second.get();
+}
+
+Model::EntryList ModelImpl::PeekEntries() {
+  EntryList entries;
+  for (const auto& it : entries_)
+    entries.push_back(it.second.get());
+
+  return entries;
+}
+
+void ModelImpl::OnInitializedFinished(
+    bool success,
+    std::unique_ptr<std::vector<Entry>> entries) {
+  if (!success) {
+    client_->OnInitialized(false);
+    return;
+  }
+
+  for (const auto& entry : *entries)
+    entries_.emplace(entry.guid, base::MakeUnique<Entry>(entry));
+
+  client_->OnInitialized(true);
+}
+
+void ModelImpl::OnDestroyFinished(bool success) {
+  store_.reset();
+  entries_.clear();
+  client_->OnDestroyed(success);
+}
+
+void ModelImpl::OnAddFinished(DownloadClient client,
+                              const std::string& guid,
+                              bool success) {
+  // Don't notify the Client if the entry was already removed.
+  if (entries_.find(guid) == entries_.end())
+    return;
+
+  // Remove the entry from the map if the add failed.
+  if (!success)
+    entries_.erase(guid);
+
+  client_->OnItemAdded(success, client, guid);
+}
+
+void ModelImpl::OnUpdateFinished(DownloadClient client,
+                                 const std::string& guid,
+                                 bool success) {
+  // Don't notify the Client if the entry was already removed.
+  if (entries_.find(guid) == entries_.end())
+    return;
+
+  client_->OnItemUpdated(success, client, guid);
+}
+
+void ModelImpl::OnRemoveFinished(DownloadClient client,
+                                 const std::string& guid,
+                                 bool success) {
+  DCHECK(entries_.find(guid) == entries_.end());
+  client_->OnItemRemoved(success, client, guid);
+}
+
+}  // namespace download