blob: b392a36daf47d7a3f75b57a07c60ddab912addec [file] [log] [blame]
// Copyright 2017 The Fuchsia 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 <memory>
#include <vector>
#include <fuchsia/ledger/cloud/cpp/fidl.h>
#include <lib/backoff/backoff.h>
#include <lib/callback/scoped_task_runner.h>
#include <lib/fit/function.h>
#include <lib/fxl/memory/weak_ptr.h>
#include "peridot/bin/ledger/cloud_sync/impl/batch_upload.h"
#include "peridot/bin/ledger/cloud_sync/public/sync_state_watcher.h"
#include "peridot/bin/ledger/encryption/public/encryption_service.h"
#include "peridot/bin/ledger/storage/public/commit.h"
#include "peridot/bin/ledger/storage/public/commit_watcher.h"
#include "peridot/bin/ledger/storage/public/types.h"
namespace cloud_sync {
// Internal state of PageUpload.
// This ensures there is only one stream of work at any given time, and one in
// "backlog".
enum PageUploadState {
// No upload attempt is in progress.
// An upload attempt is in progress and after completing we should become
// idle.
// An upload attempt is in progress and after completing we should start a new
// one.
// PageUpload handles all the upload operations for a page.
class PageUpload : public storage::CommitWatcher {
// Delegate ensuring coordination between PageUpload and the class that owns
// it.
class Delegate {
// Reports that the upload state changed.
virtual void SetUploadState(UploadSyncState sync_state) = 0;
// Returns true if no download is in progress.
virtual bool IsDownloadIdle() = 0;
PageUpload(callback::ScopedTaskRunner* task_runner,
storage::PageStorage* storage,
encryption::EncryptionService* encryption_service,
cloud_provider::PageCloudPtr* page_cloud, Delegate* delegate,
std::unique_ptr<backoff::Backoff> backoff);
~PageUpload() override;
// Starts or restarts the upload process.
// The first time this method is called this sets up the storage watcher. It
// might be called again in the future to restart the upload after it's
// stopped due to a remote download in progress.
void StartOrRestartUpload();
// Returns true if PageUpload is idle.
bool IsIdle();
// storage::CommitWatcher:
void OnNewCommits(
const std::vector<std::unique_ptr<const storage::Commit>>& /*commits*/,
storage::ChangeSource source) override;
void UploadUnsyncedCommits();
void VerifyUnsyncedCommits(
std::vector<std::unique_ptr<const storage::Commit>> commits);
void HandleUnsyncedCommits(
std::vector<std::unique_ptr<const storage::Commit>> commits);
// Sets the internal state.
void SetState(UploadSyncState new_state);
void HandleError(const char error_description[]);
void RetryWithBackoff(fit::closure callable);
// These methods manage the internal state machine.
// Registers a signal to trigger an upload attempt, and triggers it if
// appropriate, that is, if we don't have an upload process already in
// progress.
void NextState();
// Registers completion of an upload attempt, for example due to an error, or
// because it completed. This will trigger another upload attempt if
// appropriate, that is, if a signal to trigger an upload attempt was
// delivered while an earlier upload attempt was in progress.
void PreviousState();
// Owned by whoever owns this class.
callback::ScopedTaskRunner* const task_runner_;
storage::PageStorage* const storage_;
encryption::EncryptionService* const encryption_service_;
cloud_provider::PageCloudPtr* const page_cloud_;
Delegate* const delegate_;
const std::string log_prefix_;
std::unique_ptr<backoff::Backoff> backoff_;
// Work queue:
// Current batch of local commits being uploaded.
std::unique_ptr<BatchUpload> batch_upload_;
// Internal state.
PageUploadState internal_state_ = PageUploadState::NO_COMMIT;
// External state.
UploadSyncState external_state_ = UPLOAD_NOT_STARTED;
// Must be the last member.
fxl::WeakPtrFactory<PageUpload> weak_ptr_factory_;
} // namespace cloud_sync