blob: 90fbe59f41c2b039997d5e3bf422fd2d09db2afb [file] [log] [blame]
// Copyright 2018 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.
#pragma once
#ifndef __Fuchsia__
#error Fuchsia-only Header
#endif
#include <utility>
#include <blobfs/transaction-manager.h>
#include <blobfs/writeback-work.h>
#include <fbl/ref_ptr.h>
#include <lib/zx/vmo.h>
namespace blobfs {
// An object compatible with the WritebackWork interface, which contains a single blob reference.
// When the writeback is completed, this reference will go out of scope.
//
// This class helps WritebackWork avoid concurrent writes and reads to blobs: if a BlobWork
// is alive, the impacted Blob is still alive.
class BlobWork : public WritebackWork {
public:
BlobWork(TransactionManager* transaction_manager, fbl::RefPtr<Blob> vnode)
: WritebackWork(transaction_manager), vnode_(std::move(vnode)) {}
private:
fbl::RefPtr<Blob> vnode_;
};
// A wrapper around "Enqueue" for content which risks being larger
// than the writeback buffer.
//
// For content which is smaller than 3/4 the size of the writeback buffer: the
// content is enqueued to |work| without flushing.
//
// For content which is larger than 3/4 the size of the writeback buffer: flush
// the data by enqueueing it to the writeback thread in chunks until the
// remainder is small enough to comfortably fit within the writeback buffer.
zx_status_t EnqueuePaginated(std::unique_ptr<WritebackWork>* work,
TransactionManager* transaction_manager, Blob* vn,
const zx::vmo& vmo, uint64_t relative_block, uint64_t absolute_block,
uint64_t nblocks);
} // namespace blobfs