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// Copyright 2020 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.
#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_NATIVE_IO_NATIVE_IO_FILE_SYNC_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_NATIVE_IO_NATIVE_IO_FILE_SYNC_H_
#include <stdint.h>
#include "base/files/file.h"
#include "third_party/blink/public/mojom/native_io/native_io.mojom-blink.h"
#include "third_party/blink/renderer/core/execution_context/execution_context_lifecycle_observer.h"
#include "third_party/blink/renderer/core/typed_arrays/array_buffer_view_helpers.h"
#include "third_party/blink/renderer/core/typed_arrays/dom_array_buffer_view.h"
#include "third_party/blink/renderer/modules/native_io/native_io_capacity_tracker.h"
#include "third_party/blink/renderer/platform/bindings/script_wrappable.h"
#include "third_party/blink/renderer/platform/heap/handle.h"
#include "third_party/blink/renderer/platform/mojo/heap_mojo_remote.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
#include "third_party/blink/renderer/platform/wtf/vector.h"
namespace blink {
class ExceptionState;
class ExecutionContext;
class NativeIOFileSync final : public ScriptWrappable {
DEFINE_WRAPPERTYPEINFO();
public:
NativeIOFileSync(base::File backing_file,
int64_t backing_file_size,
HeapMojoRemote<mojom::blink::NativeIOFileHost> backend_file,
NativeIOCapacityTracker* capacity_tracker,
ExecutionContext*);
NativeIOFileSync(const NativeIOFileSync&) = delete;
NativeIOFileSync& operator=(const NativeIOFileSync&) = delete;
// Needed because of the mojo::Remote<mojom::blink::NativeIOFile>.
~NativeIOFileSync() override;
void close();
uint64_t getLength(ExceptionState&);
void setLength(uint64_t length, ExceptionState&);
uint64_t read(MaybeShared<DOMArrayBufferView> buffer,
uint64_t file_offset,
ExceptionState&);
uint64_t write(MaybeShared<DOMArrayBufferView> buffer,
uint64_t file_offset,
ExceptionState&);
void flush(ExceptionState&);
// GarbageCollected
void Trace(Visitor* visitor) const override;
private:
// Called when the mojo backend disconnects.
void OnBackendDisconnect();
// The file on disk backing this NativeIOFile.
base::File backing_file_;
// The length of the file used in capacity accounting. This should equal the
// current file's length, unless that length cannot be reliably determined
// using base::GetLength(). In the latter case, the file will be force-closed
// to prevent further corruption.
//
// Operations that increase the file's length must first allocate capacity,
// update `file_length_` to reflect the increased length, and then perform the
// I/O. If the I/O fails, GetLength() must be used to obtain the actual file
// length. The result must first be compared against `file_length_` to account
// for the unused capacity, then used to update `file_length_`.
//
// Operations that decrease the file's length must first perform the I/O, and
// then update `file_length_` and return freed up capacity. I/O failures can
// be handled using the same logic as above.
int64_t file_length_ = 0;
// Mojo pipe that holds the renderer's lock on the file.
HeapMojoRemote<mojom::blink::NativeIOFileHost> backend_file_;
// Manages the capacity allocation for this file manager's execution context.
Member<NativeIOCapacityTracker> capacity_tracker_;
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_MODULES_NATIVE_IO_NATIVE_IO_FILE_SYNC_H_
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