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// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_ASH_EXTENSIONS_FILE_MANAGER_FILE_STREAM_MD5_DIGESTER_H_
#define CHROME_BROWSER_ASH_EXTENSIONS_FILE_MANAGER_FILE_STREAM_MD5_DIGESTER_H_
#include <memory>
#include "base/functional/callback.h"
#include "base/hash/md5.h"
#include "base/memory/ref_counted.h"
#include "net/base/io_buffer.h"
namespace storage {
class FileStreamReader;
}
namespace drive {
namespace util {
// Computes the (base-16 encoded) MD5 digest of data extracted from a file
// stream.
class FileStreamMd5Digester
: public base::RefCountedThreadSafe<FileStreamMd5Digester> {
public:
using ResultCallback = base::OnceCallback<void(std::string)>;
FileStreamMd5Digester();
FileStreamMd5Digester(const FileStreamMd5Digester&) = delete;
FileStreamMd5Digester& operator=(const FileStreamMd5Digester&) = delete;
// Computes an MD5 digest of data read from the given |streamReader|. The
// work occurs asynchronously, and the resulting hash is returned via the
// |callback|. If an error occurs, |callback| is called with an empty string.
// Only one stream can be processed at a time by each digester. Do not call
// GetMd5Digest before the results of a previous call have been returned.
void GetMd5Digest(std::unique_ptr<storage::FileStreamReader> stream_reader,
ResultCallback callback);
private:
friend class base::RefCountedThreadSafe<FileStreamMd5Digester>;
~FileStreamMd5Digester();
// Kicks off a read of the next chunk from the stream.
void ReadNextChunk();
// Handles the incoming chunk of data from a stream read.
void OnChunkRead(int bytes_read);
// Maximum chunk size for read operations.
std::unique_ptr<storage::FileStreamReader> reader_;
scoped_refptr<net::IOBuffer> buffer_;
base::MD5Context md5_context_;
ResultCallback callback_;
};
} // namespace util
} // namespace drive
#endif // CHROME_BROWSER_ASH_EXTENSIONS_FILE_MANAGER_FILE_STREAM_MD5_DIGESTER_H_
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