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68d0cd2441
input_stream's constructor had an unused buf_size parameter. Such a parameter is not needed - whenever the input_stream needs more data it calls the underlying data_source's get(), and thus only the data_source gets to decide the buffer size. Moreover, in some implementations, this read buffer size will be different each time - e.g., in a chunk-compressed file, the uncompressed chunk's size will be different each time. Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
72 lines
2.3 KiB
C++
72 lines
2.3 KiB
C++
/*
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* This file is open source software, licensed to you under the terms
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* of the Apache License, Version 2.0 (the "License"). See the NOTICE file
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* distributed with this work for additional information regarding copyright
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* ownership. You may not use this file except in compliance with the License.
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*
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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/*
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* Copyright (C) 2015 Cloudius Systems, Ltd.
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*/
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#pragma once
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// File <-> streams adapters
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//
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// Seastar files are block-based due to the reliance on DMA - you must read
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// on sector boundaries. The adapters in this file provide a byte stream
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// interface to files, while retaining the zero-copy characteristics of
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// seastar files.
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#include "file.hh"
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#include "reactor.hh"
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// FIXME: caching support
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class file_data_source_impl : public data_source_impl {
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file _file;
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size_t _buffer_size;
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uint64_t _pos = 0;
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public:
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file_data_source_impl(file&& f, size_t buffer_size)
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: _file(std::move(f)), _buffer_size(buffer_size) {}
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virtual future<temporary_buffer<char>> get() override;
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file& fd() { return _file; }
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void seek(uint64_t pos) { _pos = pos; }
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};
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class file_data_source : public data_source {
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file_data_source_impl* impl() {
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return static_cast<file_data_source_impl*>(data_source::impl());
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}
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public:
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file_data_source(file&& f, size_t buffer_size = 8192)
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: data_source(std::make_unique<file_data_source_impl>(std::move(f), buffer_size)) {}
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file& fd() { return impl()->fd(); }
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void seek(uint64_t pos) { impl()->seek(pos); }
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};
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// Extends input_stream with file-specific operations, such as seeking.
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class file_input_stream : public input_stream<char> {
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file_data_source* fd() {
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return static_cast<file_data_source*>(input_stream::fd());
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}
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public:
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explicit file_input_stream(file&& f, size_t buffer_size = 8192)
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: input_stream(file_data_source(std::move(f), buffer_size)) {}
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void seek(uint64_t pos) {
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reset();
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fd()->seek(pos);
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}
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};
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