74 lines
2.2 KiB
C
74 lines
2.2 KiB
C
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// Copyright 2017 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BASE_FILE_DESCRIPTOR_STORE_H_
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#define BASE_FILE_DESCRIPTOR_STORE_H_
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#include <map>
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#include <string>
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#include "base/files/memory_mapped_file.h"
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#include "base/files/scoped_file.h"
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#include "base/macros.h"
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namespace base {
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// The file descriptor store is used to associate file descriptors with keys
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// that must be unique.
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// It is used to share file descriptors from a process to its child.
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class BASE_EXPORT FileDescriptorStore {
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public:
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struct Descriptor {
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Descriptor(const std::string& key, base::ScopedFD fd);
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Descriptor(const std::string& key,
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base::ScopedFD fd,
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base::MemoryMappedFile::Region region);
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Descriptor(Descriptor&& other);
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~Descriptor();
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Descriptor& operator=(Descriptor&& other) = default;
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// Globally unique key.
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std::string key;
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// Actual FD.
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base::ScopedFD fd;
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// Optional region, defaults to kWholeFile.
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base::MemoryMappedFile::Region region;
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};
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using Mapping = std::map<std::string, Descriptor>;
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// Returns the singleton instance of FileDescriptorStore.
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static FileDescriptorStore& GetInstance();
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// Gets a descriptor given a key and also populates |region|.
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// It is a fatal error if the key is not known.
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base::ScopedFD TakeFD(const std::string& key,
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base::MemoryMappedFile::Region* region);
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// Gets a descriptor given a key. Returns an empty ScopedFD on error.
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base::ScopedFD MaybeTakeFD(const std::string& key,
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base::MemoryMappedFile::Region* region);
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// Sets the descriptor for the given |key|. This sets the region associated
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// with |key| to kWholeFile.
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void Set(const std::string& key, base::ScopedFD fd);
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// Sets the descriptor and |region| for the given |key|.
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void Set(const std::string& key,
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base::ScopedFD fd,
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base::MemoryMappedFile::Region region);
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private:
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FileDescriptorStore();
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~FileDescriptorStore();
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Mapping descriptors_;
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DISALLOW_COPY_AND_ASSIGN(FileDescriptorStore);
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};
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} // namespace base
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#endif // BASE_FILE_DESCRIPTOR_STORE_H_
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