зеркало из https://github.com/mozilla/gecko-dev.git
65 строки
2.3 KiB
C++
65 строки
2.3 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef AutoObjectMapper_h
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#define AutoObjectMapper_h
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#include <string>
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#include "mozilla/Attributes.h"
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#include "PlatformMacros.h"
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// A (nearly-) RAII class that maps an object in and then unmaps it on
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// destruction. This base class version uses the "normal" POSIX
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// functions: open, fstat, close, mmap, munmap.
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class MOZ_STACK_CLASS AutoObjectMapperPOSIX {
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public:
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// The constructor does not attempt to map the file, because that
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// might fail. Instead, once the object has been constructed,
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// call Map() to attempt the mapping. There is no corresponding
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// Unmap() since the unmapping is done in the destructor. Failure
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// messages are sent to |aLog|.
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explicit AutoObjectMapperPOSIX(void (*aLog)(const char*));
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// Unmap the file on destruction of this object.
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~AutoObjectMapperPOSIX();
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// Map |fileName| into the address space and return the mapping
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// extents. If the file is zero sized this will fail. The file is
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// mapped read-only and private. Returns true iff the mapping
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// succeeded, in which case *start and *length hold its extent.
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// Once a call to Map succeeds, all subsequent calls to it will
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// fail.
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bool Map(/*OUT*/ void** start, /*OUT*/ size_t* length, std::string fileName);
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protected:
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// If we are currently holding a mapped object, these record the
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// mapped address range.
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void* mImage;
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size_t mSize;
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// A logging sink, for complaining about mapping failures.
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void (*mLog)(const char*);
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private:
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// Are we currently holding a mapped object? This is private to
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// the base class. Derived classes need to have their own way to
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// track whether they are holding a mapped object.
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bool mIsMapped;
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// Disable copying and assignment.
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AutoObjectMapperPOSIX(const AutoObjectMapperPOSIX&);
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AutoObjectMapperPOSIX& operator=(const AutoObjectMapperPOSIX&);
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// Disable heap allocation of this class.
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void* operator new(size_t);
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void* operator new[](size_t);
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void operator delete(void*);
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void operator delete[](void*);
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};
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#endif // AutoObjectMapper_h
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