memory_segment.h

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// Copyright (C) 2012-2015 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
#ifndef MEMORY_SEGMENT_H
#define MEMORY_SEGMENT_H
 
#include <exceptions/exceptions.h>
 
#include <utility>
 
#include <stdlib.h>
 
namespace isc {
namespace util {
 
class MemorySegmentOpenError : public Exception {
public:
    MemorySegmentOpenError(const char* file, size_t line, const char* what) :
        isc::Exception(file, line, what) {}
};
 
class MemorySegmentGrown : public Exception {
public:
    MemorySegmentGrown(const char* file, size_t line, const char* what) :
        isc::Exception(file, line, what) {}
};
 
class MemorySegmentError : public Exception {
public:
    MemorySegmentError(const char* file, size_t line, const char* what) :
        isc::Exception(file, line, what) {}
};
 
class MemorySegment {
public:
    virtual ~MemorySegment() {}
 
    virtual void* allocate(size_t size) = 0;
 
    virtual void deallocate(void* ptr, size_t size) = 0;
 
    virtual bool allMemoryDeallocated() const = 0;
 
    bool setNamedAddress(const char* name, void* addr) {
        // This public method implements common validation.  The actual
        // work specific to the derived segment is delegated to the
        // corresponding protected method.
        validateName(name);
        return (setNamedAddressImpl(name, addr));
    }
 
    typedef std::pair<bool, void*> NamedAddressResult;
 
    NamedAddressResult getNamedAddress(const char* name) const {
        // This public method implements common validation.  The actual
        // work specific to the derived segment is delegated to the
        // corresponding protected method.
        validateName(name);
        return (getNamedAddressImpl(name));
    }
 
    bool clearNamedAddress(const char* name) {
        // This public method implements common validation.  The actual
        // work specific to the derived segment is delegated to the
        // corresponding protected method.
        validateName(name);
        return (clearNamedAddressImpl(name));
    }
 
private:
    static void validateName(const char* name) {
        if (!name) {
            isc_throw(InvalidParameter, "NULL is invalid for a name.");
        } else if (*name == '\0') {
            isc_throw(InvalidParameter, "Empty names are invalid.");
        } else if (*name == '_') {
            isc_throw(InvalidParameter,
                      "Names beginning with '_' are reserved for "
                      "internal use only.");
        }
    }
 
protected:
    virtual bool setNamedAddressImpl(const char* name, void* addr) = 0;
 
    virtual NamedAddressResult getNamedAddressImpl(const char* name) const = 0;
 
    virtual bool clearNamedAddressImpl(const char* name) = 0;
};
 
} // namespace util
} // namespace isc
 
#endif // MEMORY_SEGMENT_H
 
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