92 lines
2.5 KiB
C++
92 lines
2.5 KiB
C++
/*
|
|
* Copyright 2003,2004 The Apache Software Foundation.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#ifndef _LOG4CXX_HELPERS_CYCLICBUFFER_H
|
|
#define _LOG4CXX_HELPERS_CYCLICBUFFER_H
|
|
|
|
#include <log4cxx/spi/loggingevent.h>
|
|
#include <vector>
|
|
|
|
namespace log4cxx
|
|
{
|
|
namespace helpers
|
|
{
|
|
/**
|
|
CyclicBuffer is used by other appenders to hold {@link spi::LoggingEvent
|
|
LoggingEvents} for immediate or differed display.
|
|
<p>This buffer gives read access to any element in the buffer not
|
|
just the first or last element.
|
|
*/
|
|
class LOG4CXX_EXPORT CyclicBuffer
|
|
{
|
|
std::vector<spi::LoggingEventPtr> ea;
|
|
int first;
|
|
int last;
|
|
int numElems;
|
|
int maxSize;
|
|
|
|
public:
|
|
/**
|
|
Instantiate a new CyclicBuffer of at most <code>maxSize</code>
|
|
events.
|
|
The <code>maxSize</code> argument must a positive integer.
|
|
@param maxSize The maximum number of elements in the buffer.
|
|
@throws IllegalArgumentException if <code>maxSize</code>
|
|
is negative.
|
|
*/
|
|
CyclicBuffer(int maxSize);
|
|
~CyclicBuffer();
|
|
|
|
/**
|
|
Add an <code>event</code> as the last event in the buffer.
|
|
*/
|
|
void add(const spi::LoggingEventPtr& event);
|
|
|
|
/**
|
|
Get the <i>i</i>th oldest event currently in the buffer. If
|
|
<em>i</em> is outside the range 0 to the number of elements
|
|
currently in the buffer, then <code>null</code> is returned.
|
|
*/
|
|
spi::LoggingEventPtr get(int i);
|
|
|
|
int getMaxSize() const
|
|
{ return maxSize; }
|
|
|
|
/**
|
|
Get the oldest (first) element in the buffer. The oldest element
|
|
is removed from the buffer.
|
|
*/
|
|
spi::LoggingEventPtr get();
|
|
|
|
/**
|
|
Get the number of elements in the buffer. This number is
|
|
guaranteed to be in the range 0 to <code>maxSize</code>
|
|
(inclusive).
|
|
*/
|
|
int length() const
|
|
{ return numElems; }
|
|
|
|
/**
|
|
Resize the cyclic buffer to <code>newSize</code>.
|
|
@throws IllegalArgumentException if <code>newSize</code> is negative.
|
|
*/
|
|
void resize(int newSize);
|
|
}; // class CyclicBuffer
|
|
} //namespace helpers
|
|
}; //namespace log4cxx
|
|
|
|
#endif //_LOG4CXX_HELPERS_CYCLICBUFFER_H
|