| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| #include <log4cxx/logstring.h> |
| #include <log4cxx/helpers/cyclicbuffer.h> |
| #include <log4cxx/spi/loggingevent.h> |
| #include <log4cxx/helpers/exception.h> |
| #include <log4cxx/helpers/pool.h> |
| #include <log4cxx/helpers/stringhelper.h> |
| |
| using namespace log4cxx; |
| using namespace log4cxx::helpers; |
| using namespace log4cxx::spi; |
| |
| |
| /** |
| 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. |
| */ |
| CyclicBuffer::CyclicBuffer(int maxSize1) |
| : ea(maxSize1), first(0), last(0), numElems(0), maxSize(maxSize1) |
| { |
| if (maxSize1 < 1) |
| { |
| LogString msg(LOG4CXX_STR("The maxSize argument (")); |
| Pool p; |
| StringHelper::toString(maxSize1, p, msg); |
| msg.append(LOG4CXX_STR(") is not a positive integer.")); |
| throw IllegalArgumentException(msg); |
| } |
| } |
| |
| CyclicBuffer::~CyclicBuffer() |
| { |
| } |
| |
| /** |
| Add an <code>event</code> as the last event in the buffer. |
| */ |
| void CyclicBuffer::add(const spi::LoggingEventPtr& event) |
| { |
| ea[last] = event; |
| |
| if (++last == maxSize) |
| { |
| last = 0; |
| } |
| |
| if (numElems < maxSize) |
| { |
| numElems++; |
| } |
| else if (++first == maxSize) |
| { |
| first = 0; |
| } |
| } |
| |
| |
| /** |
| 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 CyclicBuffer::get(int i) |
| { |
| if (i < 0 || i >= numElems) |
| { |
| return 0; |
| } |
| |
| return ea[(first + i) % maxSize]; |
| } |
| |
| /** |
| Get the oldest (first) element in the buffer. The oldest element |
| is removed from the buffer. |
| */ |
| spi::LoggingEventPtr CyclicBuffer::get() |
| { |
| LoggingEventPtr r; |
| |
| if (numElems > 0) |
| { |
| numElems--; |
| r = ea[first]; |
| ea[first] = 0; |
| |
| if (++first == maxSize) |
| { |
| first = 0; |
| } |
| } |
| |
| return r; |
| } |
| |
| /** |
| Resize the cyclic buffer to <code>newSize</code>. |
| @throws IllegalArgumentException if <code>newSize</code> is negative. |
| */ |
| void CyclicBuffer::resize(int newSize) |
| { |
| if (newSize < 0) |
| { |
| LogString msg(LOG4CXX_STR("Negative array size [")); |
| Pool p; |
| StringHelper::toString(newSize, p, msg); |
| msg.append(LOG4CXX_STR("] not allowed.")); |
| throw IllegalArgumentException(msg); |
| } |
| |
| if (newSize == numElems) |
| { |
| return; // nothing to do |
| } |
| |
| LoggingEventList temp(newSize); |
| |
| int loopLen = newSize < numElems ? newSize : numElems; |
| int i; |
| |
| for (i = 0; i < loopLen; i++) |
| { |
| temp[i] = ea[first]; |
| ea[first] = 0; |
| |
| if (++first == numElems) |
| { |
| first = 0; |
| } |
| } |
| |
| ea = temp; |
| first = 0; |
| numElems = loopLen; |
| maxSize = newSize; |
| |
| if (loopLen == newSize) |
| { |
| last = 0; |
| } |
| else |
| { |
| last = loopLen; |
| } |
| } |