/*

 * 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.

 */

#if !defined(_LOG4CXX_ROLLING_FIXED_WINDOW_ROLLING_POLICY_H)

#define _LOG4CXX_ROLLING_FIXED_WINDOW_ROLLING_POLICY_H

#include <log4cxx/rolling/rollingpolicybase.h>

namespace LOG4CXX_NS

{

namespace helpers

{

class Pool;

}

namespace rolling

{

/**

 * When rolling over, <code>FixedWindowRollingPolicy</code> renames files

 * according to a fixed window algorithm as described below.

 *

 * <p>The <b>ActiveFileName</b> property, which is required, represents the name

 * of the file where current logging output will be written.

 * The <b>FileNamePattern</b>  option represents the file name pattern for the

 * archived (rolled over) log files. If present, the <b>FileNamePattern</b>

 * option must include an integer token, that is the string "%i" somwhere

 * within the pattern.

 *

 * <p>Let <em>max</em> and <em>min</em> represent the values of respectively

 * the <b>MaxIndex</b> and <b>MinIndex</b> options. Let "foo.log" be the value

 * of the <b>ActiveFile</b> option and "foo.%i.log" the value of

 * <b>FileNamePattern</b>. Then, when rolling over, the file

 * <code>foo.<em>max</em>.log</code> will be deleted, the file

 * <code>foo.<em>max-1</em>.log</code> will be renamed as

 * <code>foo.<em>max</em>.log</code>, the file <code>foo.<em>max-2</em>.log</code>

 * renamed as <code>foo.<em>max-1</em>.log</code>, and so on,

 * the file <code>foo.<em>min+1</em>.log</code> renamed as

 * <code>foo.<em>min+2</em>.log</code>. Lastly, the active file <code>foo.log</code>

 * will be renamed as <code>foo.<em>min</em>.log</code> and a new active file name

 * <code>foo.log</code> will be created.

 *

 * <p>Given that this rollover algorithm requires as many file renaming

 * operations as the window size, large window sizes are discouraged. The

 * current implementation will automatically reduce the window size to 12 when

 * larger values are specified by the user.

 *

 *

 *

 *

 * */

class LOG4CXX_EXPORT FixedWindowRollingPolicy : public RollingPolicyBase

{

    DECLARE_LOG4CXX_OBJECT(FixedWindowRollingPolicy)

    BEGIN_LOG4CXX_CAST_MAP()

    LOG4CXX_CAST_ENTRY(FixedWindowRollingPolicy)

    LOG4CXX_CAST_ENTRY_CHAIN(RollingPolicyBase)

    END_LOG4CXX_CAST_MAP()

    struct FixedWindowRollingPolicyPrivate;

    /**

     * It's almost always a bad idea to have a large window size, say over 12.

     */

    enum { MAX_WINDOW_SIZE = 12 };

    bool purge(int purgeStart, int maxIndex, LOG4CXX_NS::helpers::Pool& p) const;

  public:

    FixedWindowRollingPolicy();

    ~FixedWindowRollingPolicy();

    /**

    \copybrief RollingPolicyBase::activateOptions()

    Logs a warning if an option is not valid.

    \sa RollingPolicyBase::activateOptions()

    */

    void activateOptions(helpers::Pool& p) override;

    /**

    \copybrief RollingPolicyBase::setOption()

    Supported options | Supported values | Default value

    :-------------- | :----------------: | :---------------:

    MinIndex | 1-12 | 1

    MaxIndex | 1-12 | 7

    ThrowIOExceptionOnForkFailure | True,False | True

    \sa RollingPolicyBase::setOption()

    */

    void setOption(const LogString& option, const LogString& value) override;

    void rollover();

    int getMaxIndex() const;

    int getMinIndex() const;

    void setMaxIndex(int newVal);

    void setMinIndex(int newVal);

    /**

     * {@inheritDoc}

     */

    RolloverDescriptionPtr initialize(

      const   LogString&              currentActiveFile,

      const   bool                    append,

      helpers::Pool& pool) override;

    /**

     * {@inheritDoc}

     */

    RolloverDescriptionPtr rollover(

      const   LogString&              currentActiveFile,

      const   bool                    append,

      helpers::Pool& pool) override;

  protected:

    /**

     * A map from "i" and "index" to a integer conversion formatter.

     *

     * \sa IntegerPatternConverter

     */

    LOG4CXX_NS::pattern::PatternMap getFormatSpecifiers() const override;

};

LOG4CXX_PTR_DEF(FixedWindowRollingPolicy);

}

}

#endif