ScanCache.h

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/*
 * File:   ScanCache.h
 *
 * Copyright 2013 Heinrich Schuchardt <xypron.glpk@gmx.de>
 *
 * 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 SCANCACHE_H
#define SCANCACHE_H

#include <pthread.h>
#include <set>
#include <sys/stat.h>
#include <sys/types.h>
#include "Environment.h"

class Environment;

struct ScanResult {
public:
    dev_t dev;
    ino_t ino; /* inode number */
    time_t mtime; /* time of last modification */
    unsigned int response; /* FAN_ALLOW or FAN_DENY */
    time_t age;
    ScanResult *left;
    ScanResult *right;
};

struct ScanResultComperator {
public:

    bool operator() (ScanResult *value1, ScanResult *value2) const {
        if (value1->dev < value2->dev) {
            return 1;
        } else if (value1->dev > value2->dev) {
            return 0;
        } else if (value1->ino < value2->ino) {
            return 1;
        } else {
            return 0;
        };
    }
};


class ScanCache {
public:
    static const unsigned int CACHE_MISS = 0xfffd;
    ScanCache(Environment *);
    void add(const struct stat *, const unsigned int);
    void clear();
    int get(const struct stat *);
    void remove(const struct stat *);
    virtual ~ScanCache();
private:
    std::set<ScanResult *, ScanResultComperator> *s;
    pthread_mutex_t mutex;
    Environment *e;
    unsigned long long misses;
    unsigned long long hits;
    ScanResult root;

    // Do not allow copying.
    ScanCache(const ScanCache&);
};

#endif  /* SCANCACHE_H */