com.jsquant.util.FileCache.java Source code

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Here is the source code for com.jsquant.util.FileCache.java

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// Copyright 2010 Alexander Schonfeld
//
// 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.
package com.jsquant.util;

import java.io.File;
import java.io.IOException;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.google.common.collect.MapMaker;

public class FileCache {
    static private Log log = LogFactory.getLog(FileCache.class);

    private File cacheDir;
    private Map<String, String> memCache = new MapMaker().softValues().makeMap();

    public FileCache(String cacheDirPath) {
        cacheDir = new File(cacheDirPath);
        cacheDir.mkdirs();
        try {
            log.info("cacheDir=" + cacheDir.getCanonicalPath() + " exists=" + cacheDir.exists());
        } catch (IOException e) {
            log.error("cacheDir=" + cacheDir.getAbsolutePath() + " exists=" + cacheDir.exists());
        }
    }

    public void put(String key, String value) throws IOException {
        File f = new File(cacheDir, key);
        synchronized (this) {
            memCache.put(key, value);
            if (!f.exists()) {
                log.info("writing cachePath=" + f.getCanonicalPath());
                FileUtils.writeFile(f, value);
                //Files.write(value.getBytes(Charsets.UTF_8), f);
            }
        }
    }

    public String get(String key) throws IOException {
        String value = memCache.get(key);
        if (value == null) {
            File f = new File(cacheDir, key);
            if (f.exists()) {
                log.info("reading cachePath=" + f.getCanonicalPath());
                value = FileUtils.readFile(f);
                //value = Files.toString(f, Charsets.UTF_8);
                memCache.put(key, value);
            }
        }
        return value;
    }

}