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package com.litongjava.tio.http.common;

import java.util.HashMap;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.litongjava.tio.utils.HashUtils;
import com.litongjava.tio.utils.hutool.StrUtil;
import com.litongjava.tio.utils.lock.LockUtils;

/**
 * 本类主要用于可枚举的String，不要滥用
 * @author tanyaowu
 */
public class StrCache {
  private static Logger log = LoggerFactory.getLogger(StrCache.class);
  private static final int MAX_SIZE = 5000;
  /**
   * key: byte[]对应的hashcode
   * value: byte[]对应的字符串
   */
  private static final Map BYTES_STRING_MAP = new HashMap<>(100);
  /**
   * key : 原字符串
   * value: 小写后的字符串
   */
  private static final Map INIT_LOWERCASE_MAP = new HashMap<>(100);

  /**
   * 
   */
  public StrCache() {

  }

  /**
   * 
   * @param allbs
   * @param start
   * @param len
   * @return
   */
  public static String get(byte[] allbs, int start, int len) {
    int hashcode = HashUtils.hash31(allbs, start, len);
    String str = BYTES_STRING_MAP.get(hashcode);
    if (str == null) {
      if (BYTES_STRING_MAP.size() > MAX_SIZE) {
        return new String(allbs, start, len);
      }

      try {
        LockUtils.runWriteOrWaitRead("StrCache:getBytes" + hashcode, BYTES_STRING_MAP, () -> {
          String str2 = BYTES_STRING_MAP.get(hashcode);
          if (str2 == null) {
            str2 = new String(allbs, start, len);
            BYTES_STRING_MAP.put(hashcode, str2);
          }
        });
      } catch (Exception e) {
        log.error(e.toString(), e);
      }

      str = BYTES_STRING_MAP.get(hashcode);
    }
    return str;
  }

  /**
   * 
   * @param initStr
   * @return
   */
  public static String getLowercase(String initStr) {
    if (StrUtil.isBlank(initStr)) {
      return initStr;
    }
    int hashcode = initStr.hashCode();
    String str = INIT_LOWERCASE_MAP.get(hashcode);
    if (str == null) {
      if (INIT_LOWERCASE_MAP.size() > MAX_SIZE) {
        return initStr.toLowerCase();
      }

      try {
        LockUtils.runWriteOrWaitRead("StrCache:getLowercase" + hashcode, INIT_LOWERCASE_MAP, () -> {
          String str2 = INIT_LOWERCASE_MAP.get(hashcode);
          if (str2 == null) {
            str2 = initStr.toLowerCase();
            INIT_LOWERCASE_MAP.put(hashcode, str2);
          }
        });
      } catch (Exception e) {
        log.error(e.toString(), e);
      }

      str = INIT_LOWERCASE_MAP.get(hashcode);
    }
    return str;

  }

}