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通过链接替换文件重复项。

概述

面向脚本的扫描目录中相等文件的工具，将最新文件通过硬链接或软链接替换旧文件。硬链接允许在不影响链接实例的情况下删除父文件，但文件或链接实例的修改将对两者产生影响。通过删除副本来减小存储大小的有用工具。

用法

定义缓存和服务的存储。

      $scanStorage = new UnixScanStorage([__DIR_PATH_FOR_SCAN__]);
      $cacheStorage = new FileIndexStorage(__DIR_PATH_FOR_CACHE_STORAGE__);
      $replacementService = new ReplacementService($scanStorage, $cacheStorage);

扫描目录以构建索引。

      $replacementService->scan(function (Record $file)
      {
         // Hash consists from concatenation file size + first byte + last byte.
         $fp = fopen($file->path, 'r');
         fseek($fp, 10);
         $firstChar = fgetc($fp);
         fseek($fp, -10, SEEK_END);
         $lastChar = fgetc($fp);
         $fileSize = filesize($file->path);
         $hash = $fileSize . ord($firstChar) . ord($lastChar);
         return $hash;
      }, function (string $hashA = null, string $hashB = null)
      {
         // Compare hashes.
         $result = strnatcmp($hashA, $hashB);
         return $result;
      }, function (Record $file)
      {
         // Filter only txt files for scan.
         $ext = pathinfo($file->path, PATHINFO_EXTENSION);
         return in_array($ext, ['txt']);
      });

扫描后查找重复项并通过硬链接进行替换。

      $duplicatesGen = $replacementService->findDuplicates();
      while (($records = $duplicatesGen->current()))
      {
         $replacementService->replaceDuplicatesHard($records);
         $duplicatesGen->next();
      }

计算重复项的字节大小。

      $duplicatesGen = $replacementService->findDuplicates();
      $duplicateSize = 0;
      $linkBlock = 1;
      while (($records = $duplicatesGen->current()))
      {
         /* @var $record Record */
         $record = reset($records);
         $stat = stat($record->path);
         if (0 < $stat['blocks'])
         {
            $duplicateSize += ($stat['blocks'] * 512) - $stat['blksize'];
         }
         $duplicatesGen->next();
      }