text: /**
   * 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.
   */
  
  
  #include <hdfs.h>
  #include <strings.h>
  
  #include "fuse_dfs.h"
  #include "fuse_trash.h"
  #include "fuse_context_handle.h"
  
  
  const char *const TrashPrefixDir = "/user/root/.Trash";
  const char *const TrashDir = "/user/root/.Trash/Current";
  
  #define TRASH_RENAME_TRIES  100
  
  //
  // NOTE: this function is a c implementation of org.apache.hadoop.fs.Trash.moveToTrash(Path path).
  //
  
  int move_to_trash(const char *item, hdfsFS userFS) {
  
    // retrieve dfs specific data
    dfs_context *dfs = (dfs_context*)fuse_get_context()->private_data;
  
    // check params and the context var
    assert(item);
    assert(dfs);
    assert('/' == *item);
    assert(rindex(item,'/') >= 0);
  
  
    char fname[4096]; // or last element of the directory path
    char parent_directory[4096]; // the directory the fname resides in
  
    if (strlen(item) > sizeof(fname) - strlen(TrashDir)) {
      syslog(LOG_ERR, "ERROR: internal buffer too small to accomodate path of length %d %s:%d\n", (int)strlen(item), __FILE__, __LINE__);
      return -EIO;
    }
  
    // separate the file name and the parent directory of the item to be deleted
    {
      int length_of_parent_dir = rindex(item, '/') - item ;
      int length_of_fname = strlen(item) - length_of_parent_dir - 1; // the '/'
  
      // note - the below strncpys should be safe from overflow because of the check on item's string length above.
      strncpy(parent_directory, item, length_of_parent_dir);
      parent_directory[length_of_parent_dir ] = 0;
      strncpy(fname, item + length_of_parent_dir + 1, strlen(item));
      fname[length_of_fname + 1] = 0;
    }
  
    // create the target trash directory
    char trash_dir[4096];
    if (snprintf(trash_dir, sizeof(trash_dir), "%s%s",TrashDir,parent_directory) >= sizeof trash_dir) {
      syslog(LOG_ERR, "move_to_trash error target is not big enough to hold new name for %s %s:%d\n",item, __FILE__, __LINE__);
      return -EIO;
    }
  
    // create the target trash directory in trash (if needed)
    if ( hdfsExists(userFS, trash_dir)) {
      // make the directory to put it in in the Trash - NOTE
      // hdfsCreateDirectory also creates parents, so Current will be created if it does not exist.
      if (hdfsCreateDirectory(userFS, trash_dir)) {
        return -EIO;
      }
    }
  
    //
    // if the target path in Trash already exists, then append with
    // a number. Start from 1.
    //
    char target[4096];
    int j ;
    if ( snprintf(target, sizeof target,"%s/%s",trash_dir, fname) >= sizeof target) {
      syslog(LOG_ERR, "move_to_trash error target is not big enough to hold new name for %s %s:%d\n",item, __FILE__, __LINE__);
      return -EIO;
    }
  
    // NOTE: this loop differs from the java version by capping the #of tries
    for (j = 1; ! hdfsExists(userFS, target) && j < TRASH_RENAME_TRIES ; j++) {
      if (snprintf(target, sizeof target,"%s/%s.%d",trash_dir, fname, j) >= sizeof target) {
        syslog(LOG_ERR, "move_to_trash error target is not big enough to hold new name for %s %s:%d\n",item, __FILE__, __LINE__);
        return -EIO;
      }
    }
    if (hdfsRename(userFS, item, target)) {
      syslog(LOG_ERR,"ERROR: hdfs trying to rename %s to %s",item, target);
      return -EIO;
    }
    return 0;
  } 
  
  
  int hdfsDeleteWithTrash(hdfsFS userFS, const char *path, int useTrash) {
  
    // move the file to the trash if this is enabled and its not actually in the trash.
    if (useTrash && strncmp(path, TrashPrefixDir, strlen(TrashPrefixDir)) != 0) {
      int ret= move_to_trash(path, userFS);
      return ret;
    }
  
    if (hdfsDelete(userFS, path, 1)) {
      syslog(LOG_ERR,"ERROR: hdfs trying to delete the file %s",path);
      return -EIO;
    }
    return 0;
  
  }
  