text: /*
   * dblist.c -- directory block list functions
   *
   * Copyright 1997 by Theodore Ts'o
   *
   * %Begin-Header%
   * This file may be redistributed under the terms of the GNU Library
   * General Public License, version 2.
   * %End-Header%
   */
  
  #include "config.h"
  
  #include <stdio.h>
  #if HAVE_UNISTD_H
  #include <unistd.h>
  #endif
  #include <string.h>
  #include <time.h>
  
  #include "ext2_fs.h"
  #include "ext2fsP.h"
  
  static EXT2_QSORT_TYPE dir_block_cmp(const void* a, const void* b);
  static EXT2_QSORT_TYPE dir_block_cmp2(const void* a, const void* b);
  static EXT2_QSORT_TYPE (*sortfunc32)(const void* a, const void* b);
  
  /*
   * helper function for making a new directory block list (for
   * initialize and copy).
   */
  static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size, ext2_ino_t count,
                               struct ext2_db_entry2* list,
                               ext2_dblist* ret_dblist)
  {
      ext2_dblist dblist = NULL;
      errcode_t retval;
      ext2_ino_t num_dirs;
      size_t len;
  
      EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  
      if ((ret_dblist == 0) && fs->dblist &&
          (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
          return 0;
  
      retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
      if (retval)
          goto cleanup;
      memset(dblist, 0, sizeof(struct ext2_struct_dblist));
  
      dblist->magic = EXT2_ET_MAGIC_DBLIST;
      dblist->fs = fs;
      if (size)
          dblist->size = size;
      else
      {
          retval = ext2fs_get_num_dirs(fs, &num_dirs);
          if (retval)
              goto cleanup;
          dblist->size = (num_dirs * 2) + 12;
      }
      len = (size_t)sizeof(struct ext2_db_entry2) * dblist->size;
      dblist->count = count;
      retval = ext2fs_get_array(dblist->size, sizeof(struct ext2_db_entry2),
                                &dblist->list);
      if (retval)
          goto cleanup;
  
      if (list)
          memcpy(dblist->list, list, len);
      else
          memset(dblist->list, 0, len);
      if (ret_dblist)
          *ret_dblist = dblist;
      else
          fs->dblist = dblist;
      return 0;
  cleanup:
      if (dblist)
          ext2fs_free_mem(&dblist);
      return retval;
  }
  
  /*
   * Initialize a directory block list
   */
  errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist* ret_dblist)
  {
      ext2_dblist dblist;
      errcode_t retval;
  
      retval = make_dblist(fs, 0, 0, 0, &dblist);
      if (retval)
          return retval;
  
      dblist->sorted = 1;
      if (ret_dblist)
          *ret_dblist = dblist;
      else
          fs->dblist = dblist;
  
      return 0;
  }
  
  /*
   * Copy a directory block list
   */
  errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist* dest)
  {
      ext2_dblist dblist;
      errcode_t retval;
  
      retval = make_dblist(src->fs, src->size, src->count, src->list, &dblist);
      if (retval)
          return retval;
      dblist->sorted = src->sorted;
      *dest = dblist;
      return 0;
  }
  
  /*
   * Close a directory block list
   *
   * (moved to closefs.c)
   */
  
  /*
   * Add a directory block to the directory block list
   */
  errcode_t ext2fs_add_dir_block2(ext2_dblist dblist, ext2_ino_t ino, blk64_t blk,
                                  e2_blkcnt_t blockcnt)
  {
      struct ext2_db_entry2* new_entry;
      errcode_t retval;
      unsigned long old_size;
  
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
  
      if (dblist->count >= dblist->size)
      {
          old_size = dblist->size * sizeof(struct ext2_db_entry2);
          dblist->size += dblist->size > 200 ? dblist->size / 2 : 100;
          retval = ext2fs_resize_mem(
              old_size, (size_t)dblist->size * sizeof(struct ext2_db_entry2),
              &dblist->list);
          if (retval)
          {
              dblist->size = old_size / sizeof(struct ext2_db_entry2);
              return retval;
          }
      }
      new_entry = dblist->list + (dblist->count++);
      new_entry->blk = blk;
      new_entry->ino = ino;
      new_entry->blockcnt = blockcnt;
  
      dblist->sorted = 0;
  
      return 0;
  }
  
  /*
   * Change the directory block to the directory block list
   */
  errcode_t ext2fs_set_dir_block2(ext2_dblist dblist, ext2_ino_t ino, blk64_t blk,
                                  e2_blkcnt_t blockcnt)
  {
      dgrp_t i;
  
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
  
      for (i = 0; i < dblist->count; i++)
      {
          if ((dblist->list[i].ino != ino) ||
              (dblist->list[i].blockcnt != blockcnt))
              continue;
          dblist->list[i].blk = blk;
          dblist->sorted = 0;
          return 0;
      }
      return EXT2_ET_DB_NOT_FOUND;
  }
  
  void ext2fs_dblist_sort2(ext2_dblist dblist,
                           EXT2_QSORT_TYPE (*sortfunc)(const void*, const void*))
  {
      if (!sortfunc)
          sortfunc = dir_block_cmp2;
      qsort(dblist->list, (size_t)dblist->count, sizeof(struct ext2_db_entry2),
            sortfunc);
      dblist->sorted = 1;
  }
  
  /*
   * This function iterates over the directory block list
   */
  errcode_t ext2fs_dblist_iterate3(ext2_dblist dblist,
                                   int (*func)(ext2_filsys fs,
                                               struct ext2_db_entry2* db_info,
                                               void* priv_data),
                                   unsigned long long start,
                                   unsigned long long count, void* priv_data)
  {
      unsigned long long i, end;
      int ret;
  
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
  
      end = start + count;
      if (!dblist->sorted)
          ext2fs_dblist_sort2(dblist, 0);
      if (end > dblist->count)
          end = dblist->count;
      for (i = start; i < end; i++)
      {
          ret = (*func)(dblist->fs, &dblist->list[i], priv_data);
          if (ret & DBLIST_ABORT)
              return 0;
      }
      return 0;
  }
  
  errcode_t ext2fs_dblist_iterate2(ext2_dblist dblist,
                                   int (*func)(ext2_filsys fs,
                                               struct ext2_db_entry2* db_info,
                                               void* priv_data),
                                   void* priv_data)
  {
      return ext2fs_dblist_iterate3(dblist, func, 0, dblist->count, priv_data);
  }
  
  static EXT2_QSORT_TYPE dir_block_cmp2(const void* a, const void* b)
  {
      const struct ext2_db_entry2* db_a = (const struct ext2_db_entry2*)a;
      const struct ext2_db_entry2* db_b = (const struct ext2_db_entry2*)b;
  
      if (db_a->blk != db_b->blk)
          return (int)(db_a->blk - db_b->blk);
  
      if (db_a->ino != db_b->ino)
          return (int)(db_a->ino - db_b->ino);
  
      return (db_a->blockcnt - db_b->blockcnt);
  }
  
  blk64_t ext2fs_dblist_count2(ext2_dblist dblist)
  {
      return dblist->count;
  }
  
  errcode_t ext2fs_dblist_get_last2(ext2_dblist dblist,
                                    struct ext2_db_entry2** entry)
  {
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
  
      if (dblist->count == 0)
          return EXT2_ET_DBLIST_EMPTY;
  
      if (entry)
          *entry = dblist->list + (dblist->count - 1);
      return 0;
  }
  
  errcode_t ext2fs_dblist_drop_last(ext2_dblist dblist)
  {
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
  
      if (dblist->count == 0)
          return EXT2_ET_DBLIST_EMPTY;
  
      dblist->count--;
      return 0;
  }
  
  /*
   * Legacy 32-bit versions
   */
  
  /*
   * Add a directory block to the directory block list
   */
  errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
                                 int blockcnt)
  {
      return ext2fs_add_dir_block2(dblist, ino, blk, blockcnt);
  }
  
  /*
   * Change the directory block to the directory block list
   */
  errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
                                 int blockcnt)
  {
      return ext2fs_set_dir_block2(dblist, ino, blk, blockcnt);
  }
  
  void ext2fs_dblist_sort(ext2_dblist dblist,
                          EXT2_QSORT_TYPE (*sortfunc)(const void*, const void*))
  {
      if (sortfunc)
      {
          sortfunc32 = sortfunc;
          sortfunc = dir_block_cmp;
      }
      else
          sortfunc = dir_block_cmp2;
      qsort(dblist->list, (size_t)dblist->count, sizeof(struct ext2_db_entry2),
            sortfunc);
      dblist->sorted = 1;
  }
  
  /*
   * This function iterates over the directory block list
   */
  struct iterate_passthrough
  {
      int (*func)(ext2_filsys fs, struct ext2_db_entry* db_info, void* priv_data);
      void* priv_data;
  };
  
  static int passthrough_func(ext2_filsys fs, struct ext2_db_entry2* db_info,
                              void* priv_data)
  {
      struct iterate_passthrough* p = priv_data;
      struct ext2_db_entry db;
      int ret;
  
      db.ino = db_info->ino;
      db.blk = (blk_t)db_info->blk;
      db.blockcnt = (int)db_info->blockcnt;
      ret = (p->func)(fs, &db, p->priv_data);
      db_info->ino = db.ino;
      db_info->blk = db.blk;
      db_info->blockcnt = db.blockcnt;
      return ret;
  }
  
  errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
                                  int (*func)(ext2_filsys fs,
                                              struct ext2_db_entry* db_info,
                                              void* priv_data),
                                  void* priv_data)
  {
      struct iterate_passthrough pass;
  
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
      pass.func = func;
      pass.priv_data = priv_data;
  
      return ext2fs_dblist_iterate2(dblist, passthrough_func, &pass);
  }
  
  static EXT2_QSORT_TYPE dir_block_cmp(const void* a, const void* b)
  {
      const struct ext2_db_entry2* db_a = (const struct ext2_db_entry2*)a;
      const struct ext2_db_entry2* db_b = (const struct ext2_db_entry2*)b;
  
      struct ext2_db_entry a32, b32;
  
      a32.ino = db_a->ino;
      a32.blk = db_a->blk;
      a32.blockcnt = db_a->blockcnt;
  
      b32.ino = db_b->ino;
      b32.blk = db_b->blk;
      b32.blockcnt = db_b->blockcnt;
  
      return sortfunc32(&a32, &b32);
  }
  
  int ext2fs_dblist_count(ext2_dblist dblist)
  {
      return dblist->count;
  }
  
  errcode_t ext2fs_dblist_get_last(ext2_dblist dblist,
                                   struct ext2_db_entry** entry)
  {
      static struct ext2_db_entry ret_entry;
      struct ext2_db_entry2* last;
  
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
  
      if (dblist->count == 0)
          return EXT2_ET_DBLIST_EMPTY;
  
      if (!entry)
          return 0;
  
      last = dblist->list + dblist->count - 1;
  
      ret_entry.ino = last->ino;
      ret_entry.blk = last->blk;
      ret_entry.blockcnt = last->blockcnt;
      *entry = &ret_entry;
  
      return 0;
  }
  