Class DumpArchiveEntry

All Implemented Interfaces:

public class DumpArchiveEntry extends Object implements ArchiveEntry
This class represents an entry in a Dump archive. It consists of the entry's header, the entry's File and any extended attributes.

DumpEntries that are created from the header bytes read from an archive are instantiated with the DumpArchiveEntry( byte[] ) constructor. These entries will be used when extracting from or listing the contents of an archive. These entries have their header filled in using the header bytes. They also set the File to null, since they reference an archive entry not a file.

DumpEntries can also be constructed from nothing but a name. This allows the programmer to construct the entry by hand, for instance when only an InputStream is available for writing to the archive, and the header information is constructed from other information. In this case the header fields are set to defaults and the File is set to null.

The C structure for a Dump Entry's header is:

 #define TP_BSIZE    1024          // size of each file block
 #define NTREC       10            // number of blocks to write at once
 #define HIGHDENSITYTREC 32        // number of blocks to write on high-density tapes
 #define TP_NINDIR   (TP_BSIZE/2)  // number if indirect inodes in record
 #define TP_NINOS    (TP_NINDIR / sizeof (int32_t))
 #define LBLSIZE     16
 #define NAMELEN     64

 #define OFS_MAGIC     (int) 60011  // old format magic value
 #define NFS_MAGIC     (int) 60012  // new format magic value
 #define FS_UFS2_MAGIC (int) 0x19540119
 #define CHECKSUM      (int) 84446  // constant used in checksum algorithm

 struct  s_spcl {
   int32_t c_type;             // record type (see below)
   int32_t c_date;             // date of this dump
   int32_t c_ddate;            // date of previous dump
   int32_t c_volume;           // dump volume number
   u_int32_t c_tapea;          // logical block of this record
   dump_ino_t c_ino;           // number of inode
   int32_t c_magic;            // magic number (see above)
   int32_t c_checksum;         // record checksum
 #ifdef  __linux__
   struct  new_bsd_inode c_dinode;
 #ifdef sunos
   struct  new_bsd_inode c_dinode;
   struct  dinode  c_dinode;   // ownership and mode of inode
   int32_t c_count;            // number of valid c_addr entries
   union u_data c_data;        // see above
   char    c_label[LBLSIZE];   // dump label
   int32_t c_level;            // level of this dump
   char    c_filesys[NAMELEN]; // name of dumpped file system
   char    c_dev[NAMELEN];     // name of dumpped device
   char    c_host[NAMELEN];    // name of dumpped host
   int32_t c_flags;            // additional information (see below)
   int32_t c_firstrec;         // first record on volume
   int32_t c_ntrec;            // blocksize on volume
   int32_t c_extattributes;    // additional inode info (see below)
   int32_t c_spare[30];        // reserved for future uses
 } s_spcl;

 // flag values
 #define DR_NEWHEADER     0x0001  // new format tape header
 #define DR_NEWINODEFMT   0x0002  // new format inodes on tape
 #define DR_COMPRESSED    0x0080  // dump tape is compressed
 #define DR_METAONLY      0x0100  // only the metadata of the inode has been dumped
 #define DR_INODEINFO     0x0002  // [SIC] TS_END header contains c_inos information
 #define DR_EXTATTRIBUTES 0x8000

 // extattributes inode info
 #define EXT_REGULAR         0
 #define EXT_MACOSRESFORK    2
 #define EXT_XATTR           3

 // used for EA on tape
 #define EXT2_GOOD_OLD_INODE_SIZE    128
 #define EXT2_XATTR_MAGIC        0xEA020000  // block EA
 #define EXT2_XATTR_MAGIC2       0xEA020001  // in inode EA

The fields in bold are the same for all blocks. (This permitted multiple dumps to be written to a single tape.)

The C structure for the inode (file) information is:

 struct bsdtimeval {           //  **** alpha-*-linux is deviant
   __u32   tv_sec;
   __u32   tv_usec;

 #define NDADDR      12
 #define NIADDR       3

 // This is the new (4.4) BSD inode structure
 // copied from the FreeBSD 2.0 <ufs/ufs/dinode.h> include file
 struct new_bsd_inode {
   __u16       di_mode;           // file type, standard UNIX permissions
   __s16       di_nlink;          // number of hard links to file.
   union {
      __u16       oldids[2];
      __u32       inumber;
   }           di_u;
   u_quad_t    di_size;           // file size
   struct bsdtimeval   di_atime;  // time file was last accessed
   struct bsdtimeval   di_mtime;  // time file was last modified
   struct bsdtimeval   di_ctime;  // time file was created
   __u32       di_db[NDADDR];
   __u32       di_ib[NIADDR];
   __u32       di_flags;          //
   __s32       di_blocks;         // number of disk blocks
   __s32       di_gen;            // generation number
   __u32       di_uid;            // user id (see /etc/passwd)
   __u32       di_gid;            // group id (see /etc/group)
   __s32       di_spare[2];       // unused

It is important to note that the header DOES NOT have the name of the file. It can't since hard links mean that you may have multiple file names for a single physical file. You must read the contents of the directory entries to learn the mapping(s) from file name to inode.

The C structure that indicates if a specific block is a real block that contains data or is a sparse block that is not persisted to the disk is:

 #define TP_BSIZE    1024
 #define TP_NINDIR   (TP_BSIZE/2)

 union u_data {
   char    s_addrs[TP_NINDIR]; // 1 => data; 0 => hole in inode
   int32_t s_inos[TP_NINOS];   // table of first inode on each volume
 } u_data;
This class is not thread-safe
  • Constructor Details

    • DumpArchiveEntry

      Constructs a default instance.
    • DumpArchiveEntry

      public DumpArchiveEntry(String name, String simpleName)
      Constructs a new instance with only names.
      name - path name
      simpleName - actual file name.
    • DumpArchiveEntry

      protected DumpArchiveEntry(String name, String simpleName, int ino, DumpArchiveEntry.TYPE type)
      Constructs a new instance with name, inode and type.
      name - the name
      simpleName - the simple name
      ino - the ino
      type - the type
  • Method Details

    • equals

      public boolean equals(Object o)
      equals in class Object
    • getAccessTime

      public Date getAccessTime()
      Returns the time the file was last accessed.
      the access time
    • getCreationTime

      Gets file creation time.
      the creation time
    • getGeneration

      public int getGeneration()
      Gets the generation of the file.
      the generation
    • getGroupId

      public int getGroupId()
      Gets the group id
      the group id
    • getHeaderCount

      public int getHeaderCount()
      Gets the number of records in this segment.
      the number of records
    • getHeaderHoles

      public int getHeaderHoles()
      Gets the number of sparse records in this segment.
      the number of sparse records
    • getHeaderType

      Gets the type of the tape segment header.
      the segment header
    • getIno

      public int getIno()
      Returns the ino of the entry.
      the ino
    • getLastModifiedDate

      The last modified date.
      Specified by:
      getLastModifiedDate in interface ArchiveEntry
      the last modified date
    • getMode

      public int getMode()
      Gets the access permissions on the entry.
      the access permissions
    • getName

      public String getName()
      Returns the name of the entry.

      This method returns the raw name as it is stored inside of the archive.

      Specified by:
      getName in interface ArchiveEntry
      the name of the entry.
    • getNlink

      public int getNlink()
      Gets the number of hard links to the entry.
      the number of hard links
    • getOffset

      public long getOffset()
      Gets the offset within the archive
      the offset
    • getPermissions

      Returns the permissions on the entry.
      the permissions
    • getSimpleName

      Returns the path of the entry.
      the path of the entry.
    • getSize

      public long getSize()
      Returns the size of the entry.
      Specified by:
      getSize in interface ArchiveEntry
      the size
    • getType

      Gets the type of the entry.
      the type
    • getUserId

      public int getUserId()
      Gets the user id.
      the user id
    • getVolume

      public int getVolume()
      Gets the tape volume where this file is located.
      the volume
    • hashCode

      public int hashCode()
      hashCode in class Object
    • isBlkDev

      public boolean isBlkDev()
      Is this a block device?
      whether this is a block device
    • isChrDev

      public boolean isChrDev()
      Is this a character device?
      whether this is a character device
    • isDeleted

      public boolean isDeleted()
      Has this file been deleted? (On valid on incremental dumps.)
      whether the file has been deleted
    • isDirectory

      public boolean isDirectory()
      Is this a directory?
      Specified by:
      isDirectory in interface ArchiveEntry
      whether this is a directory
    • isFifo

      public boolean isFifo()
      Is this a fifo/pipe?
      whether this is a fifo
    • isFile

      public boolean isFile()
      Is this a regular file?
      whether this is a regular file
    • isSocket

      public boolean isSocket()
      Is this a network device?
      whether this is a socket
    • isSparseRecord

      public boolean isSparseRecord(int idx)
      Is this a sparse record?
      idx - index of the record to check
      whether this is a sparse record
    • setAccessTime

      public void setAccessTime(Date atime)
      Sets the time the file was last accessed.
      atime - the access time
    • setCreationTime

      public void setCreationTime(Date ctime)
      Sets the file creation time.
      ctime - the creation time
    • setDeleted

      public void setDeleted(boolean isDeleted)
      Sets whether this file has been deleted.
      isDeleted - whether the file has been deleted
    • setGeneration

      public void setGeneration(int generation)
      Sets the generation of the file.
      generation - the generation
    • setGroupId

      public void setGroupId(int gid)
      Sets the group id.
      gid - the group id
    • setLastModifiedDate

      public void setLastModifiedDate(Date mtime)
      Sets the time the file was last modified.
      mtime - the last modified time
    • setMode

      public void setMode(int mode)
      Sets the access permissions on the entry.
      mode - the access permissions
    • setName

      public final void setName(String name)
      Sets the name of the entry.
      name - the name
    • setNlink

      public void setNlink(int nlink)
      Sets the number of hard links.
      nlink - the number of hard links
    • setOffset

      public void setOffset(long offset)
      Sets the offset within the archive.
      offset - the offset
    • setSimpleName

      protected void setSimpleName(String simpleName)
      Sets the path of the entry.
      simpleName - the simple name
    • setSize

      public void setSize(long size)
      Sets the size of the entry.
      size - the size
    • setType

      public void setType(DumpArchiveEntry.TYPE type)
      Sets the type of the entry.
      type - the type
    • setUserId

      public void setUserId(int uid)
      Sets the user id.
      uid - the user id
    • setVolume

      public void setVolume(int volume)
      Sets the tape volume.
      volume - the volume
    • toString

      public String toString()
      toString in class Object