Class DumpArchiveEntry

  • All Implemented Interfaces:

    public class DumpArchiveEntryextends Objectimplements 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; #else #ifdef sunos   struct  new_bsd_inode c_dinode; #else   struct  dinode  c_dinode;   // ownership and mode of inode #endif #endif   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_MACOSFNDRINFO   1 #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 filenames for a single physical file. You must read the contents of the directory entries to learn the mapping(s) from filename 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 Detail

      • DumpArchiveEntry

        public DumpArchiveEntry(String name,                String simpleName)
        Constructor taking only filename.
        name - pathname
        simpleName - actual filename.
    • Method Detail

      • getSimpleName

        public String getSimpleName()
        Returns the path of the entry.
        the path of the entry.
      • setSimpleName

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

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

        public int getNlink()
        Return the number of hard links to the entry.
        the number of hard links
      • setNlink

        public void setNlink(int nlink)
        Set the number of hard links.
        nlink - the number of hard links
      • setCreationTime

        public void setCreationTime(Date ctime)
        Set the file creation time.
        ctime - the creation time
      • getGeneration

        public int getGeneration()
        Return the generation of the file.
        the generation
      • setGeneration

        public void setGeneration(int generation)
        Set the generation of the file.
        generation - the generation
      • isDeleted

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

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

        public long getOffset()
        Return the offset within the archive
        the offset
      • setOffset

        public void setOffset(long offset)
        Set the offset within the archive.
        offset - the offset
      • getVolume

        public int getVolume()
        Return the tape volume where this file is located.
        the volume
      • setVolume

        public void setVolume(int volume)
        Set the tape volume.
        volume - the volume
      • getHeaderCount

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

        public int getHeaderHoles()
        Return the number of sparse records in this segment.
        the number of sparse records
      • isSparseRecord

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

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

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

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

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

        public int getMode()
        Return the access permissions on the entry.
        the access permissions
      • setMode

        public void setMode(int mode)
        Set the access permissions on the entry.
        mode - the access permissions
      • setSize

        public void setSize(long size)
        Set the size of the entry.
        size - the size
      • setLastModifiedDate

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

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

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

        public int getUserId()
        Return the user id.
        the user id
      • setUserId

        public void setUserId(int uid)
        Set the user id.
        uid - the user id
      • getGroupId

        public int getGroupId()
        Return the group id
        the group id
      • setGroupId

        public void setGroupId(int gid)
        Set the group id.
        gid - the group id

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