man.doc

btree的实现源代码

        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string



























                                    - 16 -            Formatted:  May 1, 1997









 Decrement(3)                   c2man btree.c                   Decrement(3)
                                13 April 1995



 NAME
      Decrement - Decrement

 SYNOPSIS
      struct KeyGroup *Decrement(BTREE *btree);

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

 DESCRIPTION
      Decrement the internal pointers to the next key in the tree.

 RETURNS
      Pointer to previous key group structure in the tree.  NULL on failure.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string




















                                    - 17 -            Formatted:  May 1, 1997









 DeleteKey(3)                   c2man btree.c                   DeleteKey(3)
                                13 April 1995



 NAME
      DeleteKey - DeleteKey

 SYNOPSIS
      int DeleteKey
      (
           BTREE *btree,
           union Key *delete_key
      );

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

      union Key *delete_key
           An encapsolated key.

 DESCRIPTION
      Delete a key, pointed to by a union Key pointer.

 RETURNS
      SUCCESS or FAIL.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string













                                    - 18 -            Formatted:  May 1, 1997








 DisplayHeader(3)               c2man utils.c               DisplayHeader(3)
                                10 April 1995



 NAME
      DisplayHeader - DisplayHeader

 SYNOPSIS
      void DisplayHeader(BTREE *btree);

 PARAMETERS
      BTREE *btree
           Not Documented.

 DESCRIPTION
      DisplayHeader.

 RETURNS
      NONE.

 DISCUSSION
      Displays information concerning the active node.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string

















                                    - 19 -            Formatted:  May 1, 1997






 First(3)                       c2man btree.c                       First(3)
                                13 April 1995



 NAME
      First - First

 SYNOPSIS
      struct KeyGroup *First(BTREE *btree);

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

 DESCRIPTION
      Locate and return a pointer to the first key group in the tree.

 RETURNS
      Pointer the the first key group in the tree, or NULL on failure.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string




















                                    - 20 -            Formatted:  May 1, 1997









 FlushHierarchy(3)              c2man btree.c              FlushHierarchy(3)
                                13 April 1995



 NAME
      FlushHierarchy - FlushHierarchy

 SYNOPSIS
      int FlushHierarchy(BTREE *btree);

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

 DESCRIPTION
      The hierarchy leading to a node is held in a vector of nodes beginning
      with the root node and ending with the active node.  Nodes that have
      been modified are marked in the hierarchy as "dirty".  When a new node
      is being listed into the hierarchy, it may overlay a node already
      listed in the node.  The underlying node is written back to disk
      before the new node overwrites.  This function walks the hierarchy,
      writes dirty nodes to disk and marking them clean.

 RETURNS
      SUCCESS or FAIL.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string














                                    - 21 -            Formatted:  May 1, 1997









 Increment(3)                   c2man btree.c                   Increment(3)
                                13 April 1995



 NAME
      Increment - Increment

 SYNOPSIS
      struct KeyGroup *Increment(BTREE *btree);

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

 DESCRIPTION
      Increment the internal pointers to the next key in the tree.

 RETURNS
      Pointer to next key group structure in the tree.  NULL on failure.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string




















                                    - 22 -            Formatted:  May 1, 1997






 InsertKey(3)                   c2man btree.c                   InsertKey(3)
                                13 April 1995



 NAME
      InsertKey - InsertKey

 SYNOPSIS
      int InsertKey
      (
           BTREE *btree,
           struct KeyGroup *insert_group
      );

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

      struct KeyGroup *insert_group
           An encapsolated key.

 DESCRIPTION
      Insert a key into the tree, provide the key as a pointer to a
      completed KeyGroup structure.

 RETURNS
      SUCCESS or FAIL.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string












                                    - 23 -            Formatted:  May 1, 1997








 InstallCompare(3)              c2man btree.c              InstallCompare(3)
                                13 April 1995



 NAME
      InstallCompare - InstallCompare

 SYNOPSIS
      int InstallCompare
      (
           BTREE *btree,
           int (*fn)(union Key *,struct KeyGroup *,int)
      );

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

      int (*fn)(union Key *,struct KeyGroup *,int)
           Not Documented.

 DESCRIPTION
      Installs a new compare function for fixed length keys - composite
      keys.

 RETURNS
      SUCCESS or FAIL.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string












                                    - 24 -            Formatted:  May 1, 1997





 Last(3)                        c2man btree.c                        Last(3)
                                13 April 1995



 NAME
      Last - Last

 SYNOPSIS
      struct KeyGroup *Last(BTREE *btree);

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

 DESCRIPTION
      Find the last key in the tree.

 RETURNS
      Pointer to last key group structure in the tree.  NULL on failure.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string




















                                    - 25 -            Formatted:  May 1, 1997








 OpenBtree(3)                   c2man btree.c                   OpenBtree(3)
                                13 April 1995



 NAME
      OpenBtree - Btree

 SYNOPSIS
      BTREE *OpenBtree
      (
           char *index_name,
           int create,
           int tok,
           int dups,
           int fix_key_size
      );

 PARAMETERS
      char *index_name
           Disk file name.

      int create
           True or false.

      int tok
           VAR_LNG_KEY or FIX_LNG_KEY or LONG_KEY or DOUBLE_KEY.

      int dups
           Duplicate keys allowed, true or false.

      int fix_key_size
           Ignored, or size of key if fixed length.

 DESCRIPTION
      Btree initialization function.  Will create a new index if second
      parameter is CREATE and index does not already exist.  The first
      parameter is the name of the index.  The third parameter is the type
      of key.  If the fourth parameter is set to 1, duplicate keys will be
      allowed.  If 0 duplicates will not be allowed.  If the keys are not
      variable length, the fixed key length size should be the fifth
      parameter.  For example, long keys would be sizeof(long).

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string





 OpenBtree(3)                   c2man btree.c                   OpenBtree(3)
                                13 April 1995



      DLL_Free(3), DUMP(3), DUMPOne(3), TreeDebug(3), DisplayHeader(3),
      DisplayKey(3), CHECK(3), NodePosn(3), ReportState(3),
      PrintBtDescriptor(3)


















































                                    - 27 -            Formatted:  May 1, 1997






 Update(3)                      c2man btree.c                      Update(3)
                                13 April 1995



 NAME
      Update - Update

 SYNOPSIS
      int Update
      (
           BTREE *btree,
           void *new_data
      );

 PARAMETERS
      BTREE *btree
           Pointer to tree descriptor.

      void *new_data
           New key data, consistent in type to data being replaced.

 DESCRIPTION
      Update the data of the current key.

 RETURNS
      Overwrites the key data or the address stored in a key.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string













                                    - 28 -            Formatted:  May 1, 1997







 create_c_string(3)             c2man btree.c             create_c_string(3)
                                13 April 1995



 NAME
      create_c_string - create_c_string

 SYNOPSIS
      int create_c_string
      (
           char *to,
           char *fm
      );

 PARAMETERS
      char *to
           Put the new string here.

      char *fm
           Get the pascal string from here.

 DESCRIPTION
      This utility will take an index type (pascal type) string and create a
      standard null terminated C string.

 RETURNS
      Always returns SUCCESS.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string












                                    - 29 -            Formatted:  May 1, 1997









 create_index_string(3)         c2man btree.c         create_index_string(3)
                                13 April 1995



 NAME
      create_index_string - create_index_string

 SYNOPSIS
      int create_index_string
      (
           char *to,
           char *fm
      );

 PARAMETERS
      char *to
           Place the results here.

      char *fm
           Convert this string.

 DESCRIPTION
      This utility will take a null terminated C string and create a pascal
      type string as required for indexing.  The first byte of the string
      provides the length of the string.  The length of the string is
      therefor limited to 255 characters.  In actual indexing practice the
      it isnt reasonable to assume that variable length keys should be
      allowed to be more than about 64 characters.  If you want your index
      to fail, change the commented code.  As it is, it will simply take the
      first MASVARSTR characters from the string to create the index key
      string.

 RETURNS
      SUCCESS or FAIL.

 SEE ALSO

        CHECK Close CurrentKey DUMP DebugIsOpen
        DebugLevel Decrement DeleteKey DisplayHeader
        First FlushHierarchy Increment InsertKey
        InstallCompare Last OpenBtree OpenBtree
        Update create_c_string create_index_string





                                    - 30 -            Formatted:  May 1, 1997