ubi_bintree.h

samba-3.0.22.tar.gz 编译smb服务器的源码

 *
 *                      static ubi_trNewTree( MyTree, cmpfn, ubi_trDUPKEY );
 *
 *                    is equivalent to
 *
 *                      static ubi_trRoot MyTree[1]
 *                        = {{ NULL, cmpfn, 0, ubi_trDUPKEY }};
 *
 * -------------------------------------------------------------------------- **
 */

#define ubi_trCount( R ) (((ubi_trRootPtr)(R))->count)

#define ubi_trNewTree( N, C, F ) ubi_trRoot (N)[1] = {{ NULL, (C), 0, (F) }}

/* -------------------------------------------------------------------------- **
 * Typedefs...
 * 
 * ubi_trBool   - Your typcial true or false...
 *
 * Item Pointer:  The ubi_btItemPtr is a generic pointer. It is used to
 *                indicate a key that is being searched for within the tree.
 *                Searching occurs whenever the ubi_trFind(), ubi_trLocate(),
 *                or ubi_trInsert() functions are called.
 * -------------------------------------------------------------------------- **
 */

typedef unsigned char ubi_trBool;

typedef void *ubi_btItemPtr;          /* A pointer to key data within a node. */

/*  ------------------------------------------------------------------------- **
 *  Binary Tree Node Structure:  This structure defines the basic elements of
 *       the tree nodes.  In general you *SHOULD NOT PLAY WITH THESE FIELDS*!
 *       But, of course, I have to put the structure into this header so that
 *       you can use it as a building block.
 *
 *  The fields are as follows:
 *    Link     -  an array of pointers.  These pointers are manipulated by
 *                the BT routines.  The pointers indicate the left and right
 *                child nodes and the parent node.  By keeping track of the
 *                parent pointer, we avoid the need for recursive routines or
 *                hand-tooled stacks to keep track of our path back to the
 *                root.  The use of these pointers is subject to change without
 *                notice.
 *    gender   -  a one-byte field indicating whether the node is the RIGHT or
 *                LEFT child of its parent.  If the node is the root of the
 *                tree, gender will be PARENT.
 *    balance  -  only used by the AVL tree module.  This field indicates
 *                the height balance at a given node.  See ubi_AVLtree for
 *                details.
 *
 *  ------------------------------------------------------------------------- **
 */

typedef struct ubi_btNodeStruct {
  struct ubi_btNodeStruct *Link[ 3 ];
  char                     gender;
  char                     balance;
  } ubi_btNode;

typedef ubi_btNode *ubi_btNodePtr;     /* Pointer to an ubi_btNode structure. */

/*  ------------------------------------------------------------------------- **
 * The next three typedefs define standard function types used by the binary
 * tree management routines.  In particular:
 *
 *    ubi_btCompFunc    is a pointer to a comparison function.  Comparison
 *                      functions are passed an ubi_btItemPtr and an
 *                      ubi_btNodePtr.  They return a value that is (<0), 0,
 *                      or (>0) to indicate that the Item is (respectively)
 *                      "less than", "equal to", or "greater than" the Item
 *                      contained within the node.  (See ubi_btInitTree()).
 *    ubi_btActionRtn   is a pointer to a function that may be called for each
 *                      node visited when performing a tree traversal (see
 *                      ubi_btTraverse()).  The function will be passed two
 *                      parameters: the first is a pointer to a node in the
 *                      tree, the second is a generic pointer that may point to
 *                      anything that you like.
 *    ubi_btKillNodeRtn is a pointer to a function that will deallocate the
 *                      memory used by a node (see ubi_btKillTree()).  Since
 *                      memory management is left up to you, deallocation may
 *                      mean anything that you want it to mean.  Just remember
 *                      that the tree *will* be destroyed and that none of the
 *                      node pointers will be valid any more.
 *  ------------------------------------------------------------------------- **
 */

typedef  int (*ubi_btCompFunc)( ubi_btItemPtr, ubi_btNodePtr );

typedef void (*ubi_btActionRtn)( ubi_btNodePtr, void * );

typedef void (*ubi_btKillNodeRtn)( ubi_btNodePtr );

/* -------------------------------------------------------------------------- **
 * Tree Root Structure: This structure gives us a convenient handle for
 *                      accessing whole binary trees.  The fields are:
 *    root  -  A pointer to the root node of the tree.
 *    count -  A count of the number of nodes stored in the tree.
 *    cmp   -  A pointer to the comparison routine to be used when building or
 *             searching the tree.
 *    flags -  A set of bit flags.  Two flags are currently defined:
 *
 *       ubi_trOVERWRITE -  If set, this flag indicates that a new node should
 *         (bit 0x01)       overwrite an old node if the two have identical
 *                          keys (ie., the keys are equal).
 *       ubi_trDUPKEY    -  If set, this flag indicates that the tree is
 *         (bit 0x02)       allowed to contain nodes with duplicate keys.
 *
 *       NOTE: ubi_trInsert() tests ubi_trDUPKEY before ubi_trOVERWRITE.
 *
 * All of these values are set when you initialize the root structure by
 * calling ubi_trInitTree().
 * -------------------------------------------------------------------------- **
 */

typedef struct {
  ubi_btNodePtr  root;     /* A pointer to the root node of the tree       */
  ubi_btCompFunc cmp;      /* A pointer to the tree's comparison function  */
  unsigned long  count;    /* A count of the number of nodes in the tree   */
  char           flags;    /* Overwrite Y|N, Duplicate keys Y|N...         */
  } ubi_btRoot;

typedef ubi_btRoot *ubi_btRootPtr;  /* Pointer to an ubi_btRoot structure. */


/* -------------------------------------------------------------------------- **
 * Function Prototypes.
 */

long ubi_btSgn( long x );
  /* ------------------------------------------------------------------------ **
   * Return the sign of x; {negative,zero,positive} ==> {-1, 0, 1}.
   *
   *  Input:  x - a signed long integer value.
   *
   *  Output: the "sign" of x, represented as follows:
   *            -1 == negative
   *             0 == zero (no sign)
   *             1 == positive
   *
   * Note: This utility is provided in order to facilitate the conversion
   *       of C comparison function return values into BinTree direction
   *       values: {LEFT, PARENT, EQUAL}.  It is INCORPORATED into the
   *       AbNormal() conversion macro!
   *
   * ------------------------------------------------------------------------ **
   */

ubi_btNodePtr ubi_btInitNode( ubi_btNodePtr NodePtr );
  /* ------------------------------------------------------------------------ **
   * Initialize a tree node.
   *
   *  Input:   a pointer to a ubi_btNode structure to be initialized.
   *  Output:  a pointer to the initialized ubi_btNode structure (ie. the
   *           same as the input pointer).
   * ------------------------------------------------------------------------ **
   */

ubi_btRootPtr  ubi_btInitTree( ubi_btRootPtr   RootPtr,
                               ubi_btCompFunc  CompFunc,
                               char            Flags );
  /* ------------------------------------------------------------------------ **
   * Initialize the fields of a Tree Root header structure.
   *  
   *  Input:   RootPtr   - a pointer to an ubi_btRoot structure to be
   *                       initialized.   
   *           CompFunc  - a pointer to a comparison function that will be used
   *                       whenever nodes in the tree must be compared against
   *                       outside values.
   *           Flags     - One bytes worth of flags.  Flags include
   *                       ubi_trOVERWRITE and ubi_trDUPKEY.  See the header
   *                       file for more info.
   *
   *  Output:  a pointer to the initialized ubi_btRoot structure (ie. the
   *           same value as RootPtr).
   * 
   *  Note:    The interface to this function has changed from that of 
   *           previous versions.  The <Flags> parameter replaces two      
   *           boolean parameters that had the same basic effect.
   * ------------------------------------------------------------------------ **
   */

ubi_trBool ubi_btInsert( ubi_btRootPtr  RootPtr,
                         ubi_btNodePtr  NewNode,
                         ubi_btItemPtr  ItemPtr,
                         ubi_btNodePtr *OldNode );
  /* ------------------------------------------------------------------------ **
   * This function uses a non-recursive algorithm to add a new element to the
   * tree.
   *
   *  Input:   RootPtr  -  a pointer to the ubi_btRoot structure that indicates
   *                       the root of the tree to which NewNode is to be added.
   *           NewNode  -  a pointer to an ubi_btNode structure that is NOT
   *                       part of any tree.
   *           ItemPtr  -  A pointer to the sort key that is stored within
   *                       *NewNode.  ItemPtr MUST point to information stored
   *                       in *NewNode or an EXACT DUPLICATE.  The key data
   *                       indicated by ItemPtr is used to place the new node
   *                       into the tree.
   *           OldNode  -  a pointer to an ubi_btNodePtr.  When searching
   *                       the tree, a duplicate node may be found.  If
   *                       duplicates are allowed, then the new node will
   *                       be simply placed into the tree.  If duplicates
   *                       are not allowed, however, then one of two things
   *                       may happen.
   *                       1) if overwritting *is not* allowed, this
   *                          function will return FALSE (indicating that
   *                          the new node could not be inserted), and
   *                          *OldNode will point to the duplicate that is
   *                          still in the tree.
   *                       2) if overwritting *is* allowed, then this
   *                          function will swap **OldNode for *NewNode.
   *                          In this case, *OldNode will point to the node
   *                          that was removed (thus allowing you to free
   *                          the node).
   *                          **  If you are using overwrite mode, ALWAYS  **
   *                          ** check the return value of this parameter! **
   *                 Note: You may pass NULL in this parameter, the
   *                       function knows how to cope.  If you do this,
   *                       however, there will be no way to return a
   *                       pointer to an old (ie. replaced) node (which is
   *                       a problem if you are using overwrite mode).
   *
   *  Output:  a boolean value indicating success or failure.  The function
   *           will return FALSE if the node could not be added to the tree.
   *           Such failure will only occur if duplicates are not allowed,
   *           nodes cannot be overwritten, AND a duplicate key was found
   *           within the tree.
   * ------------------------------------------------------------------------ **
   */

ubi_btNodePtr ubi_btRemove( ubi_btRootPtr RootPtr,
                            ubi_btNodePtr DeadNode );
  /* ------------------------------------------------------------------------ **
   * This function removes the indicated node from the tree.
   *
   *  Input:   RootPtr  -  A pointer to the header of the tree that contains
   *                       the node to be removed.
   *           DeadNode -  A pointer to the node that will be removed.
   *
   *  Output:  This function returns a pointer to the node that was removed
   *           from the tree (ie. the same as DeadNode).
   *
   *  Note:    The node MUST be in the tree indicated by RootPtr.  If not,
   *           strange and evil things will happen to your trees.
   * ------------------------------------------------------------------------ **
   */

ubi_btNodePtr ubi_btLocate( ubi_btRootPtr RootPtr,
                            ubi_btItemPtr FindMe,
                            ubi_trCompOps CompOp );
  /* ------------------------------------------------------------------------ **
   * The purpose of ubi_btLocate() is to find a node or set of nodes given
   * a target value and a "comparison operator".  The Locate() function is
   * more flexible and (in the case of trees that may contain dupicate keys)
   * more precise than the ubi_btFind() function.  The latter is faster,
   * but it only searches for exact matches and, if the tree contains
   * duplicates, Find() may return a pointer to any one of the duplicate-
   * keyed records.
   *
   *  Input:
   *     RootPtr  -  A pointer to the header of the tree to be searched.
   *     FindMe   -  An ubi_btItemPtr that indicates the key for which to
   *                 search.
   *     CompOp   -  One of the following:
   *                    CompOp     Return a pointer to the node with
   *                    ------     ---------------------------------
   *                   ubi_trLT - the last key value that is less
   *                              than FindMe.
   *                   ubi_trLE - the first key matching FindMe, or
   *                              the last key that is less than
   *                              FindMe.
   *                   ubi_trEQ - the first key matching FindMe.
   *                   ubi_trGE - the first key matching FindMe, or the
   *                              first key greater than FindMe.
   *                   ubi_trGT - the first key greater than FindMe.
   *  Output:
   *     A pointer to the node matching the criteria listed above under
   *     CompOp, or NULL if no node matched the criteria.
   *
   *  Notes:
   *     In the case of trees with duplicate keys, Locate() will behave as
   *     follows:
   *
   *     Find:  3                       Find: 3
   *     Keys:  1 2 2 2 3 3 3 3 3 4 4   Keys: 1 1 2 2 2 4 4 5 5 5 6
   *                  ^ ^         ^                   ^ ^
   *                 LT EQ        GT                 LE GE
   *
   *     That is, when returning a pointer to a node with a key that is LESS
   *     THAN the target key (FindMe), Locate() will return a pointer to the
   *     LAST matching node.
   *     When returning a pointer to a node with a key that is GREATER
   *     THAN the target key (FindMe), Locate() will return a pointer to the
   *     FIRST matching node.