Man Linux: Main Page and Category List


       JudyHS  functions  -  C  library  for  creating and accessing a dynamic
       array, using an array-of-bytes of a length: Length as an  Index  and  a
       word as a Value.


       PPvoid_t JudyHSIns(PPvoid_t PPJHS, void *Index, Word_t Length, PJError_t PJError);
       int      JudyHSDel(PPvoid_t PPJHS, void *Index, Word_t Length, PJError_t PJError);
       PPvoid_t JudyHSGet(Pcvoid_t  PJHS, void *Index, Word_t Length, PJError_t PJError);
       Word_t   JudyHSFreeArray(PPvoid_t PPJHS, PJError_t PJError);


       A  macro  equivalent  exists for each function call.  Because the macro
       forms are sometimes faster and have a simpler error handling  interface
       than  the  equivalent  functions, they are the preferred way of calling
       the  JudyHS  functions.   See  JudyHS(3)  for  more  information.   The
       function call definitions are included here for completeness.

       One  of  the  difficulties  in  using the JudyHS function calls lies in
       determining whether to pass a pointer or  the  address  of  a  pointer.
       Since  the  functions that modify the JudyHS array must also modify the
       pointer to the JudyHS array, you must pass the address of  the  pointer
       rather  than  the  pointer  itself.   This often leads to hard-to-debug
       programmatic errors.  In practice, the macros  allow  the  compiler  to
       catch programming errors when pointers instead of addresses of pointers
       are passed.

       The JudyHS function calls have an  additional  parameter  beyond  those
       specified in the macro calls.  This parameter is either a pointer to an
       error structure, or NULL (in which case the error  information  is  not
       returned -- only PJERR in the return parameter).

       In  the following descriptions, the functions are described in terms of
       how the macros use them.  This is the suggested use of the macros after
       your  program has been fully debugged.  When the JUDYERROR_NOTEST macro
       is not specified,  an  error  structure  is  declared  to  store  error
       information returned from the JudyHS functions when an error occurs.

       Notice the placement of the & in the different functions.

        JudyHSIns(&PJHS, Index, Length, &JError)

                      #define JHSI(PValue, PJHS, Index) \
                         PValue = JudyLIns(&PJHS, Index, PJE0)

        JudyHSDel(&PJHS, Index, Length, &JError)

                      #define JHSD(Rc_int, PJHS, Index, Length) \
                         Rc_int = JudyHSDel(&PJHS, Index, Length, PJE0)

        JudyHSGet(PJHS, Index, Length)

                      #define JHSG(PValue, PJHS, Index, Length) \
                         PValue = JudyHSIns(PJHS, Index, Length)

        JudyHSFreeArray(&PJHS, &JError)

                      #define JHSFA(Rc_word, PJHS) \
                         Rc_word = JudyHSFreeArray(&PJHS, PJE0)

       Definitions  for  all  the Judy functions, the types Pvoid_t, Pcvoid_t,
       PPvoid_t,  Word_t  ,  JError_t,  and  PJError_t,  the  constants  NULL,
       JU_ERRNO_*,  JERR,  PPJERR,  and PJE0 are provided in the Judy.h header
       file (/usr/include/Judy.h).  Note:  Callers should define JudyHS arrays
       as  type  Pvoid_t,  which can be passed by value to functions that take
       Pcvoid_t (constant Pvoid_t), and also by address to functions that take

       The  return  type  from  most  JudyHS functions is PPvoid_t so that the
       values stored in the array can be pointers to other objects, which is a
       typical  usage,  or  cast  to  a  Word_t * when a pointer to a value is
       required instead of a pointer to a pointer.


       JudyHS was invented and implemented by Doug Baskins after retiring from


       Judy(3), Judy1(3), JudyL(3), JudySL(3), JudyHS(3),
       the Judy website,, for more information and
       Application Notes.