Provided by: libjudy-dev_1.0.5-5.1build1_amd64 bug

NAME

       JudyL  - C library for creating and accessing a dynamic array of words, using a word as an
       index.

SYNOPSIS

       cc [flags] sourcefiles -lJudy

       #include <Judy.h>

       int      Rc_int;                          // return code - integer
       Word_t   Rc_word;                         // return code - unsigned word
       Word_t   Index, Index1, Index2, Nth;
       PWord_t  PValue;                          // pointer to return value
       Pvoid_t PJLArray = (Pvoid_t) NULL;        // initialize JudyL array

       JLI( PValue,  PJLArray, Index);          // JudyLIns()
       JLD( Rc_int,  PJLArray, Index);          // JudyLDel()
       JLG( PValue,  PJLArray, Index);          // JudyLGet()
       JLC( Rc_word, PJLArray, Index1, Index2); // JudyLCount()
       JLBC(PValue,  PJLArray, Nth, Index);     // JudyLByCount()
       JLFA(Rc_word, PJLArray);                 // JudyLFreeArray()
       JLMU(Rc_word, PJLArray);                 // JudyLMemUsed()
       JLF( PValue,  PJLArray, Index);          // JudyLFirst()
       JLN( PValue,  PJLArray, Index);          // JudyLNext()
       JLL( PValue,  PJLArray, Index);          // JudyLLast()
       JLP( PValue,  PJLArray, Index);          // JudyLPrev()
       JLFE(Rc_int,  PJLArray, Index);          // JudyLFirstEmpty()
       JLNE(Rc_int,  PJLArray, Index);          // JudyLNextEmpty()
       JLLE(Rc_int,  PJLArray, Index);          // JudyLLastEmpty()
       JLPE(Rc_int,  PJLArray, Index);          // JudyLPrevEmpty()

DESCRIPTION

       A JudyL array is the equivalent of an array of word-sized values.  A Value is addressed by
       an  Index  (key).   The  array  may be sparse, and the Index may be any word-sized number.
       Memory to support the array is allocated as index/value pairs are inserted,  and  released
       as  index/value pairs are deleted.  A JudyL array can also be thought of as a mapper, that
       is "map" a word to another word/pointer.

       As with an ordinary array, there are no duplicate indexes in a JudyL array.

       The value may be used as a scalar, or a pointer to a structure or block of data  (or  even
       another Judy array).

       A JudyL array is allocated with a NULL pointer

       Pvoid_t PJLArray = (Pvoid_t) NULL;

       Using  the  macros described here, rather than the JudyL function calls, the default error
       handling sends a message to the standard error and terminates the program  with  exit(1);.
       For other error handling methods, see the ERRORS section.  JLI( PValue,  PJLArray, Index);
       // JudyLIns()

       Because the macro forms are sometimes faster and have a simpler error  handling  interface
       than  the  equivalent  JudyL  functions,  they  are the preferred way of calling the JudyL
       functions.

        JLI(PValue, PJLArray, Index) // JudyLIns()
                      Insert an Index and Value into the JudyL array PJLArray.  If the  Index  is
                      successfully  inserted,  the  Value  is  initialized to 0. If the Index was
                      already present, the Value is not modified.

                      Return PValue pointing to Value.  Your program can use this pointer to read
                      or  modify  Value  until  the next JLI() (insert), JLD() (delete) or JLFA()
                      (freearray) is executed on PJLArray. Examples:

                      *PValue = 1234;
                      Value = *PValue;

                      Return PValue set to PJERR if a malloc() fail  occured.   Note:  JLI()  and
                      JLD() reorganize the JudyL array.  Therefore, PValue returned from previous
                      JudyL calls become invalid and must be re-acquired.

        JLD(Rc_int, PJLArray, Index) // JudyLDel()
                      Delete the Index/Value pair from the JudyL array.

                      Return Rc_int set to 1 if successful.  Return Rc_int set to 0 if Index  was
                      not present.  Return Rc_int set to JERR if a malloc() fail occured.

        JLG(PValue, PJLArray, Index) // JudyLGet()
                      Get the pointer PValue associated with Index in the PJLArray Judy array.

                      Return  PValue  pointing  to Value.  Return PValue set to NULL if the Index
                      was not present.  Return PValue set to PJERR if a malloc() fail occured.

        JLC(Rc_word, PJLArray, Index1, Index2) // JudyLCount()
                      Count the number of indexes present in the  JudyL  array  PJLArray  between
                      Index1 and Index2 (inclusive).

                      Return  Rc_word  set  to  the count.  A return value of 0 can be valid as a
                      count.

                      To count all indexes present in a JudyL array, use:

                      JLC(Rc_word, PJLArray, 0, -1);

        JLBC(PValue, PJLArray, Nth, Index) // JudyLByCount()
                      Locate the Nth index that is present in the JudyL array PJLArray (Nth  =  1
                      returns the first index present).

                      Return  PValue  pointing  to  its  Value  and Index set to the Nth index if
                      found, otherwise  return  PValue  set  to  NULL  (the  value  of  Index  is
                      undefined).

        JLFA(Rc_word, PJLArray) // JudyLFreeArray()
                      Given  a  pointer to a JudyL array, free the entire array (much faster than
                      using a JLN(), JLD() loop).

                      Return Rc_word set to the number of bytes freed and PJLArray set to NULL.

        JLMU(Rc_word, PJLArray) // JudyLMemUsed()
                      Return Rc_word set  to  the  number  of  bytes  of  memory  malloc()'ed  by
                      PJLArray.   This is a very fast routine, and may be used before and after a
                      JLI() or JLD() call with little performance impact.

        JudyL Search Functions
                      JLF(), JLN(), JLL(), JLP() allow you to search for indexes  in  the  array.
                      You  may  search  inclusively  or exclusively, in either forward or reverse
                      directions.  If successful, Index is returned set to the found  index,  and
                      PValue  is  returned  set  to a pointer to Index's Value.  If unsuccessful,
                      PValue is returned set to NULL, and Index contains no  useful  information.
                      PValue  must  be  tested  for non-NULL prior to using Index, since a search
                      failure is possible.

                      JLFE(), JLNE(), JLLE(), JLPE() allow you to search for indexes that are not
                      present ("empty") in the array.  You may search inclusively or exclusively,
                      in either forward or reverse directions.  If successful, Index is  returned
                      set  to a not present ("empty") index, and Rc_int is returned set to 1.  If
                      unsuccessful, Rc_int is returned set to 0, and and Index contains no useful
                      information.   Rc_int  must be checked prior to using Index, since a search
                      failure is possible.

        JLF(PValue, PJLArray, Index) // JudyLFirst()
                      Search (inclusive) for the first index present that is equal to or  greater
                      than  the  passed  Index.  (Start with Index = 0 to find the first index in
                      the array.)  JLF() is typically used to begin a sorted-order  scan  of  the
                      indexes present in a JudyL array.

        JLN(PValue, PJLArray, Index) // JudyLNext()
                      Search  (exclusive)  for  the  next  index present that is greater than the
                      passed Index.  JLN() is typically used to continue a sorted-order  scan  of
                      the  indexes present in a JudyL array, or to locate a "neighbor" of a given
                      index.

        JLL(PValue, PJLArray, Index) // JudyLLast()
                      Search (inclusive) for the last index present that is equal to or less than
                      the  passed  Index.  (Start with Index = -1, that is, all ones, to find the
                      last index in the array.)  JLL() is typically  used  to  begin  a  reverse-
                      sorted-order scan of the indexes present in a JudyL array.

        JLP(PValue, PJLArray, Index) // JudyLPrev()
                      Search  (exclusive)  for  the  previous index present that is less than the
                      passed Index.  JLP() is typically used to continue  a  reverse-sorted-order
                      scan  of the indexes present in a JudyL array, or to locate a "neighbor" of
                      a given index.

        JLFE(Rc_int, PJLArray, Index) // JudyLFirstEmpty()
                      Search (inclusive) for the first index absent that is equal to  or  greater
                      than  the  passed  Index.   (Start  with  Index = 0 to find the first index
                      absent in the array.)

        JLNE(Rc_int, PJLArray, Index) // JudyLNextEmpty()
                      Search (exclusive) for the next index  absent  that  is  greater  than  the
                      passed Index.

        JLLE(Rc_int, PJLArray, Index) // JudyLLastEmpty()
                      Search  (inclusive) for the last index absent that is equal to or less than
                      the passed Index.  (Start with Index = -1, that is, all ones, to  find  the
                      last index absent in the array.)

        JLPE(Rc_int, PJLArray, Index) // JudyLPrevEmpty()
                      Search  (exclusive)  for  the  previous  index absent that is less than the
                      passed Index.

Multi-dimensional JudyL Arrays

       Storing a pointer to another JudyL array in a JudyL array's  Value  is  a  simple  way  to
       support  dynamic  multi-dimensional  arrays.   These  arrays  (or trees) built using JudyL
       arrays are very fast and memory efficient. (In fact, that is how  JudySL  and  JudyHS  are
       implemented).   An  arbitrary number of dimensions can be realized this way.  To terminate
       the number of dimensions (or tree), the Value pointer is marked to NOT  point  to  another
       Judy  array.  A  JLAP_INVALID flag is used in the least significant bit(s) of the pointer.
       After the flag JLAP_INVALID is removed, it is used as a pointer to the  users  data.   The
       Judy.h header file defines JLAP_INVALID.  See code fragment below.

       Note:  The  current  version  of  Judy.h  changed this flag from 0x4 to 0x1 to allow for a
       malloc() that does not deliver memory on an 8 byte aligned boundry (such as  old  versions
       of valgrind).

       The  following  example  code  segment  can  be used to determine whether or not a pointer
       points to another JudyL:

       PValue = (PWord_t)PMultiDimArray;

       for (Dim = 0; ;Dim++)
       {
          if (PValue == (PWord_t)NULL) goto IndexNotFound;

          /* Advance to next dimension in array */
          JLG(PValue, (Pvoid_t)*PValue, Index[Dim]);

          /* Check if pointer to user buffer: */
          if (*PValue & JLAP_INVALID)) break;
       }
       UPointer = (UPointer_t) (*PValue & ~JLAP_INVALID);  // mask and cast.
       printf("User object pointer is 0x%lx\n", (Word_t) UPointer);
              &.&.&.

       Note:  This works because malloc() guarantees to return a pointer with the least bit(s) ==
       0x0.  You must remove JLAP_INVALID before using the pointer.

ERRORS: See: Judy_3.htm#ERRORS

EXAMPLE

       Read  a  series  of index/value pairs from the standard input, store in a JudyL array, and
       then print out in sorted order.

       #include <stdio.h>
       #include <Judy.h>

       Word_t   Index;                     // array index
       Word_t   Value;                     // array element value
       Word_t * PValue;                    // pointer to array element value
       int      Rc_int;                    // return code

       Pvoid_t  PJLArray = (Pvoid_t) NULL; // initialize JudyL array

       while (scanf("%lu %lu", &Index, &Value))
       {
           JLI(PValue, PJLArray, Index);
           If (PValue == PJERR) goto process_malloc_failure;
           *PValue = Value;                 // store new value
       }
       // Next, visit all the stored indexes in sorted order, first ascending,
       // then descending, and delete each index during the descending pass.

       Index = 0;
       JLF(PValue, PJLArray, Index);
       while (PValue != NULL)
       {
           printf("%lu %lu\n", Index, *PValue));
           JLN(PValue, PJLArray, Index);
       }

       Index = -1;
       JLL(PValue, PJLArray, Index);
       while (PValue != NULL)
       {
           printf("%lu %lu\n", Index, *PValue));

           JLD(Rc_int, PJLArray, Index);
           if (Rc_int == JERR) goto process_malloc_failure;

           JLP(PValue, PJLArray, Index);
       }

AUTHOR

       Judy was invented by Doug Baskins and implemented -Packard.

SEE ALSO

       Judy(3), Judy1(3), JudySL(3), JudyHS(3),
       malloc(),
       http://judy.sourceforge.net, for more information and Application Notes.

                                                                                         JudyL(3)