Judy1_funcs(3) Library Functions Manual Judy1_funcs(3) NAME Judy1 functions - C library for creating and accessing a dynamic array of bits, using any value of a word as an index SYNOPSIS int Judy1Set( PPvoid_t PPJ1Array, Word_t Index, PJError_t PJError); int Judy1Unset( PPvoid_t PPJ1Array, Word_t Index, PJError_t PJError); int Judy1Test( Pcvoid_t PJ1Array, Word_t Index, PJError_t PJError); Word_t Judy1Count( Pcvoid_t PJ1Array, Word_t Index1, Word_t Index2, PJError_t PJError); int Judy1ByCount( Pcvoid_t PJ1Array, Word_t Nth, Word_t * PIndex, PJError_t PJError); Word_t Judy1FreeArray( PPvoid_t PPJ1Array, PJError_t PJError); Word_t Judy1MemUsed( Pcvoid_t PJ1Array); int Judy1First( Pcvoid_t PJ1Array, Word_t * PIndex, PJError_t PJError); int Judy1Next( Pcvoid_t PJ1Array, Word_t * PIndex, PJError_t PJError); int Judy1Last( Pcvoid_t PJ1Array, Word_t * PIndex, PJError_t PJError); int Judy1Prev( Pcvoid_t PJ1Array, Word_t * PIndex, PJError_t PJError); int Judy1FirstEmpty(Pcvoid_t PJ1Array, Word_t * PIndex, PJError_t PJError); int Judy1NextEmpty( Pcvoid_t PJ1Array, Word_t * PIndex, PJError_t PJError); int Judy1LastEmpty( Pcvoid_t PJ1Array, Word_t * PIndex, PJError_t PJError); int Judy1PrevEmpty( Pcvoid_t PJ1Array, Word_t * PIndex, PJError_t PJError); DESCRIPTION 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 Judy1 func- tions. See Judy1(3) for more information. The function call definitions are included here for completeness. One of the difficulties in using the Judy1 function calls lies in determin- ing whether to pass a pointer or the address of a pointer. Since the func- tions that modify the Judy1 array must also modify the pointer to the Judy1 array, you must pass the address of the pointer rather than the pointer it- self. This often leads to hard-to-debug programmatic errors. In practice, the macros allow the compiler to catch programming errors when pointers in- stead of addresses of pointers are passed. The Judy1 function calls have an additional parameter beyond those speci- fied in the macro calls. This parameter is either a pointer to an error structure, or NULL (in which case the detailed error information is not re- turned). In the following descriptions, the functions are described in terms of how the macros use them (only in the case of #define JUDYERROR_NOTEST 1). This is the suggested use of the macros after your program has been fully de- bugged. When the JUDYERROR_NOTEST macro is not specified, an error struc- ture is declared to store error information returned from the Judy1 func- tions when an error occurs. Notice the placement of the & in the different functions. Judy1Set(&PJ1Array, Index, &JError) #define J1S(Rc_int, PJ1Array, Index) \ Rc_int = Judy1Set(&PJ1Array, Index, PJE0) Judy1Unset(&PJ1Array, Index, &JError) #define J1U(Rc_int, PJ1Array, Index) \ Rc_int = Judy1Unset(&PJ1Array, Index, PJE0) Judy1Test(PJ1Array, Index, &JError) #define J1T(Rc_int, PJ1Array, Index) \ Rc_int = Judy1Test(PJ1Array, Index, PJE0) Judy1Count(PJ1Array, Index1, Index2, &JError) #define J1C(Rc_word, PJ1Array, Index1, Index2) \ Rc_word = Judy1Count(PJ1Array, Index1, Index2, PJE0) A return value of 0 can be an error, valid as a count, or it can indicate a special case for a fully-populated array (32-bit machines only). If necessary, the following code can be used to disambiguate this return: JError_t JError; Rc_word = Judy1Count(PJ1Array, Index1, Index2, &JError); if (Rc_word == 0) { if (JU_ERRNO(&JError) == JU_ERRNO_NONE) printf("Judy1 array population == 0\n"); if (JU_ERRNO(&JError) == JU_ERRNO_FULL) printf("Judy1 array population == 2^32\n"); if (JU_ERRNO(&JError) == JU_ERRNO_NULLPPARRAY) goto NullArray; if (JU_ERRNO(&JError) > JU_ERRNO_NFMAX) goto Null_or_CorruptArray; } Judy1ByCount(PJ1Array, Nth, &Index, &JError) #define J1BC(Rc_int, PJ1Array, Nth, Index) \ Rc_int = Judy1ByCount(PJ1Array, Nth, &Index, PJE0) Judy1FreeArray(&PJ1Array, &JError) #define J1FA(Rc_word, PJ1Array) \ Rc_word = Judy1FreeArray(&PJ1Array, PJE0) Judy1MemUsed(PJ1Array) #define J1MU(Rc_word, PJ1Array) \ Rc_word = Judy1MemUsed(PJ1Array) Judy1First(PJ1Array, &Index, &JError) #define J1F(Rc_int, PJ1Array, Index) \ Rc_int = Judy1First(PJ1Array, &Index, PJE0) Judy1Next(PJ1Array, &Index, &JError) #define J1N(Rc_int, PJ1Array, Index) \ Rc_int = Judy1Next(PJ1Array, &Index, PJE0) Judy1Last(PJ1Array, &Index, &JError) #define J1L(Rc_int, PJ1Array, Index) \ Rc_int = Judy1Last(PJ1Array, &Index, PJE0) Judy1Prev(PJ1Array, &Index, &JError) #define J1P(Rc_int, PJ1Array, Index) \ Rc_int = Judy1Prev(PJ1Array, &Index, PJE0) Judy1FirstEmpty(PJ1Array, &Index, &JError) #define J1FE(Rc_int, PJ1Array, Index) \ Rc_int = Judy1FirstEmpty(PJ1Array, &Index, PJE0) Judy1NextEmpty(PJ1Array, &Index, &JError) #define J1NE(Rc_int, PJ1Array, Index) \ Rc_int = Judy1NextEmpty(PJ1Array, &Index, PJE0) Judy1LastEmpty(PJ1Array, &Index, &JError) #define J1LE(Rc_int, PJ1Array, Index) \ Rc_int = Judy1LastEmpty(PJ1Array, &Index, PJE0) Judy1PrevEmpty(PJ1Array, &Index, &JError) #define J1PE(Rc_int, PJ1Array, Index) \ Rc_int = Judy1PrevEmpty(PJ1Array, &Index, PJE0) Definitions for all of the Judy functions, the types Pvoid_t, Pcvoid_t, PPvoid_t, Word_t, JError_t, and PJError_t, the constants NULL, JU_ERRNO_*, JERR, and PJE0, are provided in the Judy.h header file (/usr/in- clude/Judy.h). Note: Callers should define Judy1 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 PPvoid_t. AUTHOR Judy was invented by Doug Baskins and implemented by Hewlett-Packard. SEE ALSO Judy(3), JudyL(3), JudySL(3), JudyHS(3), malloc(), the Judy website, http://judy.sourceforge.net, for more information and Ap- plication Notes. Judy1_funcs(3)
NAME | SYNOPSIS | DESCRIPTION | AUTHOR | SEE ALSO
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=Judy1Prev&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>