1JudyHS_funcs(3) Library Functions Manual JudyHS_funcs(3)
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6 JudyHS functions - C library for creating and accessing a dynamic
7 array, using an array-of-bytes of a length: Length as an Index and a
8 word as a Value.
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11 PPvoid_t JudyHSIns(PPvoid_t PPJHS, void *Index, Word_t Length, PJError_t PJError);
12 int JudyHSDel(PPvoid_t PPJHS, void *Index, Word_t Length, PJError_t PJError);
13 PPvoid_t JudyHSGet(Pcvoid_t PJHS, void *Index, Word_t Length, PJError_t PJError);
14 Word_t JudyHSFreeArray(PPvoid_t PPJHS, PJError_t PJError);
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17 A macro equivalent exists for each function call. Because the macro
18 forms are sometimes faster and have a simpler error handling interface
19 than the equivalent functions, they are the preferred way of calling
20 the JudyHS functions. See JudyHS(3) for more information. The func‐
21 tion call definitions are included here for completeness.
22 One of the difficulties in using the JudyHS function calls lies in
24 determining whether to pass a pointer or the address of a pointer.
25 Since the functions that modify the JudyHS array must also modify the
26 pointer to the JudyHS array, you must pass the address of the pointer
27 rather than the pointer itself. This often leads to hard-to-debug pro‐
28 grammatic errors. In practice, the macros allow the compiler to catch
29 programming errors when pointers instead of addresses of pointers are
30 passed.
31 The JudyHS function calls have an additional parameter beyond those
33 specified in the macro calls. This parameter is either a pointer to an
34 error structure, or NULL (in which case the error information is not
35 returned -- only PJERR in the return parameter).
36 In the following descriptions, the functions are described in terms of
38 how the macros use them. This is the suggested use of the macros after
39 your program has been fully debugged. When the JUDYERROR_NOTEST macro
40 is not specified, an error structure is declared to store error infor‐
41 mation returned from the JudyHS functions when an error occurs.
42 Notice the placement of the & in the different functions.
44 JudyHSIns(&PJHS, Index, Length, &JError)
46 #define JHSI(PValue, PJHS, Index) \
48 PValue = JudyLIns(&PJHS, Index, PJE0)
49 JudyHSDel(&PJHS, Index, Length, &JError)
51 #define JHSD(Rc_int, PJHS, Index, Length) \
53 Rc_int = JudyHSDel(&PJHS, Index, Length, PJE0)
54 JudyHSGet(PJHS, Index, Length)
56 #define JHSG(PValue, PJHS, Index, Length) \
58 PValue = JudyHSIns(PJHS, Index, Length)
59 JudyHSFreeArray(&PJHS, &JError)
61 #define JHSFA(Rc_word, PJHS) \
63 Rc_word = JudyHSFreeArray(&PJHS, PJE0)
64 Definitions for all the Judy functions, the types Pvoid_t, Pcvoid_t,
66 PPvoid_t, Word_t , JError_t, and PJError_t, the constants NULL,
67 JU_ERRNO_*, JERR, PPJERR, and PJE0 are provided in the Judy.h header
68 file (/usr/include/Judy.h). Note: Callers should define JudyHS arrays
69 as type Pvoid_t, which can be passed by value to functions that take
70 Pcvoid_t (constant Pvoid_t), and also by address to functions that take
71 PPvoid_t.
72 The return type from most JudyHS functions is PPvoid_t so that the val‐
74 ues stored in the array can be pointers to other objects, which is a
75 typical usage, or cast to a Word_t * when a pointer to a value is
76 required instead of a pointer to a pointer.
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79 JudyHS was invented and implemented by Doug Baskins after retiring from
80 Hewlett-Packard.
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83 Judy(3), Judy1(3), JudyL(3), JudySL(3), JudyHS(3),
84 malloc(),
85 the Judy website, http://judy.sourceforge.net, for more information and
86 Application Notes.
87 JudyHS_funcs(3)