projects / unix-history / blame
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1 | /* |
| 2 | * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| d4808d39 | 4 | * |
| fc03cc72 KB |
5 | * This code is derived from software contributed to Berkeley by |
| 6 | * Adam de Boor. | |
| d4808d39 | 7 | * |
| f15db449 | 8 | * %sccs.include.redist.c% |
| d4808d39 | 9 | * |
| fc46faab | 10 | * @(#)lstInt.h 5.4 (Berkeley) %G% |
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11 | */ |
| 12 | ||
| 13 | /*- | |
| 14 | * lstInt.h -- | |
| 15 | * Internals for the list library | |
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16 | */ |
| 17 | #ifndef _LSTINT_H_ | |
| 18 | #define _LSTINT_H_ | |
| 19 | ||
| 20 | #include "lst.h" | |
| 21 | ||
| 22 | typedef struct ListNode { | |
| 23 | struct ListNode *prevPtr; /* previous element in list */ | |
| 24 | struct ListNode *nextPtr; /* next in list */ | |
| 25 | short useCount:8, /* Count of functions using the node. | |
| 26 | * node may not be deleted until count | |
| 27 | * goes to 0 */ | |
| 28 | flags:8; /* Node status flags */ | |
| 29 | ClientData datum; /* datum associated with this element */ | |
| 30 | } *ListNode; | |
| 31 | /* | |
| 32 | * Flags required for synchronization | |
| 33 | */ | |
| 34 | #define LN_DELETED 0x0001 /* List node should be removed when done */ | |
| 35 | ||
| 36 | #define NilListNode ((ListNode)-1) | |
| 37 | ||
| 38 | typedef enum { | |
| 39 | Head, Middle, Tail, Unknown | |
| 40 | } Where; | |
| 41 | ||
| 42 | typedef struct { | |
| 43 | ListNode firstPtr; /* first node in list */ | |
| 44 | ListNode lastPtr; /* last node in list */ | |
| 45 | Boolean isCirc; /* true if the list should be considered | |
| 46 | * circular */ | |
| 47 | /* | |
| 48 | * fields for sequential access | |
| 49 | */ | |
| 50 | Where atEnd; /* Where in the list the last access was */ | |
| 51 | Boolean isOpen; /* true if list has been Lst_Open'ed */ | |
| 52 | ListNode curPtr; /* current node, if open. NilListNode if | |
| 53 | * *just* opened */ | |
| 54 | ListNode prevPtr; /* Previous node, if open. Used by | |
| 55 | * Lst_Remove */ | |
| 56 | } *List; | |
| 57 | ||
| 58 | #define NilList ((List)-1) | |
| 59 | ||
| 60 | /* | |
| 61 | * PAlloc (var, ptype) -- | |
| 62 | * Allocate a pointer-typedef structure 'ptype' into the variable 'var' | |
| 63 | */ | |
| fc46faab | 64 | #define PAlloc(var,ptype) var = (ptype) malloc (sizeof (*var)) |
| d4808d39 KB |
65 | |
| 66 | /* | |
| 67 | * LstValid (l) -- | |
| 68 | * Return TRUE if the list l is valid | |
| 69 | */ | |
| 70 | #define LstValid(l) (((Lst)l == NILLST) ? FALSE : TRUE) | |
| 71 | ||
| 72 | /* | |
| 73 | * LstNodeValid (ln, l) -- | |
| 74 | * Return TRUE if the LstNode ln is valid with respect to l | |
| 75 | */ | |
| 76 | #define LstNodeValid(ln, l) ((((LstNode)ln) == NILLNODE) ? FALSE : TRUE) | |
| 77 | ||
| 78 | /* | |
| 79 | * LstIsEmpty (l) -- | |
| 80 | * TRUE if the list l is empty. | |
| 81 | */ | |
| 82 | #define LstIsEmpty(l) (((List)l)->firstPtr == NilListNode) | |
| 83 | ||
| 84 | #endif _LSTINT_H_ |