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1 
2 /*--------------------------------------------------------------------*/
3 /*--- An expandable array implementation.        pub_tool_xarray.h ---*/
4 /*--------------------------------------------------------------------*/
5 
6 /*
7    This file is part of Valgrind, a dynamic binary instrumentation
8    framework.
9 
10    Copyright (C) 2007-2015 OpenWorks LLP
11       info@open-works.co.uk
12 
13    This program is free software; you can redistribute it and/or
14    modify it under the terms of the GNU General Public License as
15    published by the Free Software Foundation; either version 2 of the
16    License, or (at your option) any later version.
17 
18    This program is distributed in the hope that it will be useful, but
19    WITHOUT ANY WARRANTY; without even the implied warranty of
20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21    General Public License for more details.
22 
23    You should have received a copy of the GNU General Public License
24    along with this program; if not, write to the Free Software
25    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26    02111-1307, USA.
27 
28    The GNU General Public License is contained in the file COPYING.
29 */
30 
31 #ifndef __PUB_TOOL_XARRAY_H
32 #define __PUB_TOOL_XARRAY_H
33 
34 #include "pub_tool_basics.h"    // Word
35 
36 //--------------------------------------------------------------------
37 // PURPOSE: Provides a simple but useful structure, which is an array
38 // in which elements can be added at the end.  The array is expanded
39 // as needed by multiplying its size by a constant factor (usually 2).
40 // This gives amortised O(1) insertion cost, and, following sorting,
41 // the usual O(log N) binary search cost.  Arbitrary element sizes
42 // are allowed; the comparison function for sort/lookup can be changed
43 // at any time, and duplicates (modulo the comparison function) are
44 // allowed.
45 //--------------------------------------------------------------------
46 
47 
48 /* It's an abstract type.  Bwaha. */
49 typedef  struct _XArray  XArray;
50 
51 typedef Int (*XACmpFn_t)(const void *, const void *);
52 
53 /* Create new XArray, using given allocation and free function, and
54    for elements of the specified size.  alloc_fn must not return NULL (that
55    is, if it returns it must have succeeded.)
56    This function never returns NULL. */
57 extern XArray* VG_(newXA) ( void*(*alloc_fn)(const HChar*,SizeT),
58                             const HChar* cc,
59                             void(*free_fn)(void*),
60                             Word elemSzB );
61 
62 /* Free all memory associated with an XArray. */
63 extern void VG_(deleteXA) ( XArray* );
64 
65 /* Set the comparison function for this XArray.  This clears an
66    internal 'array is sorted' flag, which means you must call sortXA
67    before making further queries with lookupXA. */
68 extern void VG_(setCmpFnXA) ( XArray*, XACmpFn_t);
69 
70 /* Add an element to an XArray.  Element is copied into the XArray.
71    Index at which it was added is returned.  Note this will be
72    invalidated if the array is later sortXA'd. */
73 extern Word VG_(addToXA) ( XArray*, const void* elem );
74 
75 /* Add a sequence of bytes to an XArray of bytes.  Asserts if nbytes
76    is negative or the array's element size is not 1.  Returns the
77    index at which the first byte was added. */
78 extern Word VG_(addBytesToXA) ( XArray* xao, const void* bytesV, Word nbytes );
79 
80 /* Sort an XArray using its comparison function, if set; else bomb.
81    Probably not a stable sort w.r.t. equal elements module cmpFn. */
82 extern void VG_(sortXA) ( XArray* );
83 
84 /* Lookup (by binary search) 'key' in the array.  Set *first to be the
85    index of the first, and *last to be the index of the last matching
86    value found.  If any values are found, return True, else return
87    False, and don't change *first or *last.  first and/or last may be
88    NULL.  Bomb if the array is not sorted. */
89 extern Bool VG_(lookupXA) ( const XArray*, const void* key,
90                             /*OUT*/Word* first, /*OUT*/Word* last );
91 
92 /* A version of VG_(lookupXA) in which you can specify your own
93    comparison function.  This is unsafe in the sense that if the array
94    is not totally ordered as defined by your comparison function, then
95    this function may loop indefinitely, so it is up to you to ensure
96    that the array is suitably ordered.  This is in comparison to
97    VG_(lookupXA), which refuses to do anything (asserts) unless the
98    array has first been sorted using the same comparison function as
99    is being used for the lookup. */
100 extern Bool VG_(lookupXA_UNSAFE) ( const XArray* xao, const void* key,
101                                    /*OUT*/Word* first, /*OUT*/Word* last,
102                                    XACmpFn_t cmpFn );
103 
104 /* How elements are there in this XArray now? */
105 extern Word VG_(sizeXA) ( const XArray* );
106 
107 /* If you know how many elements an XArray will have, you can
108    optimise memory usage and number of reallocation needed
109    to insert these elements. The call to VG_(hintSizeXA) must be
110    done just after the call to VG_(newXA), before any element
111    has been inserted. */
112 extern void VG_(hintSizeXA) ( XArray*, Word);
113 
114 /* Index into the XArray.  Checks bounds and bombs if the index is
115    invalid.  What this returns is the address of the specified element
116    in the array, not (of course) the element itself.  Note that the
117    element may get moved by subsequent calls to addToXA / sortXA /
118    insertIndexXA, so you should copy it out immediately and not regard
119    its address as unchanging.  Note also that indexXA will of course
120    not return NULL if it succeeds. */
121 extern void* VG_(indexXA) ( const XArray*, Word );
122 
123 /* Drop the last n elements of an XArray.  Bombs if there are less
124    than n elements in the array.  This is an O(1) operation. */
125 extern void VG_(dropTailXA) ( XArray*, Word );
126 
127 /* Drop the first n elements of an XArray.  Bombs if there are less
128    than n elements in the array.  This is an O(N) operation, where N
129    is the number of elements remaining in the XArray. */
130 extern void VG_(dropHeadXA) ( XArray*, Word );
131 
132 /* Remove the specified element of an XArray, and slide all elements
133    beyond it back one place.  This is an O(N) operation, where N is
134    the number of elements after the specified element, in the
135    array. */
136 extern void VG_(removeIndexXA)( XArray*, Word );
137 
138 /* Insert an element into an XArray at the given index.  The existing
139    element at the index and all above it are slid upwards one slot so
140    as to make space.  Element is copied into the XArray.  This is an
141    O(N) operation, when N is the number of elements after the
142    specified element, in the array. */
143 extern void VG_(insertIndexXA)( XArray*, Word, const void* elem );
144 
145 /* Make a new, completely independent copy of the given XArray, using
146    the existing allocation function to allocate the new space.
147    Space for the clone (and all additions to it) is billed to 'cc' unless
148    that is NULL, in which case the parent's cost-center is used.
149    Ths function never returns NULL. */
150 extern XArray* VG_(cloneXA)( const HChar* cc, const XArray* xa );
151 
152 /* Get the raw array and size so callers can index it really fast.
153    This is dangerous in the sense that there's no range or
154    anything-else checking.  It's also dangerous in that if
155    VG_(addToXA) is used, the contents may be re-located without
156    warning, hence making the contents address returned here
157    invalid. */
158 extern void VG_(getContentsXA_UNSAFE)( XArray* sr,
159                                        /*OUT*/void** ctsP,
160                                        /*OUT*/Word*  usedP );
161 
162 /* Convenience function: printf into an XArray of HChar, adding stuff
163    at the end.  This is very convenient for concocting arbitrary
164    length printf output in an XArray.  Note that the resulting string
165    is NOT zero-terminated. */
166 extern void VG_(xaprintf)( XArray* dst, const HChar* format, ... )
167                          PRINTF_CHECK(2, 3);
168 
169 #endif   // __PUB_TOOL_XARRAY_H
170 
171 /*--------------------------------------------------------------------*/
172 /*--- end                                        pub_tool_xarray.h ---*/
173 /*--------------------------------------------------------------------*/
174