include/pub_tool_xarray.h

   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) 2007-2013 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 /*--------------------------------------------------------------------*/