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Vector Packet Processing
vec_bootstrap.h
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1 /*
2  * Copyright (c) 2015 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
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15 /*
16  Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus
17 
18  Permission is hereby granted, free of charge, to any person obtaining
19  a copy of this software and associated documentation files (the
20  "Software"), to deal in the Software without restriction, including
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37 
38 #ifndef included_clib_vec_bootstrap_h
39 #define included_clib_vec_bootstrap_h
40 
41 /** \file
42  Vector bootsrap header file
43 */
44 
45 /* Bootstrap include so that #include <vppinfra/mem.h> can include e.g.
46  <vppinfra/mheap.h> which depends on <vppinfra/vec.h>. */
47 
48 /** \brief vector header structure
49 
50  Bookeeping header preceding vector elements in memory.
51  User header information may preceed standard vec header.
52  If you change u32 len -> u64 len, single vectors can
53  exceed 2**32 elements. Clib heaps are vectors. */
54 
55 typedef struct
56 {
57 #if CLIB_VEC64 > 0
58  u64 len;
59 #else
60  u32 len; /**< Number of elements in vector (NOT its allocated length). */
61 #endif
62  u8 vector_data[0]; /**< Vector data . */
63 } vec_header_t;
64 
65 /** \brief Find the vector header
66 
67  Given the user's pointer to a vector, find the corresponding
68  vector header
69 
70  @param v pointer to a vector
71  @return pointer to the vector's vector_header_t
72 */
73 #define _vec_find(v) ((vec_header_t *) (v) - 1)
74 
75 #define _vec_round_size(s) \
76  (((s) + sizeof (uword) - 1) &~ (sizeof (uword) - 1))
77 
79 vec_header_bytes (uword header_bytes)
80 {
81  return round_pow2 (header_bytes + sizeof (vec_header_t),
82  sizeof (vec_header_t));
83 }
84 
85 /** \brief Find a user vector header
86 
87  Finds the user header of a vector with unspecified alignment given
88  the user pointer to the vector.
89 */
90 
91 always_inline void *
92 vec_header (void *v, uword header_bytes)
93 {
94  return v - vec_header_bytes (header_bytes);
95 }
96 
97 /** \brief Find the end of user vector header
98 
99  Finds the end of the user header of a vector with unspecified
100  alignment given the user pointer to the vector.
101 */
102 
103 always_inline void *
104 vec_header_end (void *v, uword header_bytes)
105 {
106  return v + vec_header_bytes (header_bytes);
107 }
108 
110 vec_aligned_header_bytes (uword header_bytes, uword align)
111 {
112  return round_pow2 (header_bytes + sizeof (vec_header_t), align);
113 }
114 
115 always_inline void *
116 vec_aligned_header (void *v, uword header_bytes, uword align)
117 {
118  return v - vec_aligned_header_bytes (header_bytes, align);
119 }
120 
121 always_inline void *
122 vec_aligned_header_end (void *v, uword header_bytes, uword align)
123 {
124  return v + vec_aligned_header_bytes (header_bytes, align);
125 }
126 
127 
128 /** \brief Number of elements in vector (lvalue-capable)
129 
130  _vec_len (v) does not check for null, but can be used as a lvalue
131  (e.g. _vec_len (v) = 99).
132 */
133 
134 #define _vec_len(v) (_vec_find(v)->len)
135 
136 /** \brief Number of elements in vector (rvalue-only, NULL tolerant)
137 
138  vec_len (v) checks for NULL, but cannot be used as an lvalue.
139  If in doubt, use vec_len...
140 */
141 
142 #define vec_len(v) ((v) ? _vec_len(v) : 0)
143 
144 /** \brief Reset vector length to zero
145  NULL-pointer tolerant
146 */
147 
148 #define vec_reset_length(v) do { if (v) _vec_len (v) = 0; } while (0)
149 
150 /** \brief Number of data bytes in vector. */
151 
152 #define vec_bytes(v) (vec_len (v) * sizeof (v[0]))
153 
154 /** \brief Total number of bytes that can fit in vector with current allocation. */
155 
156 #define vec_capacity(v,b) \
157 ({ \
158  void * _vec_capacity_v = (void *) (v); \
159  uword _vec_capacity_b = (b); \
160  _vec_capacity_b = sizeof (vec_header_t) + _vec_round_size (_vec_capacity_b); \
161  _vec_capacity_v ? clib_mem_size (_vec_capacity_v - _vec_capacity_b) : 0; \
162 })
163 
164 /** \brief Total number of elements that can fit into vector. */
165 #define vec_max_len(v) (vec_capacity(v,0) / sizeof (v[0]))
166 
167 /** \brief End (last data address) of vector. */
168 #define vec_end(v) ((v) + vec_len (v))
169 
170 /** \brief True if given pointer is within given vector. */
171 #define vec_is_member(v,e) ((e) >= (v) && (e) < vec_end (v))
172 
173 /** \brief Get vector value at index i checking that i is in bounds. */
174 #define vec_elt_at_index(v,i) \
175 ({ \
176  ASSERT ((i) < vec_len (v)); \
177  (v) + (i); \
178 })
179 
180 /** \brief Get vector value at index i */
181 #define vec_elt(v,i) (vec_elt_at_index(v,i))[0]
182 
183 /** \brief Vector iterator */
184 #define vec_foreach(var,vec) for (var = (vec); var < vec_end (vec); var++)
185 
186 /** \brief Vector iterator (reverse) */
187 #define vec_foreach_backwards(var,vec) \
188 for (var = vec_end (vec) - 1; var >= (vec); var--)
189 
190 /** \brief Iterate over vector indices. */
191 #define vec_foreach_index(var,v) for ((var) = 0; (var) < vec_len (v); (var)++)
192 
193 #endif /* included_clib_vec_bootstrap_h */
194 
195 /*
196  * fd.io coding-style-patch-verification: ON
197  *
198  * Local Variables:
199  * eval: (c-set-style "gnu")
200  * End:
201  */
static uword vec_header_bytes(uword header_bytes)
Definition: vec_bootstrap.h:79
#define always_inline
Definition: clib.h:92
unsigned long u64
Definition: types.h:89
static uword vec_aligned_header_bytes(uword header_bytes, uword align)
#define v
Definition: acl.c:341
static void * vec_aligned_header(void *v, uword header_bytes, uword align)
static uword round_pow2(uword x, uword pow2)
Definition: clib.h:286
u32 len
Number of elements in vector (NOT its allocated length).
Definition: vec_bootstrap.h:60
unsigned int u32
Definition: types.h:88
vector header structure
Definition: vec_bootstrap.h:55
u64 uword
Definition: types.h:112
unsigned char u8
Definition: types.h:56
static void * vec_aligned_header_end(void *v, uword header_bytes, uword align)
static void * vec_header(void *v, uword header_bytes)
Find a user vector header.
Definition: vec_bootstrap.h:92
static void * vec_header_end(void *v, uword header_bytes)
Find the end of user vector header.