Turn normal_url_char into a bit array.

Makes http_parser slightly more cache friendly.

Author: bnoordhuis

http_parser.c

@@ -41,6 +41,12 @@
 # define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 #endif
 
+#ifndef BIT_AT
+# define BIT_AT(a, i)                                                \
+  (!!((unsigned int) (a)[(unsigned int) (i) >> 3] &                  \
+   (1 << ((unsigned int) (i) & 7))))
+#endif
+
 #ifndef ELEM_AT
 # define ELEM_AT(a, i, v) ((unsigned int) (i) < ARRAY_SIZE(a) ? (a)[(i)] : (v))
 #endif
@@ -192,45 +198,45 @@ static const int8_t unhex[256] =
 
 
 #if HTTP_PARSER_STRICT
-# define T 0
+# define T(v) 0
 #else
-# define T 1
+# define T(v) v
 #endif
 
 
-static const uint8_t normal_url_char[256] = {
+static const uint8_t normal_url_char[32] = {
 /*   0 nul    1 soh    2 stx    3 etx    4 eot    5 enq    6 ack    7 bel  */
-        0,       0,       0,       0,       0,       0,       0,       0,
+        0    |   0    |   0    |   0    |   0    |   0    |   0    |   0,
 /*   8 bs     9 ht    10 nl    11 vt    12 np    13 cr    14 so    15 si   */
-        0,       T,       0,       0,       T,       0,       0,       0,
+        0    | T(2)   |   0    |   0    | T(16)  |   0    |   0    |   0,
 /*  16 dle   17 dc1   18 dc2   19 dc3   20 dc4   21 nak   22 syn   23 etb */
-        0,       0,       0,       0,       0,       0,       0,       0,
+        0    |   0    |   0    |   0    |   0    |   0    |   0    |   0,
 /*  24 can   25 em    26 sub   27 esc   28 fs    29 gs    30 rs    31 us  */
-        0,       0,       0,       0,       0,       0,       0,       0,
+        0    |   0    |   0    |   0    |   0    |   0    |   0    |   0,
 /*  32 sp    33  !    34  "    35  #    36  $    37  %    38  &    39  '  */
-        0,       1,       1,       0,       1,       1,       1,       1,
+        0    |   2    |   4    |   0    |   16   |   32   |   64   |  128,
 /*  40  (    41  )    42  *    43  +    44  ,    45  -    46  .    47  /  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /*  48  0    49  1    50  2    51  3    52  4    53  5    54  6    55  7  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /*  56  8    57  9    58  :    59  ;    60  <    61  =    62  >    63  ?  */
-        1,       1,       1,       1,       1,       1,       1,       0,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |   0,
 /*  64  @    65  A    66  B    67  C    68  D    69  E    70  F    71  G  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /*  72  H    73  I    74  J    75  K    76  L    77  M    78  N    79  O  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /*  80  P    81  Q    82  R    83  S    84  T    85  U    86  V    87  W  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /*  88  X    89  Y    90  Z    91  [    92  \    93  ]    94  ^    95  _  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /*  96  `    97  a    98  b    99  c   100  d   101  e   102  f   103  g  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /* 104  h   105  i   106  j   107  k   108  l   109  m   110  n   111  o  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /* 112  p   113  q   114  r   115  s   116  t   117  u   118  v   119  w  */
-        1,       1,       1,       1,       1,       1,       1,       1,
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |  128,
 /* 120  x   121  y   122  z   123  {   124  |   125  }   126  ~   127 del */
-        1,       1,       1,       1,       1,       1,       1,       0, };
+        1    |   2    |   4    |   8    |   16   |   32   |   64   |   0, };
 
 #undef T
 
@@ -371,12 +377,12 @@ enum http_host_state
 
 #if HTTP_PARSER_STRICT
 #define TOKEN(c)            (tokens[(unsigned char)c])
-#define IS_URL_CHAR(c)      (normal_url_char[(unsigned char) (c)])
+#define IS_URL_CHAR(c)      (BIT_AT(normal_url_char, (unsigned char)c))
 #define IS_HOST_CHAR(c)     (IS_ALPHANUM(c) || (c) == '.' || (c) == '-')
 #else
 #define TOKEN(c)            ((c == ' ') ? ' ' : tokens[(unsigned char)c])
 #define IS_URL_CHAR(c)                                                         \
-  (normal_url_char[(unsigned char) (c)] || ((c) & 0x80))
+  (BIT_AT(normal_url_char, (unsigned char)c) || ((c) & 0x80))
 #define IS_HOST_CHAR(c)                                                        \
   (IS_ALPHANUM(c) || (c) == '.' || (c) == '-' || (c) == '_')
 #endif