Update brotli to v1.0.0-snapshot.

third_party/brotli/enc/context.h

 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 
-// Functions to map previous bytes into a context id.
+/* Functions to map previous bytes into a context id. */
 
 #ifndef BROTLI_ENC_CONTEXT_H_
 #define BROTLI_ENC_CONTEXT_H_
 
-#include "./types.h"
+#include <brotli/port.h>
+#include <brotli/types.h>
 
-namespace brotli {
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
 
-// Second-order context lookup table for UTF8 byte streams.
-//
-// If p1 and p2 are the previous two bytes, we calculate the context as
-//
-//   context = kUTF8ContextLookup[p1] | kUTF8ContextLookup[p2 + 256].
-//
-// If the previous two bytes are ASCII characters (i.e. < 128), this will be
-// equivalent to
-//
-//   context = 4 * context1(p1) + context2(p2),
-//
-// where context1 is based on the previous byte in the following way:
-//
-//   0  : non-ASCII control
-//   1  : \t, \n, \r
-//   2  : space
-//   3  : other punctuation
-//   4  : " '
-//   5  : %
-//   6  : ( < [ {
-//   7  : ) > ] }
-//   8  : , ; :
-//   9  : .
-//   10 : =
-//   11 : number
-//   12 : upper-case vowel
-//   13 : upper-case consonant
-//   14 : lower-case vowel
-//   15 : lower-case consonant
-//
-// and context2 is based on the second last byte:
-//
-//   0 : control, space
-//   1 : punctuation
-//   2 : upper-case letter, number
-//   3 : lower-case letter
-//
-// If the last byte is ASCII, and the second last byte is not (in a valid UTF8
-// stream it will be a continuation byte, value between 128 and 191), the
-// context is the same as if the second last byte was an ASCII control or space.
-//
-// If the last byte is a UTF8 lead byte (value >= 192), then the next byte will
-// be a continuation byte and the context id is 2 or 3 depending on the LSB of
-// the last byte and to a lesser extent on the second last byte if it is ASCII.
-//
-// If the last byte is a UTF8 continuation byte, the second last byte can be:
-//   - continuation byte: the next byte is probably ASCII or lead byte (assuming
-//     4-byte UTF8 characters are rare) and the context id is 0 or 1.
-//   - lead byte (192 - 207): next byte is ASCII or lead byte, context is 0 or 1
-//   - lead byte (208 - 255): next byte is continuation byte, context is 2 or 3
-//
-// The possible value combinations of the previous two bytes, the range of
-// context ids and the type of the next byte is summarized in the table below:
-//
-// |--------\-----------------------------------------------------------------|
-// |         \                         Last byte                              |
-// | Second   \---------------------------------------------------------------|
-// | last byte \    ASCII            |   cont. byte        |   lead byte      |
-// |            \   (0-127)          |   (128-191)         |   (192-)         |
-// |=============|===================|=====================|==================|
-// |  ASCII      | next: ASCII/lead  |  not valid          |  next: cont.     |
-// |  (0-127)    | context: 4 - 63   |                     |  context: 2 - 3  |
-// |-------------|-------------------|---------------------|------------------|
-// |  cont. byte | next: ASCII/lead  |  next: ASCII/lead   |  next: cont.     |
-// |  (128-191)  | context: 4 - 63   |  context: 0 - 1     |  context: 2 - 3  |
-// |-------------|-------------------|---------------------|------------------|
-// |  lead byte  | not valid         |  next: ASCII/lead   |  not valid       |
-// |  (192-207)  |                   |  context: 0 - 1     |                  |
-// |-------------|-------------------|---------------------|------------------|
-// |  lead byte  | not valid         |  next: cont.        |  not valid       |
-// |  (208-)     |                   |  context: 2 - 3     |                  |
-// |-------------|-------------------|---------------------|------------------|
+/* Second-order context lookup table for UTF8 byte streams.
+
+   If p1 and p2 are the previous two bytes, we calculate the context as
+
+     context = kUTF8ContextLookup[p1] | kUTF8ContextLookup[p2 + 256].
+
+   If the previous two bytes are ASCII characters (i.e. < 128), this will be
+   equivalent to
+
+     context = 4 * context1(p1) + context2(p2),
+
+   where context1 is based on the previous byte in the following way:
+
+     0  : non-ASCII control
+     1  : \t, \n, \r
+     2  : space
+     3  : other punctuation
+     4  : " '
+     5  : %
+     6  : ( < [ {
+     7  : ) > ] }
+     8  : , ; :
+     9  : .
+     10 : =
+     11 : number
+     12 : upper-case vowel
+     13 : upper-case consonant
+     14 : lower-case vowel
+     15 : lower-case consonant
+
+   and context2 is based on the second last byte:
+
+     0 : control, space
+     1 : punctuation
+     2 : upper-case letter, number
+     3 : lower-case letter
+
+   If the last byte is ASCII, and the second last byte is not (in a valid UTF8
+   stream it will be a continuation byte, value between 128 and 191), the
+   context is the same as if the second last byte was an ASCII control or space.
+
+   If the last byte is a UTF8 lead byte (value >= 192), then the next byte will
+   be a continuation byte and the context id is 2 or 3 depending on the LSB of
+   the last byte and to a lesser extent on the second last byte if it is ASCII.
+
+   If the last byte is a UTF8 continuation byte, the second last byte can be:
+     - continuation byte: the next byte is probably ASCII or lead byte (assuming
+       4-byte UTF8 characters are rare) and the context id is 0 or 1.
+     - lead byte (192 - 207): next byte is ASCII or lead byte, context is 0 or 1
+     - lead byte (208 - 255): next byte is continuation byte, context is 2 or 3
+
+   The possible value combinations of the previous two bytes, the range of
+   context ids and the type of the next byte is summarized in the table below:
+
+   |--------\-----------------------------------------------------------------|
+   |         \                         Last byte                              |
+   | Second   \---------------------------------------------------------------|
+   | last byte \    ASCII            |   cont. byte        |   lead byte      |
+   |            \   (0-127)          |   (128-191)         |   (192-)         |
+   |=============|===================|=====================|==================|
+   |  ASCII      | next: ASCII/lead  |  not valid          |  next: cont.     |
+   |  (0-127)    | context: 4 - 63   |                     |  context: 2 - 3  |
+   |-------------|-------------------|---------------------|------------------|
+   |  cont. byte | next: ASCII/lead  |  next: ASCII/lead   |  next: cont.     |
+   |  (128-191)  | context: 4 - 63   |  context: 0 - 1     |  context: 2 - 3  |
+   |-------------|-------------------|---------------------|------------------|
+   |  lead byte  | not valid         |  next: ASCII/lead   |  not valid       |
+   |  (192-207)  |                   |  context: 0 - 1     |                  |
+   |-------------|-------------------|---------------------|------------------|
+   |  lead byte  | not valid         |  next: cont.        |  not valid       |
+   |  (208-)     |                   |  context: 2 - 3     |                  |
+   |-------------|-------------------|---------------------|------------------|
+*/
 static const uint8_t kUTF8ContextLookup[512] = {
-  // Last byte.
-  //
-  // ASCII range.
+  /* Last byte. */
+  /* */
+  /* ASCII range. */
    0,  0,  0,  0,  0,  0,  0,  0,  0,  4,  4,  0,  0,  4,  0,  0,
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    8, 12, 16, 12, 12, 20, 12, 16, 24, 28, 12, 12, 32, 12, 36, 12,
   44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 32, 32, 24, 40, 28, 12,
   12, 48, 52, 52, 52, 48, 52, 52, 52, 48, 52, 52, 52, 52, 52, 48,
   52, 52, 52, 52, 52, 48, 52, 52, 52, 52, 52, 24, 12, 28, 12, 12,
   12, 56, 60, 60, 60, 56, 60, 60, 60, 56, 60, 60, 60, 60, 60, 56,
   60, 60, 60, 60, 60, 56, 60, 60, 60, 60, 60, 24, 12, 28, 12,  0,
-  // UTF8 continuation byte range.
+  /* UTF8 continuation byte range. */
   0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
   0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
   0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
   0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
-  // UTF8 lead byte range.
+  /* UTF8 lead byte range. */
   2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
   2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
   2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
   2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
-  // Second last byte.
-  //
-  // ASCII range.
+  /* Second last byte. */
+  /* */
+  /* ASCII range. */
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1,
   1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1,
   1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
   3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, 0,
-  // UTF8 continuation byte range.
+  /* UTF8 continuation byte range. */
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-  // UTF8 lead byte range.
+  /* UTF8 lead byte range. */
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
 };
 
-// Context lookup table for small signed integers.
+/* Context lookup table for small signed integers. */
 static const uint8_t kSigned3BitContextLookup[] = {
   0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
   3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
   3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
   3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
   3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
   4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
   4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
   4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
   4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
   5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
   5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
   5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
   6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7,
 };
 
-enum ContextType {
+typedef enum ContextType {
   CONTEXT_LSB6         = 0,
   CONTEXT_MSB6         = 1,
   CONTEXT_UTF8         = 2,
   CONTEXT_SIGNED       = 3
-};
+} ContextType;
 
-static inline uint8_t Context(uint8_t p1, uint8_t p2, ContextType mode) {
+static BROTLI_INLINE uint8_t Context(uint8_t p1, uint8_t p2, ContextType mode) {
   switch (mode) {
     case CONTEXT_LSB6:
       return p1 & 0x3f;
     case CONTEXT_MSB6:
-      return static_cast<uint8_t>(p1 >> 2);
+      return (uint8_t)(p1 >> 2);
     case CONTEXT_UTF8:
       return kUTF8ContextLookup[p1] | kUTF8ContextLookup[p2 + 256];
     case CONTEXT_SIGNED:
-      return static_cast<uint8_t>((kSigned3BitContextLookup[p1] << 3) +
-                                  kSigned3BitContextLookup[p2]);
+      return (uint8_t)((kSigned3BitContextLookup[p1] << 3) +
+                       kSigned3BitContextLookup[p2]);
     default:
       return 0;
   }
 }
 
-}  // namespace brotli
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif
 
-#endif  // BROTLI_ENC_CONTEXT_H_
+#endif  /* BROTLI_ENC_CONTEXT_H_ */