Added brotli enc/ and tools/ directories.

third_party/brotli/enc/static_dict.cc

+/* Copyright 2013 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+#include "./static_dict.h"
+
+#include <algorithm>
+
+#include "./dictionary.h"
+#include "./find_match_length.h"
+#include "./static_dict_lut.h"
+#include "./transform.h"
+
+namespace brotli {
+
+inline uint32_t Hash(const uint8_t *data) {
+  uint32_t h = BROTLI_UNALIGNED_LOAD32(data) * kDictHashMul32;
+  // The higher bits contain more mixture from the multiplication,
+  // so we take our results from there.
+  return h >> (32 - kDictNumBits);
+}
+
+inline void AddMatch(size_t distance, size_t len, size_t len_code,
+                     uint32_t* matches) {
+  uint32_t match = static_cast<uint32_t>((distance << 5) + len_code);
+  matches[len] = std::min(matches[len], match);
+}
+
+inline size_t DictMatchLength(const uint8_t* data,
+                              size_t id,
+                              size_t len,
+                              size_t maxlen) {
+  const size_t offset = kBrotliDictionaryOffsetsByLength[len] + len * id;
+  return FindMatchLengthWithLimit(&kBrotliDictionary[offset], data,
+                                  std::min(len, maxlen));
+}
+
+inline bool IsMatch(DictWord w, const uint8_t* data, size_t max_length) {
+  if (w.len > max_length) return false;
+  const size_t offset = kBrotliDictionaryOffsetsByLength[w.len] + w.len * w.idx;
+  const uint8_t* dict = &kBrotliDictionary[offset];
+  if (w.transform == 0) {
+    // Match against base dictionary word.
+    return FindMatchLengthWithLimit(dict, data, w.len) == w.len;
+  } else if (w.transform == 10) {
+    // Match against uppercase first transform.
+    // Note that there are only ASCII uppercase words in the lookup table.
+    return (dict[0] >= 'a' && dict[0] <= 'z' &&
+            (dict[0] ^ 32) == data[0] &&
+            FindMatchLengthWithLimit(&dict[1], &data[1], w.len - 1u) ==
+            w.len - 1u);
+  } else {
+    // Match against uppercase all transform.
+    // Note that there are only ASCII uppercase words in the lookup table.
+    for (size_t i = 0; i < w.len; ++i) {
+      if (dict[i] >= 'a' && dict[i] <= 'z') {
+        if ((dict[i] ^ 32) != data[i]) return false;
+      } else {
+        if (dict[i] != data[i]) return false;
+      }
+    }
+    return true;
+  }
+}
+
+bool FindAllStaticDictionaryMatches(const uint8_t* data,
+                                    size_t min_length,
+                                    size_t max_length,
+                                    uint32_t* matches) {
+  bool found_match = false;
+  size_t key = Hash(data);
+  size_t bucket = kStaticDictionaryBuckets[key];
+  if (bucket != 0) {
+    size_t num = bucket & 0xff;
+    size_t offset = bucket >> 8;
+    for (size_t i = 0; i < num; ++i) {
+      const DictWord w = kStaticDictionaryWords[offset + i];
+      const size_t l = w.len;
+      const size_t n = 1u << kBrotliDictionarySizeBitsByLength[l];
+      const size_t id = w.idx;
+      if (w.transform == 0) {
+        const size_t matchlen = DictMatchLength(data, id, l, max_length);
+        // Transform "" + kIdentity + ""
+        if (matchlen == l) {
+          AddMatch(id, l, l, matches);
+          found_match = true;
+        }
+        // Transforms "" + kOmitLast1 + "" and "" + kOmitLast1 + "ing "
+        if (matchlen >= l - 1) {
+          AddMatch(id + 12 * n, l - 1, l, matches);
+          if (l + 2 < max_length &&
+              data[l - 1] == 'i' && data[l] == 'n' && data[l + 1] == 'g' &&
+              data[l + 2] == ' ') {
+            AddMatch(id + 49 * n, l + 3, l, matches);
+          }
+          found_match = true;
+        }
+        // Transform "" + kOmitLastN + "" (N = 2 .. 9)
+        size_t minlen = min_length;
+        if (l > 9) minlen = std::max(minlen, l - 9);
+        size_t maxlen = std::min(matchlen, l - 2);
+        for (size_t len = minlen; len <= maxlen; ++len) {
+          AddMatch(id + kOmitLastNTransforms[l - len] * n, len, l, matches);
+          found_match = true;
+        }
+        if (matchlen < l || l + 6 >= max_length) {
+          continue;
+        }
+        const uint8_t* s = &data[l];
+        // Transforms "" + kIdentity + <suffix>
+        if (s[0] == ' ') {
+          AddMatch(id + n, l + 1, l, matches);
+          if (s[1] == 'a') {
+            if (s[2] == ' ') {
+              AddMatch(id + 28 * n, l + 3, l, matches);
+            } else if (s[2] == 's') {
+              if (s[3] == ' ') AddMatch(id + 46 * n, l + 4, l, matches);
+            } else if (s[2] == 't') {
+              if (s[3] == ' ') AddMatch(id + 60 * n, l + 4, l, matches);
+            } else if (s[2] == 'n') {
+              if (s[3] == 'd' && s[4] == ' ') {
+                AddMatch(id + 10 * n, l + 5, l, matches);
+              }
+            }
+          } else if (s[1] == 'b') {
+            if (s[2] == 'y' && s[3] == ' ') {
+              AddMatch(id + 38 * n, l + 4, l, matches);
+          }
+          } else if (s[1] == 'i') {
+            if (s[2] == 'n') {
+              if (s[3] == ' ') AddMatch(id + 16 * n, l + 4, l, matches);
+            } else if (s[2] == 's') {
+              if (s[3] == ' ') AddMatch(id + 47 * n, l + 4, l, matches);
+            }
+          } else if (s[1] == 'f') {
+            if (s[2] == 'o') {
+              if (s[3] == 'r' && s[4] == ' ') {
+                AddMatch(id + 25 * n, l + 5, l, matches);
+              }
+            } else if (s[2] == 'r') {
+              if (s[3] == 'o' && s[4] == 'm' && s[5] == ' ') {
+                AddMatch(id + 37 * n, l + 6, l, matches);
+              }
+            }
+          } else if (s[1] == 'o') {
+            if (s[2] == 'f') {
+              if (s[3] == ' ') AddMatch(id + 8 * n, l + 4, l, matches);
+            } else if (s[2] == 'n') {
+              if (s[3] == ' ') AddMatch(id + 45 * n, l + 4, l, matches);
+            }
+          } else if (s[1] == 'n') {
+            if (s[2] == 'o' && s[3] == 't' && s[4] == ' ') {
+              AddMatch(id + 80 * n, l + 5, l, matches);
+            }
+          } else if (s[1] == 't') {
+            if (s[2] == 'h') {
+              if (s[3] == 'e') {
+                if (s[4] == ' ') AddMatch(id + 5 * n, l + 5, l, matches);
+              } else if (s[3] == 'a') {
+                if (s[4] == 't' && s[5] == ' ') {
+                  AddMatch(id + 29 * n, l + 6, l, matches);
+                }
+              }
+            } else if (s[2] == 'o') {
+              if (s[3] == ' ') AddMatch(id + 17 * n, l + 4, l, matches);
+            }
+          } else if (s[1] == 'w') {
+            if (s[2] == 'i' && s[3] == 't' && s[4] == 'h' && s[5] == ' ') {
+              AddMatch(id + 35 * n, l + 6, l, matches);
+            }
+          }
+        } else if (s[0] == '"') {
+          AddMatch(id + 19 * n, l + 1, l, matches);
+          if (s[1] == '>') {
+            AddMatch(id + 21 * n, l + 2, l, matches);
+          }
+        } else if (s[0] == '.') {
+          AddMatch(id + 20 * n, l + 1, l, matches);
+          if (s[1] == ' ') {
+            AddMatch(id + 31 * n, l + 2, l, matches);
+            if (s[2] == 'T' && s[3] == 'h') {
+              if (s[4] == 'e') {
+                if (s[5] == ' ') AddMatch(id + 43 * n, l + 6, l, matches);
+              } else if (s[4] == 'i') {
+                if (s[5] == 's' && s[6] == ' ') {
+                  AddMatch(id + 75 * n, l + 7, l, matches);
+                }
+              }
+            }
+          }
+        } else if (s[0] == ',') {
+          AddMatch(id + 76 * n, l + 1, l, matches);
+          if (s[1] == ' ') {
+            AddMatch(id + 14 * n, l + 2, l, matches);
+          }
+        } else if (s[0] == '\n') {
+          AddMatch(id + 22 * n, l + 1, l, matches);
+          if (s[1] == '\t') {
+            AddMatch(id + 50 * n, l + 2, l, matches);
+          }
+        } else if (s[0] == ']') {
+          AddMatch(id + 24 * n, l + 1, l, matches);
+        } else if (s[0] == '\'') {
+          AddMatch(id + 36 * n, l + 1, l, matches);
+        } else if (s[0] == ':') {
+          AddMatch(id + 51 * n, l + 1, l, matches);
+        } else if (s[0] == '(') {
+          AddMatch(id + 57 * n, l + 1, l, matches);
+        } else if (s[0] == '=') {
+          if (s[1] == '"') {
+            AddMatch(id + 70 * n, l + 2, l, matches);
+          } else if (s[1] == '\'') {
+            AddMatch(id + 86 * n, l + 2, l, matches);
+          }
+        } else if (s[0] == 'a') {
+          if (s[1] == 'l' && s[2] == ' ') {
+            AddMatch(id + 84 * n, l + 3, l, matches);
+          }
+        } else if (s[0] == 'e') {
+          if (s[1] == 'd') {
+            if (s[2] == ' ') AddMatch(id + 53 * n, l + 3, l, matches);
+          } else if (s[1] == 'r') {
+            if (s[2] == ' ') AddMatch(id + 82 * n, l + 3, l, matches);
+          } else if (s[1] == 's') {
+            if (s[2] == 't' && s[3] == ' ') {
+              AddMatch(id + 95 * n, l + 4, l, matches);
+            }
+          }
+        } else if (s[0] == 'f') {
+          if (s[1] == 'u' && s[2] == 'l' && s[3] == ' ') {
+            AddMatch(id + 90 * n, l + 4, l, matches);
+          }
+        } else if (s[0] == 'i') {
+          if (s[1] == 'v') {
+            if (s[2] == 'e' && s[3] == ' ') {
+            AddMatch(id + 92 * n, l + 4, l, matches);
+            }
+          } else if (s[1] == 'z') {
+            if (s[2] == 'e' && s[3] == ' ') {
+              AddMatch(id + 100 * n, l + 4, l, matches);
+            }
+          }
+        } else if (s[0] == 'l') {
+          if (s[1] == 'e') {
+            if (s[2] == 's' && s[3] == 's' && s[4] == ' ') {
+              AddMatch(id + 93 * n, l + 5, l, matches);
+            }
+          } else if (s[1] == 'y') {
+            if (s[2] == ' ') AddMatch(id + 61 * n, l + 3, l, matches);
+          }
+        } else if (s[0] == 'o') {
+          if (s[1] == 'u' && s[2] == 's' && s[3] == ' ') {
+            AddMatch(id + 106 * n, l + 4, l, matches);
+          }
+        }
+      } else {
+        // Set t=false for kUppercaseFirst and
+        //     t=true otherwise (kUppercaseAll) transform.
+        const bool t = w.transform != kUppercaseFirst;
+        if (!IsMatch(w, data, max_length)) {
+          continue;
+        }
+        // Transform "" + kUppercase{First,All} + ""
+        AddMatch(id + (t ? 44 : 9) * n, l, l, matches);
+        found_match = true;
+        if (l + 1 >= max_length) {
+          continue;
+        }
+        // Transforms "" + kUppercase{First,All} + <suffix>
+        const uint8_t* s = &data[l];
+        if (s[0] == ' ') {
+          AddMatch(id + (t ? 68 : 4) * n, l + 1, l, matches);
+        } else if (s[0] == '"') {
+          AddMatch(id + (t ? 87 : 66) * n, l + 1, l, matches);
+          if (s[1] == '>') {
+            AddMatch(id + (t ? 97 : 69) * n, l + 2, l, matches);
+          }
+        } else if (s[0] == '.') {
+          AddMatch(id + (t ? 101 : 79) * n, l + 1, l, matches);
+          if (s[1] == ' ') {
+            AddMatch(id + (t ? 114 : 88) * n, l + 2, l, matches);
+          }
+        } else if (s[0] == ',') {
+          AddMatch(id + (t ? 112 : 99) * n, l + 1, l, matches);
+          if (s[1] == ' ') {
+            AddMatch(id + (t ? 107 : 58) * n, l + 2, l, matches);
+          }
+        } else if (s[0] == '\'') {
+          AddMatch(id + (t ? 94 : 74) * n, l + 1, l, matches);
+        } else if (s[0] == '(') {
+          AddMatch(id + (t ? 113 : 78) * n, l + 1, l, matches);
+        } else if (s[0] == '=') {
+          if (s[1] == '"') {
+            AddMatch(id + (t ? 105 : 104) * n, l + 2, l, matches);
+          } else if (s[1] == '\'') {
+            AddMatch(id + (t ? 116 : 108) * n, l + 2, l, matches);
+          }
+        }
+      }
+    }
+  }
+  // Transforms with prefixes " " and "."
+  if (max_length >= 5 && (data[0] == ' ' || data[0] == '.')) {
+    bool is_space = (data[0] == ' ');
+    key = Hash(&data[1]);
+    bucket = kStaticDictionaryBuckets[key];
+    size_t num = bucket & 0xff;
+    size_t offset = bucket >> 8;
+    for (size_t i = 0; i < num; ++i) {
+      const DictWord w = kStaticDictionaryWords[offset + i];
+      const size_t l = w.len;
+      const size_t n = 1u << kBrotliDictionarySizeBitsByLength[l];
+      const size_t id = w.idx;
+      if (w.transform == 0) {
+        if (!IsMatch(w, &data[1], max_length - 1)) {
+          continue;
+        }
+        // Transforms " " + kIdentity + "" and "." + kIdentity + ""
+        AddMatch(id + (is_space ? 6 : 32) * n, l + 1, l, matches);
+        found_match = true;
+        if (l + 2 >= max_length) {
+          continue;
+        }
+        // Transforms " " + kIdentity + <suffix> and "." + kIdentity + <suffix>
+        const uint8_t* s = &data[l + 1];
+        if (s[0] == ' ') {
+          AddMatch(id + (is_space ? 2 : 77) * n, l + 2, l, matches);
+        } else if (s[0] == '(') {
+          AddMatch(id + (is_space ? 89 : 67) * n, l + 2, l, matches);
+        } else if (is_space) {
+          if (s[0] == ',') {
+            AddMatch(id + 103 * n, l + 2, l, matches);
+            if (s[1] == ' ') {
+              AddMatch(id + 33 * n, l + 3, l, matches);
+            }
+          } else if (s[0] == '.') {
+            AddMatch(id + 71 * n, l + 2, l, matches);
+            if (s[1] == ' ') {
+              AddMatch(id + 52 * n, l + 3, l, matches);
+            }
+          } else if (s[0] == '=') {
+            if (s[1] == '"') {
+              AddMatch(id + 81 * n, l + 3, l, matches);
+            } else if (s[1] == '\'') {
+              AddMatch(id + 98 * n, l + 3, l, matches);
+            }
+          }
+        }
+      } else if (is_space) {
+        // Set t=false for kUppercaseFirst and
+        //     t=true otherwise (kUppercaseAll) transform.
+        const bool t = w.transform != kUppercaseFirst;
+        if (!IsMatch(w, &data[1], max_length - 1)) {
+          continue;
+        }
+        // Transforms " " + kUppercase{First,All} + ""
+        AddMatch(id + (t ? 85 : 30) * n, l + 1, l, matches);
+        found_match = true;
+        if (l + 2 >= max_length) {
+          continue;
+        }
+        // Transforms " " + kUppercase{First,All} + <suffix>
+        const uint8_t* s = &data[l + 1];
+        if (s[0] == ' ') {
+          AddMatch(id + (t ? 83 : 15) * n, l + 2, l, matches);
+        } else if (s[0] == ',') {
+          if (!t) {
+            AddMatch(id + 109 * n, l + 2, l, matches);
+        }
+          if (s[1] == ' ') {
+            AddMatch(id + (t ? 111 : 65) * n, l + 3, l, matches);
+          }
+        } else if (s[0] == '.') {
+          AddMatch(id + (t ? 115 : 96) * n, l + 2, l, matches);
+          if (s[1] == ' ') {
+            AddMatch(id + (t ? 117 : 91) * n, l + 3, l, matches);
+          }
+        } else if (s[0] == '=') {
+          if (s[1] == '"') {
+            AddMatch(id + (t ? 110 : 118) * n, l + 3, l, matches);
+          } else if (s[1] == '\'') {
+            AddMatch(id + (t ? 119 : 120) * n, l + 3, l, matches);
+          }
+        }
+      }
+    }
+  }
+  if (max_length >= 6) {
+    // Transforms with prefixes "e ", "s ", ", " and "\xc2\xa0"
+    if ((data[1] == ' ' &&
+         (data[0] == 'e' || data[0] == 's' || data[0] == ',')) ||
+        (data[0] == 0xc2 && data[1] == 0xa0)) {
+      key = Hash(&data[2]);
+      bucket = kStaticDictionaryBuckets[key];
+      size_t num = bucket & 0xff;
+      size_t offset = bucket >> 8;
+      for (size_t i = 0; i < num; ++i) {
+        const DictWord w = kStaticDictionaryWords[offset + i];
+        const size_t l = w.len;
+        const size_t n = 1u << kBrotliDictionarySizeBitsByLength[l];
+        const size_t id = w.idx;
+        if (w.transform == 0 && IsMatch(w, &data[2], max_length - 2)) {
+          if (data[0] == 0xc2) {
+            AddMatch(id + 102 * n, l + 2, l, matches);
+            found_match = true;
+          } else if (l + 2 < max_length && data[l + 2] == ' ') {
+            size_t t = data[0] == 'e' ? 18 : (data[0] == 's' ? 7 : 13);
+            AddMatch(id + t * n, l + 3, l, matches);
+            found_match = true;
+          }
+        }
+      }
+    }
+  }
+  if (max_length >= 9) {
+    // Transforms with prefixes " the " and ".com/"
+    if ((data[0] == ' ' && data[1] == 't' && data[2] == 'h' &&
+         data[3] == 'e' && data[4] == ' ') ||
+        (data[0] == '.' && data[1] == 'c' && data[2] == 'o' &&
+         data[3] == 'm' && data[4] == '/')) {
+      key = Hash(&data[5]);
+      bucket = kStaticDictionaryBuckets[key];
+      size_t num = bucket & 0xff;
+      size_t offset = bucket >> 8;
+      for (size_t i = 0; i < num; ++i) {
+        const DictWord w = kStaticDictionaryWords[offset + i];
+        const size_t l = w.len;
+        const size_t n = 1u << kBrotliDictionarySizeBitsByLength[l];
+        const size_t id = w.idx;
+        if (w.transform == 0 && IsMatch(w, &data[5], max_length - 5)) {
+          AddMatch(id + (data[0] == ' ' ? 41 : 72) * n, l + 5, l, matches);
+          found_match = true;
+          if (l + 5 < max_length) {
+            const uint8_t* s = &data[l + 5];
+            if (data[0] == ' ') {
+              if (l + 8 < max_length &&
+                  s[0] == ' ' && s[1] == 'o' && s[2] == 'f' && s[3] == ' ') {
+                AddMatch(id + 62 * n, l + 9, l, matches);
+                if (l + 12 < max_length &&
+                    s[4] == 't' && s[5] == 'h' && s[6] == 'e' && s[7] == ' ') {
+                  AddMatch(id + 73 * n, l + 13, l, matches);
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+  return found_match;
+}
+
+}  // namespace brotli