diff options
Diffstat (limited to 'vendor/github.com/gobwas/glob/match/btree.go')
-rw-r--r-- | vendor/github.com/gobwas/glob/match/btree.go | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/vendor/github.com/gobwas/glob/match/btree.go b/vendor/github.com/gobwas/glob/match/btree.go new file mode 100644 index 0000000000..a8130e93ea --- /dev/null +++ b/vendor/github.com/gobwas/glob/match/btree.go @@ -0,0 +1,146 @@ +package match + +import ( + "fmt" + "unicode/utf8" +) + +type BTree struct { + Value Matcher + Left Matcher + Right Matcher + ValueLengthRunes int + LeftLengthRunes int + RightLengthRunes int + LengthRunes int +} + +func NewBTree(Value, Left, Right Matcher) (tree BTree) { + tree.Value = Value + tree.Left = Left + tree.Right = Right + + lenOk := true + if tree.ValueLengthRunes = Value.Len(); tree.ValueLengthRunes == -1 { + lenOk = false + } + + if Left != nil { + if tree.LeftLengthRunes = Left.Len(); tree.LeftLengthRunes == -1 { + lenOk = false + } + } + + if Right != nil { + if tree.RightLengthRunes = Right.Len(); tree.RightLengthRunes == -1 { + lenOk = false + } + } + + if lenOk { + tree.LengthRunes = tree.LeftLengthRunes + tree.ValueLengthRunes + tree.RightLengthRunes + } else { + tree.LengthRunes = -1 + } + + return tree +} + +func (self BTree) Len() int { + return self.LengthRunes +} + +// todo? +func (self BTree) Index(s string) (int, []int) { + return -1, nil +} + +func (self BTree) Match(s string) bool { + inputLen := len(s) + + // self.Length, self.RLen and self.LLen are values meaning the length of runes for each part + // here we manipulating byte length for better optimizations + // but these checks still works, cause minLen of 1-rune string is 1 byte. + if self.LengthRunes != -1 && self.LengthRunes > inputLen { + return false + } + + // try to cut unnecessary parts + // by knowledge of length of right and left part + var offset, limit int + if self.LeftLengthRunes >= 0 { + offset = self.LeftLengthRunes + } + if self.RightLengthRunes >= 0 { + limit = inputLen - self.RightLengthRunes + } else { + limit = inputLen + } + + for offset < limit { + // search for matching part in substring + index, segments := self.Value.Index(s[offset:limit]) + if index == -1 { + releaseSegments(segments) + return false + } + + l := s[:offset+index] + var left bool + if self.Left != nil { + left = self.Left.Match(l) + } else { + left = l == "" + } + + if left { + for i := len(segments) - 1; i >= 0; i-- { + length := segments[i] + + var right bool + var r string + // if there is no string for the right branch + if inputLen <= offset+index+length { + r = "" + } else { + r = s[offset+index+length:] + } + + if self.Right != nil { + right = self.Right.Match(r) + } else { + right = r == "" + } + + if right { + releaseSegments(segments) + return true + } + } + } + + _, step := utf8.DecodeRuneInString(s[offset+index:]) + offset += index + step + + releaseSegments(segments) + } + + return false +} + +func (self BTree) String() string { + const n string = "<nil>" + var l, r string + if self.Left == nil { + l = n + } else { + l = self.Left.String() + } + if self.Right == nil { + r = n + } else { + r = self.Right.String() + } + + return fmt.Sprintf("<btree:[%s<-%s->%s]>", l, self.Value, r) +} |