1 files changed, 174 insertions, 0 deletions
diff --git a/vendor/github.com/authzed/cel-go/common/source.go b/vendor/github.com/authzed/cel-go/common/source.go
new file mode 100644
index 0000000..a5a07a3
--- /dev/null
+++ b/vendor/github.com/authzed/cel-go/common/source.go
@@ -0,0 +1,174 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package common
+
+import (
+	"github.com/authzed/cel-go/common/runes"
+
+	exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
+)
+
+// Source interface for filter source contents.
+type Source interface {
+	// Content returns the source content represented as a string.
+	// Examples contents are the single file contents, textbox field,
+	// or url parameter.
+	Content() string
+
+	// Description gives a brief description of the source.
+	// Example descriptions are a file name or ui element.
+	Description() string
+
+	// LineOffsets gives the character offsets at which lines occur.
+	// The zero-th entry should refer to the break between the first
+	// and second line, or EOF if there is only one line of source.
+	LineOffsets() []int32
+
+	// LocationOffset translates a Location to an offset.
+	// Given the line and column of the Location returns the
+	// Location's character offset in the Source, and a bool
+	// indicating whether the Location was found.
+	LocationOffset(location Location) (int32, bool)
+
+	// OffsetLocation translates a character offset to a Location, or
+	// false if the conversion was not feasible.
+	OffsetLocation(offset int32) (Location, bool)
+
+	// NewLocation takes an input line and column and produces a Location.
+	// The default behavior is to treat the line and column as absolute,
+	// but concrete derivations may use this method to convert a relative
+	// line and column position into an absolute location.
+	NewLocation(line, col int) Location
+
+	// Snippet returns a line of content and whether the line was found.
+	Snippet(line int) (string, bool)
+}
+
+// The sourceImpl type implementation of the Source interface.
+type sourceImpl struct {
+	runes.Buffer
+	description string
+	lineOffsets []int32
+}
+
+var _ runes.Buffer = &sourceImpl{}
+
+// TODO(jimlarson) "Character offsets" should index the code points
+// within the UTF-8 encoded string.  It currently indexes bytes.
+// Can be accomplished by using rune[] instead of string for contents.
+
+// NewTextSource creates a new Source from the input text string.
+func NewTextSource(text string) Source {
+	return NewStringSource(text, "<input>")
+}
+
+// NewStringSource creates a new Source from the given contents and description.
+func NewStringSource(contents string, description string) Source {
+	// Compute line offsets up front as they are referred to frequently.
+	buf, offs := runes.NewBufferAndLineOffsets(contents)
+	return &sourceImpl{
+		Buffer:      buf,
+		description: description,
+		lineOffsets: offs,
+	}
+}
+
+// NewInfoSource creates a new Source from a SourceInfo.
+func NewInfoSource(info *exprpb.SourceInfo) Source {
+	return &sourceImpl{
+		Buffer:      runes.NewBuffer(""),
+		description: info.GetLocation(),
+		lineOffsets: info.GetLineOffsets(),
+	}
+}
+
+// Content implements the Source interface method.
+func (s *sourceImpl) Content() string {
+	return s.Slice(0, s.Len())
+}
+
+// Description implements the Source interface method.
+func (s *sourceImpl) Description() string {
+	return s.description
+}
+
+// LineOffsets implements the Source interface method.
+func (s *sourceImpl) LineOffsets() []int32 {
+	return s.lineOffsets
+}
+
+// LocationOffset implements the Source interface method.
+func (s *sourceImpl) LocationOffset(location Location) (int32, bool) {
+	if lineOffset, found := s.findLineOffset(location.Line()); found {
+		return lineOffset + int32(location.Column()), true
+	}
+	return -1, false
+}
+
+// NewLocation implements the Source interface method.
+func (s *sourceImpl) NewLocation(line, col int) Location {
+	return NewLocation(line, col)
+}
+
+// OffsetLocation implements the Source interface method.
+func (s *sourceImpl) OffsetLocation(offset int32) (Location, bool) {
+	line, lineOffset := s.findLine(offset)
+	return NewLocation(int(line), int(offset-lineOffset)), true
+}
+
+// Snippet implements the Source interface method.
+func (s *sourceImpl) Snippet(line int) (string, bool) {
+	charStart, found := s.findLineOffset(line)
+	if !found || s.Len() == 0 {
+		return "", false
+	}
+	charEnd, found := s.findLineOffset(line + 1)
+	if found {
+		return s.Slice(int(charStart), int(charEnd-1)), true
+	}
+	return s.Slice(int(charStart), s.Len()), true
+}
+
+// findLineOffset returns the offset where the (1-indexed) line begins,
+// or false if line doesn't exist.
+func (s *sourceImpl) findLineOffset(line int) (int32, bool) {
+	if line == 1 {
+		return 0, true
+	}
+	if line > 1 && line <= int(len(s.lineOffsets)) {
+		offset := s.lineOffsets[line-2]
+		return offset, true
+	}
+	return -1, false
+}
+
+// findLine finds the line that contains the given character offset and
+// returns the line number and offset of the beginning of that line.
+// Note that the last line is treated as if it contains all offsets
+// beyond the end of the actual source.
+func (s *sourceImpl) findLine(characterOffset int32) (int32, int32) {
+	var line int32 = 1
+	for _, lineOffset := range s.lineOffsets {
+		if lineOffset > characterOffset {
+			break
+		} else {
+			line++
+		}
+	}
+	if line == 1 {
+		return line, 0
+	}
+	return line, s.lineOffsets[line-2]
+}