1 files changed, 210 insertions, 0 deletions
diff --git a/vendor/github.com/exponent-io/jsonpath/decoder.go b/vendor/github.com/exponent-io/jsonpath/decoder.go
new file mode 100644
index 000000000..31de46c73
--- /dev/null
+++ b/vendor/github.com/exponent-io/jsonpath/decoder.go
@@ -0,0 +1,210 @@
+package jsonpath
+
+import (
+	"encoding/json"
+	"io"
+)
+
+// KeyString is returned from Decoder.Token to represent each key in a JSON object value.
+type KeyString string
+
+// Decoder extends the Go runtime's encoding/json.Decoder to support navigating in a stream of JSON tokens.
+type Decoder struct {
+	json.Decoder
+
+	path    JsonPath
+	context jsonContext
+}
+
+// NewDecoder creates a new instance of the extended JSON Decoder.
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{Decoder: *json.NewDecoder(r)}
+}
+
+// SeekTo causes the Decoder to move forward to a given path in the JSON structure.
+//
+// The path argument must consist of strings or integers. Each string specifies an JSON object key, and
+// each integer specifies an index into a JSON array.
+//
+// Consider the JSON structure
+//
+//  { "a": [0,"s",12e4,{"b":0,"v":35} ] }
+//
+// SeekTo("a",3,"v") will move to the value referenced by the "a" key in the current object,
+// followed by a move to the 4th value (index 3) in the array, followed by a move to the value at key "v".
+// In this example, a subsequent call to the decoder's Decode() would unmarshal the value 35.
+//
+// SeekTo returns a boolean value indicating whether a match was found.
+//
+// Decoder is intended to be used with a stream of tokens. As a result it navigates forward only.
+func (d *Decoder) SeekTo(path ...interface{}) (bool, error) {
+
+	if len(path) == 0 {
+		return len(d.path) == 0, nil
+	}
+	last := len(path) - 1
+	if i, ok := path[last].(int); ok {
+		path[last] = i - 1
+	}
+
+	for {
+		if d.path.Equal(path) {
+			return true, nil
+		}
+		_, err := d.Token()
+		if err == io.EOF {
+			return false, nil
+		} else if err != nil {
+			return false, err
+		}
+	}
+}
+
+// Decode reads the next JSON-encoded value from its input and stores it in the value pointed to by v. This is
+// equivalent to encoding/json.Decode().
+func (d *Decoder) Decode(v interface{}) error {
+	switch d.context {
+	case objValue:
+		d.context = objKey
+		break
+	case arrValue:
+		d.path.incTop()
+		break
+	}
+	return d.Decoder.Decode(v)
+}
+
+// Path returns a slice of string and/or int values representing the path from the root of the JSON object to the
+// position of the most-recently parsed token.
+func (d *Decoder) Path() JsonPath {
+	p := make(JsonPath, len(d.path))
+	copy(p, d.path)
+	return p
+}
+
+// Token is equivalent to the Token() method on json.Decoder. The primary difference is that it distinguishes
+// between strings that are keys and and strings that are values. String tokens that are object keys are returned as a
+// KeyString rather than as a native string.
+func (d *Decoder) Token() (json.Token, error) {
+	t, err := d.Decoder.Token()
+	if err != nil {
+		return t, err
+	}
+
+	if t == nil {
+		switch d.context {
+		case objValue:
+			d.context = objKey
+			break
+		case arrValue:
+			d.path.incTop()
+			break
+		}
+		return t, err
+	}
+
+	switch t := t.(type) {
+	case json.Delim:
+		switch t {
+		case json.Delim('{'):
+			if d.context == arrValue {
+				d.path.incTop()
+			}
+			d.path.push("")
+			d.context = objKey
+			break
+		case json.Delim('}'):
+			d.path.pop()
+			d.context = d.path.inferContext()
+			break
+		case json.Delim('['):
+			if d.context == arrValue {
+				d.path.incTop()
+			}
+			d.path.push(-1)
+			d.context = arrValue
+			break
+		case json.Delim(']'):
+			d.path.pop()
+			d.context = d.path.inferContext()
+			break
+		}
+	case float64, json.Number, bool:
+		switch d.context {
+		case objValue:
+			d.context = objKey
+			break
+		case arrValue:
+			d.path.incTop()
+			break
+		}
+		break
+	case string:
+		switch d.context {
+		case objKey:
+			d.path.nameTop(t)
+			d.context = objValue
+			return KeyString(t), err
+		case objValue:
+			d.context = objKey
+		case arrValue:
+			d.path.incTop()
+		}
+		break
+	}
+
+	return t, err
+}
+
+// Scan moves forward over the JSON stream consuming all the tokens at the current level (current object, current array)
+// invoking each matching PathAction along the way.
+//
+// Scan returns true if there are more contiguous values to scan (for example in an array).
+func (d *Decoder) Scan(ext *PathActions) (bool, error) {
+
+	rootPath := d.Path()
+
+	// If this is an array path, increment the root path in our local copy.
+	if rootPath.inferContext() == arrValue {
+		rootPath.incTop()
+	}
+
+	for {
+		// advance the token position
+		_, err := d.Token()
+		if err != nil {
+			return false, err
+		}
+
+	match:
+		var relPath JsonPath
+
+		// capture the new JSON path
+		path := d.Path()
+
+		if len(path) > len(rootPath) {
+			// capture the path relative to where the scan started
+			relPath = path[len(rootPath):]
+		} else {
+			// if the path is not longer than the root, then we are done with this scan
+			// return boolean flag indicating if there are more items to scan at the same level
+			return d.Decoder.More(), nil
+		}
+
+		// match the relative path against the path actions
+		if node := ext.node.match(relPath); node != nil {
+			if node.action != nil {
+				// we have a match so execute the action
+				err = node.action(d)
+				if err != nil {
+					return d.Decoder.More(), err
+				}
+				// The action may have advanced the decoder. If we are in an array, advancing it further would
+				// skip tokens. So, if we are scanning an array, jump to the top without advancing the token.
+				if d.path.inferContext() == arrValue && d.Decoder.More() {
+					goto match
+				}
+			}
+		}
+	}
+}