Add support for array idx keys

Author: buger

README.md

@@ -60,11 +60,34 @@ jsonparser.ArrayEach(data, func(value []byte, dataType jsonparser.ValueType, off
 	fmt.Println(jsonparser.Get(value, "url"))
 }, "person", "avatars")
 
+// Or use can access fields by index!
+jsonparser.GetInt("person", "avatars", "[0]", "url")
+
 // You can use `ObjectEach` helper to iterate objects { "key1":object1, "key2":object2, .... "keyN":objectN }
 jsonparser.ObjectEach(data, func(key []byte, value []byte, dataType jsonparser.ValueType, offset int) error {
         fmt.Printf("Key: '%s'\n Value: '%s'\n Type: %s\n", string(key), string(value), dataType)
 	return nil
 }, "person", "name")
+
+// The most efficient way to extract multiple keys is `EachKey`
+
+paths := [][]string{
+  []string{"person", "name", "fullName"},
+  []string{"person", "avatars", "[0]", "url"},
+  []string{"company", "url"},
+}
+jsonparser.EachKey(data, func(idx int, value []byte, vt jsonparser.ValueType, err error){
+  switch idx {
+  case 0: // []string{"person", "name", "fullName"}
+    ...
+  case 1: // []string{"person", "avatars", "[0]", "url"}
+    ...
+  case 2: // []string{"company", "url"},
+    ...
+  }
+}, paths...)
+
+// For more information see docs below
 ```
 
 ## Need to speedup your app?
@@ -93,6 +116,8 @@ Returns:
 Accepts multiple keys to specify path to JSON value (in case of quering nested structures).
 If no keys are provided it will try to extract the closest JSON value (simple ones or object/array), useful for reading streams or arrays, see `ArrayEach` implementation.
 
+Note that keys can be an array indexes: `jsonparser.GetInt("person", "avatars", "[0]", "url")`, pretty cool, yeah?
+
 ### **`GetString`**
 ```go
 func GetString(data []byte, keys ...string) (val string, err error)

parser.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"strconv"
 )
 
 // Errors
@@ -31,7 +32,7 @@ func tokenEnd(data []byte) int {
 		}
 	}
 
-	return -1
+	return len(data)
 }
 
 // Find position of next character which is not whitespace
@@ -116,6 +117,10 @@ func searchKeys(data []byte, keys ...string) int {
 	ln := len(data)
 	lk := len(keys)
 
+	if lk == 0 {
+		return 0
+	}
+
 	var stackbuf [unescapeStackBufSize]byte // stack-allocated array for allocation-free unescaping of small strings
 
 	for i < ln {
@@ -168,11 +173,34 @@ func searchKeys(data []byte, keys ...string) int {
 		case '}':
 			level--
 		case '[':
-			// Do not search for keys inside arrays
-			if arraySkip := blockEnd(data[i:], '[', ']'); arraySkip == -1 {
-				return -1
+			// If we want to get array element by index
+			if keyLevel == level && keys[level][0] == '[' {
+				aIdx, _ := strconv.Atoi(keys[level][1 : len(keys[level])-1])
+
+				var curIdx int
+				var valueFound []byte
+				var valueOffset int
+
+				ArrayEach(data[i:], func(value []byte, dataType ValueType, offset int, err error) {
+					if (curIdx == aIdx) {
+						valueFound = value
+						valueOffset = offset
+					}
+					curIdx += 1
+				})
+
+				if valueFound == nil {
+					return -1
+				} else {
+					return i + valueOffset + searchKeys(valueFound, keys[level+1:]...)
+				}
 			} else {
-				i += arraySkip - 1
+				// Do not search for keys inside arrays
+				if arraySkip := blockEnd(data[i:], '[', ']'); arraySkip == -1 {
+					return -1
+				} else {
+					i += arraySkip - 1
+				}
 			}
 		}
 
@@ -191,15 +219,12 @@ func init() {
 }
 
 func sameTree(p1, p2 []string) bool {
-	if len(p1) == 1 && len(p2) == 1 {
-		return true
+	minLen := len(p1)
+	if len(p2) < minLen {
+		minLen = len(p2)
 	}
 
-	for pi_1, p_1 := range p1[:len(p1)-1] {
-		if len(p2)-2 < pi_1 {
-			break
-		}
-
+	for pi_1, p_1 := range p1[:minLen] {
 		if p2[pi_1] != p_1 {
 			return false
 		}
@@ -209,11 +234,19 @@ func sameTree(p1, p2 []string) bool {
 }
 
 func EachKey(data []byte, cb func(int, []byte, ValueType, error), paths ...[]string) int {
-	var pathFlags, ignorePathFlags int64
+	var pathFlags int64
 	var level, pathsMatched, i int
 	ln := len(data)
 
+	var maxPath int
+	for _, p := range paths {
+		if len(p) > maxPath {
+			maxPath = len(p)
+		}
+	}
+
 	var stackbuf [unescapeStackBufSize]byte // stack-allocated array for allocation-free unescaping of small strings
+	pathsBuf := make([]string, maxPath)
 
 	for i < ln {
 		switch data[i] {
@@ -252,58 +285,41 @@ func EachKey(data []byte, cb func(int, []byte, ValueType, error), paths ...[]str
 					keyUnesc = ku
 				}
 
-				for pi, p := range paths {
-					if len(p) < level || (pathFlags&bitwiseFlags[pi]) != 0 || (ignorePathFlags&bitwiseFlags[pi] != 0) {
-						continue
-					}
+				if maxPath >= level {
+					pathsBuf[level-1] = bytesToString(&keyUnesc)
+
+					for pi, p := range paths {
+						if len(p) != level || pathFlags&bitwiseFlags[pi+1] != 0 || !equalStr(&keyUnesc, p[level-1]) || !sameTree(p, pathsBuf[:level]) {
+							continue
+						}
 
-					if equalStr(&keyUnesc, p[level-1]) {
 						match = pi
 
-						if len(p) == level {
-							i++
-							pathsMatched++
-							pathFlags |= bitwiseFlags[pi]
+						i++
+						pathsMatched++
+						pathFlags |= bitwiseFlags[pi+1]
 
-							v, dt, of, e := Get(data[i:])
-							cb(pi, v, dt, e)
+						v, dt, of, e := Get(data[i:])
+						cb(pi, v, dt, e)
 
-							if of != -1 {
-								i += of
-							}
+						if of != -1 {
+							i += of
+						}
 
-							if pathsMatched == len(paths) {
-								return i
-							}
+						if pathsMatched == len(paths) {
+							return i
 						}
 					}
 				}
 
 				if match == -1 {
-					ignorePathFlags = 0
 					tokenOffset := nextToken(data[i+1:])
 					i += tokenOffset
 
 					if data[i] == '{' {
 						blockSkip := blockEnd(data[i:], '{', '}')
 						i += blockSkip + 1
 					}
-				} else {
-					m_p := paths[match]
-
-					for pi, p := range paths {
-						if pi == match {
-							continue
-						}
-
-						if len(p) < level || (pathFlags&bitwiseFlags[pi]) != 0 || (ignorePathFlags&bitwiseFlags[pi] != 0) {
-							continue
-						}
-
-						if !sameTree(m_p, p) {
-							ignorePathFlags |= bitwiseFlags[pi]
-						}
-					}
 				}
 
 				switch data[i] {
@@ -318,12 +334,61 @@ func EachKey(data []byte, cb func(int, []byte, ValueType, error), paths ...[]str
 		case '}':
 			level--
 		case '[':
-			// Do not search for keys inside arrays
-			if arraySkip := blockEnd(data[i:], '[', ']'); arraySkip == -1 {
-				return -1
+			var arrIdxFlags int64
+			var pIdxFlags int64
+			for pi, p := range paths {
+				if len(p) < level+1 || pathFlags&bitwiseFlags[pi+1] != 0 || p[level][0] != '[' || !sameTree(p, pathsBuf[:level]) {
+					continue
+				}
+
+				aIdx, _ := strconv.Atoi(p[level][1: len(p[level]) - 1])
+				arrIdxFlags |= bitwiseFlags[aIdx+1]
+				pIdxFlags |= bitwiseFlags[pi+1]
+			}
+
+			if arrIdxFlags > 0 {
+				level++
+
+				var curIdx int
+				arrOff, _ := ArrayEach(data[i:], func(value []byte, dataType ValueType, offset int, err error) {
+					if (arrIdxFlags&bitwiseFlags[curIdx+1] != 0) {
+						for pi, p := range paths {
+							if pIdxFlags&bitwiseFlags[pi+1] != 0 {
+								aIdx, _ := strconv.Atoi(p[level-1][1: len(p[level-1]) - 1])
+
+								if curIdx == aIdx {
+									of := searchKeys(value, p[level:]...)
+
+									pathsMatched++
+									pathFlags |= bitwiseFlags[pi+1]
+
+									if of != -1 {
+										v, dt, _, e := Get(value[of:])
+										cb(pi, v, dt, e)
+									}
+								}
+							}
+						}
+					}
+
+					curIdx += 1
+				})
+
+				if pathsMatched == len(paths) {
+					return i
+				}
+
+				i += arrOff - 1
 			} else {
-				i += arraySkip - 1
+				// Do not search for keys inside arrays
+				if arraySkip := blockEnd(data[i:], '[', ']'); arraySkip == -1 {
+					return -1
+				} else {
+					i += arraySkip - 1
+				}
 			}
+		case ']':
+			level--
 		}
 
 		i++
@@ -476,28 +541,28 @@ func Get(data []byte, keys ...string) (value []byte, dataType ValueType, offset
 }
 
 // ArrayEach is used when iterating arrays, accepts a callback function with the same return arguments as `Get`.
-func ArrayEach(data []byte, cb func(value []byte, dataType ValueType, offset int, err error), keys ...string) (err error) {
+func ArrayEach(data []byte, cb func(value []byte, dataType ValueType, offset int, err error), keys ...string) (offset int, err error) {
 	if len(data) == 0 {
-		return MalformedObjectError
+		return -1, MalformedObjectError
 	}
 
-	offset := 1
+	offset = 1
 
 	if len(keys) > 0 {
 		if offset = searchKeys(data, keys...); offset == -1 {
-			return KeyPathNotFoundError
+			return offset, KeyPathNotFoundError
 		}
 
 		// Go to closest value
 		nO := nextToken(data[offset:])
 		if nO == -1 {
-			return MalformedJsonError
+			return offset, MalformedJsonError
 		}
 
 		offset += nO
 
 		if data[offset] != '[' {
-			return MalformedArrayError
+			return offset, MalformedArrayError
 		}
 
 		offset++
@@ -511,7 +576,7 @@ func ArrayEach(data []byte, cb func(value []byte, dataType ValueType, offset int
 		}
 
 		if t != NotExist {
-			cb(v, t, o, e)
+			cb(v, t, offset + o - len(v), e)
 		}
 
 		if e != nil {
@@ -522,7 +587,7 @@ func ArrayEach(data []byte, cb func(value []byte, dataType ValueType, offset int
 
 		skipToToken := nextToken(data[offset:])
 		if skipToToken == -1 {
-			return MalformedArrayError
+			return offset, MalformedArrayError
 		}
 		offset += skipToToken
 
@@ -531,13 +596,13 @@ func ArrayEach(data []byte, cb func(value []byte, dataType ValueType, offset int
 		}
 
 		if data[offset] != ',' {
-			return MalformedArrayError
+			return offset, MalformedArrayError
 		}
 
 		offset++
 	}
 
-	return nil
+	return offset, nil
 }
 
 // ObjectEach iterates over the key-value pairs of a JSON object, invoking a given callback for each such entry