Update to last common bleve (#3986)

vendor/github.com/tinylib/msgp/msgp/edit.go

@@ -0,0 +1,242 @@
+package msgp
+
+import (
+	"math"
+)
+
+// Locate returns a []byte pointing to the field
+// in a messagepack map with the provided key. (The returned []byte
+// points to a sub-slice of 'raw'; Locate does no allocations.) If the
+// key doesn't exist in the map, a zero-length []byte will be returned.
+func Locate(key string, raw []byte) []byte {
+	s, n := locate(raw, key)
+	return raw[s:n]
+}
+
+// Replace takes a key ("key") in a messagepack map ("raw")
+// and replaces its value with the one provided and returns
+// the new []byte. The returned []byte may point to the same
+// memory as "raw". Replace makes no effort to evaluate the validity
+// of the contents of 'val'. It may use up to the full capacity of 'raw.'
+// Replace returns 'nil' if the field doesn't exist or if the object in 'raw'
+// is not a map.
+func Replace(key string, raw []byte, val []byte) []byte {
+	start, end := locate(raw, key)
+	if start == end {
+		return nil
+	}
+	return replace(raw, start, end, val, true)
+}
+
+// CopyReplace works similarly to Replace except that the returned
+// byte slice does not point to the same memory as 'raw'. CopyReplace
+// returns 'nil' if the field doesn't exist or 'raw' isn't a map.
+func CopyReplace(key string, raw []byte, val []byte) []byte {
+	start, end := locate(raw, key)
+	if start == end {
+		return nil
+	}
+	return replace(raw, start, end, val, false)
+}
+
+// Remove removes a key-value pair from 'raw'. It returns
+// 'raw' unchanged if the key didn't exist.
+func Remove(key string, raw []byte) []byte {
+	start, end := locateKV(raw, key)
+	if start == end {
+		return raw
+	}
+	raw = raw[:start+copy(raw[start:], raw[end:])]
+	return resizeMap(raw, -1)
+}
+
+// HasKey returns whether the map in 'raw' has
+// a field with key 'key'
+func HasKey(key string, raw []byte) bool {
+	sz, bts, err := ReadMapHeaderBytes(raw)
+	if err != nil {
+		return false
+	}
+	var field []byte
+	for i := uint32(0); i < sz; i++ {
+		field, bts, err = ReadStringZC(bts)
+		if err != nil {
+			return false
+		}
+		if UnsafeString(field) == key {
+			return true
+		}
+	}
+	return false
+}
+
+func replace(raw []byte, start int, end int, val []byte, inplace bool) []byte {
+	ll := end - start // length of segment to replace
+	lv := len(val)
+
+	if inplace {
+		extra := lv - ll
+
+		// fastest case: we're doing
+		// a 1:1 replacement
+		if extra == 0 {
+			copy(raw[start:], val)
+			return raw
+
+		} else if extra < 0 {
+			// 'val' smaller than replaced value
+			// copy in place and shift back
+
+			x := copy(raw[start:], val)
+			y := copy(raw[start+x:], raw[end:])
+			return raw[:start+x+y]
+
+		} else if extra < cap(raw)-len(raw) {
+			// 'val' less than (cap-len) extra bytes
+			// copy in place and shift forward
+			raw = raw[0 : len(raw)+extra]
+			// shift end forward
+			copy(raw[end+extra:], raw[end:])
+			copy(raw[start:], val)
+			return raw
+		}
+	}
+
+	// we have to allocate new space
+	out := make([]byte, len(raw)+len(val)-ll)
+	x := copy(out, raw[:start])
+	y := copy(out[x:], val)
+	copy(out[x+y:], raw[end:])
+	return out
+}
+
+// locate does a naive O(n) search for the map key; returns start, end
+// (returns 0,0 on error)
+func locate(raw []byte, key string) (start int, end int) {
+	var (
+		sz    uint32
+		bts   []byte
+		field []byte
+		err   error
+	)
+	sz, bts, err = ReadMapHeaderBytes(raw)
+	if err != nil {
+		return
+	}
+
+	// loop and locate field
+	for i := uint32(0); i < sz; i++ {
+		field, bts, err = ReadStringZC(bts)
+		if err != nil {
+			return 0, 0
+		}
+		if UnsafeString(field) == key {
+			// start location
+			l := len(raw)
+			start = l - len(bts)
+			bts, err = Skip(bts)
+			if err != nil {
+				return 0, 0
+			}
+			end = l - len(bts)
+			return
+		}
+		bts, err = Skip(bts)
+		if err != nil {
+			return 0, 0
+		}
+	}
+	return 0, 0
+}
+
+// locate key AND value
+func locateKV(raw []byte, key string) (start int, end int) {
+	var (
+		sz    uint32
+		bts   []byte
+		field []byte
+		err   error
+	)
+	sz, bts, err = ReadMapHeaderBytes(raw)
+	if err != nil {
+		return 0, 0
+	}
+
+	for i := uint32(0); i < sz; i++ {
+		tmp := len(bts)
+		field, bts, err = ReadStringZC(bts)
+		if err != nil {
+			return 0, 0
+		}
+		if UnsafeString(field) == key {
+			start = len(raw) - tmp
+			bts, err = Skip(bts)
+			if err != nil {
+				return 0, 0
+			}
+			end = len(raw) - len(bts)
+			return
+		}
+		bts, err = Skip(bts)
+		if err != nil {
+			return 0, 0
+		}
+	}
+	return 0, 0
+}
+
+// delta is delta on map size
+func resizeMap(raw []byte, delta int64) []byte {
+	var sz int64
+	switch raw[0] {
+	case mmap16:
+		sz = int64(big.Uint16(raw[1:]))
+		if sz+delta <= math.MaxUint16 {
+			big.PutUint16(raw[1:], uint16(sz+delta))
+			return raw
+		}
+		if cap(raw)-len(raw) >= 2 {
+			raw = raw[0 : len(raw)+2]
+			copy(raw[5:], raw[3:])
+			raw[0] = mmap32
+			big.PutUint32(raw[1:], uint32(sz+delta))
+			return raw
+		}
+		n := make([]byte, 0, len(raw)+5)
+		n = AppendMapHeader(n, uint32(sz+delta))
+		return append(n, raw[3:]...)
+
+	case mmap32:
+		sz = int64(big.Uint32(raw[1:]))
+		big.PutUint32(raw[1:], uint32(sz+delta))
+		return raw
+
+	default:
+		sz = int64(rfixmap(raw[0]))
+		if sz+delta < 16 {
+			raw[0] = wfixmap(uint8(sz + delta))
+			return raw
+		} else if sz+delta <= math.MaxUint16 {
+			if cap(raw)-len(raw) >= 2 {
+				raw = raw[0 : len(raw)+2]
+				copy(raw[3:], raw[1:])
+				raw[0] = mmap16
+				big.PutUint16(raw[1:], uint16(sz+delta))
+				return raw
+			}
+			n := make([]byte, 0, len(raw)+5)
+			n = AppendMapHeader(n, uint32(sz+delta))
+			return append(n, raw[1:]...)
+		}
+		if cap(raw)-len(raw) >= 4 {
+			raw = raw[0 : len(raw)+4]
+			copy(raw[5:], raw[1:])
+			raw[0] = mmap32
+			big.PutUint32(raw[1:], uint32(sz+delta))
+			return raw
+		}
+		n := make([]byte, 0, len(raw)+5)
+		n = AppendMapHeader(n, uint32(sz+delta))
+		return append(n, raw[1:]...)
+	}
+}