Update dependencies

vendor/github.com/go-json-experiment/json/jsontext/value.go

@@ -0,0 +1,305 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package jsontext
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"slices"
+	"strings"
+	"sync"
+
+	"github.com/go-json-experiment/json/internal/jsonflags"
+	"github.com/go-json-experiment/json/internal/jsonwire"
+)
+
+// NOTE: Value is analogous to v1 json.RawMessage.
+
+// Value represents a single raw JSON value, which may be one of the following:
+//   - a JSON literal (i.e., null, true, or false)
+//   - a JSON string (e.g., "hello, world!")
+//   - a JSON number (e.g., 123.456)
+//   - an entire JSON object (e.g., {"fizz":"buzz"} )
+//   - an entire JSON array (e.g., [1,2,3] )
+//
+// Value can represent entire array or object values, while [Token] cannot.
+// Value may contain leading and/or trailing whitespace.
+type Value []byte
+
+// Clone returns a copy of v.
+func (v Value) Clone() Value {
+	return bytes.Clone(v)
+}
+
+// String returns the string formatting of v.
+func (v Value) String() string {
+	if v == nil {
+		return "null"
+	}
+	return string(v)
+}
+
+// IsValid reports whether the raw JSON value is syntactically valid
+// according to RFC 7493.
+//
+// It verifies whether the input is properly encoded as UTF-8,
+// that escape sequences within strings decode to valid Unicode codepoints, and
+// that all names in each object are unique.
+// It does not verify whether numbers are representable within the limits
+// of any common numeric type (e.g., float64, int64, or uint64).
+func (v Value) IsValid() bool {
+	d := getBufferedDecoder(v)
+	defer putBufferedDecoder(d)
+	_, errVal := d.ReadValue()
+	_, errEOF := d.ReadToken()
+	return errVal == nil && errEOF == io.EOF
+}
+
+// Compact removes all whitespace from the raw JSON value.
+//
+// It does not reformat JSON strings to use any other representation.
+// It is guaranteed to succeed if the input is valid.
+// If the value is already compacted, then the buffer is not mutated.
+func (v *Value) Compact() error {
+	return v.reformat(false, false, "", "")
+}
+
+// Indent reformats the whitespace in the raw JSON value so that each element
+// in a JSON object or array begins on a new, indented line beginning with
+// prefix followed by one or more copies of indent according to the nesting.
+// The value does not begin with the prefix nor any indention,
+// to make it easier to embed inside other formatted JSON data.
+//
+// It does not reformat JSON strings to use any other representation.
+// It is guaranteed to succeed if the input is valid.
+// If the value is already indented properly, then the buffer is not mutated.
+//
+// The prefix and indent strings must be composed of only spaces and/or tabs.
+func (v *Value) Indent(prefix, indent string) error {
+	return v.reformat(false, true, prefix, indent)
+}
+
+// Canonicalize canonicalizes the raw JSON value according to the
+// JSON Canonicalization Scheme (JCS) as defined by RFC 8785
+// where it produces a stable representation of a JSON value.
+//
+// The output stability is dependent on the stability of the application data
+// (see RFC 8785, Appendix E). It cannot produce stable output from
+// fundamentally unstable input. For example, if the JSON value
+// contains ephemeral data (e.g., a frequently changing timestamp),
+// then the value is still unstable regardless of whether this is called.
+//
+// Note that JCS treats all JSON numbers as IEEE 754 double precision numbers.
+// Any numbers with precision beyond what is representable by that form
+// will lose their precision when canonicalized. For example, integer values
+// beyond ±2⁵³ will lose their precision. It is recommended that
+// int64 and uint64 data types be represented as a JSON string.
+//
+// It is guaranteed to succeed if the input is valid.
+// If the value is already canonicalized, then the buffer is not mutated.
+func (v *Value) Canonicalize() error {
+	return v.reformat(true, false, "", "")
+}
+
+// TODO: Instead of implementing the v1 Marshaler/Unmarshaler,
+// consider implementing the v2 versions instead.
+
+// MarshalJSON returns v as the JSON encoding of v.
+// It returns the stored value as the raw JSON output without any validation.
+// If v is nil, then this returns a JSON null.
+func (v Value) MarshalJSON() ([]byte, error) {
+	// NOTE: This matches the behavior of v1 json.RawMessage.MarshalJSON.
+	if v == nil {
+		return []byte("null"), nil
+	}
+	return v, nil
+}
+
+// UnmarshalJSON sets v as the JSON encoding of b.
+// It stores a copy of the provided raw JSON input without any validation.
+func (v *Value) UnmarshalJSON(b []byte) error {
+	// NOTE: This matches the behavior of v1 json.RawMessage.UnmarshalJSON.
+	if v == nil {
+		return errors.New("json.Value: UnmarshalJSON on nil pointer")
+	}
+	*v = append((*v)[:0], b...)
+	return nil
+}
+
+// Kind returns the starting token kind.
+// For a valid value, this will never include '}' or ']'.
+func (v Value) Kind() Kind {
+	if v := v[jsonwire.ConsumeWhitespace(v):]; len(v) > 0 {
+		return Kind(v[0]).normalize()
+	}
+	return invalidKind
+}
+
+func (v *Value) reformat(canonical, multiline bool, prefix, indent string) error {
+	// Write the entire value to reformat all tokens and whitespace.
+	e := getBufferedEncoder()
+	defer putBufferedEncoder(e)
+	eo := &e.s.Struct
+	if canonical {
+		eo.Flags.Set(jsonflags.AllowInvalidUTF8 | 0)    // per RFC 8785, section 3.2.4
+		eo.Flags.Set(jsonflags.AllowDuplicateNames | 0) // per RFC 8785, section 3.1
+		eo.Flags.Set(jsonflags.CanonicalizeNumbers | 1) // per RFC 8785, section 3.2.2.3
+		eo.Flags.Set(jsonflags.PreserveRawStrings | 0)  // per RFC 8785, section 3.2.2.2
+		eo.Flags.Set(jsonflags.EscapeForHTML | 0)       // per RFC 8785, section 3.2.2.2
+		eo.Flags.Set(jsonflags.EscapeForJS | 0)         // per RFC 8785, section 3.2.2.2
+		eo.Flags.Set(jsonflags.Expand | 0)              // per RFC 8785, section 3.2.1
+	} else {
+		if s := strings.TrimLeft(prefix, " \t"); len(s) > 0 {
+			panic("json: invalid character " + jsonwire.QuoteRune(s) + " in indent prefix")
+		}
+		if s := strings.TrimLeft(indent, " \t"); len(s) > 0 {
+			panic("json: invalid character " + jsonwire.QuoteRune(s) + " in indent")
+		}
+		eo.Flags.Set(jsonflags.AllowInvalidUTF8 | 1)
+		eo.Flags.Set(jsonflags.AllowDuplicateNames | 1)
+		eo.Flags.Set(jsonflags.PreserveRawStrings | 1)
+		if multiline {
+			eo.Flags.Set(jsonflags.Expand | 1)
+			eo.Flags.Set(jsonflags.Indent | 1)
+			eo.Flags.Set(jsonflags.IndentPrefix | 1)
+			eo.IndentPrefix = prefix
+			eo.Indent = indent
+		} else {
+			eo.Flags.Set(jsonflags.Expand | 0)
+		}
+	}
+	eo.Flags.Set(jsonflags.OmitTopLevelNewline | 1)
+	if err := e.s.WriteValue(*v); err != nil {
+		return err
+	}
+
+	// For canonical output, we may need to reorder object members.
+	if canonical {
+		// Obtain a buffered encoder just to use its internal buffer as
+		// a scratch buffer in reorderObjects for reordering object members.
+		e2 := getBufferedEncoder()
+		defer putBufferedEncoder(e2)
+
+		// Disable redundant checks performed earlier during encoding.
+		d := getBufferedDecoder(e.s.Buf)
+		defer putBufferedDecoder(d)
+		d.s.Flags.Set(jsonflags.AllowDuplicateNames | jsonflags.AllowInvalidUTF8 | 1)
+		reorderObjects(d, &e2.s.Buf) // per RFC 8785, section 3.2.3
+	}
+
+	// Store the result back into the value if different.
+	if !bytes.Equal(*v, e.s.Buf) {
+		*v = append((*v)[:0], e.s.Buf...)
+	}
+	return nil
+}
+
+type memberName struct {
+	// name is the unescaped name.
+	name []byte
+	// before and after are byte offsets into Decoder.buf that represents
+	// the entire name/value pair. It may contain leading commas.
+	before, after int64
+}
+
+var memberNamePool = sync.Pool{New: func() any { return new([]memberName) }}
+
+func getMemberNames() *[]memberName {
+	ns := memberNamePool.Get().(*[]memberName)
+	*ns = (*ns)[:0]
+	return ns
+}
+func putMemberNames(ns *[]memberName) {
+	if cap(*ns) < 1<<10 {
+		clear(*ns) // avoid pinning name
+		memberNamePool.Put(ns)
+	}
+}
+
+// reorderObjects recursively reorders all object members in place
+// according to the ordering specified in RFC 8785, section 3.2.3.
+//
+// Pre-conditions:
+//   - The value is valid (i.e., no decoder errors should ever occur).
+//   - The value is compact (i.e., no whitespace is present).
+//   - Initial call is provided a Decoder reading from the start of v.
+//
+// Post-conditions:
+//   - Exactly one JSON value is read from the Decoder.
+//   - All fully-parsed JSON objects are reordered by directly moving
+//     the members in the value buffer.
+//
+// The runtime is approximately O(n·log(n)) + O(m·log(m)),
+// where n is len(v) and m is the total number of object members.
+func reorderObjects(d *Decoder, scratch *[]byte) {
+	switch tok, _ := d.ReadToken(); tok.Kind() {
+	case '{':
+		// Iterate and collect the name and offsets for every object member.
+		members := getMemberNames()
+		defer putMemberNames(members)
+		var prevName []byte
+		isSorted := true
+
+		beforeBody := d.InputOffset() // offset after '{'
+		for d.PeekKind() != '}' {
+			beforeName := d.InputOffset()
+			var flags jsonwire.ValueFlags
+			name, _ := d.s.ReadValue(&flags)
+			name = jsonwire.UnquoteMayCopy(name, flags.IsVerbatim())
+			reorderObjects(d, scratch)
+			afterValue := d.InputOffset()
+
+			if isSorted && len(*members) > 0 {
+				isSorted = jsonwire.CompareUTF16(prevName, []byte(name)) < 0
+			}
+			*members = append(*members, memberName{name, beforeName, afterValue})
+			prevName = name
+		}
+		afterBody := d.InputOffset() // offset before '}'
+		d.ReadToken()
+
+		// Sort the members; return early if it's already sorted.
+		if isSorted {
+			return
+		}
+		slices.SortFunc(*members, func(x, y memberName) int {
+			return jsonwire.CompareUTF16(x.name, y.name)
+		})
+
+		// Append the reordered members to a new buffer,
+		// then copy the reordered members back over the original members.
+		// Avoid swapping in place since each member may be a different size
+		// where moving a member over a smaller member may corrupt the data
+		// for subsequent members before they have been moved.
+		//
+		// The following invariant must hold:
+		//	sum([m.after-m.before for m in members]) == afterBody-beforeBody
+		sorted := (*scratch)[:0]
+		for i, member := range *members {
+			if d.s.buf[member.before] == ',' {
+				member.before++ // trim leading comma
+			}
+			sorted = append(sorted, d.s.buf[member.before:member.after]...)
+			if i < len(*members)-1 {
+				sorted = append(sorted, ',') // append trailing comma
+			}
+		}
+		if int(afterBody-beforeBody) != len(sorted) {
+			panic("BUG: length invariant violated")
+		}
+		copy(d.s.buf[beforeBody:afterBody], sorted)
+
+		// Update scratch buffer to the largest amount ever used.
+		if len(sorted) > len(*scratch) {
+			*scratch = sorted
+		}
+	case '[':
+		for d.PeekKind() != ']' {
+			reorderObjects(d, scratch)
+		}
+		d.ReadToken()
+	}
+}