diff options
Diffstat (limited to 'vendor/google.golang.org/protobuf/internal')
5 files changed, 1153 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/internal/encoding/json/decode.go b/vendor/google.golang.org/protobuf/internal/encoding/json/decode.go new file mode 100644 index 000000000..b13fd29e8 --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/encoding/json/decode.go @@ -0,0 +1,340 @@ +// Copyright 2018 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 json + +import ( + "bytes" + "fmt" + "io" + "regexp" + "unicode/utf8" + + "google.golang.org/protobuf/internal/errors" +) + +// call specifies which Decoder method was invoked. +type call uint8 + +const ( + readCall call = iota + peekCall +) + +const unexpectedFmt = "unexpected token %s" + +// ErrUnexpectedEOF means that EOF was encountered in the middle of the input. +var ErrUnexpectedEOF = errors.New("%v", io.ErrUnexpectedEOF) + +// Decoder is a token-based JSON decoder. +type Decoder struct { + // lastCall is last method called, either readCall or peekCall. + // Initial value is readCall. + lastCall call + + // lastToken contains the last read token. + lastToken Token + + // lastErr contains the last read error. + lastErr error + + // openStack is a stack containing ObjectOpen and ArrayOpen values. The + // top of stack represents the object or the array the current value is + // directly located in. + openStack []Kind + + // orig is used in reporting line and column. + orig []byte + // in contains the unconsumed input. + in []byte +} + +// NewDecoder returns a Decoder to read the given []byte. +func NewDecoder(b []byte) *Decoder { + return &Decoder{orig: b, in: b} +} + +// Peek looks ahead and returns the next token kind without advancing a read. +func (d *Decoder) Peek() (Token, error) { + defer func() { d.lastCall = peekCall }() + if d.lastCall == readCall { + d.lastToken, d.lastErr = d.Read() + } + return d.lastToken, d.lastErr +} + +// Read returns the next JSON token. +// It will return an error if there is no valid token. +func (d *Decoder) Read() (Token, error) { + const scalar = Null | Bool | Number | String + + defer func() { d.lastCall = readCall }() + if d.lastCall == peekCall { + return d.lastToken, d.lastErr + } + + tok, err := d.parseNext() + if err != nil { + return Token{}, err + } + + switch tok.kind { + case EOF: + if len(d.openStack) != 0 || + d.lastToken.kind&scalar|ObjectClose|ArrayClose == 0 { + return Token{}, ErrUnexpectedEOF + } + + case Null: + if !d.isValueNext() { + return Token{}, d.newSyntaxError(tok.pos, unexpectedFmt, tok.RawString()) + } + + case Bool, Number: + if !d.isValueNext() { + return Token{}, d.newSyntaxError(tok.pos, unexpectedFmt, tok.RawString()) + } + + case String: + if d.isValueNext() { + break + } + // This string token should only be for a field name. + if d.lastToken.kind&(ObjectOpen|comma) == 0 { + return Token{}, d.newSyntaxError(tok.pos, unexpectedFmt, tok.RawString()) + } + if len(d.in) == 0 { + return Token{}, ErrUnexpectedEOF + } + if c := d.in[0]; c != ':' { + return Token{}, d.newSyntaxError(d.currPos(), `unexpected character %s, missing ":" after field name`, string(c)) + } + tok.kind = Name + d.consume(1) + + case ObjectOpen, ArrayOpen: + if !d.isValueNext() { + return Token{}, d.newSyntaxError(tok.pos, unexpectedFmt, tok.RawString()) + } + d.openStack = append(d.openStack, tok.kind) + + case ObjectClose: + if len(d.openStack) == 0 || + d.lastToken.kind == comma || + d.openStack[len(d.openStack)-1] != ObjectOpen { + return Token{}, d.newSyntaxError(tok.pos, unexpectedFmt, tok.RawString()) + } + d.openStack = d.openStack[:len(d.openStack)-1] + + case ArrayClose: + if len(d.openStack) == 0 || + d.lastToken.kind == comma || + d.openStack[len(d.openStack)-1] != ArrayOpen { + return Token{}, d.newSyntaxError(tok.pos, unexpectedFmt, tok.RawString()) + } + d.openStack = d.openStack[:len(d.openStack)-1] + + case comma: + if len(d.openStack) == 0 || + d.lastToken.kind&(scalar|ObjectClose|ArrayClose) == 0 { + return Token{}, d.newSyntaxError(tok.pos, unexpectedFmt, tok.RawString()) + } + } + + // Update d.lastToken only after validating token to be in the right sequence. + d.lastToken = tok + + if d.lastToken.kind == comma { + return d.Read() + } + return tok, nil +} + +// Any sequence that looks like a non-delimiter (for error reporting). +var errRegexp = regexp.MustCompile(`^([-+._a-zA-Z0-9]{1,32}|.)`) + +// parseNext parses for the next JSON token. It returns a Token object for +// different types, except for Name. It does not handle whether the next token +// is in a valid sequence or not. +func (d *Decoder) parseNext() (Token, error) { + // Trim leading spaces. + d.consume(0) + + in := d.in + if len(in) == 0 { + return d.consumeToken(EOF, 0), nil + } + + switch in[0] { + case 'n': + if n := matchWithDelim("null", in); n != 0 { + return d.consumeToken(Null, n), nil + } + + case 't': + if n := matchWithDelim("true", in); n != 0 { + return d.consumeBoolToken(true, n), nil + } + + case 'f': + if n := matchWithDelim("false", in); n != 0 { + return d.consumeBoolToken(false, n), nil + } + + case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + if n, ok := parseNumber(in); ok { + return d.consumeToken(Number, n), nil + } + + case '"': + s, n, err := d.parseString(in) + if err != nil { + return Token{}, err + } + return d.consumeStringToken(s, n), nil + + case '{': + return d.consumeToken(ObjectOpen, 1), nil + + case '}': + return d.consumeToken(ObjectClose, 1), nil + + case '[': + return d.consumeToken(ArrayOpen, 1), nil + + case ']': + return d.consumeToken(ArrayClose, 1), nil + + case ',': + return d.consumeToken(comma, 1), nil + } + return Token{}, d.newSyntaxError(d.currPos(), "invalid value %s", errRegexp.Find(in)) +} + +// newSyntaxError returns an error with line and column information useful for +// syntax errors. +func (d *Decoder) newSyntaxError(pos int, f string, x ...interface{}) error { + e := errors.New(f, x...) + line, column := d.Position(pos) + return errors.New("syntax error (line %d:%d): %v", line, column, e) +} + +// Position returns line and column number of given index of the original input. +// It will panic if index is out of range. +func (d *Decoder) Position(idx int) (line int, column int) { + b := d.orig[:idx] + line = bytes.Count(b, []byte("\n")) + 1 + if i := bytes.LastIndexByte(b, '\n'); i >= 0 { + b = b[i+1:] + } + column = utf8.RuneCount(b) + 1 // ignore multi-rune characters + return line, column +} + +// currPos returns the current index position of d.in from d.orig. +func (d *Decoder) currPos() int { + return len(d.orig) - len(d.in) +} + +// matchWithDelim matches s with the input b and verifies that the match +// terminates with a delimiter of some form (e.g., r"[^-+_.a-zA-Z0-9]"). +// As a special case, EOF is considered a delimiter. It returns the length of s +// if there is a match, else 0. +func matchWithDelim(s string, b []byte) int { + if !bytes.HasPrefix(b, []byte(s)) { + return 0 + } + + n := len(s) + if n < len(b) && isNotDelim(b[n]) { + return 0 + } + return n +} + +// isNotDelim returns true if given byte is a not delimiter character. +func isNotDelim(c byte) bool { + return (c == '-' || c == '+' || c == '.' || c == '_' || + ('a' <= c && c <= 'z') || + ('A' <= c && c <= 'Z') || + ('0' <= c && c <= '9')) +} + +// consume consumes n bytes of input and any subsequent whitespace. +func (d *Decoder) consume(n int) { + d.in = d.in[n:] + for len(d.in) > 0 { + switch d.in[0] { + case ' ', '\n', '\r', '\t': + d.in = d.in[1:] + default: + return + } + } +} + +// isValueNext returns true if next type should be a JSON value: Null, +// Number, String or Bool. +func (d *Decoder) isValueNext() bool { + if len(d.openStack) == 0 { + return d.lastToken.kind == 0 + } + + start := d.openStack[len(d.openStack)-1] + switch start { + case ObjectOpen: + return d.lastToken.kind&Name != 0 + case ArrayOpen: + return d.lastToken.kind&(ArrayOpen|comma) != 0 + } + panic(fmt.Sprintf( + "unreachable logic in Decoder.isValueNext, lastToken.kind: %v, openStack: %v", + d.lastToken.kind, start)) +} + +// consumeToken constructs a Token for given Kind with raw value derived from +// current d.in and given size, and consumes the given size-lenght of it. +func (d *Decoder) consumeToken(kind Kind, size int) Token { + tok := Token{ + kind: kind, + raw: d.in[:size], + pos: len(d.orig) - len(d.in), + } + d.consume(size) + return tok +} + +// consumeBoolToken constructs a Token for a Bool kind with raw value derived from +// current d.in and given size. +func (d *Decoder) consumeBoolToken(b bool, size int) Token { + tok := Token{ + kind: Bool, + raw: d.in[:size], + pos: len(d.orig) - len(d.in), + boo: b, + } + d.consume(size) + return tok +} + +// consumeStringToken constructs a Token for a String kind with raw value derived +// from current d.in and given size. +func (d *Decoder) consumeStringToken(s string, size int) Token { + tok := Token{ + kind: String, + raw: d.in[:size], + pos: len(d.orig) - len(d.in), + str: s, + } + d.consume(size) + return tok +} + +// Clone returns a copy of the Decoder for use in reading ahead the next JSON +// object, array or other values without affecting current Decoder. +func (d *Decoder) Clone() *Decoder { + ret := *d + ret.openStack = append([]Kind(nil), ret.openStack...) + return &ret +} diff --git a/vendor/google.golang.org/protobuf/internal/encoding/json/decode_number.go b/vendor/google.golang.org/protobuf/internal/encoding/json/decode_number.go new file mode 100644 index 000000000..2999d7133 --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/encoding/json/decode_number.go @@ -0,0 +1,254 @@ +// Copyright 2018 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 json + +import ( + "bytes" + "strconv" +) + +// parseNumber reads the given []byte for a valid JSON number. If it is valid, +// it returns the number of bytes. Parsing logic follows the definition in +// https://tools.ietf.org/html/rfc7159#section-6, and is based off +// encoding/json.isValidNumber function. +func parseNumber(input []byte) (int, bool) { + var n int + + s := input + if len(s) == 0 { + return 0, false + } + + // Optional - + if s[0] == '-' { + s = s[1:] + n++ + if len(s) == 0 { + return 0, false + } + } + + // Digits + switch { + case s[0] == '0': + s = s[1:] + n++ + + case '1' <= s[0] && s[0] <= '9': + s = s[1:] + n++ + for len(s) > 0 && '0' <= s[0] && s[0] <= '9' { + s = s[1:] + n++ + } + + default: + return 0, false + } + + // . followed by 1 or more digits. + if len(s) >= 2 && s[0] == '.' && '0' <= s[1] && s[1] <= '9' { + s = s[2:] + n += 2 + for len(s) > 0 && '0' <= s[0] && s[0] <= '9' { + s = s[1:] + n++ + } + } + + // e or E followed by an optional - or + and + // 1 or more digits. + if len(s) >= 2 && (s[0] == 'e' || s[0] == 'E') { + s = s[1:] + n++ + if s[0] == '+' || s[0] == '-' { + s = s[1:] + n++ + if len(s) == 0 { + return 0, false + } + } + for len(s) > 0 && '0' <= s[0] && s[0] <= '9' { + s = s[1:] + n++ + } + } + + // Check that next byte is a delimiter or it is at the end. + if n < len(input) && isNotDelim(input[n]) { + return 0, false + } + + return n, true +} + +// numberParts is the result of parsing out a valid JSON number. It contains +// the parts of a number. The parts are used for integer conversion. +type numberParts struct { + neg bool + intp []byte + frac []byte + exp []byte +} + +// parseNumber constructs numberParts from given []byte. The logic here is +// similar to consumeNumber above with the difference of having to construct +// numberParts. The slice fields in numberParts are subslices of the input. +func parseNumberParts(input []byte) (numberParts, bool) { + var neg bool + var intp []byte + var frac []byte + var exp []byte + + s := input + if len(s) == 0 { + return numberParts{}, false + } + + // Optional - + if s[0] == '-' { + neg = true + s = s[1:] + if len(s) == 0 { + return numberParts{}, false + } + } + + // Digits + switch { + case s[0] == '0': + // Skip first 0 and no need to store. + s = s[1:] + + case '1' <= s[0] && s[0] <= '9': + intp = s + n := 1 + s = s[1:] + for len(s) > 0 && '0' <= s[0] && s[0] <= '9' { + s = s[1:] + n++ + } + intp = intp[:n] + + default: + return numberParts{}, false + } + + // . followed by 1 or more digits. + if len(s) >= 2 && s[0] == '.' && '0' <= s[1] && s[1] <= '9' { + frac = s[1:] + n := 1 + s = s[2:] + for len(s) > 0 && '0' <= s[0] && s[0] <= '9' { + s = s[1:] + n++ + } + frac = frac[:n] + } + + // e or E followed by an optional - or + and + // 1 or more digits. + if len(s) >= 2 && (s[0] == 'e' || s[0] == 'E') { + s = s[1:] + exp = s + n := 0 + if s[0] == '+' || s[0] == '-' { + s = s[1:] + n++ + if len(s) == 0 { + return numberParts{}, false + } + } + for len(s) > 0 && '0' <= s[0] && s[0] <= '9' { + s = s[1:] + n++ + } + exp = exp[:n] + } + + return numberParts{ + neg: neg, + intp: intp, + frac: bytes.TrimRight(frac, "0"), // Remove unnecessary 0s to the right. + exp: exp, + }, true +} + +// normalizeToIntString returns an integer string in normal form without the +// E-notation for given numberParts. It will return false if it is not an +// integer or if the exponent exceeds than max/min int value. +func normalizeToIntString(n numberParts) (string, bool) { + intpSize := len(n.intp) + fracSize := len(n.frac) + + if intpSize == 0 && fracSize == 0 { + return "0", true + } + + var exp int + if len(n.exp) > 0 { + i, err := strconv.ParseInt(string(n.exp), 10, 32) + if err != nil { + return "", false + } + exp = int(i) + } + + var num []byte + if exp >= 0 { + // For positive E, shift fraction digits into integer part and also pad + // with zeroes as needed. + + // If there are more digits in fraction than the E value, then the + // number is not an integer. + if fracSize > exp { + return "", false + } + + // Make sure resulting digits are within max value limit to avoid + // unnecessarily constructing a large byte slice that may simply fail + // later on. + const maxDigits = 20 // Max uint64 value has 20 decimal digits. + if intpSize+exp > maxDigits { + return "", false + } + + // Set cap to make a copy of integer part when appended. + num = n.intp[:len(n.intp):len(n.intp)] + num = append(num, n.frac...) + for i := 0; i < exp-fracSize; i++ { + num = append(num, '0') + } + } else { + // For negative E, shift digits in integer part out. + + // If there are fractions, then the number is not an integer. + if fracSize > 0 { + return "", false + } + + // index is where the decimal point will be after adjusting for negative + // exponent. + index := intpSize + exp + if index < 0 { + return "", false + } + + num = n.intp + // If any of the digits being shifted to the right of the decimal point + // is non-zero, then the number is not an integer. + for i := index; i < intpSize; i++ { + if num[i] != '0' { + return "", false + } + } + num = num[:index] + } + + if n.neg { + return "-" + string(num), true + } + return string(num), true +} diff --git a/vendor/google.golang.org/protobuf/internal/encoding/json/decode_string.go b/vendor/google.golang.org/protobuf/internal/encoding/json/decode_string.go new file mode 100644 index 000000000..f7fea7d8d --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/encoding/json/decode_string.go @@ -0,0 +1,91 @@ +// Copyright 2018 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 json + +import ( + "strconv" + "unicode" + "unicode/utf16" + "unicode/utf8" + + "google.golang.org/protobuf/internal/strs" +) + +func (d *Decoder) parseString(in []byte) (string, int, error) { + in0 := in + if len(in) == 0 { + return "", 0, ErrUnexpectedEOF + } + if in[0] != '"' { + return "", 0, d.newSyntaxError(d.currPos(), "invalid character %q at start of string", in[0]) + } + in = in[1:] + i := indexNeedEscapeInBytes(in) + in, out := in[i:], in[:i:i] // set cap to prevent mutations + for len(in) > 0 { + switch r, n := utf8.DecodeRune(in); { + case r == utf8.RuneError && n == 1: + return "", 0, d.newSyntaxError(d.currPos(), "invalid UTF-8 in string") + case r < ' ': + return "", 0, d.newSyntaxError(d.currPos(), "invalid character %q in string", r) + case r == '"': + in = in[1:] + n := len(in0) - len(in) + return string(out), n, nil + case r == '\\': + if len(in) < 2 { + return "", 0, ErrUnexpectedEOF + } + switch r := in[1]; r { + case '"', '\\', '/': + in, out = in[2:], append(out, r) + case 'b': + in, out = in[2:], append(out, '\b') + case 'f': + in, out = in[2:], append(out, '\f') + case 'n': + in, out = in[2:], append(out, '\n') + case 'r': + in, out = in[2:], append(out, '\r') + case 't': + in, out = in[2:], append(out, '\t') + case 'u': + if len(in) < 6 { + return "", 0, ErrUnexpectedEOF + } + v, err := strconv.ParseUint(string(in[2:6]), 16, 16) + if err != nil { + return "", 0, d.newSyntaxError(d.currPos(), "invalid escape code %q in string", in[:6]) + } + in = in[6:] + + r := rune(v) + if utf16.IsSurrogate(r) { + if len(in) < 6 { + return "", 0, ErrUnexpectedEOF + } + v, err := strconv.ParseUint(string(in[2:6]), 16, 16) + r = utf16.DecodeRune(r, rune(v)) + if in[0] != '\\' || in[1] != 'u' || + r == unicode.ReplacementChar || err != nil { + return "", 0, d.newSyntaxError(d.currPos(), "invalid escape code %q in string", in[:6]) + } + in = in[6:] + } + out = append(out, string(r)...) + default: + return "", 0, d.newSyntaxError(d.currPos(), "invalid escape code %q in string", in[:2]) + } + default: + i := indexNeedEscapeInBytes(in[n:]) + in, out = in[n+i:], append(out, in[:n+i]...) + } + } + return "", 0, ErrUnexpectedEOF +} + +// indexNeedEscapeInBytes returns the index of the character that needs +// escaping. If no characters need escaping, this returns the input length. +func indexNeedEscapeInBytes(b []byte) int { return indexNeedEscapeInString(strs.UnsafeString(b)) } diff --git a/vendor/google.golang.org/protobuf/internal/encoding/json/decode_token.go b/vendor/google.golang.org/protobuf/internal/encoding/json/decode_token.go new file mode 100644 index 000000000..50578d659 --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/encoding/json/decode_token.go @@ -0,0 +1,192 @@ +// Copyright 2019 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 json + +import ( + "bytes" + "fmt" + "strconv" +) + +// Kind represents a token kind expressible in the JSON format. +type Kind uint16 + +const ( + Invalid Kind = (1 << iota) / 2 + EOF + Null + Bool + Number + String + Name + ObjectOpen + ObjectClose + ArrayOpen + ArrayClose + + // comma is only for parsing in between tokens and + // does not need to be exported. + comma +) + +func (k Kind) String() string { + switch k { + case EOF: + return "eof" + case Null: + return "null" + case Bool: + return "bool" + case Number: + return "number" + case String: + return "string" + case ObjectOpen: + return "{" + case ObjectClose: + return "}" + case Name: + return "name" + case ArrayOpen: + return "[" + case ArrayClose: + return "]" + case comma: + return "," + } + return "<invalid>" +} + +// Token provides a parsed token kind and value. +// +// Values are provided by the difference accessor methods. The accessor methods +// Name, Bool, and ParsedString will panic if called on the wrong kind. There +// are different accessor methods for the Number kind for converting to the +// appropriate Go numeric type and those methods have the ok return value. +type Token struct { + // Token kind. + kind Kind + // pos provides the position of the token in the original input. + pos int + // raw bytes of the serialized token. + // This is a subslice into the original input. + raw []byte + // boo is parsed boolean value. + boo bool + // str is parsed string value. + str string +} + +// Kind returns the token kind. +func (t Token) Kind() Kind { + return t.kind +} + +// RawString returns the read value in string. +func (t Token) RawString() string { + return string(t.raw) +} + +// Pos returns the token position from the input. +func (t Token) Pos() int { + return t.pos +} + +// Name returns the object name if token is Name, else it panics. +func (t Token) Name() string { + if t.kind == Name { + return t.str + } + panic(fmt.Sprintf("Token is not a Name: %v", t.RawString())) +} + +// Bool returns the bool value if token kind is Bool, else it panics. +func (t Token) Bool() bool { + if t.kind == Bool { + return t.boo + } + panic(fmt.Sprintf("Token is not a Bool: %v", t.RawString())) +} + +// ParsedString returns the string value for a JSON string token or the read +// value in string if token is not a string. +func (t Token) ParsedString() string { + if t.kind == String { + return t.str + } + panic(fmt.Sprintf("Token is not a String: %v", t.RawString())) +} + +// Float returns the floating-point number if token kind is Number. +// +// The floating-point precision is specified by the bitSize parameter: 32 for +// float32 or 64 for float64. If bitSize=32, the result still has type float64, +// but it will be convertible to float32 without changing its value. It will +// return false if the number exceeds the floating point limits for given +// bitSize. +func (t Token) Float(bitSize int) (float64, bool) { + if t.kind != Number { + return 0, false + } + f, err := strconv.ParseFloat(t.RawString(), bitSize) + if err != nil { + return 0, false + } + return f, true +} + +// Int returns the signed integer number if token is Number. +// +// The given bitSize specifies the integer type that the result must fit into. +// It returns false if the number is not an integer value or if the result +// exceeds the limits for given bitSize. +func (t Token) Int(bitSize int) (int64, bool) { + s, ok := t.getIntStr() + if !ok { + return 0, false + } + n, err := strconv.ParseInt(s, 10, bitSize) + if err != nil { + return 0, false + } + return n, true +} + +// Uint returns the signed integer number if token is Number. +// +// The given bitSize specifies the unsigned integer type that the result must +// fit into. It returns false if the number is not an unsigned integer value +// or if the result exceeds the limits for given bitSize. +func (t Token) Uint(bitSize int) (uint64, bool) { + s, ok := t.getIntStr() + if !ok { + return 0, false + } + n, err := strconv.ParseUint(s, 10, bitSize) + if err != nil { + return 0, false + } + return n, true +} + +func (t Token) getIntStr() (string, bool) { + if t.kind != Number { + return "", false + } + parts, ok := parseNumberParts(t.raw) + if !ok { + return "", false + } + return normalizeToIntString(parts) +} + +// TokenEquals returns true if given Tokens are equal, else false. +func TokenEquals(x, y Token) bool { + return x.kind == y.kind && + x.pos == y.pos && + bytes.Equal(x.raw, y.raw) && + x.boo == y.boo && + x.str == y.str +} diff --git a/vendor/google.golang.org/protobuf/internal/encoding/json/encode.go b/vendor/google.golang.org/protobuf/internal/encoding/json/encode.go new file mode 100644 index 000000000..fbdf34873 --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/encoding/json/encode.go @@ -0,0 +1,276 @@ +// Copyright 2018 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 json + +import ( + "math" + "math/bits" + "strconv" + "strings" + "unicode/utf8" + + "google.golang.org/protobuf/internal/detrand" + "google.golang.org/protobuf/internal/errors" +) + +// kind represents an encoding type. +type kind uint8 + +const ( + _ kind = (1 << iota) / 2 + name + scalar + objectOpen + objectClose + arrayOpen + arrayClose +) + +// Encoder provides methods to write out JSON constructs and values. The user is +// responsible for producing valid sequences of JSON constructs and values. +type Encoder struct { + indent string + lastKind kind + indents []byte + out []byte +} + +// NewEncoder returns an Encoder. +// +// If indent is a non-empty string, it causes every entry for an Array or Object +// to be preceded by the indent and trailed by a newline. +func NewEncoder(indent string) (*Encoder, error) { + e := &Encoder{} + if len(indent) > 0 { + if strings.Trim(indent, " \t") != "" { + return nil, errors.New("indent may only be composed of space or tab characters") + } + e.indent = indent + } + return e, nil +} + +// Bytes returns the content of the written bytes. +func (e *Encoder) Bytes() []byte { + return e.out +} + +// WriteNull writes out the null value. +func (e *Encoder) WriteNull() { + e.prepareNext(scalar) + e.out = append(e.out, "null"...) +} + +// WriteBool writes out the given boolean value. +func (e *Encoder) WriteBool(b bool) { + e.prepareNext(scalar) + if b { + e.out = append(e.out, "true"...) + } else { + e.out = append(e.out, "false"...) + } +} + +// WriteString writes out the given string in JSON string value. Returns error +// if input string contains invalid UTF-8. +func (e *Encoder) WriteString(s string) error { + e.prepareNext(scalar) + var err error + if e.out, err = appendString(e.out, s); err != nil { + return err + } + return nil +} + +// Sentinel error used for indicating invalid UTF-8. +var errInvalidUTF8 = errors.New("invalid UTF-8") + +func appendString(out []byte, in string) ([]byte, error) { + out = append(out, '"') + i := indexNeedEscapeInString(in) + in, out = in[i:], append(out, in[:i]...) + for len(in) > 0 { + switch r, n := utf8.DecodeRuneInString(in); { + case r == utf8.RuneError && n == 1: + return out, errInvalidUTF8 + case r < ' ' || r == '"' || r == '\\': + out = append(out, '\\') + switch r { + case '"', '\\': + out = append(out, byte(r)) + case '\b': + out = append(out, 'b') + case '\f': + out = append(out, 'f') + case '\n': + out = append(out, 'n') + case '\r': + out = append(out, 'r') + case '\t': + out = append(out, 't') + default: + out = append(out, 'u') + out = append(out, "0000"[1+(bits.Len32(uint32(r))-1)/4:]...) + out = strconv.AppendUint(out, uint64(r), 16) + } + in = in[n:] + default: + i := indexNeedEscapeInString(in[n:]) + in, out = in[n+i:], append(out, in[:n+i]...) + } + } + out = append(out, '"') + return out, nil +} + +// indexNeedEscapeInString returns the index of the character that needs +// escaping. If no characters need escaping, this returns the input length. +func indexNeedEscapeInString(s string) int { + for i, r := range s { + if r < ' ' || r == '\\' || r == '"' || r == utf8.RuneError { + return i + } + } + return len(s) +} + +// WriteFloat writes out the given float and bitSize in JSON number value. +func (e *Encoder) WriteFloat(n float64, bitSize int) { + e.prepareNext(scalar) + e.out = appendFloat(e.out, n, bitSize) +} + +// appendFloat formats given float in bitSize, and appends to the given []byte. +func appendFloat(out []byte, n float64, bitSize int) []byte { + switch { + case math.IsNaN(n): + return append(out, `"NaN"`...) + case math.IsInf(n, +1): + return append(out, `"Infinity"`...) + case math.IsInf(n, -1): + return append(out, `"-Infinity"`...) + } + + // JSON number formatting logic based on encoding/json. + // See floatEncoder.encode for reference. + fmt := byte('f') + if abs := math.Abs(n); abs != 0 { + if bitSize == 64 && (abs < 1e-6 || abs >= 1e21) || + bitSize == 32 && (float32(abs) < 1e-6 || float32(abs) >= 1e21) { + fmt = 'e' + } + } + out = strconv.AppendFloat(out, n, fmt, -1, bitSize) + if fmt == 'e' { + n := len(out) + if n >= 4 && out[n-4] == 'e' && out[n-3] == '-' && out[n-2] == '0' { + out[n-2] = out[n-1] + out = out[:n-1] + } + } + return out +} + +// WriteInt writes out the given signed integer in JSON number value. +func (e *Encoder) WriteInt(n int64) { + e.prepareNext(scalar) + e.out = append(e.out, strconv.FormatInt(n, 10)...) +} + +// WriteUint writes out the given unsigned integer in JSON number value. +func (e *Encoder) WriteUint(n uint64) { + e.prepareNext(scalar) + e.out = append(e.out, strconv.FormatUint(n, 10)...) +} + +// StartObject writes out the '{' symbol. +func (e *Encoder) StartObject() { + e.prepareNext(objectOpen) + e.out = append(e.out, '{') +} + +// EndObject writes out the '}' symbol. +func (e *Encoder) EndObject() { + e.prepareNext(objectClose) + e.out = append(e.out, '}') +} + +// WriteName writes out the given string in JSON string value and the name +// separator ':'. Returns error if input string contains invalid UTF-8, which +// should not be likely as protobuf field names should be valid. +func (e *Encoder) WriteName(s string) error { + e.prepareNext(name) + var err error + // Append to output regardless of error. + e.out, err = appendString(e.out, s) + e.out = append(e.out, ':') + return err +} + +// StartArray writes out the '[' symbol. +func (e *Encoder) StartArray() { + e.prepareNext(arrayOpen) + e.out = append(e.out, '[') +} + +// EndArray writes out the ']' symbol. +func (e *Encoder) EndArray() { + e.prepareNext(arrayClose) + e.out = append(e.out, ']') +} + +// prepareNext adds possible comma and indentation for the next value based +// on last type and indent option. It also updates lastKind to next. +func (e *Encoder) prepareNext(next kind) { + defer func() { + // Set lastKind to next. + e.lastKind = next + }() + + if len(e.indent) == 0 { + // Need to add comma on the following condition. + if e.lastKind&(scalar|objectClose|arrayClose) != 0 && + next&(name|scalar|objectOpen|arrayOpen) != 0 { + e.out = append(e.out, ',') + // For single-line output, add a random extra space after each + // comma to make output unstable. + if detrand.Bool() { + e.out = append(e.out, ' ') + } + } + return + } + + switch { + case e.lastKind&(objectOpen|arrayOpen) != 0: + // If next type is NOT closing, add indent and newline. + if next&(objectClose|arrayClose) == 0 { + e.indents = append(e.indents, e.indent...) + e.out = append(e.out, '\n') + e.out = append(e.out, e.indents...) + } + + case e.lastKind&(scalar|objectClose|arrayClose) != 0: + switch { + // If next type is either a value or name, add comma and newline. + case next&(name|scalar|objectOpen|arrayOpen) != 0: + e.out = append(e.out, ',', '\n') + + // If next type is a closing object or array, adjust indentation. + case next&(objectClose|arrayClose) != 0: + e.indents = e.indents[:len(e.indents)-len(e.indent)] + e.out = append(e.out, '\n') + } + e.out = append(e.out, e.indents...) + + case e.lastKind&name != 0: + e.out = append(e.out, ' ') + // For multi-line output, add a random extra space after key: to make + // output unstable. + if detrand.Bool() { + e.out = append(e.out, ' ') + } + } +} |