diff options
Diffstat (limited to 'vendor/gopkg.in/square/go-jose.v2/json/scanner.go')
-rw-r--r-- | vendor/gopkg.in/square/go-jose.v2/json/scanner.go | 623 |
1 files changed, 0 insertions, 623 deletions
diff --git a/vendor/gopkg.in/square/go-jose.v2/json/scanner.go b/vendor/gopkg.in/square/go-jose.v2/json/scanner.go deleted file mode 100644 index ee6622e8c..000000000 --- a/vendor/gopkg.in/square/go-jose.v2/json/scanner.go +++ /dev/null @@ -1,623 +0,0 @@ -// Copyright 2010 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 - -// JSON value parser state machine. -// Just about at the limit of what is reasonable to write by hand. -// Some parts are a bit tedious, but overall it nicely factors out the -// otherwise common code from the multiple scanning functions -// in this package (Compact, Indent, checkValid, nextValue, etc). -// -// This file starts with two simple examples using the scanner -// before diving into the scanner itself. - -import "strconv" - -// checkValid verifies that data is valid JSON-encoded data. -// scan is passed in for use by checkValid to avoid an allocation. -func checkValid(data []byte, scan *scanner) error { - scan.reset() - for _, c := range data { - scan.bytes++ - if scan.step(scan, c) == scanError { - return scan.err - } - } - if scan.eof() == scanError { - return scan.err - } - return nil -} - -// nextValue splits data after the next whole JSON value, -// returning that value and the bytes that follow it as separate slices. -// scan is passed in for use by nextValue to avoid an allocation. -func nextValue(data []byte, scan *scanner) (value, rest []byte, err error) { - scan.reset() - for i, c := range data { - v := scan.step(scan, c) - if v >= scanEndObject { - switch v { - // probe the scanner with a space to determine whether we will - // get scanEnd on the next character. Otherwise, if the next character - // is not a space, scanEndTop allocates a needless error. - case scanEndObject, scanEndArray: - if scan.step(scan, ' ') == scanEnd { - return data[:i+1], data[i+1:], nil - } - case scanError: - return nil, nil, scan.err - case scanEnd: - return data[:i], data[i:], nil - } - } - } - if scan.eof() == scanError { - return nil, nil, scan.err - } - return data, nil, nil -} - -// A SyntaxError is a description of a JSON syntax error. -type SyntaxError struct { - msg string // description of error - Offset int64 // error occurred after reading Offset bytes -} - -func (e *SyntaxError) Error() string { return e.msg } - -// A scanner is a JSON scanning state machine. -// Callers call scan.reset() and then pass bytes in one at a time -// by calling scan.step(&scan, c) for each byte. -// The return value, referred to as an opcode, tells the -// caller about significant parsing events like beginning -// and ending literals, objects, and arrays, so that the -// caller can follow along if it wishes. -// The return value scanEnd indicates that a single top-level -// JSON value has been completed, *before* the byte that -// just got passed in. (The indication must be delayed in order -// to recognize the end of numbers: is 123 a whole value or -// the beginning of 12345e+6?). -type scanner struct { - // The step is a func to be called to execute the next transition. - // Also tried using an integer constant and a single func - // with a switch, but using the func directly was 10% faster - // on a 64-bit Mac Mini, and it's nicer to read. - step func(*scanner, byte) int - - // Reached end of top-level value. - endTop bool - - // Stack of what we're in the middle of - array values, object keys, object values. - parseState []int - - // Error that happened, if any. - err error - - // 1-byte redo (see undo method) - redo bool - redoCode int - redoState func(*scanner, byte) int - - // total bytes consumed, updated by decoder.Decode - bytes int64 -} - -// These values are returned by the state transition functions -// assigned to scanner.state and the method scanner.eof. -// They give details about the current state of the scan that -// callers might be interested to know about. -// It is okay to ignore the return value of any particular -// call to scanner.state: if one call returns scanError, -// every subsequent call will return scanError too. -const ( - // Continue. - scanContinue = iota // uninteresting byte - scanBeginLiteral // end implied by next result != scanContinue - scanBeginObject // begin object - scanObjectKey // just finished object key (string) - scanObjectValue // just finished non-last object value - scanEndObject // end object (implies scanObjectValue if possible) - scanBeginArray // begin array - scanArrayValue // just finished array value - scanEndArray // end array (implies scanArrayValue if possible) - scanSkipSpace // space byte; can skip; known to be last "continue" result - - // Stop. - scanEnd // top-level value ended *before* this byte; known to be first "stop" result - scanError // hit an error, scanner.err. -) - -// These values are stored in the parseState stack. -// They give the current state of a composite value -// being scanned. If the parser is inside a nested value -// the parseState describes the nested state, outermost at entry 0. -const ( - parseObjectKey = iota // parsing object key (before colon) - parseObjectValue // parsing object value (after colon) - parseArrayValue // parsing array value -) - -// reset prepares the scanner for use. -// It must be called before calling s.step. -func (s *scanner) reset() { - s.step = stateBeginValue - s.parseState = s.parseState[0:0] - s.err = nil - s.redo = false - s.endTop = false -} - -// eof tells the scanner that the end of input has been reached. -// It returns a scan status just as s.step does. -func (s *scanner) eof() int { - if s.err != nil { - return scanError - } - if s.endTop { - return scanEnd - } - s.step(s, ' ') - if s.endTop { - return scanEnd - } - if s.err == nil { - s.err = &SyntaxError{"unexpected end of JSON input", s.bytes} - } - return scanError -} - -// pushParseState pushes a new parse state p onto the parse stack. -func (s *scanner) pushParseState(p int) { - s.parseState = append(s.parseState, p) -} - -// popParseState pops a parse state (already obtained) off the stack -// and updates s.step accordingly. -func (s *scanner) popParseState() { - n := len(s.parseState) - 1 - s.parseState = s.parseState[0:n] - s.redo = false - if n == 0 { - s.step = stateEndTop - s.endTop = true - } else { - s.step = stateEndValue - } -} - -func isSpace(c byte) bool { - return c == ' ' || c == '\t' || c == '\r' || c == '\n' -} - -// stateBeginValueOrEmpty is the state after reading `[`. -func stateBeginValueOrEmpty(s *scanner, c byte) int { - if c <= ' ' && isSpace(c) { - return scanSkipSpace - } - if c == ']' { - return stateEndValue(s, c) - } - return stateBeginValue(s, c) -} - -// stateBeginValue is the state at the beginning of the input. -func stateBeginValue(s *scanner, c byte) int { - if c <= ' ' && isSpace(c) { - return scanSkipSpace - } - switch c { - case '{': - s.step = stateBeginStringOrEmpty - s.pushParseState(parseObjectKey) - return scanBeginObject - case '[': - s.step = stateBeginValueOrEmpty - s.pushParseState(parseArrayValue) - return scanBeginArray - case '"': - s.step = stateInString - return scanBeginLiteral - case '-': - s.step = stateNeg - return scanBeginLiteral - case '0': // beginning of 0.123 - s.step = state0 - return scanBeginLiteral - case 't': // beginning of true - s.step = stateT - return scanBeginLiteral - case 'f': // beginning of false - s.step = stateF - return scanBeginLiteral - case 'n': // beginning of null - s.step = stateN - return scanBeginLiteral - } - if '1' <= c && c <= '9' { // beginning of 1234.5 - s.step = state1 - return scanBeginLiteral - } - return s.error(c, "looking for beginning of value") -} - -// stateBeginStringOrEmpty is the state after reading `{`. -func stateBeginStringOrEmpty(s *scanner, c byte) int { - if c <= ' ' && isSpace(c) { - return scanSkipSpace - } - if c == '}' { - n := len(s.parseState) - s.parseState[n-1] = parseObjectValue - return stateEndValue(s, c) - } - return stateBeginString(s, c) -} - -// stateBeginString is the state after reading `{"key": value,`. -func stateBeginString(s *scanner, c byte) int { - if c <= ' ' && isSpace(c) { - return scanSkipSpace - } - if c == '"' { - s.step = stateInString - return scanBeginLiteral - } - return s.error(c, "looking for beginning of object key string") -} - -// stateEndValue is the state after completing a value, -// such as after reading `{}` or `true` or `["x"`. -func stateEndValue(s *scanner, c byte) int { - n := len(s.parseState) - if n == 0 { - // Completed top-level before the current byte. - s.step = stateEndTop - s.endTop = true - return stateEndTop(s, c) - } - if c <= ' ' && isSpace(c) { - s.step = stateEndValue - return scanSkipSpace - } - ps := s.parseState[n-1] - switch ps { - case parseObjectKey: - if c == ':' { - s.parseState[n-1] = parseObjectValue - s.step = stateBeginValue - return scanObjectKey - } - return s.error(c, "after object key") - case parseObjectValue: - if c == ',' { - s.parseState[n-1] = parseObjectKey - s.step = stateBeginString - return scanObjectValue - } - if c == '}' { - s.popParseState() - return scanEndObject - } - return s.error(c, "after object key:value pair") - case parseArrayValue: - if c == ',' { - s.step = stateBeginValue - return scanArrayValue - } - if c == ']' { - s.popParseState() - return scanEndArray - } - return s.error(c, "after array element") - } - return s.error(c, "") -} - -// stateEndTop is the state after finishing the top-level value, -// such as after reading `{}` or `[1,2,3]`. -// Only space characters should be seen now. -func stateEndTop(s *scanner, c byte) int { - if c != ' ' && c != '\t' && c != '\r' && c != '\n' { - // Complain about non-space byte on next call. - s.error(c, "after top-level value") - } - return scanEnd -} - -// stateInString is the state after reading `"`. -func stateInString(s *scanner, c byte) int { - if c == '"' { - s.step = stateEndValue - return scanContinue - } - if c == '\\' { - s.step = stateInStringEsc - return scanContinue - } - if c < 0x20 { - return s.error(c, "in string literal") - } - return scanContinue -} - -// stateInStringEsc is the state after reading `"\` during a quoted string. -func stateInStringEsc(s *scanner, c byte) int { - switch c { - case 'b', 'f', 'n', 'r', 't', '\\', '/', '"': - s.step = stateInString - return scanContinue - case 'u': - s.step = stateInStringEscU - return scanContinue - } - return s.error(c, "in string escape code") -} - -// stateInStringEscU is the state after reading `"\u` during a quoted string. -func stateInStringEscU(s *scanner, c byte) int { - if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' { - s.step = stateInStringEscU1 - return scanContinue - } - // numbers - return s.error(c, "in \\u hexadecimal character escape") -} - -// stateInStringEscU1 is the state after reading `"\u1` during a quoted string. -func stateInStringEscU1(s *scanner, c byte) int { - if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' { - s.step = stateInStringEscU12 - return scanContinue - } - // numbers - return s.error(c, "in \\u hexadecimal character escape") -} - -// stateInStringEscU12 is the state after reading `"\u12` during a quoted string. -func stateInStringEscU12(s *scanner, c byte) int { - if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' { - s.step = stateInStringEscU123 - return scanContinue - } - // numbers - return s.error(c, "in \\u hexadecimal character escape") -} - -// stateInStringEscU123 is the state after reading `"\u123` during a quoted string. -func stateInStringEscU123(s *scanner, c byte) int { - if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' { - s.step = stateInString - return scanContinue - } - // numbers - return s.error(c, "in \\u hexadecimal character escape") -} - -// stateNeg is the state after reading `-` during a number. -func stateNeg(s *scanner, c byte) int { - if c == '0' { - s.step = state0 - return scanContinue - } - if '1' <= c && c <= '9' { - s.step = state1 - return scanContinue - } - return s.error(c, "in numeric literal") -} - -// state1 is the state after reading a non-zero integer during a number, -// such as after reading `1` or `100` but not `0`. -func state1(s *scanner, c byte) int { - if '0' <= c && c <= '9' { - s.step = state1 - return scanContinue - } - return state0(s, c) -} - -// state0 is the state after reading `0` during a number. -func state0(s *scanner, c byte) int { - if c == '.' { - s.step = stateDot - return scanContinue - } - if c == 'e' || c == 'E' { - s.step = stateE - return scanContinue - } - return stateEndValue(s, c) -} - -// stateDot is the state after reading the integer and decimal point in a number, -// such as after reading `1.`. -func stateDot(s *scanner, c byte) int { - if '0' <= c && c <= '9' { - s.step = stateDot0 - return scanContinue - } - return s.error(c, "after decimal point in numeric literal") -} - -// stateDot0 is the state after reading the integer, decimal point, and subsequent -// digits of a number, such as after reading `3.14`. -func stateDot0(s *scanner, c byte) int { - if '0' <= c && c <= '9' { - return scanContinue - } - if c == 'e' || c == 'E' { - s.step = stateE - return scanContinue - } - return stateEndValue(s, c) -} - -// stateE is the state after reading the mantissa and e in a number, -// such as after reading `314e` or `0.314e`. -func stateE(s *scanner, c byte) int { - if c == '+' || c == '-' { - s.step = stateESign - return scanContinue - } - return stateESign(s, c) -} - -// stateESign is the state after reading the mantissa, e, and sign in a number, -// such as after reading `314e-` or `0.314e+`. -func stateESign(s *scanner, c byte) int { - if '0' <= c && c <= '9' { - s.step = stateE0 - return scanContinue - } - return s.error(c, "in exponent of numeric literal") -} - -// stateE0 is the state after reading the mantissa, e, optional sign, -// and at least one digit of the exponent in a number, -// such as after reading `314e-2` or `0.314e+1` or `3.14e0`. -func stateE0(s *scanner, c byte) int { - if '0' <= c && c <= '9' { - return scanContinue - } - return stateEndValue(s, c) -} - -// stateT is the state after reading `t`. -func stateT(s *scanner, c byte) int { - if c == 'r' { - s.step = stateTr - return scanContinue - } - return s.error(c, "in literal true (expecting 'r')") -} - -// stateTr is the state after reading `tr`. -func stateTr(s *scanner, c byte) int { - if c == 'u' { - s.step = stateTru - return scanContinue - } - return s.error(c, "in literal true (expecting 'u')") -} - -// stateTru is the state after reading `tru`. -func stateTru(s *scanner, c byte) int { - if c == 'e' { - s.step = stateEndValue - return scanContinue - } - return s.error(c, "in literal true (expecting 'e')") -} - -// stateF is the state after reading `f`. -func stateF(s *scanner, c byte) int { - if c == 'a' { - s.step = stateFa - return scanContinue - } - return s.error(c, "in literal false (expecting 'a')") -} - -// stateFa is the state after reading `fa`. -func stateFa(s *scanner, c byte) int { - if c == 'l' { - s.step = stateFal - return scanContinue - } - return s.error(c, "in literal false (expecting 'l')") -} - -// stateFal is the state after reading `fal`. -func stateFal(s *scanner, c byte) int { - if c == 's' { - s.step = stateFals - return scanContinue - } - return s.error(c, "in literal false (expecting 's')") -} - -// stateFals is the state after reading `fals`. -func stateFals(s *scanner, c byte) int { - if c == 'e' { - s.step = stateEndValue - return scanContinue - } - return s.error(c, "in literal false (expecting 'e')") -} - -// stateN is the state after reading `n`. -func stateN(s *scanner, c byte) int { - if c == 'u' { - s.step = stateNu - return scanContinue - } - return s.error(c, "in literal null (expecting 'u')") -} - -// stateNu is the state after reading `nu`. -func stateNu(s *scanner, c byte) int { - if c == 'l' { - s.step = stateNul - return scanContinue - } - return s.error(c, "in literal null (expecting 'l')") -} - -// stateNul is the state after reading `nul`. -func stateNul(s *scanner, c byte) int { - if c == 'l' { - s.step = stateEndValue - return scanContinue - } - return s.error(c, "in literal null (expecting 'l')") -} - -// stateError is the state after reaching a syntax error, -// such as after reading `[1}` or `5.1.2`. -func stateError(s *scanner, c byte) int { - return scanError -} - -// error records an error and switches to the error state. -func (s *scanner) error(c byte, context string) int { - s.step = stateError - s.err = &SyntaxError{"invalid character " + quoteChar(c) + " " + context, s.bytes} - return scanError -} - -// quoteChar formats c as a quoted character literal -func quoteChar(c byte) string { - // special cases - different from quoted strings - if c == '\'' { - return `'\''` - } - if c == '"' { - return `'"'` - } - - // use quoted string with different quotation marks - s := strconv.Quote(string(c)) - return "'" + s[1:len(s)-1] + "'" -} - -// undo causes the scanner to return scanCode from the next state transition. -// This gives callers a simple 1-byte undo mechanism. -func (s *scanner) undo(scanCode int) { - if s.redo { - panic("json: invalid use of scanner") - } - s.redoCode = scanCode - s.redoState = s.step - s.step = stateRedo - s.redo = true -} - -// stateRedo helps implement the scanner's 1-byte undo. -func stateRedo(s *scanner, c byte) int { - s.redo = false - s.step = s.redoState - return s.redoCode -} |