130 lines
3.2 KiB
Go
130 lines
3.2 KiB
Go
package jsoniter
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import "fmt"
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// ReadNil reads a json object as nil and
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// returns whether it's a nil or not
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func (iter *Iterator) ReadNil() (ret bool) {
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c := iter.nextToken()
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if c == 'n' {
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iter.skipThreeBytes('u', 'l', 'l') // null
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return true
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}
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iter.unreadByte()
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return false
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}
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// ReadBool reads a json object as BoolValue
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func (iter *Iterator) ReadBool() (ret bool) {
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c := iter.nextToken()
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if c == 't' {
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iter.skipThreeBytes('r', 'u', 'e')
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return true
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}
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if c == 'f' {
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iter.skipFourBytes('a', 'l', 's', 'e')
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return false
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}
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iter.ReportError("ReadBool", "expect t or f, but found "+string([]byte{c}))
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return
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}
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// SkipAndReturnBytes skip next JSON element, and return its content as []byte.
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// The []byte can be kept, it is a copy of data.
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func (iter *Iterator) SkipAndReturnBytes() []byte {
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iter.startCapture(iter.head)
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iter.Skip()
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return iter.stopCapture()
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}
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type captureBuffer struct {
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startedAt int
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captured []byte
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}
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func (iter *Iterator) startCapture(captureStartedAt int) {
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if iter.captured != nil {
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panic("already in capture mode")
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}
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iter.captureStartedAt = captureStartedAt
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iter.captured = make([]byte, 0, 32)
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}
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func (iter *Iterator) stopCapture() []byte {
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if iter.captured == nil {
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panic("not in capture mode")
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}
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captured := iter.captured
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remaining := iter.buf[iter.captureStartedAt:iter.head]
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iter.captureStartedAt = -1
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iter.captured = nil
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if len(captured) == 0 {
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copied := make([]byte, len(remaining))
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copy(copied, remaining)
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return copied
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}
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captured = append(captured, remaining...)
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return captured
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}
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// Skip skips a json object and positions to relatively the next json object
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func (iter *Iterator) Skip() {
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c := iter.nextToken()
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switch c {
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case '"':
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iter.skipString()
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case 'n':
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iter.skipThreeBytes('u', 'l', 'l') // null
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case 't':
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iter.skipThreeBytes('r', 'u', 'e') // true
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case 'f':
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iter.skipFourBytes('a', 'l', 's', 'e') // false
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case '0':
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iter.unreadByte()
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iter.ReadFloat32()
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case '-', '1', '2', '3', '4', '5', '6', '7', '8', '9':
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iter.skipNumber()
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case '[':
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iter.skipArray()
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case '{':
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iter.skipObject()
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default:
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iter.ReportError("Skip", fmt.Sprintf("do not know how to skip: %v", c))
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return
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}
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}
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func (iter *Iterator) skipFourBytes(b1, b2, b3, b4 byte) {
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if iter.readByte() != b1 {
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iter.ReportError("skipFourBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3, b4})))
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return
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}
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if iter.readByte() != b2 {
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iter.ReportError("skipFourBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3, b4})))
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return
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}
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if iter.readByte() != b3 {
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iter.ReportError("skipFourBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3, b4})))
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return
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}
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if iter.readByte() != b4 {
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iter.ReportError("skipFourBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3, b4})))
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return
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}
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}
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func (iter *Iterator) skipThreeBytes(b1, b2, b3 byte) {
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if iter.readByte() != b1 {
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iter.ReportError("skipThreeBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3})))
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return
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}
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if iter.readByte() != b2 {
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iter.ReportError("skipThreeBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3})))
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return
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}
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if iter.readByte() != b3 {
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iter.ReportError("skipThreeBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3})))
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return
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}
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}
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