package metric import ( "bytes" "errors" "fmt" "strconv" "time" "github.com/influxdata/telegraf" ) var ( ErrInvalidNumber = errors.New("invalid number") ) const ( // the number of characters for the largest possible int64 (9223372036854775807) maxInt64Digits = 19 // the number of characters for the smallest possible int64 (-9223372036854775808) minInt64Digits = 20 // the number of characters required for the largest float64 before a range check // would occur during parsing maxFloat64Digits = 25 // the number of characters required for smallest float64 before a range check occur // would occur during parsing minFloat64Digits = 27 MaxKeyLength = 65535 ) // The following constants allow us to specify which state to move to // next, when scanning sections of a Point. const ( tagKeyState = iota tagValueState fieldsState ) func Parse(buf []byte) ([]telegraf.Metric, error) { return ParseWithDefaultTimePrecision(buf, time.Now(), "") } func ParseWithDefaultTime(buf []byte, t time.Time) ([]telegraf.Metric, error) { return ParseWithDefaultTimePrecision(buf, t, "") } func ParseWithDefaultTimePrecision( buf []byte, t time.Time, precision string, ) ([]telegraf.Metric, error) { if len(buf) == 0 { return []telegraf.Metric{}, nil } if len(buf) <= 6 { return []telegraf.Metric{}, makeError("buffer too short", buf, 0) } metrics := make([]telegraf.Metric, 0, bytes.Count(buf, []byte("\n"))+1) var errStr string i := 0 for { j := bytes.IndexByte(buf[i:], '\n') if j == -1 { break } if len(buf[i:i+j]) < 2 { i += j + 1 // increment i past the previous newline continue } m, err := parseMetric(buf[i:i+j], t, precision) if err != nil { i += j + 1 // increment i past the previous newline errStr += " " + err.Error() continue } i += j + 1 // increment i past the previous newline metrics = append(metrics, m) } if len(errStr) > 0 { return metrics, fmt.Errorf(errStr) } return metrics, nil } func parseMetric(buf []byte, defaultTime time.Time, precision string, ) (telegraf.Metric, error) { var dTime string // scan the first block which is measurement[,tag1=value1,tag2=value=2...] pos, key, err := scanKey(buf, 0) if err != nil { return nil, err } // measurement name is required if len(key) == 0 { return nil, fmt.Errorf("missing measurement") } if len(key) > MaxKeyLength { return nil, fmt.Errorf("max key length exceeded: %v > %v", len(key), MaxKeyLength) } // scan the second block is which is field1=value1[,field2=value2,...] pos, fields, err := scanFields(buf, pos) if err != nil { return nil, err } // at least one field is required if len(fields) == 0 { return nil, fmt.Errorf("missing fields") } // scan the last block which is an optional integer timestamp pos, ts, err := scanTime(buf, pos) if err != nil { return nil, err } // apply precision multiplier var nsec int64 multiplier := getPrecisionMultiplier(precision) if len(ts) > 0 && multiplier > 1 { tsint, err := parseIntBytes(ts, 10, 64) if err != nil { return nil, err } nsec := multiplier * tsint ts = []byte(strconv.FormatInt(nsec, 10)) } m := &metric{ fields: fields, t: ts, nsec: nsec, } // parse out the measurement name // namei is the index at which the "name" ends namei := indexUnescapedByte(key, ',') if namei < 1 { // no tags m.name = key } else { m.name = key[0:namei] m.tags = key[namei:] } if len(m.t) == 0 { if len(dTime) == 0 { dTime = fmt.Sprint(defaultTime.UnixNano()) } // use default time m.t = []byte(dTime) } // here we copy on return because this allows us to later call // AddTag, AddField, RemoveTag, RemoveField, etc. without worrying about // modifying 'tag' bytes having an affect on 'field' bytes, for example. return m.Copy(), nil } // scanKey scans buf starting at i for the measurement and tag portion of the point. // It returns the ending position and the byte slice of key within buf. If there // are tags, they will be sorted if they are not already. func scanKey(buf []byte, i int) (int, []byte, error) { start := skipWhitespace(buf, i) i = start // First scan the Point's measurement. state, i, err := scanMeasurement(buf, i) if err != nil { return i, buf[start:i], err } // Optionally scan tags if needed. if state == tagKeyState { i, err = scanTags(buf, i) if err != nil { return i, buf[start:i], err } } return i, buf[start:i], nil } // scanMeasurement examines the measurement part of a Point, returning // the next state to move to, and the current location in the buffer. func scanMeasurement(buf []byte, i int) (int, int, error) { // Check first byte of measurement, anything except a comma is fine. // It can't be a space, since whitespace is stripped prior to this // function call. if i >= len(buf) || buf[i] == ',' { return -1, i, makeError("missing measurement", buf, i) } for { i++ if i >= len(buf) { // cpu return -1, i, makeError("missing fields", buf, i) } if buf[i-1] == '\\' { // Skip character (it's escaped). continue } // Unescaped comma; move onto scanning the tags. if buf[i] == ',' { return tagKeyState, i + 1, nil } // Unescaped space; move onto scanning the fields. if buf[i] == ' ' { // cpu value=1.0 return fieldsState, i, nil } } } // scanTags examines all the tags in a Point, keeping track of and // returning the updated indices slice, number of commas and location // in buf where to start examining the Point fields. func scanTags(buf []byte, i int) (int, error) { var ( err error state = tagKeyState ) for { switch state { case tagKeyState: i, err = scanTagsKey(buf, i) state = tagValueState // tag value always follows a tag key case tagValueState: state, i, err = scanTagsValue(buf, i) case fieldsState: return i, nil } if err != nil { return i, err } } } // scanTagsKey scans each character in a tag key. func scanTagsKey(buf []byte, i int) (int, error) { // First character of the key. if i >= len(buf) || buf[i] == ' ' || buf[i] == ',' || buf[i] == '=' { // cpu,{'', ' ', ',', '='} return i, makeError("missing tag key", buf, i) } // Examine each character in the tag key until we hit an unescaped // equals (the tag value), or we hit an error (i.e., unescaped // space or comma). for { i++ // Either we reached the end of the buffer or we hit an // unescaped comma or space. if i >= len(buf) || ((buf[i] == ' ' || buf[i] == ',') && buf[i-1] != '\\') { // cpu,tag{'', ' ', ','} return i, makeError("missing tag value", buf, i) } if buf[i] == '=' && buf[i-1] != '\\' { // cpu,tag= return i + 1, nil } } } // scanTagsValue scans each character in a tag value. func scanTagsValue(buf []byte, i int) (int, int, error) { // Tag value cannot be empty. if i >= len(buf) || buf[i] == ',' || buf[i] == ' ' { // cpu,tag={',', ' '} return -1, i, makeError("missing tag value", buf, i) } // Examine each character in the tag value until we hit an unescaped // comma (move onto next tag key), an unescaped space (move onto // fields), or we error out. for { i++ if i >= len(buf) { // cpu,tag=value return -1, i, makeError("missing fields", buf, i) } // An unescaped equals sign is an invalid tag value. if buf[i] == '=' && buf[i-1] != '\\' { // cpu,tag={'=', 'fo=o'} return -1, i, makeError("invalid tag format", buf, i) } if buf[i] == ',' && buf[i-1] != '\\' { // cpu,tag=foo, return tagKeyState, i + 1, nil } // cpu,tag=foo value=1.0 // cpu, tag=foo\= value=1.0 if buf[i] == ' ' && buf[i-1] != '\\' { return fieldsState, i, nil } } } // scanFields scans buf, starting at i for the fields section of a point. It returns // the ending position and the byte slice of the fields within buf func scanFields(buf []byte, i int) (int, []byte, error) { start := skipWhitespace(buf, i) i = start quoted := false // tracks how many '=' we've seen equals := 0 // tracks how many commas we've seen commas := 0 for { // reached the end of buf? if i >= len(buf) { break } // escaped characters? if buf[i] == '\\' && i+1 < len(buf) { i += 2 continue } // If the value is quoted, scan until we get to the end quote // Only quote values in the field value since quotes are not significant // in the field key if buf[i] == '"' && equals > commas { quoted = !quoted i++ continue } // If we see an =, ensure that there is at least on char before and after it if buf[i] == '=' && !quoted { equals++ // check for "... =123" but allow "a\ =123" if buf[i-1] == ' ' && buf[i-2] != '\\' { return i, buf[start:i], makeError("missing field key", buf, i) } // check for "...a=123,=456" but allow "a=123,a\,=456" if buf[i-1] == ',' && buf[i-2] != '\\' { return i, buf[start:i], makeError("missing field key", buf, i) } // check for "... value=" if i+1 >= len(buf) { return i, buf[start:i], makeError("missing field value", buf, i) } // check for "... value=,value2=..." if buf[i+1] == ',' || buf[i+1] == ' ' { return i, buf[start:i], makeError("missing field value", buf, i) } if isNumeric(buf[i+1]) || buf[i+1] == '-' || buf[i+1] == 'N' || buf[i+1] == 'n' { var err error i, err = scanNumber(buf, i+1) if err != nil { return i, buf[start:i], err } continue } // If next byte is not a double-quote, the value must be a boolean if buf[i+1] != '"' { var err error i, _, err = scanBoolean(buf, i+1) if err != nil { return i, buf[start:i], err } continue } } if buf[i] == ',' && !quoted { commas++ } // reached end of block? if buf[i] == ' ' && !quoted { break } i++ } if quoted { return i, buf[start:i], makeError("unbalanced quotes", buf, i) } // check that all field sections had key and values (e.g. prevent "a=1,b" if equals == 0 || commas != equals-1 { return i, buf[start:i], makeError("invalid field format", buf, i) } return i, buf[start:i], nil } // scanTime scans buf, starting at i for the time section of a point. It // returns the ending position and the byte slice of the timestamp within buf // and and error if the timestamp is not in the correct numeric format. func scanTime(buf []byte, i int) (int, []byte, error) { start := skipWhitespace(buf, i) i = start for { // reached the end of buf? if i >= len(buf) { break } // Reached end of block or trailing whitespace? if buf[i] == '\n' || buf[i] == ' ' { break } // Handle negative timestamps if i == start && buf[i] == '-' { i++ continue } // Timestamps should be integers, make sure they are so we don't need // to actually parse the timestamp until needed. if buf[i] < '0' || buf[i] > '9' { return i, buf[start:i], makeError("invalid timestamp", buf, i) } i++ } return i, buf[start:i], nil } func isNumeric(b byte) bool { return (b >= '0' && b <= '9') || b == '.' } // scanNumber returns the end position within buf, start at i after // scanning over buf for an integer, or float. It returns an // error if a invalid number is scanned. func scanNumber(buf []byte, i int) (int, error) { start := i var isInt bool // Is negative number? if i < len(buf) && buf[i] == '-' { i++ // There must be more characters now, as just '-' is illegal. if i == len(buf) { return i, ErrInvalidNumber } } // how many decimal points we've see decimal := false // indicates the number is float in scientific notation scientific := false for { if i >= len(buf) { break } if buf[i] == ',' || buf[i] == ' ' { break } if buf[i] == 'i' && i > start && !isInt { isInt = true i++ continue } if buf[i] == '.' { // Can't have more than 1 decimal (e.g. 1.1.1 should fail) if decimal { return i, ErrInvalidNumber } decimal = true } // `e` is valid for floats but not as the first char if i > start && (buf[i] == 'e' || buf[i] == 'E') { scientific = true i++ continue } // + and - are only valid at this point if they follow an e (scientific notation) if (buf[i] == '+' || buf[i] == '-') && (buf[i-1] == 'e' || buf[i-1] == 'E') { i++ continue } // NaN is an unsupported value if i+2 < len(buf) && (buf[i] == 'N' || buf[i] == 'n') { return i, ErrInvalidNumber } if !isNumeric(buf[i]) { return i, ErrInvalidNumber } i++ } if isInt && (decimal || scientific) { return i, ErrInvalidNumber } numericDigits := i - start if isInt { numericDigits-- } if decimal { numericDigits-- } if buf[start] == '-' { numericDigits-- } if numericDigits == 0 { return i, ErrInvalidNumber } // It's more common that numbers will be within min/max range for their type but we need to prevent // out or range numbers from being parsed successfully. This uses some simple heuristics to decide // if we should parse the number to the actual type. It does not do it all the time because it incurs // extra allocations and we end up converting the type again when writing points to disk. if isInt { // Make sure the last char is an 'i' for integers (e.g. 9i10 is not valid) if buf[i-1] != 'i' { return i, ErrInvalidNumber } // Parse the int to check bounds the number of digits could be larger than the max range // We subtract 1 from the index to remove the `i` from our tests if len(buf[start:i-1]) >= maxInt64Digits || len(buf[start:i-1]) >= minInt64Digits { if _, err := parseIntBytes(buf[start:i-1], 10, 64); err != nil { return i, makeError(fmt.Sprintf("unable to parse integer %s: %s", buf[start:i-1], err), buf, i) } } } else { // Parse the float to check bounds if it's scientific or the number of digits could be larger than the max range if scientific || len(buf[start:i]) >= maxFloat64Digits || len(buf[start:i]) >= minFloat64Digits { if _, err := parseFloatBytes(buf[start:i], 10); err != nil { return i, makeError("invalid float", buf, i) } } } return i, nil } // scanBoolean returns the end position within buf, start at i after // scanning over buf for boolean. Valid values for a boolean are // t, T, true, TRUE, f, F, false, FALSE. It returns an error if a invalid boolean // is scanned. func scanBoolean(buf []byte, i int) (int, []byte, error) { start := i if i < len(buf) && (buf[i] != 't' && buf[i] != 'f' && buf[i] != 'T' && buf[i] != 'F') { return i, buf[start:i], makeError("invalid value", buf, i) } i++ for { if i >= len(buf) { break } if buf[i] == ',' || buf[i] == ' ' { break } i++ } // Single char bool (t, T, f, F) is ok if i-start == 1 { return i, buf[start:i], nil } // length must be 4 for true or TRUE if (buf[start] == 't' || buf[start] == 'T') && i-start != 4 { return i, buf[start:i], makeError("invalid boolean", buf, i) } // length must be 5 for false or FALSE if (buf[start] == 'f' || buf[start] == 'F') && i-start != 5 { return i, buf[start:i], makeError("invalid boolean", buf, i) } // Otherwise valid := false switch buf[start] { case 't': valid = bytes.Equal(buf[start:i], []byte("true")) case 'f': valid = bytes.Equal(buf[start:i], []byte("false")) case 'T': valid = bytes.Equal(buf[start:i], []byte("TRUE")) || bytes.Equal(buf[start:i], []byte("True")) case 'F': valid = bytes.Equal(buf[start:i], []byte("FALSE")) || bytes.Equal(buf[start:i], []byte("False")) } if !valid { return i, buf[start:i], makeError("invalid boolean", buf, i) } return i, buf[start:i], nil } // skipWhitespace returns the end position within buf, starting at i after // scanning over spaces in tags func skipWhitespace(buf []byte, i int) int { for i < len(buf) { if buf[i] != ' ' && buf[i] != '\t' && buf[i] != 0 { break } i++ } return i } // makeError is a helper function for making a metric parsing error. // reason is the reason why the error occurred. // buf should be the current buffer we are parsing. // i is the current index, to give some context on where in the buffer we are. func makeError(reason string, buf []byte, i int) error { return fmt.Errorf("metric parsing error, reason: [%s], buffer: [%s], index: [%d]", reason, buf, i) } // getPrecisionMultiplier will return a multiplier for the precision specified. func getPrecisionMultiplier(precision string) int64 { d := time.Nanosecond switch precision { case "u": d = time.Microsecond case "ms": d = time.Millisecond case "s": d = time.Second case "m": d = time.Minute case "h": d = time.Hour } return int64(d) }