Implement telegraf's own full metric type
main reasons behind this: - make adding/removing tags cheap - make adding/removing fields cheap - make parsing cheaper - make parse -> decorate -> write out bytes metric flow much faster Refactor serializer to use byte buffer
This commit is contained in:
Cameron Sparr
624
metric/parse.go
Normal file
624
metric/parse.go
Normal file
@@ -0,0 +1,624 @@
|
||||
package metric
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"errors"
|
||||
"fmt"
|
||||
"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 ParseWithDefaultTime(buf, time.Now())
|
||||
}
|
||||
|
||||
func ParseWithDefaultTime(buf []byte, t time.Time) ([]telegraf.Metric, error) {
|
||||
metrics := make([]telegraf.Metric, 0, bytes.Count(buf, []byte("\n"))+1)
|
||||
var (
|
||||
errStr string
|
||||
line []byte
|
||||
err error
|
||||
)
|
||||
b := bytes.NewBuffer(buf)
|
||||
for {
|
||||
line, err = b.ReadBytes('\n')
|
||||
if err != nil {
|
||||
break
|
||||
}
|
||||
if len(line) < 2 {
|
||||
continue
|
||||
}
|
||||
// trim the newline:
|
||||
line = line[0 : len(line)-1]
|
||||
|
||||
m, err := parseMetric(line, t)
|
||||
if err != nil {
|
||||
errStr += " " + err.Error()
|
||||
continue
|
||||
}
|
||||
|
||||
metrics = append(metrics, m)
|
||||
}
|
||||
|
||||
if len(errStr) > 0 {
|
||||
return metrics, fmt.Errorf(errStr)
|
||||
}
|
||||
return metrics, nil
|
||||
}
|
||||
|
||||
func parseMetric(buf []byte, defaultTime time.Time) (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
|
||||
}
|
||||
|
||||
m := &metric{
|
||||
fields: fields,
|
||||
t: ts,
|
||||
}
|
||||
|
||||
// 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)
|
||||
}
|
||||
|
||||
return m, 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, fmt.Errorf("missing measurement")
|
||||
}
|
||||
|
||||
for {
|
||||
i++
|
||||
if i >= len(buf) {
|
||||
// cpu
|
||||
return -1, i, fmt.Errorf("missing fields")
|
||||
}
|
||||
|
||||
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, fmt.Errorf("missing tag key")
|
||||
}
|
||||
|
||||
// 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, fmt.Errorf("missing tag value")
|
||||
}
|
||||
|
||||
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, fmt.Errorf("missing tag value")
|
||||
}
|
||||
|
||||
// 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, fmt.Errorf("missing fields")
|
||||
}
|
||||
|
||||
// An unescaped equals sign is an invalid tag value.
|
||||
if buf[i] == '=' && buf[i-1] != '\\' {
|
||||
// cpu,tag={'=', 'fo=o'}
|
||||
return -1, i, fmt.Errorf("invalid tag format")
|
||||
}
|
||||
|
||||
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], fmt.Errorf("missing field key")
|
||||
}
|
||||
|
||||
// check for "...a=123,=456" but allow "a=123,a\,=456"
|
||||
if buf[i-1] == ',' && buf[i-2] != '\\' {
|
||||
return i, buf[start:i], fmt.Errorf("missing field key")
|
||||
}
|
||||
|
||||
// check for "... value="
|
||||
if i+1 >= len(buf) {
|
||||
return i, buf[start:i], fmt.Errorf("missing field value")
|
||||
}
|
||||
|
||||
// check for "... value=,value2=..."
|
||||
if buf[i+1] == ',' || buf[i+1] == ' ' {
|
||||
return i, buf[start:i], fmt.Errorf("missing field value")
|
||||
}
|
||||
|
||||
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], fmt.Errorf("unbalanced quotes")
|
||||
}
|
||||
|
||||
// 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], fmt.Errorf("invalid field format")
|
||||
}
|
||||
|
||||
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], fmt.Errorf("bad timestamp")
|
||||
}
|
||||
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, fmt.Errorf("unable to parse integer %s: %s", buf[start:i-1], err)
|
||||
}
|
||||
}
|
||||
} 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, fmt.Errorf("invalid float")
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
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], fmt.Errorf("invalid boolean")
|
||||
}
|
||||
|
||||
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], fmt.Errorf("invalid boolean")
|
||||
}
|
||||
|
||||
// length must be 5 for false or FALSE
|
||||
if (buf[start] == 'f' || buf[start] == 'F') && i-start != 5 {
|
||||
return i, buf[start:i], fmt.Errorf("invalid boolean")
|
||||
}
|
||||
|
||||
// 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], fmt.Errorf("invalid boolean")
|
||||
}
|
||||
|
||||
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 that the error occured.
|
||||
// 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)
|
||||
}
|
||||
Reference in New Issue
Block a user