telegraf/plugins/parsers/influx/machine.go.rl

319 lines
5.2 KiB
Plaintext
Raw Normal View History

package influx
import (
"errors"
)
var (
ErrNameParse = errors.New("expected measurement name")
ErrFieldParse = errors.New("expected field")
ErrTagParse = errors.New("expected tag")
ErrTimestampParse = errors.New("expected timestamp")
ErrParse = errors.New("parse error")
)
%%{
machine LineProtocol;
action begin {
m.pb = m.p
}
action yield {
yield = true
fnext align;
fbreak;
}
action name_error {
m.err = ErrNameParse
fhold;
fnext discard_line;
fbreak;
}
action field_error {
m.err = ErrFieldParse
fhold;
fnext discard_line;
fbreak;
}
action tagset_error {
m.err = ErrTagParse
fhold;
fnext discard_line;
fbreak;
}
action timestamp_error {
m.err = ErrTimestampParse
fhold;
fnext discard_line;
fbreak;
}
action parse_error {
m.err = ErrParse
fhold;
fnext discard_line;
fbreak;
}
action hold_recover {
fhold;
fgoto main;
}
action discard {
fgoto align;
}
action name {
m.handler.SetMeasurement(m.text())
}
action tagkey {
key = m.text()
}
action tagvalue {
m.handler.AddTag(key, m.text())
}
action fieldkey {
key = m.text()
}
action integer {
m.handler.AddInt(key, m.text())
}
action unsigned {
m.handler.AddUint(key, m.text())
}
action float {
m.handler.AddFloat(key, m.text())
}
action bool {
m.handler.AddBool(key, m.text())
}
action string {
m.handler.AddString(key, m.text())
}
action timestamp {
m.handler.SetTimestamp(m.text())
}
ws =
[\t\v\f ];
non_zero_digit =
[1-9];
integer =
'-'? ( digit | ( non_zero_digit digit* ) );
unsigned =
( digit | ( non_zero_digit digit* ) );
number =
( integer ( '.' digit* )? ) | ( '.' digit* );
scientific =
number 'e'i ["\-+"]? digit+;
timestamp =
('-'? digit{1,19}) >begin %timestamp;
fieldkeychar =
[^\t\n\f\r ,=\\] | ( '\\' [^\t\n\f\r] );
fieldkey =
fieldkeychar+ >begin %fieldkey;
fieldfloat =
(scientific | number) >begin %float;
fieldinteger =
(integer 'i') >begin %integer;
fieldunsigned =
(unsigned 'u') >begin %unsigned;
false =
"false" | "FALSE" | "False" | "F" | "f";
true =
"true" | "TRUE" | "True" | "T" | "t";
fieldbool =
(true | false) >begin %bool;
fieldstringchar =
[^\\"] | '\\' [\\"];
fieldstring =
fieldstringchar* >begin %string;
fieldstringquoted =
'"' fieldstring '"';
fieldvalue = fieldinteger | fieldunsigned | fieldfloat | fieldstringquoted | fieldbool;
field =
fieldkey '=' fieldvalue;
fieldset =
field ( ',' field )*;
tagchar =
[^\t\n\f\r ,=\\] | ( '\\' [^\t\n\f\r] );
tagkey =
tagchar+ >begin %tagkey;
tagvalue =
tagchar+ >begin %tagvalue;
tagset =
(',' (tagkey '=' tagvalue) $err(tagset_error))*;
measurement_chars =
[^\t\n\f\r ,\\] | ( '\\' [^\t\n\f\r] );
measurement_start =
measurement_chars - '#';
measurement =
(measurement_start measurement_chars*) >begin %name;
newline =
[\r\n];
comment =
'#' (any -- newline)* newline;
eol =
ws* newline? >yield %eof(yield);
line =
measurement
tagset
(ws+ fieldset) $err(field_error)
(ws+ timestamp)? $err(timestamp_error)
eol;
# The main machine parses a single line of line protocol.
main := line $err(parse_error);
# The discard_line machine discards the current line. Useful for recovering
# on the next line when an error occurs.
discard_line :=
(any - newline)* newline @discard;
# The align machine scans forward to the start of the next line. This machine
# is used to skip over whitespace and comments, keeping this logic out of the
# main machine.
align :=
(space* comment)* space* measurement_start @hold_recover %eof(yield);
}%%
%% write data;
type Handler interface {
SetMeasurement(name []byte)
AddTag(key []byte, value []byte)
AddInt(key []byte, value []byte)
AddUint(key []byte, value []byte)
AddFloat(key []byte, value []byte)
AddString(key []byte, value []byte)
AddBool(key []byte, value []byte)
SetTimestamp(tm []byte)
}
type machine struct {
data []byte
cs int
p, pe, eof int
pb int
handler Handler
err error
}
func NewMachine(handler Handler) *machine {
m := &machine{
handler: handler,
}
%% access m.;
%% variable p m.p;
%% variable pe m.pe;
%% variable eof m.eof;
%% variable data m.data;
%% write init;
return m
}
func (m *machine) SetData(data []byte) {
m.data = data
m.p = 0
m.pb = 0
m.pe = len(data)
m.eof = len(data)
m.err = nil
%% write init;
m.cs = LineProtocol_en_align
}
// ParseLine parses a line of input and returns true if more data can be
// parsed.
func (m *machine) ParseLine() bool {
if m.data == nil || m.p >= m.pe {
m.err = nil
return false
}
m.err = nil
var key []byte
var yield bool
%% write exec;
// Even if there was an error, return true. On the next call to this
// function we will attempt to scan to the next line of input and recover.
if m.err != nil {
return true
}
// Don't check the error state in the case that we just yielded, because
// the yield indicates we just completed parsing a line.
if !yield && m.cs == LineProtocol_error {
m.err = ErrParse
return true
}
return true
}
// Err returns the error that occurred on the last call to ParseLine. If the
// result is nil, then the line was parsed successfully.
func (m *machine) Err() error {
return m.err
}
// Position returns the current position into the input.
func (m *machine) Position() int {
return m.p
}
func (m *machine) text() []byte {
return m.data[m.pb:m.p]
}