/usr/share/gocode/src/github.com/influxdb/influxdb/tsdb/shard.go is in golang-github-influxdb-influxdb-dev 0.10.0+dfsg1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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import (
"encoding/binary"
"encoding/json"
"errors"
"expvar"
"fmt"
"io"
"math"
"os"
"sync"
"github.com/influxdb/influxdb"
"github.com/influxdb/influxdb/influxql"
"github.com/influxdb/influxdb/models"
"github.com/influxdb/influxdb/tsdb/internal"
"github.com/gogo/protobuf/proto"
)
const (
statWriteReq = "writeReq"
statSeriesCreate = "seriesCreate"
statFieldsCreate = "fieldsCreate"
statWritePointsFail = "writePointsFail"
statWritePointsOK = "writePointsOk"
statWriteBytes = "writeBytes"
)
var (
// ErrFieldOverflow is returned when too many fields are created on a measurement.
ErrFieldOverflow = errors.New("field overflow")
// ErrFieldTypeConflict is returned when a new field already exists with a different type.
ErrFieldTypeConflict = errors.New("field type conflict")
// ErrFieldNotFound is returned when a field cannot be found.
ErrFieldNotFound = errors.New("field not found")
// ErrFieldUnmappedID is returned when the system is presented, during decode, with a field ID
// there is no mapping for.
ErrFieldUnmappedID = errors.New("field ID not mapped")
)
// Shard represents a self-contained time series database. An inverted index of
// the measurement and tag data is kept along with the raw time series data.
// Data can be split across many shards. The query engine in TSDB is responsible
// for combining the output of many shards into a single query result.
type Shard struct {
index *DatabaseIndex
path string
walPath string
id uint64
engine Engine
options EngineOptions
mu sync.RWMutex
measurementFields map[string]*MeasurementFields // measurement name to their fields
// expvar-based stats.
statMap *expvar.Map
// The writer used by the logger.
LogOutput io.Writer
}
// NewShard returns a new initialized Shard. walPath doesn't apply to the b1 type index
func NewShard(id uint64, index *DatabaseIndex, path string, walPath string, options EngineOptions) *Shard {
// Configure statistics collection.
key := fmt.Sprintf("shard:%s:%d", path, id)
tags := map[string]string{"path": path, "id": fmt.Sprintf("%d", id), "engine": options.EngineVersion}
statMap := influxdb.NewStatistics(key, "shard", tags)
return &Shard{
index: index,
path: path,
walPath: walPath,
id: id,
options: options,
measurementFields: make(map[string]*MeasurementFields),
statMap: statMap,
LogOutput: os.Stderr,
}
}
// Path returns the path set on the shard when it was created.
func (s *Shard) Path() string { return s.path }
// PerformMaintenance gets called periodically to have the engine perform
// any maintenance tasks like WAL flushing and compaction
func (s *Shard) PerformMaintenance() {
s.engine.PerformMaintenance()
}
// open initializes and opens the shard's store.
func (s *Shard) Open() error {
if err := func() error {
s.mu.Lock()
defer s.mu.Unlock()
s.index.mu.Lock()
defer s.index.mu.Unlock()
// Return if the shard is already open
if s.engine != nil {
return nil
}
// Initialize underlying engine.
e, err := NewEngine(s.path, s.walPath, s.options)
if err != nil {
return fmt.Errorf("new engine: %s", err)
}
s.engine = e
// Set log output on the engine.
s.engine.SetLogOutput(s.LogOutput)
// Open engine.
if err := s.engine.Open(); err != nil {
return fmt.Errorf("open engine: %s", err)
}
// Load metadata index.
if err := s.engine.LoadMetadataIndex(s, s.index, s.measurementFields); err != nil {
return fmt.Errorf("load metadata index: %s", err)
}
return nil
}(); err != nil {
s.close()
return err
}
return nil
}
// Close shuts down the shard's store.
func (s *Shard) Close() error {
s.mu.Lock()
defer s.mu.Unlock()
return s.close()
}
func (s *Shard) close() error {
if s.engine != nil {
return s.engine.Close()
}
return nil
}
// DiskSize returns the size on disk of this shard
func (s *Shard) DiskSize() (int64, error) {
s.mu.RLock()
defer s.mu.RUnlock()
stats, err := os.Stat(s.path)
var size int64
if err != nil {
return 0, err
}
size += stats.Size()
return size, nil
}
// ReadOnlyTx returns a read-only transaction for the shard. The transaction must be rolled back to
// release resources.
func (s *Shard) ReadOnlyTx() (Tx, error) {
return s.engine.Begin(false)
}
// TODO: this is temporarily exported to make tx.go work. When the query engine gets refactored
// into the tsdb package this should be removed. No one outside tsdb should know the underlying field encoding scheme.
func (s *Shard) FieldCodec(measurementName string) *FieldCodec {
s.mu.RLock()
defer s.mu.RUnlock()
m := s.measurementFields[measurementName]
if m == nil {
return NewFieldCodec(nil)
}
return m.Codec
}
// struct to hold information for a field to create on a measurement
type FieldCreate struct {
Measurement string
Field *Field
}
// struct to hold information for a series to create
type SeriesCreate struct {
Measurement string
Series *Series
}
// WritePoints will write the raw data points and any new metadata to the index in the shard
func (s *Shard) WritePoints(points []models.Point) error {
s.statMap.Add(statWriteReq, 1)
seriesToCreate, fieldsToCreate, seriesToAddShardTo, err := s.validateSeriesAndFields(points)
if err != nil {
return err
}
s.statMap.Add(statSeriesCreate, int64(len(seriesToCreate)))
s.statMap.Add(statFieldsCreate, int64(len(fieldsToCreate)))
// add any new series to the in-memory index
if len(seriesToCreate) > 0 {
s.index.mu.Lock()
for _, ss := range seriesToCreate {
s.index.CreateSeriesIndexIfNotExists(ss.Measurement, ss.Series)
}
s.index.mu.Unlock()
}
if len(seriesToAddShardTo) > 0 {
s.index.mu.Lock()
for _, k := range seriesToAddShardTo {
ss := s.index.series[k]
if ss != nil {
ss.shardIDs[s.id] = true
}
}
s.index.mu.Unlock()
}
// add any new fields and keep track of what needs to be saved
measurementFieldsToSave, err := s.createFieldsAndMeasurements(fieldsToCreate)
if err != nil {
return err
}
// make sure all data is encoded before attempting to save to bolt
// only required for the b1 and bz1 formats
if s.engine.Format() != TSM1Format {
for _, p := range points {
// Ignore if raw data has already been marshaled.
if p.Data() != nil {
continue
}
// This was populated earlier, don't need to validate that it's there.
s.mu.RLock()
mf := s.measurementFields[p.Name()]
s.mu.RUnlock()
// If a measurement is dropped while writes for it are in progress, this could be nil
if mf == nil {
return ErrFieldNotFound
}
data, err := mf.Codec.EncodeFields(p.Fields())
if err != nil {
return err
}
p.SetData(data)
}
}
// Write to the engine.
if err := s.engine.WritePoints(points, measurementFieldsToSave, seriesToCreate); err != nil {
s.statMap.Add(statWritePointsFail, 1)
return fmt.Errorf("engine: %s", err)
}
s.statMap.Add(statWritePointsOK, int64(len(points)))
return nil
}
func (s *Shard) ValidateAggregateFieldsInStatement(measurementName string, stmt *influxql.SelectStatement) error {
s.mu.RLock()
defer s.mu.RUnlock()
validateType := func(aname, fname string, t influxql.DataType) error {
if t != influxql.Float && t != influxql.Integer {
return fmt.Errorf("aggregate '%s' requires numerical field values. Field '%s' is of type %s",
aname, fname, t)
}
return nil
}
m := s.measurementFields[measurementName]
if m == nil {
return fmt.Errorf("measurement not found: %s", measurementName)
}
// If a numerical aggregate is requested, ensure it is only performed on numeric data or on a
// nested aggregate on numeric data.
for _, a := range stmt.FunctionCalls() {
// Check for fields like `derivative(mean(value), 1d)`
var nested *influxql.Call = a
if fn, ok := nested.Args[0].(*influxql.Call); ok {
nested = fn
}
switch lit := nested.Args[0].(type) {
case *influxql.VarRef:
if IsNumeric(nested) {
f := m.Fields[lit.Val]
if err := validateType(a.Name, f.Name, f.Type); err != nil {
return err
}
}
case *influxql.Distinct:
if nested.Name != "count" {
return fmt.Errorf("aggregate call didn't contain a field %s", a.String())
}
if IsNumeric(nested) {
f := m.Fields[lit.Val]
if err := validateType(a.Name, f.Name, f.Type); err != nil {
return err
}
}
default:
return fmt.Errorf("aggregate call didn't contain a field %s", a.String())
}
}
return nil
}
// DeleteSeries deletes a list of series.
func (s *Shard) DeleteSeries(keys []string) error {
return s.engine.DeleteSeries(keys)
}
// DeleteMeasurement deletes a measurement and all underlying series.
func (s *Shard) DeleteMeasurement(name string, seriesKeys []string) error {
s.mu.Lock()
defer s.mu.Unlock()
if err := s.engine.DeleteMeasurement(name, seriesKeys); err != nil {
return err
}
// Remove entry from shard index.
delete(s.measurementFields, name)
return nil
}
func (s *Shard) createFieldsAndMeasurements(fieldsToCreate []*FieldCreate) (map[string]*MeasurementFields, error) {
if len(fieldsToCreate) == 0 {
return nil, nil
}
s.index.mu.Lock()
s.mu.Lock()
defer s.index.mu.Unlock()
defer s.mu.Unlock()
// add fields
measurementsToSave := make(map[string]*MeasurementFields)
for _, f := range fieldsToCreate {
m := s.measurementFields[f.Measurement]
if m == nil {
m = measurementsToSave[f.Measurement]
if m == nil {
m = &MeasurementFields{Fields: make(map[string]*Field)}
}
s.measurementFields[f.Measurement] = m
}
measurementsToSave[f.Measurement] = m
// add the field to the in memory index
// only limit the field count for non-tsm eninges
limitFieldCount := s.engine.Format() == B1Format || s.engine.Format() == BZ1Format
if err := m.CreateFieldIfNotExists(f.Field.Name, f.Field.Type, limitFieldCount); err != nil {
return nil, err
}
// ensure the measurement is in the index and the field is there
measurement := s.index.CreateMeasurementIndexIfNotExists(f.Measurement)
measurement.SetFieldName(f.Field.Name)
}
return measurementsToSave, nil
}
// validateSeriesAndFields checks which series and fields are new and whose metadata should be saved and indexed
func (s *Shard) validateSeriesAndFields(points []models.Point) ([]*SeriesCreate, []*FieldCreate, []string, error) {
var seriesToCreate []*SeriesCreate
var fieldsToCreate []*FieldCreate
var seriesToAddShardTo []string
// get the mutex for the in memory index, which is shared across shards
s.index.mu.RLock()
defer s.index.mu.RUnlock()
// get the shard mutex for locally defined fields
s.mu.RLock()
defer s.mu.RUnlock()
for _, p := range points {
// see if the series should be added to the index
if ss := s.index.series[string(p.Key())]; ss == nil {
series := NewSeries(string(p.Key()), p.Tags())
seriesToCreate = append(seriesToCreate, &SeriesCreate{p.Name(), series})
seriesToAddShardTo = append(seriesToAddShardTo, series.Key)
} else if !ss.shardIDs[s.id] {
// this is the first time this series is being written into this shard, persist it
seriesToCreate = append(seriesToCreate, &SeriesCreate{p.Name(), ss})
seriesToAddShardTo = append(seriesToAddShardTo, ss.Key)
}
// see if the field definitions need to be saved to the shard
mf := s.measurementFields[p.Name()]
if mf == nil {
for name, value := range p.Fields() {
fieldsToCreate = append(fieldsToCreate, &FieldCreate{p.Name(), &Field{Name: name, Type: influxql.InspectDataType(value)}})
}
continue // skip validation since all fields are new
}
// validate field types and encode data
for name, value := range p.Fields() {
if f := mf.Fields[name]; f != nil {
// Field present in shard metadata, make sure there is no type conflict.
if f.Type != influxql.InspectDataType(value) {
return nil, nil, nil, fmt.Errorf("field type conflict: input field \"%s\" on measurement \"%s\" is type %T, already exists as type %s", name, p.Name(), value, f.Type)
}
continue // Field is present, and it's of the same type. Nothing more to do.
}
fieldsToCreate = append(fieldsToCreate, &FieldCreate{p.Name(), &Field{Name: name, Type: influxql.InspectDataType(value)}})
}
}
return seriesToCreate, fieldsToCreate, seriesToAddShardTo, nil
}
// SeriesCount returns the number of series buckets on the shard.
func (s *Shard) SeriesCount() (int, error) { return s.engine.SeriesCount() }
// WriteTo writes the shard's data to w.
func (s *Shard) WriteTo(w io.Writer) (int64, error) {
n, err := s.engine.WriteTo(w)
s.statMap.Add(statWriteBytes, int64(n))
return n, err
}
type MeasurementFields struct {
Fields map[string]*Field `json:"fields"`
Codec *FieldCodec
}
// MarshalBinary encodes the object to a binary format.
func (m *MeasurementFields) MarshalBinary() ([]byte, error) {
var pb internal.MeasurementFields
for _, f := range m.Fields {
id := int32(f.ID)
name := f.Name
t := int32(f.Type)
pb.Fields = append(pb.Fields, &internal.Field{ID: &id, Name: &name, Type: &t})
}
return proto.Marshal(&pb)
}
// UnmarshalBinary decodes the object from a binary format.
func (m *MeasurementFields) UnmarshalBinary(buf []byte) error {
var pb internal.MeasurementFields
if err := proto.Unmarshal(buf, &pb); err != nil {
return err
}
m.Fields = make(map[string]*Field)
for _, f := range pb.Fields {
m.Fields[f.GetName()] = &Field{ID: uint8(f.GetID()), Name: f.GetName(), Type: influxql.DataType(f.GetType())}
}
return nil
}
// CreateFieldIfNotExists creates a new field with an autoincrementing ID.
// Returns an error if 255 fields have already been created on the measurement or
// the fields already exists with a different type.
func (m *MeasurementFields) CreateFieldIfNotExists(name string, typ influxql.DataType, limitCount bool) error {
// Ignore if the field already exists.
if f := m.Fields[name]; f != nil {
if f.Type != typ {
return ErrFieldTypeConflict
}
return nil
}
// If we're supposed to limit the number of fields, only 255 are allowed. If we go over that then return an error.
if len(m.Fields)+1 > math.MaxUint8 && limitCount {
return ErrFieldOverflow
}
// Create and append a new field.
f := &Field{
ID: uint8(len(m.Fields) + 1),
Name: name,
Type: typ,
}
m.Fields[name] = f
m.Codec = NewFieldCodec(m.Fields)
return nil
}
// Field represents a series field.
type Field struct {
ID uint8 `json:"id,omitempty"`
Name string `json:"name,omitempty"`
Type influxql.DataType `json:"type,omitempty"`
}
// FieldCodec provides encoding and decoding functionality for the fields of a given
// Measurement. It is a distinct type to avoid locking writes on this node while
// potentially long-running queries are executing.
//
// It is not affected by changes to the Measurement object after codec creation.
// TODO: this shouldn't be exported. nothing outside the shard should know about field encodings.
// However, this is here until tx.go and the engine get refactored into tsdb.
type FieldCodec struct {
fieldsByID map[uint8]*Field
fieldsByName map[string]*Field
}
// NewFieldCodec returns a FieldCodec for the given Measurement. Must be called with
// a RLock that protects the Measurement.
func NewFieldCodec(fields map[string]*Field) *FieldCodec {
fieldsByID := make(map[uint8]*Field, len(fields))
fieldsByName := make(map[string]*Field, len(fields))
for _, f := range fields {
fieldsByID[f.ID] = f
fieldsByName[f.Name] = f
}
return &FieldCodec{fieldsByID: fieldsByID, fieldsByName: fieldsByName}
}
// EncodeFields converts a map of values with string keys to a byte slice of field
// IDs and values.
//
// If a field exists in the codec, but its type is different, an error is returned. If
// a field is not present in the codec, the system panics.
func (f *FieldCodec) EncodeFields(values map[string]interface{}) ([]byte, error) {
// Allocate byte slice
b := make([]byte, 0, 10)
for k, v := range values {
field := f.fieldsByName[k]
if field == nil {
panic(fmt.Sprintf("field does not exist for %s", k))
} else if influxql.InspectDataType(v) != field.Type {
return nil, fmt.Errorf("field \"%s\" is type %T, mapped as type %s", k, v, field.Type)
}
var buf []byte
switch field.Type {
case influxql.Float:
value := v.(float64)
buf = make([]byte, 9)
binary.BigEndian.PutUint64(buf[1:9], math.Float64bits(value))
case influxql.Integer:
var value uint64
switch v.(type) {
case int:
value = uint64(v.(int))
case int32:
value = uint64(v.(int32))
case int64:
value = uint64(v.(int64))
default:
panic(fmt.Sprintf("invalid integer type: %T", v))
}
buf = make([]byte, 9)
binary.BigEndian.PutUint64(buf[1:9], value)
case influxql.Boolean:
value := v.(bool)
// Only 1 byte need for a boolean.
buf = make([]byte, 2)
if value {
buf[1] = byte(1)
}
case influxql.String:
value := v.(string)
if len(value) > maxStringLength {
value = value[:maxStringLength]
}
// Make a buffer for field ID (1 bytes), the string length (2 bytes), and the string.
buf = make([]byte, len(value)+3)
// Set the string length, then copy the string itself.
binary.BigEndian.PutUint16(buf[1:3], uint16(len(value)))
for i, c := range []byte(value) {
buf[i+3] = byte(c)
}
default:
panic(fmt.Sprintf("unsupported value type during encode fields: %T", v))
}
// Always set the field ID as the leading byte.
buf[0] = field.ID
// Append temp buffer to the end.
b = append(b, buf...)
}
return b, nil
}
// TODO: this shouldn't be exported. remove when tx.go and engine.go get refactored into tsdb
func (f *FieldCodec) FieldIDByName(s string) (uint8, error) {
fi := f.fieldsByName[s]
if fi == nil {
return 0, ErrFieldNotFound
}
return fi.ID, nil
}
// DecodeFields decodes a byte slice into a set of field ids and values.
func (f *FieldCodec) DecodeFields(b []byte) (map[uint8]interface{}, error) {
if len(b) == 0 {
return nil, nil
}
// Create a map to hold the decoded data.
values := make(map[uint8]interface{}, 0)
for {
if len(b) < 1 {
// No more bytes.
break
}
// First byte is the field identifier.
fieldID := b[0]
field := f.fieldsByID[fieldID]
if field == nil {
// See note in DecodeByID() regarding field-mapping failures.
return nil, ErrFieldUnmappedID
}
var value interface{}
switch field.Type {
case influxql.Float:
value = math.Float64frombits(binary.BigEndian.Uint64(b[1:9]))
// Move bytes forward.
b = b[9:]
case influxql.Integer:
value = int64(binary.BigEndian.Uint64(b[1:9]))
// Move bytes forward.
b = b[9:]
case influxql.Boolean:
if b[1] == 1 {
value = true
} else {
value = false
}
// Move bytes forward.
b = b[2:]
case influxql.String:
size := binary.BigEndian.Uint16(b[1:3])
value = string(b[3 : size+3])
// Move bytes forward.
b = b[size+3:]
default:
panic(fmt.Sprintf("unsupported value type during decode fields: %T", f.fieldsByID[fieldID]))
}
values[fieldID] = value
}
return values, nil
}
// DecodeFieldsWithNames decodes a byte slice into a set of field names and values
// TODO: shouldn't be exported. refactor engine
func (f *FieldCodec) DecodeFieldsWithNames(b []byte) (map[string]interface{}, error) {
fields, err := f.DecodeFields(b)
if err != nil {
return nil, err
}
m := make(map[string]interface{})
for id, v := range fields {
field := f.fieldsByID[id]
if field != nil {
m[field.Name] = v
}
}
return m, nil
}
// DecodeByID scans a byte slice for a field with the given ID, converts it to its
// expected type, and return that value.
// TODO: shouldn't be exported. refactor engine
func (f *FieldCodec) DecodeByID(targetID uint8, b []byte) (interface{}, error) {
if len(b) == 0 {
return 0, ErrFieldNotFound
}
for {
if len(b) < 1 {
// No more bytes.
break
}
field, ok := f.fieldsByID[b[0]]
if !ok {
// This can happen, though is very unlikely. If this node receives encoded data, to be written
// to disk, and is queried for that data before its metastore is updated, there will be no field
// mapping for the data during decode. All this can happen because data is encoded by the node
// that first received the write request, not the node that actually writes the data to disk.
// So if this happens, the read must be aborted.
return 0, ErrFieldUnmappedID
}
var value interface{}
switch field.Type {
case influxql.Float:
// Move bytes forward.
value = math.Float64frombits(binary.BigEndian.Uint64(b[1:9]))
b = b[9:]
case influxql.Integer:
value = int64(binary.BigEndian.Uint64(b[1:9]))
b = b[9:]
case influxql.Boolean:
if b[1] == 1 {
value = true
} else {
value = false
}
// Move bytes forward.
b = b[2:]
case influxql.String:
size := binary.BigEndian.Uint16(b[1:3])
value = string(b[3 : 3+size])
// Move bytes forward.
b = b[size+3:]
default:
panic(fmt.Sprintf("unsupported value type during decode by id: %T", field.Type))
}
if field.ID == targetID {
return value, nil
}
}
return 0, ErrFieldNotFound
}
// DecodeByName scans a byte slice for a field with the given name, converts it to its
// expected type, and return that value.
func (f *FieldCodec) DecodeByName(name string, b []byte) (interface{}, error) {
fi := f.FieldByName(name)
if fi == nil {
return 0, ErrFieldNotFound
}
return f.DecodeByID(fi.ID, b)
}
func (f *FieldCodec) Fields() (a []*Field) {
for _, f := range f.fieldsByID {
a = append(a, f)
}
return
}
// FieldByName returns the field by its name. It will return a nil if not found
func (f *FieldCodec) FieldByName(name string) *Field {
return f.fieldsByName[name]
}
// mustMarshal encodes a value to JSON.
// This will panic if an error occurs. This should only be used internally when
// an invalid marshal will cause corruption and a panic is appropriate.
func mustMarshalJSON(v interface{}) []byte {
b, err := json.Marshal(v)
if err != nil {
panic("marshal: " + err.Error())
}
return b
}
// mustUnmarshalJSON decodes a value from JSON.
// This will panic if an error occurs. This should only be used internally when
// an invalid unmarshal will cause corruption and a panic is appropriate.
func mustUnmarshalJSON(b []byte, v interface{}) {
if err := json.Unmarshal(b, v); err != nil {
panic("unmarshal: " + err.Error())
}
}
// u64tob converts a uint64 into an 8-byte slice.
func u64tob(v uint64) []byte {
b := make([]byte, 8)
binary.BigEndian.PutUint64(b, v)
return b
}
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