feat: add subscriptions and rework interfaces

This commit is contained in:
Jon Lundy
2022-08-09 16:23:33 -06:00
parent 82f23ae323
commit 0642879c07
16 changed files with 1368 additions and 627 deletions

View File

@@ -12,6 +12,7 @@ import (
"github.com/sour-is/ev/pkg/es"
"github.com/sour-is/ev/pkg/es/driver"
"github.com/sour-is/ev/pkg/es/event"
"github.com/sour-is/ev/pkg/locker"
"github.com/sour-is/ev/pkg/math"
)
@@ -19,14 +20,17 @@ type diskStore struct {
path string
}
var _ driver.Driver = (*diskStore)(nil)
const AppendOnly = es.AppendOnly
const AllEvents = es.AllEvents
func Init(ctx context.Context) error {
es.Register(ctx, "file", &diskStore{})
return nil
}
func (diskStore) Open(dsn string) (driver.EventStore, error) {
var _ driver.Driver = (*diskStore)(nil)
func (diskStore) Open(_ context.Context, dsn string) (driver.Driver, error) {
scheme, path, ok := strings.Cut(dsn, ":")
if !ok {
return nil, fmt.Errorf("expected scheme")
@@ -45,181 +49,151 @@ func (diskStore) Open(dsn string) (driver.EventStore, error) {
return &diskStore{path: path}, nil
}
func (es *diskStore) Save(ctx context.Context, agg event.Aggregate) (uint64, error) {
l, err := es.readLog(agg.StreamID())
if err != nil {
return 0, err
}
var last uint64
if last, err = l.LastIndex(); err != nil {
return 0, err
}
if agg.StreamVersion() != last {
return 0, fmt.Errorf("current version wrong %d != %d", agg.StreamVersion(), last)
}
events := agg.Events(true)
var b []byte
batch := &wal.Batch{}
for _, e := range events {
b, err = event.MarshalText(e)
if err != nil {
return 0, err
}
batch.Write(e.EventMeta().Position, b)
}
err = l.WriteBatch(batch)
if err != nil {
return 0, err
}
agg.Commit()
return uint64(len(events)), nil
func (ds *diskStore) EventLog(ctx context.Context, streamID string) (driver.EventLog, error) {
el := &eventLog{streamID: streamID}
l, err := wal.Open(filepath.Join(ds.path, streamID), wal.DefaultOptions)
el.events = locker.New(l)
return el, err
}
func (es *diskStore) Append(ctx context.Context, streamID string, events event.Events) (uint64, error) {
event.SetStreamID(streamID, events...)
l, err := es.readLog(streamID)
if err != nil {
return 0, err
}
var last uint64
if last, err = l.LastIndex(); err != nil {
return 0, err
}
var b []byte
batch := &wal.Batch{}
for i, e := range events {
b, err = event.MarshalText(e)
if err != nil {
return 0, err
}
pos := last + uint64(i) + 1
event.SetPosition(e, pos)
batch.Write(pos, b)
}
err = l.WriteBatch(batch)
if err != nil {
return 0, err
}
return uint64(len(events)), nil
type eventLog struct {
streamID string
events *locker.Locked[wal.Log]
}
func (es *diskStore) Load(ctx context.Context, agg event.Aggregate) error {
l, err := es.readLog(agg.StreamID())
if err != nil {
return err
}
var i, first, last uint64
var _ driver.EventLog = (*eventLog)(nil)
if first, err = l.FirstIndex(); err != nil {
return err
}
if last, err = l.LastIndex(); err != nil {
return err
}
if first == 0 || last == 0 {
return nil
}
func (es *eventLog) Append(ctx context.Context, events event.Events, version uint64) (uint64, error) {
event.SetStreamID(es.streamID, events...)
var b []byte
events := make([]event.Event, last-i)
for i = 0; first+i <= last; i++ {
b, err = l.Read(first + i)
var count uint64
err := es.events.Modify(ctx, func(l *wal.Log) error {
last, err := l.LastIndex()
if err != nil {
return err
}
events[i], err = event.UnmarshalText(ctx, b, first+i)
if err != nil {
return err
if version != AppendOnly && version != last {
return fmt.Errorf("current version wrong %d != %d", version, last)
}
}
event.Append(agg, events...)
return nil
}
func (es *diskStore) Read(ctx context.Context, streamID string, pos, count int64) (event.Events, error) {
l, err := es.readLog(streamID)
if err != nil {
return nil, err
}
var first, last, start uint64
if first, err = l.FirstIndex(); err != nil {
return nil, err
}
if last, err = l.LastIndex(); err != nil {
return nil, err
}
if first == 0 || last == 0 {
return nil, nil
}
switch {
case pos >= 0:
start = first + uint64(pos)
if pos == 0 && count < 0 {
count = -count // if pos=0 assume forward count.
}
case pos < 0:
start = uint64(int64(last) + pos + 1)
if pos == -1 && count > 0 {
count = -count // if pos=-1 assume backward count.
}
}
events := make([]event.Event, math.Abs(count))
for i := range events {
var b []byte
b, err = l.Read(start)
batch := &wal.Batch{}
for i, e := range events {
b, err = event.MarshalText(e)
if err != nil {
return err
}
pos := last + uint64(i) + 1
event.SetPosition(e, pos)
batch.Write(pos, b)
}
count = uint64(len(events))
return l.WriteBatch(batch)
})
return count, err
}
func (es *eventLog) Read(ctx context.Context, pos, count int64) (event.Events, error) {
var events event.Events
err := es.events.Modify(ctx, func(stream *wal.Log) error {
first, err := stream.FirstIndex()
if err != nil {
return events, err
return err
}
events[i], err = event.UnmarshalText(ctx, b, start)
last, err := stream.LastIndex()
if err != nil {
return events, err
return err
}
// ---
if first == 0 || last == 0 {
return nil
}
if count > 0 {
start += 1
} else {
start -= 1
if count == AllEvents {
count = int64(first - last)
}
if start < first || start > last {
events = events[:i+1]
break
}
}
event.SetStreamID(streamID, events...)
return events, nil
}
func (es *diskStore) FirstIndex(ctx context.Context, streamID string) (uint64, error) {
l, err := es.readLog(streamID)
var start uint64
switch {
case pos >= 0 && count > 0:
start = first + uint64(pos)
case pos < 0 && count > 0:
start = uint64(int64(last) + pos + 1)
case pos >= 0 && count < 0:
start = first + uint64(pos)
if pos > 1 {
start -= 2 // if pos is positive and count negative start before
}
if pos <= 1 {
return nil // if pos is one or zero and negative count nothing to return
}
case pos < 0 && count < 0:
start = uint64(int64(last) + pos)
}
if start >= last {
return nil // if start is after last and positive count nothing to return
}
events = make([]event.Event, math.Abs(count))
for i := range events {
// ---
var b []byte
b, err = stream.Read(start)
if err != nil {
return err
}
events[i], err = event.UnmarshalText(ctx, b, start)
if err != nil {
return err
}
// ---
if count > 0 {
start += 1
} else {
start -= 1
}
if start < first || start > last {
events = events[:i+1]
break
}
}
return nil
})
if err != nil {
return 0, err
return nil, err
}
return l.FirstIndex()
}
func (es *diskStore) LastIndex(ctx context.Context, streamID string) (uint64, error) {
l, err := es.readLog(streamID)
if err != nil {
return 0, err
}
return l.LastIndex()
}
func (es *diskStore) readLog(name string) (*wal.Log, error) {
return wal.Open(filepath.Join(es.path, name), wal.DefaultOptions)
event.SetStreamID(es.streamID, events...)
return events, err
}
func (es *eventLog) FirstIndex(ctx context.Context) (uint64, error) {
var idx uint64
var err error
err = es.events.Modify(ctx, func(events *wal.Log) error {
idx, err = events.FirstIndex()
return err
})
return idx, err
}
func (es *eventLog) LastIndex(ctx context.Context) (uint64, error) {
var idx uint64
var err error
err = es.events.Modify(ctx, func(events *wal.Log) error {
idx, err = events.LastIndex()
return err
})
return idx, err
}