[jaeger-v2] Define an internal interface of storage v2 spanstore (jaegertracing#5399)

## Which problem is this PR solving?
- Part of jaegertracing#5334

## Description of the changes
- An API design of Storage V2 spanstore and its proto file.
- For the detailed discussion and how we arrived to this design, please
take a look at
https://docs.google.com/document/d/1IvUcDsdRxMPK-xTUE32w3NSAGTkUcmnDQttN6ijUnWs/edit?usp=sharing

## How was this change tested?
- This PR hasn't been tested yet since it only contains interfaces and
no actual implementation to be tested.

## Checklist
- [x] I have read
https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
- [x] I have signed all commits
- [ ] I have added unit tests for the new functionality
- [x] I have run lint and test steps successfully
  - for `jaeger`: `make lint test`
  - for `jaeger-ui`: `yarn lint` and `yarn test`

---------

Signed-off-by: James Ryans <[email protected]>

Author: james-ryans

storage_v2/empty_test.go

@@ -0,0 +1,14 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package storage_v2
+
+import (
+	"testing"
+
+	"github.com/jaegertracing/jaeger/pkg/testutils"
+)
+
+func TestMain(m *testing.M) {
+	testutils.VerifyGoLeaks(m)
+}

storage_v2/factory.go

@@ -0,0 +1,21 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package storage_v2
+
+import (
+	"context"
+)
+
+// Factory is a general factory interface to be reused across different storage factories.
+// It lives within the OTEL collector extension component's lifecycle.
+// The Initialize and Close functions supposed to be called from the
+// OTEL component's Start and Shutdown functions.
+type FactoryBase interface {
+	// Initialize performs internal initialization of the factory,
+	// such as opening connections to the backend store.
+	Initialize(ctx context.Context) error
+
+	// Close closes the resources held by the factory
+	Close(ctx context.Context) error
+}

storage_v2/spanstore/empty_test.go

@@ -0,0 +1,14 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package spanstore
+
+import (
+	"testing"
+
+	"github.com/jaegertracing/jaeger/pkg/testutils"
+)
+
+func TestMain(m *testing.M) {
+	testutils.VerifyGoLeaks(m)
+}

storage_v2/spanstore/factory.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package spanstore
+
+import (
+	"github.com/jaegertracing/jaeger/storage_v2"
+)
+
+// Factory defines an interface for a factory that can create implementations of
+// different span storage components.
+type Factory interface {
+	storage_v2.FactoryBase
+
+	// CreateTraceReader creates a spanstore.Reader.
+	CreateTraceReader() (Reader, error)
+
+	// CreateTraceWriter creates a spanstore.Writer.
+	CreateTraceWriter() (Writer, error)
+}

storage_v2/spanstore/reader.go

@@ -0,0 +1,71 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package spanstore
+
+import (
+	"context"
+	"time"
+
+	"go.opentelemetry.io/collector/pdata/pcommon"
+	"go.opentelemetry.io/collector/pdata/ptrace"
+
+	spanstore_v1 "github.com/jaegertracing/jaeger/storage/spanstore"
+)
+
+// ErrTraceNotFound is returned by Reader's GetTrace if no data is found for given trace ID.
+var ErrTraceNotFound = spanstore_v1.ErrTraceNotFound
+
+// Reader finds and loads traces and other data from storage.
+type Reader interface {
+	// GetTrace retrieves the trace with a given id.
+	//
+	// If no spans are stored for this trace, it returns ErrTraceNotFound.
+	GetTrace(ctx context.Context, traceID pcommon.TraceID) (ptrace.Traces, error)
+
+	// GetServices returns all service names known to the backend from spans
+	// within its retention period.
+	GetServices(ctx context.Context) ([]string, error)
+
+	// GetOperations returns all operation names for a given service
+	// known to the backend from spans within its retention period.
+	GetOperations(ctx context.Context, query OperationQueryParameters) ([]Operation, error)
+
+	// FindTraces returns all traces matching query parameters. There's currently
+	// an implementation-dependent ambiguity whether all query filters (such as
+	// multiple tags) must apply to the same span within a trace, or can be satisfied
+	// by different spans.
+	//
+	// If no matching traces are found, the function returns (nil, nil).
+	FindTraces(ctx context.Context, query TraceQueryParameters) ([]ptrace.Traces, error)
+
+	// FindTraceIDs does the same search as FindTraces, but returns only the list
+	// of matching trace IDs.
+	//
+	// If no matching traces are found, the function returns (nil, nil).
+	FindTraceIDs(ctx context.Context, query TraceQueryParameters) ([]pcommon.TraceID, error)
+}
+
+// TraceQueryParameters contains parameters of a trace query.
+type TraceQueryParameters struct {
+	ServiceName   string
+	OperationName string
+	Tags          map[string]string
+	StartTimeMin  time.Time
+	StartTimeMax  time.Time
+	DurationMin   time.Duration
+	DurationMax   time.Duration
+	NumTraces     int
+}
+
+// OperationQueryParameters contains parameters of query operations, empty spanKind means get operations for all kinds of span.
+type OperationQueryParameters struct {
+	ServiceName string
+	SpanKind    string
+}
+
+// Operation contains operation name and span kind
+type Operation struct {
+	Name     string
+	SpanKind string
+}

storage_v2/spanstore/writer.go

@@ -0,0 +1,19 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package spanstore
+
+import (
+	"context"
+
+	"go.opentelemetry.io/collector/pdata/ptrace"
+)
+
+// Writer writes spans to storage.
+type Writer interface {
+	// WriteTrace writes a batch of spans to storage. Idempotent.
+	// Implementations are not required to support atomic transactions,
+	// so if any of the spans fail to be written an error is returned.
+	// Compatible with OTLP Exporter API.
+	WriteTraces(ctx context.Context, td ptrace.Traces) error
+}