YQ Connector: prepare code base for S3 integration

1. Кодовая база Коннектора переписана с помощью Go дженериков так, чтобы добавление нового источника данных (в частности S3 + csv) максимально переиспользовало имеющийся код (чтобы сохранялась логика нарезания на блоки данных, учёт трафика и пр.)
2. API Connector расширено для работы с S3, но ещё пока не протестировано.

1 files changed, 141 insertions, 0 deletions

diff --git a/vendor/github.com/aws/aws-sdk-go-v2/internal/v4a/credentials.go b/vendor/github.com/aws/aws-sdk-go-v2/internal/v4a/credentials.go
new file mode 100644
index 0000000000..3ae3a019e6
--- /dev/null
+++ b/vendor/github.com/aws/aws-sdk-go-v2/internal/v4a/credentials.go
@@ -0,0 +1,141 @@
+package v4a
+
+import (
+	"context"
+	"crypto/ecdsa"
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/internal/sdk"
+)
+
+// Credentials is Context, ECDSA, and Optional Session Token that can be used
+// to sign requests using SigV4a
+type Credentials struct {
+	Context      string
+	PrivateKey   *ecdsa.PrivateKey
+	SessionToken string
+
+	// Time the credentials will expire.
+	CanExpire bool
+	Expires   time.Time
+}
+
+// Expired returns if the credentials have expired.
+func (v Credentials) Expired() bool {
+	if v.CanExpire {
+		return !v.Expires.After(sdk.NowTime())
+	}
+
+	return false
+}
+
+// HasKeys returns if the credentials keys are set.
+func (v Credentials) HasKeys() bool {
+	return len(v.Context) > 0 && v.PrivateKey != nil
+}
+
+// SymmetricCredentialAdaptor wraps a SigV4 AccessKey/SecretKey provider and adapts the credentials
+// to a ECDSA PrivateKey for signing with SiV4a
+type SymmetricCredentialAdaptor struct {
+	SymmetricProvider aws.CredentialsProvider
+
+	asymmetric atomic.Value
+	m          sync.Mutex
+}
+
+// Retrieve retrieves symmetric credentials from the underlying provider.
+func (s *SymmetricCredentialAdaptor) Retrieve(ctx context.Context) (aws.Credentials, error) {
+	symCreds, err := s.retrieveFromSymmetricProvider(ctx)
+	if err != nil {
+		return aws.Credentials{}, err
+	}
+
+	if asymCreds := s.getCreds(); asymCreds == nil {
+		return symCreds, nil
+	}
+
+	s.m.Lock()
+	defer s.m.Unlock()
+
+	asymCreds := s.getCreds()
+	if asymCreds == nil {
+		return symCreds, nil
+	}
+
+	// if the context does not match the access key id clear it
+	if asymCreds.Context != symCreds.AccessKeyID {
+		s.asymmetric.Store((*Credentials)(nil))
+	}
+
+	return symCreds, nil
+}
+
+// RetrievePrivateKey returns credentials suitable for SigV4a signing
+func (s *SymmetricCredentialAdaptor) RetrievePrivateKey(ctx context.Context) (Credentials, error) {
+	if asymCreds := s.getCreds(); asymCreds != nil {
+		return *asymCreds, nil
+	}
+
+	s.m.Lock()
+	defer s.m.Unlock()
+
+	if asymCreds := s.getCreds(); asymCreds != nil {
+		return *asymCreds, nil
+	}
+
+	symmetricCreds, err := s.retrieveFromSymmetricProvider(ctx)
+	if err != nil {
+		return Credentials{}, fmt.Errorf("failed to retrieve symmetric credentials: %v", err)
+	}
+
+	privateKey, err := deriveKeyFromAccessKeyPair(symmetricCreds.AccessKeyID, symmetricCreds.SecretAccessKey)
+	if err != nil {
+		return Credentials{}, fmt.Errorf("failed to derive assymetric key from credentials")
+	}
+
+	creds := Credentials{
+		Context:      symmetricCreds.AccessKeyID,
+		PrivateKey:   privateKey,
+		SessionToken: symmetricCreds.SessionToken,
+		CanExpire:    symmetricCreds.CanExpire,
+		Expires:      symmetricCreds.Expires,
+	}
+
+	s.asymmetric.Store(&creds)
+
+	return creds, nil
+}
+
+func (s *SymmetricCredentialAdaptor) getCreds() *Credentials {
+	v := s.asymmetric.Load()
+
+	if v == nil {
+		return nil
+	}
+
+	c := v.(*Credentials)
+	if c != nil && c.HasKeys() && !c.Expired() {
+		return c
+	}
+
+	return nil
+}
+
+func (s *SymmetricCredentialAdaptor) retrieveFromSymmetricProvider(ctx context.Context) (aws.Credentials, error) {
+	credentials, err := s.SymmetricProvider.Retrieve(ctx)
+	if err != nil {
+		return aws.Credentials{}, err
+	}
+
+	return credentials, nil
+}
+
+// CredentialsProvider is the interface for a provider to retrieve credentials
+// to sign requests with.
+type CredentialsProvider interface {
+	RetrievePrivateKey(context.Context) (Credentials, error)
+}