Implementation of postgres store

store/options.go

@@ -4,7 +4,7 @@ import (
 	"github.com/micro/go-micro/config/options"
 )
 
-// Set the nodes used to back the store
+// Nodes is a list of nodes used to back the store
 func Nodes(a ...string) options.Option {
 	return options.WithValue("store.nodes", a)
 }
@@ -13,3 +13,9 @@ func Nodes(a ...string) options.Option {
 func Prefix(p string) options.Option {
 	return options.WithValue("store.prefix", p)
 }
+
+// Namespace offers a way to have multiple isolated
+// stores in the same backend, if supported.
+func Namespace(n string) options.Option {
+	return options.WithValue("store.namespace", n)
+}

store/postgresql/postgresql.go

@@ -0,0 +1,244 @@
+// Package postgresql implements a micro Store backed by sql
+package postgresql
+
+import (
+	"database/sql"
+	"fmt"
+	"time"
+	"unicode"
+
+	"github.com/lib/pq"
+	"github.com/pkg/errors"
+
+	"github.com/micro/go-micro/config/options"
+	"github.com/micro/go-micro/store"
+)
+
+// DefaultNamespace is the namespace that the sql store
+// will use if no namespace is provided.
+const DefaultNamespace = "micro"
+
+type sqlStore struct {
+	db *sql.DB
+
+	table string
+	options.Options
+}
+
+// List all the known records
+func (s *sqlStore) List() ([]*store.Record, error) {
+	q, err := s.db.Prepare(fmt.Sprintf("SELECT key, value, expiry FROM micro.%s;", s.table))
+	if err != nil {
+		return nil, err
+	}
+	var records []*store.Record
+	var timehelper pq.NullTime
+	rows, err := q.Query()
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return records, nil
+		}
+		return nil, err
+	}
+	defer rows.Close()
+	for rows.Next() {
+		record := &store.Record{}
+		if err := rows.Scan(&record.Key, &record.Value, &timehelper); err != nil {
+			return records, err
+		}
+		if timehelper.Valid {
+			if timehelper.Time.Before(time.Now()) {
+				// record has expired
+				go s.Delete(record.Key)
+			} else {
+				record.Expiry = time.Until(timehelper.Time)
+				records = append(records, record)
+			}
+		} else {
+			records = append(records, record)
+		}
+
+	}
+	rowErr := rows.Close()
+	if rowErr != nil {
+		// transaction rollback or something
+		return records, rowErr
+	}
+	if err := rows.Err(); err != nil {
+		return records, err
+	}
+	return records, nil
+}
+
+// Read all records with keys
+func (s *sqlStore) Read(keys ...string) ([]*store.Record, error) {
+	q, err := s.db.Prepare(fmt.Sprintf("SELECT key, value, expiry FROM micro.%s WHERE key = $1;", s.table))
+	if err != nil {
+		return nil, err
+	}
+	var records []*store.Record
+	var timehelper pq.NullTime
+	for _, key := range keys {
+		row := q.QueryRow(key)
+		record := &store.Record{}
+		if err := row.Scan(&record.Key, &record.Value, &timehelper); err != nil {
+			if err == sql.ErrNoRows {
+				return records, store.ErrNotFound
+			}
+			return records, err
+		}
+		if timehelper.Valid {
+			if timehelper.Time.Before(time.Now()) {
+				// record has expired
+				go s.Delete(key)
+				return records, store.ErrNotFound
+			}
+			record.Expiry = time.Until(timehelper.Time)
+			records = append(records, record)
+		} else {
+			records = append(records, record)
+		}
+	}
+	return records, nil
+}
+
+// Write records
+func (s *sqlStore) Write(rec ...*store.Record) error {
+	q, err := s.db.Prepare(fmt.Sprintf(`INSERT INTO micro.%s(key, value, expiry)
+		VALUES ($1, $2::bytea, $3)
+		ON CONFLICT (key)
+		DO UPDATE
+		SET value = EXCLUDED.value, expiry = EXCLUDED.expiry;`, s.table))
+	if err != nil {
+		return err
+	}
+	for _, r := range rec {
+		var err error
+		if r.Expiry != 0 {
+			_, err = q.Exec(r.Key, r.Value, time.Now().Add(r.Expiry))
+		} else {
+			_, err = q.Exec(r.Key, r.Value, nil)
+		}
+		if err != nil {
+			return errors.Wrap(err, "Couldn't insert record "+r.Key)
+		}
+	}
+
+	return nil
+}
+
+// Delete records with keys
+func (s *sqlStore) Delete(keys ...string) error {
+	q, err := s.db.Prepare(fmt.Sprintf("DELETE FROM micro.%s WHERE key = $1;", s.table))
+	if err != nil {
+		return err
+	}
+	for _, key := range keys {
+		result, err := q.Exec(key)
+		if err != nil {
+			return err
+		}
+		_, err = result.RowsAffected()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *sqlStore) initDB(options options.Options) error {
+	// Get the store.namespace option, or use sql.DefaultNamespace
+	namespaceOpt, found := options.Values().Get("store.namespace")
+	if !found {
+		s.table = DefaultNamespace
+	} else {
+		if namespace, ok := namespaceOpt.(string); ok {
+			s.table = namespace
+		} else {
+			return errors.New("store.namespace option must be a string")
+		}
+	}
+
+	// Create "micro" schema
+	schema, err := s.db.Prepare("CREATE SCHEMA IF NOT EXISTS micro ;")
+	if err != nil {
+		return err
+	}
+	_, err = schema.Exec()
+	if err != nil {
+		return errors.Wrap(err, "Couldn't create Schema")
+	}
+
+	// Create a table for the Store namespace
+	tableq, err := s.db.Prepare(fmt.Sprintf(`CREATE TABLE IF NOT EXISTS micro.%s
+	(
+		key text COLLATE "default" NOT NULL,
+		value bytea,
+		expiry timestamp with time zone,
+		CONSTRAINT %s_pkey PRIMARY KEY (key)
+	);`, s.table, s.table))
+	_, err = tableq.Exec()
+	if err != nil {
+		return errors.Wrap(err, "Couldn't create table")
+	}
+
+	return nil
+}
+
+// New returns a new micro Store backed by sql
+func New(opts ...options.Option) (store.Store, error) {
+	options := options.NewOptions(opts...)
+	driver, dataSourceName, err := validateOptions(options)
+	if err != nil {
+		return nil, err
+	}
+	db, err := sql.Open(driver, dataSourceName)
+	if err != nil {
+		return nil, err
+	}
+	if err := db.Ping(); err != nil {
+		return nil, err
+	}
+	s := &sqlStore{
+		db: db,
+	}
+
+	return s, s.initDB(options)
+}
+
+// validateOptions checks whether the provided options are valid, then returns the driver
+// and data source name.
+func validateOptions(options options.Options) (driver, dataSourceName string, err error) {
+	driverOpt, found := options.Values().Get("store.sql.driver")
+	if !found {
+		return "", "", errors.New("No store.sql.driver option specified")
+	}
+	nodesOpt, found := options.Values().Get("store.nodes")
+	if !found {
+		return "", "", errors.New("No store.nodes option specified (expected a database connection string)")
+	}
+	driver, ok := driverOpt.(string)
+	if !ok {
+		return "", "", errors.New("store.sql.driver option must be a string")
+	}
+	nodes, ok := nodesOpt.([]string)
+	if !ok {
+		return "", "", errors.New("store.nodes option must be a []string")
+	}
+	if len(nodes) != 1 {
+		return "", "", errors.New("expected only 1 store.nodes option")
+	}
+	namespaceOpt, found := options.Values().Get("store.namespace")
+	if found {
+		namespace, ok := namespaceOpt.(string)
+		if !ok {
+			return "", "", errors.New("store.namespace must me a string")
+		}
+		for _, r := range namespace {
+			if !unicode.IsLetter(r) {
+				return "", "", errors.New("store.namespace must only contain letters")
+			}
+		}
+	}
+	return driver, nodes[0], nil
+}

store/postgresql/postgresql_test.go

@@ -0,0 +1,95 @@
+package postgresql
+
+import (
+	"database/sql"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/kr/pretty"
+	"github.com/micro/go-micro/store"
+)
+
+func TestSQL(t *testing.T) {
+	connection := fmt.Sprintf(
+		"host=%s port=%d user=%s sslmode=disable dbname=%s",
+		"localhost",
+		5432,
+		"jake",
+		"test",
+	)
+	db, err := sql.Open("postgres", connection)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Ping(); err != nil {
+		t.Skip(err)
+	}
+	db.Close()
+
+	sqlStore, err := New(
+		store.Namespace("testsql"),
+		store.Nodes(connection),
+	)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	records, err := sqlStore.List()
+	if err != nil {
+		t.Error(err)
+	} else {
+		t.Logf("%# v\n", pretty.Formatter(records))
+	}
+
+	err = sqlStore.Write(
+		&store.Record{
+			Key:   "test",
+			Value: []byte("foo"),
+		},
+		&store.Record{
+			Key:   "bar",
+			Value: []byte("baz"),
+		},
+		&store.Record{
+			Key:   "qux",
+			Value: []byte("aasad"),
+		},
+	)
+	if err != nil {
+		t.Error(err)
+	}
+	err = sqlStore.Delete("qux")
+	if err != nil {
+		t.Error(err)
+	}
+
+	err = sqlStore.Write(&store.Record{
+		Key:    "test",
+		Value:  []byte("bar"),
+		Expiry: time.Minute,
+	})
+	if err != nil {
+		t.Error(err)
+	}
+
+	records, err = sqlStore.Read("test")
+	if err != nil {
+		t.Error(err)
+	} else {
+		t.Logf("%# v\n", pretty.Formatter(records))
+		if string(records[0].Value) != "bar" {
+			t.Error("Expected bar, got ", string(records[0].Value))
+		}
+	}
+
+	time.Sleep(61 * time.Second)
+	records, err = sqlStore.Read("test")
+	if err == nil {
+		t.Error("Key test should have expired")
+	} else {
+		if err != store.ErrNotFound {
+			t.Error(err)
+		}
+	}
+}

store/store.go

@@ -7,6 +7,7 @@ import (
 )
 
 var (
+	// ErrNotFound is returned when a Read key doesn't exist
 	ErrNotFound = errors.New("not found")
 )
 
@@ -14,11 +15,11 @@ var (
 type Store interface {
 	// List all the known records
 	List() ([]*Record, error)
-	// Read a record with key
+	// Read records with keys
 	Read(key ...string) ([]*Record, error)
-	// Write a record
+	// Write records
 	Write(rec ...*Record) error
-	// Delete a record with key
+	// Delete records with keys
 	Delete(key ...string) error
 }