drop DB interface, attempt to fix max conn issues using interpolatePa…

…rams

db/db.go

@@ -7,23 +7,27 @@ import (
 	"github.com/lbryio/lbry.go/errors"
 	"github.com/lbryio/lbry.go/querytools"
 	"github.com/lbryio/reflector.go/dht/bits"
-	"github.com/lbryio/reflector.go/types"
-	// blank import for db driver
-	_ "github.com/go-sql-driver/mysql"
+
+	_ "github.com/go-sql-driver/mysql" // blank import for db driver
 	log "github.com/sirupsen/logrus"
 )
 
-// DB interface communicates to a backend database with a simple set of methods that supports tracking blobs that are
-// used together with a BlobStore. The DB tracks pointers and the BlobStore stores the data.
-type DB interface {
-	Connect(string) error
-	HasBlob(string) (bool, error)
-	AddBlob(string, int, bool) error
-	AddSDBlob(string, int, types.SdBlob) error
-	HasFullStream(string) (bool, error)
+// SdBlob is a special blob that contains information on the rest of the blobs in the stream
+type SdBlob struct {
+	StreamName string `json:"stream_name"`
+	Blobs      []struct {
+		Length   int    `json:"length"`
+		BlobNum  int    `json:"blob_num"`
+		BlobHash string `json:"blob_hash,omitempty"`
+		Iv       string `json:"iv"`
+	} `json:"blobs"`
+	StreamType        string `json:"stream_type"`
+	Key               string `json:"key"`
+	SuggestedFileName string `json:"suggested_file_name"`
+	StreamHash        string `json:"stream_hash"`
 }
 
-// SQL is the container for the supporting MySQL database connection.
+// SQL implements the DB interface
 type SQL struct {
 	conn *sql.DB
 }
@@ -40,7 +44,10 @@ func logQuery(query string, args ...interface{}) {
 // Connect will create a connection to the database
 func (s *SQL) Connect(dsn string) error {
 	var err error
-	dsn += "?parseTime=1&collation=utf8mb4_unicode_ci"
+	// interpolateParams is necessary. otherwise uploading a stream with thousands of blobs
+	// will hit MySQL's max_prepared_stmt_count limit because the prepared statements are all
+	// opened inside a transaction. closing them manually doesn't seem to help
+	dsn += "?parseTime=1&collation=utf8mb4_unicode_ci&interpolateParams=1"
 	s.conn, err = sql.Open("mysql", dsn)
 	if err != nil {
 		return errors.Err(err)
@@ -49,7 +56,7 @@ func (s *SQL) Connect(dsn string) error {
 	return errors.Err(s.conn.Ping())
 }
 
-// AddBlob adds a blobs information to the database.
+// AddBlob adds a blob to the database.
 func (s *SQL) AddBlob(hash string, length int, isStored bool) error {
 	if s.conn == nil {
 		return errors.Err("not connected")
@@ -65,17 +72,10 @@ func addBlob(tx *sql.Tx, hash string, length int, isStored bool) error {
 		return errors.Err("length must be positive")
 	}
 
-	query := "INSERT INTO blob_ (hash, is_stored, length) VALUES (?,?,?) ON DUPLICATE KEY UPDATE is_stored = (is_stored or VALUES(is_stored))"
-	args := []interface{}{hash, isStored, length}
-
-	logQuery(query, args...)
-
-	stmt, err := tx.Prepare(query)
-	if err != nil {
-		return errors.Err(err)
-	}
-
-	_, err = stmt.Exec(args...)
+	err := execPrepared(tx,
+		"INSERT INTO blob_ (hash, is_stored, length) VALUES (?,?,?) ON DUPLICATE KEY UPDATE is_stored = (is_stored or VALUES(is_stored))",
+		[]interface{}{hash, isStored, length},
+	)
 	if err != nil {
 		return errors.Err(err)
 	}
@@ -187,7 +187,7 @@ func (s *SQL) HasFullStream(sdHash string) (bool, error) {
 // AddSDBlob takes the SD Hash number of blobs and the set of blobs. In a single db tx it inserts the sdblob information
 // into a stream, and inserts the associated blobs' information in the database. If a blob fails the transaction is
 // rolled back and error(s) are returned.
-func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob types.SdBlob) error {
+func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob SdBlob) error {
 	if s.conn == nil {
 		return errors.Err("not connected")
 	}
@@ -200,17 +200,10 @@ func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob types.SdBlob) er
 		}
 
 		// insert stream
-		query := "INSERT IGNORE INTO stream (hash, sd_hash) VALUES (?,?)"
-		args := []interface{}{sdBlob.StreamHash, sdHash}
-
-		logQuery(query, args...)
-
-		stmt, err := tx.Prepare(query)
-		if err != nil {
-			return errors.Err(err)
-		}
-
-		_, err = stmt.Exec(args...)
+		err = execPrepared(tx,
+			"INSERT IGNORE INTO stream (hash, sd_hash) VALUES (?,?)",
+			[]interface{}{sdBlob.StreamHash, sdHash},
+		)
 		if err != nil {
 			return errors.Err(err)
 		}
@@ -227,22 +220,10 @@ func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob types.SdBlob) er
 				return err
 			}
 
-			query := "INSERT IGNORE INTO stream_blob (stream_hash, blob_hash, num) VALUES (?,?,?)"
-			args := []interface{}{sdBlob.StreamHash, contentBlob.BlobHash, contentBlob.BlobNum}
-
-			logQuery(query, args...)
-
-			stmt, err := tx.Prepare(query)
-			if err != nil {
-				return errors.Err(err)
-			}
-
-			_, err = stmt.Exec(args...)
-			if err != nil {
-				return errors.Err(err)
-			}
-
-			err = stmt.Close()
+			err = execPrepared(tx,
+				"INSERT IGNORE INTO stream_blob (stream_hash, blob_hash, num) VALUES (?,?,?)",
+				[]interface{}{sdBlob.StreamHash, contentBlob.BlobHash, contentBlob.BlobNum},
+			)
 			if err != nil {
 				return errors.Err(err)
 			}
@@ -371,6 +352,23 @@ func closeRows(rows *sql.Rows) {
 	}
 }
 
+func execPrepared(tx *sql.Tx, query string, args []interface{}) error {
+	logQuery(query, args...)
+
+	stmt, err := tx.Prepare(query)
+	if err != nil {
+		return errors.Err(err)
+	}
+
+	_, err = stmt.Exec(args...)
+	if err != nil {
+		return errors.Err(err)
+	}
+
+	err = stmt.Close()
+	return errors.Err(err)
+}
+
 /*  SQL schema
 
 CREATE TABLE blob_ (

store/dbbacked.go

@@ -5,17 +5,16 @@ import (
 
 	"github.com/lbryio/lbry.go/errors"
 	"github.com/lbryio/reflector.go/db"
-	"github.com/lbryio/reflector.go/types"
 )
 
 // DBBackedS3Store is an instance of an S3 Store that is backed by a DB for what is stored.
 type DBBackedS3Store struct {
 	s3 *S3BlobStore
-	db db.DB
+	db *db.SQL
 }
 
 // NewDBBackedS3Store returns an initialized store pointer.
-func NewDBBackedS3Store(s3 *S3BlobStore, db db.DB) *DBBackedS3Store {
+func NewDBBackedS3Store(s3 *S3BlobStore, db *db.SQL) *DBBackedS3Store {
 	return &DBBackedS3Store{s3: s3, db: db}
 }
 
@@ -42,7 +41,7 @@ func (d *DBBackedS3Store) Put(hash string, blob []byte) error {
 // PutSD stores the SDBlob in the S3 store. It will return an error if the sd blob is missing the stream hash or if
 // there is an error storing the blob information in the DB.
 func (d *DBBackedS3Store) PutSD(hash string, blob []byte) error {
-	var blobContents types.SdBlob
+	var blobContents db.SdBlob
 	err := json.Unmarshal(blob, &blobContents)
 	if err != nil {
 		return err