Added block consumer for SQLite3 in interleaver.

interleaver/sqlite.go

@@ -6,6 +6,7 @@ package main
 
 import (
 	"database/sql"
+	"errors"
 	"os"
 
 	"bitbucket.org/s_l_teichmann/mtredisalize/common"
@@ -14,19 +15,81 @@ import (
 )
 
 const (
-	fetchSql = "SELECT pos, data FROM blocks"
+	createSql = "CREATE TABLE blocks (pos INT NOT NULL PRIMARY KEY, data BLOB)"
+	insertSql = "INSERT INTO blocks (pos, data) VALUES (?, ?)"
+	deleteSql = "DELETE FROM blocks"
+	selectSql = "SELECT pos, data FROM blocks"
 )
 
-type SQLiteBlockProducer struct {
+var DatabaseNotExistsErr = errors.New("Database does not exists.")
-	db       *sql.DB
+
-	rows     *sql.Rows
+type (
-	splitter common.KeySplitter
+	SQLiteBlockProducer struct {
+		db       *sql.DB
+		rows     *sql.Rows
+		splitter common.KeySplitter
+	}
+
+	SQLiteBlockConsumer struct {
+		db         *sql.DB
+		insertStmt *sql.Stmt
+		joiner     common.KeyJoiner
+	}
+)
+
+func fileExists(path string) bool {
+	_, err := os.Stat(path)
+	return !os.IsNotExist(err)
 }
 
-func NewSQLiteBlockProducer(path string, splitter common.KeySplitter) (sbp *SQLiteBlockProducer, err error) {
+func NewSQLiteBlockConsumer(
+	path string,
+	joiner common.KeyJoiner) (sbc *SQLiteBlockConsumer, err error) {
 
-	// check if we can stat it -> exists.
+	createNew := !fileExists(path)
-	if _, err = os.Stat(path); err != nil {
+
+	var db *sql.DB
+	if db, err = sql.Open("sqlite3", path); err != nil {
+		return
+	}
+
+	if createNew {
+		if _, err = db.Exec(createSql); err != nil {
+			db.Close()
+			return
+		}
+	}
+
+	var insertStmt *sql.Stmt
+	if insertStmt, err = db.Prepare(insertSql); err != nil {
+		db.Close()
+		return
+	}
+
+	sbc = &SQLiteBlockConsumer{
+		db:         db,
+		insertStmt: insertStmt,
+		joiner:     joiner}
+
+	return
+}
+
+func (sbc *SQLiteBlockConsumer) Close() error {
+	sbc.insertStmt.Close()
+	return sbc.db.Close()
+}
+
+func (sbc *SQLiteBlockConsumer) Consume(block *Block) (err error) {
+	_, err = sbc.insertStmt.Exec(sbc.joiner(block.Coord), block.Data)
+	return
+}
+
+func NewSQLiteBlockProducer(
+	path string,
+	splitter common.KeySplitter) (sbp *SQLiteBlockProducer, err error) {
+
+	if !fileExists(path) {
+		err = DatabaseNotExistsErr
 		return
 	}
 
@@ -36,7 +99,7 @@ func NewSQLiteBlockProducer(path string, splitter common.KeySplitter) (sbp *SQLi
 	}
 
 	var rows *sql.Rows
-	if rows, err = db.Query(fetchSql); err != nil {
+	if rows, err = db.Query(selectSql); err != nil {
 		db.Close()
 		return
 	}