📦 postgres

Co-Authored-By: Alireza Salary <arsmn1996@gmail.com>

postgres/postgres.go

@@ -1,22 +1,96 @@
 package postgres
 
 import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"net/url"
 	"time"
+
+	"github.com/gofiber/utils"
+	_ "github.com/lib/pq"
 )
 
 // Storage interface that is implemented by storage providers
 type Storage struct {
+	db         *sql.DB
 	gcInterval time.Duration
+
+	sqlSelect string
+	sqlInsert string
+	sqlDelete string
+	sqlClear  string
+	sqlGC     string
 }
 
+var (
+	dropQuery = `DROP TABLE IF EXISTS %s;`
+	initQuery = []string{
+		`CREATE TABLE IF NOT EXISTS %s (
+			key  VARCHAR(64) PRIMARY KEY NOT NULL DEFAULT '',
+			data TEXT NOT NULL,
+			exp  BIGINT NOT NULL DEFAULT '0'
+		);`,
+		`CREATE INDEX IF NOT EXISTS exp ON %s (exp);`,
+	}
+)
+
 // New creates a new storage
 func New(config ...Config) *Storage {
 	// Set default config
 	cfg := configDefault(config...)
 
+	// Create data source name
+	dsn := fmt.Sprintf("postgresql://%s:%s@%s:%d/%s?connect_timeout=%d&sslmode=disable",
+		url.QueryEscape(cfg.Username),
+		cfg.Password,
+		url.QueryEscape(cfg.Host),
+		cfg.Port,
+		url.QueryEscape(cfg.Database),
+		int64(cfg.Timeout.Seconds()))
+
+	// Create db
+	db, err := sql.Open("postgres", dsn)
+	if err != nil {
+		panic(err)
+	}
+
+	// Set database options
+	db.SetMaxOpenConns(cfg.MaxOpenConns)
+	db.SetMaxIdleConns(cfg.MaxIdleConns)
+	db.SetConnMaxLifetime(cfg.ConnMaxLifetime)
+
+	// Ping database
+	if err := db.Ping(); err != nil {
+		panic(err)
+	}
+
+	// Drop table if set to true
+	if cfg.DropTable {
+		if _, err = db.Exec(fmt.Sprintf(dropQuery, cfg.TableName)); err != nil {
+			_ = db.Close()
+			panic(err)
+		}
+	}
+
+	// Init database queries
+	for _, query := range initQuery {
+		if _, err := db.Exec(fmt.Sprintf(query, cfg.TableName)); err != nil {
+			_ = db.Close()
+			fmt.Println(fmt.Sprintf(query, cfg.TableName))
+			panic(err)
+		}
+	}
+
 	// Create storage
 	store := &Storage{
+		db:         db,
 		gcInterval: cfg.GCInterval,
+		sqlSelect:  fmt.Sprintf(`SELECT data, exp FROM %s WHERE key=$1;`, cfg.TableName),
+		sqlInsert:  fmt.Sprintf("INSERT INTO %s (key, data, exp) VALUES ($1, $2, $3)", cfg.TableName),
+		sqlDelete:  fmt.Sprintf("DELETE FROM %s WHERE key=$1", cfg.TableName),
+		sqlClear:   fmt.Sprintf("DELETE FROM %s;", cfg.TableName),
+		sqlGC:      fmt.Sprintf("DELETE FROM %s WHERE exp <= $1", cfg.TableName),
 	}
 
 	// Start garbage collector
@@ -25,31 +99,57 @@ func New(config ...Config) *Storage {
 	return store
 }
 
+var noRows = errors.New("sql: no rows in result set")
+
 // Get value by key
 func (s *Storage) Get(key string) ([]byte, error) {
-	return nil, nil
+	row := s.db.QueryRow(s.sqlSelect, key)
+
+	// Add db response to data
+	var (
+		data       = []byte{}
+		exp  int64 = 0
+	)
+	if err := row.Scan(&data, &exp); err != nil {
+		if err != noRows {
+			return nil, err
+		}
+		return nil, nil
+	}
+
+	// If the expiration time has already passed, then return nil
+	if time.Now().After(time.Unix(exp, 0)) {
+		return nil, nil
+	}
+
+	return data, nil
 }
 
 // Set key with value
 func (s *Storage) Set(key string, val []byte, exp time.Duration) error {
-	return nil
+	_, err := s.db.Exec(s.sqlInsert, key, utils.UnsafeString(val), time.Now().Add(exp).Unix())
+	return err
 }
 
-// Delete key by key
+// Delete entry by key
 func (s *Storage) Delete(key string) error {
-	return nil
+	_, err := s.db.Exec(s.sqlDelete, key)
+	return err
 }
 
-// Clear all keys
+// Clear all entries, including unexpired
 func (s *Storage) Clear() error {
-	return nil
+	_, err := s.db.Exec(s.sqlClear)
+	return err
 }
 
-// Garbage collector to delete expired keys
+// GC deletes all expired entries
 func (s *Storage) gc() {
 	tick := time.NewTicker(s.gcInterval)
 	for {
 		<-tick.C
-		// clean entries
+		if _, err := s.db.Exec(s.sqlGC); err != nil {
+			panic(err)
+		}
 	}
 }