Refactor db access to ensure pragmas are set, fix foreign keys

cmd/add.go

@@ -2,7 +2,6 @@ package cmd
 
 import (
 	"crypto/rand"
-	"database/sql"
 	"encoding/hex"
 	"fmt"
 	"log"
@@ -58,7 +57,7 @@ func add() {
 		addId = hex.EncodeToString(bytes)
 	}
 
-	db, err := sql.Open("sqlite3", getDbPath())
+	db, err := core.OpenDb(getDbPath())
 	if err != nil {
 		log.Fatalf("Failed to open %s", dbPath)
 	}

cmd/deactivate.go

@@ -1,7 +1,6 @@
 package cmd
 
 import (
-	"database/sql"
 	"fmt"
 	"log"
 
@@ -35,7 +34,7 @@ func init() {
 }
 
 func deactivate() {
-	db, err := sql.Open("sqlite3", getDbPath())
+	db, err := core.OpenDb(getDbPath())
 	if err != nil {
 		log.Fatalf("Failed to open %s", dbPath)
 	}

cmd/feed.go

@@ -1,7 +1,6 @@
 package cmd
 
 import (
-	"database/sql"
 	"fmt"
 	"log"
 
@@ -44,7 +43,7 @@ func feed() {
 		log.Fatal(err)
 	}
 
-	db, err := sql.Open("sqlite3", getDbPath())
+	db, err := core.OpenDb(getDbPath())
 	if err != nil {
 		log.Fatalf("error: failed to open %s", dbPath)
 	}

cmd/migrate.go

@@ -1,7 +1,6 @@
 package cmd
 
 import (
-	"database/sql"
 	"fmt"
 	"log"
 
@@ -30,7 +29,7 @@ func init() {
 }
 
 func migrate() {
-	db, err := sql.Open("sqlite3", getDbPath())
+	db, err := core.OpenDb(getDbPath())
 	if err != nil {
 		log.Fatal(err)
 	}

core/db.go

@@ -0,0 +1,70 @@
+package core
+
+import (
+	"database/sql"
+	"runtime"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+type DB struct {
+	ro *sql.DB
+	rw *sql.DB
+}
+
+func (db *DB) Query(query string, args ...any) (*sql.Rows, error) {
+	return db.ro.Query(query, args...)
+}
+
+func (db *DB) QueryRow(query string, args ...any) *sql.Row {
+	return db.ro.QueryRow(query, args...)
+}
+
+func (db *DB) Exec(query string, args ...any) (sql.Result, error) {
+	return db.rw.Exec(query, args...)
+}
+
+func defaultPragma(db *sql.DB) (sql.Result, error) {
+	return db.Exec(`
+		pragma journal_mode = WAL;
+		pragma busy_timeout = 5000;
+		pragma synchronous = NORMAL;
+		pragma cache_size = 1000000000;
+		pragma foreign_keys = true;
+		pragma temp_store = memory;
+		pragma mmap_size = 3000000000;
+	`)
+}
+
+func OpenDb(dataSourceName string) (*DB, error) {
+	ro, err := sql.Open("sqlite3", dataSourceName)
+	if err != nil {
+		defer ro.Close()
+		return nil, err
+	}
+	ro.SetMaxOpenConns(max(4, runtime.NumCPU()))
+	_, err = defaultPragma(ro)
+	if err != nil {
+		defer ro.Close()
+		return nil, err
+	}
+
+	rw, err := sql.Open("sqlite3", dataSourceName)
+	if err != nil {
+		defer ro.Close()
+		defer rw.Close()
+		return nil, err
+	}
+	rw.SetMaxOpenConns(1)
+	_, err = defaultPragma(rw)
+	if err != nil {
+		defer ro.Close()
+		defer rw.Close()
+		return nil, err
+	}
+
+	wrapper := new(DB)
+	wrapper.ro = ro
+	wrapper.rw = rw
+	return wrapper, nil
+}

core/db_test.go

@@ -0,0 +1,48 @@
+package core
+
+import (
+	"testing"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func TestDeleteSourceCascade(t *testing.T) {
+	db := EphemeralDb(t)
+
+	if err := AddSource(db, "source1"); err != nil {
+		t.Fatal(err)
+	}
+	if err := AddSource(db, "source2"); err != nil {
+		t.Fatal(err)
+	}
+	if err := AddItem(db, "source1", "item1", "", "", "", "", 0); err != nil {
+		t.Fatal(err)
+	}
+	if err := AddItem(db, "source2", "item2", "", "", "", "", 0); err != nil {
+		t.Fatal(err)
+	}
+
+	items, err := GetAllActiveItems(db)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(items) != 2 {
+		t.Fatal("Expected 2 items")
+	}
+
+	if err := DeleteSource(db, "source1"); err != nil {
+		t.Fatal(err)
+	}
+	items, err = GetAllActiveItems(db)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(items) != 1 {
+		t.Fatal("Expected only 1 item after source delete")
+	}
+
+	err = AddItem(db, "source1", "item3", "", "", "", "", 0)
+	if err == nil {
+		t.Fatal("Unexpected success adding item for nonexistent source")
+	}
+}

core/migrations.go

@@ -1,7 +1,6 @@
 package core
 
 import (
-	"database/sql"
 	"embed"
 	"log"
 
@@ -12,7 +11,7 @@ import (
 var migrations embed.FS
 
 // Idempotently initialize the database. Safe to call unconditionally.
-func InitDatabase(db *sql.DB) error {
+func InitDatabase(db *DB) error {
 	rows, err := db.Query(`
 		select exists (
 			select 1
@@ -39,7 +38,7 @@ func InitDatabase(db *sql.DB) error {
 }
 
 // Get a map of migration names to whether the migration has been applied.
-func GetPendingMigrations(db *sql.DB) (map[string]bool, error) {
+func GetPendingMigrations(db *DB) (map[string]bool, error) {
 	allMigrations, err := migrations.ReadDir("sql")
 	if err != nil {
 		return nil, err
@@ -64,7 +63,7 @@ func GetPendingMigrations(db *sql.DB) (map[string]bool, error) {
 }
 
 // Apply a migration by name.
-func ApplyMigration(db *sql.DB, name string) error {
+func ApplyMigration(db *DB, name string) error {
 	data, err := migrations.ReadFile("sql/" + name)
 	if err != nil {
 		log.Fatalf("Missing migration %s", name)
@@ -79,7 +78,7 @@ func ApplyMigration(db *sql.DB, name string) error {
 }
 
 // Apply all pending migrations.
-func MigrateDatabase(db *sql.DB) error {
+func MigrateDatabase(db *DB) error {
 	pending, err := GetPendingMigrations(db)
 	if err != nil {
 		return err

core/migrations_test.go

@@ -7,11 +7,18 @@ import (
 	_ "github.com/mattn/go-sqlite3"
 )
 
-func EphemeralDb(t *testing.T) *sql.DB {
-	db, err := sql.Open("sqlite3", ":memory:")
+func EphemeralDb(t *testing.T) *DB {
+	// We don't use OpenDb here because you can't open two connections to the same memory mem
+	mem, err := sql.Open("sqlite3", ":memory:")
 	if err != nil {
 		t.Fatal(err)
 	}
+	if _, err = defaultPragma(mem); err != nil {
+		t.Fatal(err)
+	}
+	db := new(DB)
+	db.ro = mem
+	db.rw = mem
 	if err = InitDatabase(db); err != nil {
 		t.Fatal(err)
 	}
@@ -22,11 +29,13 @@ func EphemeralDb(t *testing.T) *sql.DB {
 }
 
 func TestInitIdempotency(t *testing.T) {
-	db, err := sql.Open("sqlite3", ":memory:")
+	mem, err := sql.Open("sqlite3", ":memory:")
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer db.Close()
+	db := new(DB)
+	db.ro = mem
+	db.rw = mem
 	if err = InitDatabase(db); err != nil {
 		t.Fatal(err)
 	}
@@ -37,7 +46,6 @@ func TestInitIdempotency(t *testing.T) {
 
 func TestMigrations(t *testing.T) {
 	db := EphemeralDb(t)
-	defer db.Close()
 
 	allMigrations, err := migrations.ReadDir("sql")
 	if err != nil {

core/source.go

@@ -8,7 +8,7 @@ import (
 	_ "github.com/mattn/go-sqlite3"
 )
 
-func AddSource(db *sql.DB, name string) error {
+func AddSource(db *DB, name string) error {
 	_, err := db.Exec(`
 		insert into sources (name)
 		values (?)
@@ -17,7 +17,7 @@ func AddSource(db *sql.DB, name string) error {
 	return err
 }
 
-func DeleteSource(db *sql.DB, name string) error {
+func DeleteSource(db *DB, name string) error {
 	_, err := db.Exec(`
 	delete from sources
 	where name = ?
@@ -27,7 +27,7 @@ func DeleteSource(db *sql.DB, name string) error {
 }
 
 func AddItem(
-	db *sql.DB,
+	db *DB,
 	source string,
 	id string,
 	title string,
@@ -45,7 +45,7 @@ func AddItem(
 }
 
 // Deactivate an item, returning its previous active state.
-func DeactivateItem(db *sql.DB, source string, id string) (bool, error) {
+func DeactivateItem(db *DB, source string, id string) (bool, error) {
 	row := db.QueryRow(`
 		select active
 		from items
@@ -68,7 +68,7 @@ func DeactivateItem(db *sql.DB, source string, id string) (bool, error) {
 	return active, nil
 }
 
-func GetAllActiveItems(db *sql.DB) ([]Item, error) {
+func GetAllActiveItems(db *DB) ([]Item, error) {
 	rows, err := db.Query(`
 		select
 			source, id, created, active, title, author, body, link, time
@@ -87,7 +87,7 @@ func GetAllActiveItems(db *sql.DB) ([]Item, error) {
 	return items, nil
 }
 
-func GetActiveItemsForSource(db *sql.DB, source string) ([]Item, error) {
+func GetActiveItemsForSource(db *DB, source string) ([]Item, error) {
 	rows, err := db.Query(`
 		select
 			source, id, created, active, title, author, body, link, time

core/source_test.go

@@ -10,7 +10,6 @@ import (
 
 func TestCreateSource(t *testing.T) {
 	db := EphemeralDb(t)
-	defer db.Close()
 
 	if err := AddSource(db, "one"); err != nil {
 		t.Fatal(err)
@@ -62,7 +61,6 @@ func AssertItemIs(t *testing.T, item Item, expected string) {
 
 func TestAddItem(t *testing.T) {
 	db := EphemeralDb(t)
-	defer db.Close()
 	if err := AddSource(db, "test"); err != nil {
 		t.Fatal(err)
 	}

core/sql/0001_initial_schema.sql

@@ -1,4 +1,7 @@
-create table sources(name text) strict;
+create table sources(
+    name text not null,
+    primary key (name)
+) strict;
 create table items(
     source text not null,
     id text not null,