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-rw-r--r--src/post/asset/asset.go116
-rw-r--r--src/post/asset/asset_test.go92
2 files changed, 208 insertions, 0 deletions
diff --git a/src/post/asset/asset.go b/src/post/asset/asset.go
new file mode 100644
index 0000000..d20b347
--- /dev/null
+++ b/src/post/asset/asset.go
@@ -0,0 +1,116 @@
+package asset
+
+import (
+ "bytes"
+ "database/sql"
+ "errors"
+ "fmt"
+ "io"
+
+ "github.com/mediocregopher/blog.mediocregopher.com/srv/post"
+)
+
+var (
+ // ErrNotFound is used to indicate an Asset could not be found in the
+ // Store.
+ ErrNotFound = errors.New("asset not found")
+)
+
+// Store implements the storage and retrieval of binary assets, which are
+// intended to be used by posts (e.g. images).
+type Store interface {
+
+ // Set sets the id to the contents of the given io.Reader.
+ Set(id string, from io.Reader) error
+
+ // Get writes the id's body to the given io.Writer, or returns
+ // ErrNotFound.
+ Get(id string, into io.Writer) error
+
+ // Delete's the body stored for the id, if any.
+ Delete(id string) error
+
+ // List returns all ids which are currently stored.
+ List() ([]string, error)
+}
+
+type store struct {
+ db *post.SQLDB
+}
+
+// NewStore initializes a new Store using an existing SQLDB.
+func NewStore(db *post.SQLDB) Store {
+ return &store{
+ db: db,
+ }
+}
+
+func (s *store) Set(id string, from io.Reader) error {
+
+ body, err := io.ReadAll(from)
+ if err != nil {
+ return fmt.Errorf("reading body fully into memory: %w", err)
+ }
+
+ _, err = s.db.Exec(
+ `INSERT INTO assets (id, body)
+ VALUES (?, ?)
+ ON CONFLICT (id) DO UPDATE SET body=excluded.body`,
+ id, body,
+ )
+
+ if err != nil {
+ return fmt.Errorf("inserting into assets: %w", err)
+ }
+
+ return nil
+}
+
+func (s *store) Get(id string, into io.Writer) error {
+
+ var body []byte
+
+ err := s.db.QueryRow(`SELECT body FROM assets WHERE id = ?`, id).Scan(&body)
+
+ if errors.Is(err, sql.ErrNoRows) {
+ return ErrNotFound
+ } else if err != nil {
+ return fmt.Errorf("selecting from assets: %w", err)
+ }
+
+ if _, err := io.Copy(into, bytes.NewReader(body)); err != nil {
+ return fmt.Errorf("writing body to io.Writer: %w", err)
+ }
+
+ return nil
+}
+
+func (s *store) Delete(id string) error {
+ _, err := s.db.Exec(`DELETE FROM assets WHERE id = ?`, id)
+ return err
+}
+
+func (s *store) List() ([]string, error) {
+
+ rows, err := s.db.Query(`SELECT id FROM assets ORDER BY id ASC`)
+
+ if err != nil {
+ return nil, fmt.Errorf("querying: %w", err)
+ }
+
+ defer rows.Close()
+
+ var ids []string
+
+ for rows.Next() {
+
+ var id string
+ if err := rows.Scan(&id); err != nil {
+ return nil, fmt.Errorf("scanning row: %w", err)
+ }
+
+ ids = append(ids, id)
+ }
+
+ return ids, nil
+}
diff --git a/src/post/asset/asset_test.go b/src/post/asset/asset_test.go
new file mode 100644
index 0000000..574cc08
--- /dev/null
+++ b/src/post/asset/asset_test.go
@@ -0,0 +1,92 @@
+package asset
+
+import (
+ "bytes"
+ "io"
+ "testing"
+
+ "github.com/mediocregopher/blog.mediocregopher.com/srv/post"
+ "github.com/stretchr/testify/assert"
+)
+
+type testHarness struct {
+ store Store
+}
+
+func newTestHarness(t *testing.T) *testHarness {
+
+ db := post.NewInMemSQLDB()
+ t.Cleanup(func() { db.Close() })
+
+ store := NewStore(db)
+
+ return &testHarness{
+ store: store,
+ }
+}
+
+func (h *testHarness) assertGet(t *testing.T, exp, id string) {
+ t.Helper()
+ buf := new(bytes.Buffer)
+ err := h.store.Get(id, buf)
+ assert.NoError(t, err)
+ assert.Equal(t, exp, buf.String())
+}
+
+func (h *testHarness) assertNotFound(t *testing.T, id string) {
+ t.Helper()
+ err := h.store.Get(id, io.Discard)
+ assert.ErrorIs(t, ErrNotFound, err)
+}
+
+func TestStore(t *testing.T) {
+
+ testStore := func(t *testing.T, h *testHarness) {
+ t.Helper()
+
+ h.assertNotFound(t, "foo")
+ h.assertNotFound(t, "bar")
+
+ err := h.store.Set("foo", bytes.NewBufferString("FOO"))
+ assert.NoError(t, err)
+
+ h.assertGet(t, "FOO", "foo")
+ h.assertNotFound(t, "bar")
+
+ err = h.store.Set("foo", bytes.NewBufferString("FOOFOO"))
+ assert.NoError(t, err)
+
+ h.assertGet(t, "FOOFOO", "foo")
+ h.assertNotFound(t, "bar")
+
+ assert.NoError(t, h.store.Delete("foo"))
+ h.assertNotFound(t, "foo")
+ h.assertNotFound(t, "bar")
+
+ assert.NoError(t, h.store.Delete("bar"))
+ h.assertNotFound(t, "foo")
+ h.assertNotFound(t, "bar")
+
+ // test list
+
+ ids, err := h.store.List()
+ assert.NoError(t, err)
+ assert.Empty(t, ids)
+
+ err = h.store.Set("foo", bytes.NewBufferString("FOOFOO"))
+ assert.NoError(t, err)
+ err = h.store.Set("foo", bytes.NewBufferString("FOOFOO"))
+ assert.NoError(t, err)
+ err = h.store.Set("bar", bytes.NewBufferString("FOOFOO"))
+ assert.NoError(t, err)
+
+ ids, err = h.store.List()
+ assert.NoError(t, err)
+ assert.Equal(t, []string{"bar", "foo"}, ids)
+ }
+
+ t.Run("sql", func(t *testing.T) {
+ h := newTestHarness(t)
+ testStore(t, h)
+ })
+}