internal/pkg: implement caching for files

This change contains primitives for validating and caching single-file artifacts.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 327 insertions, 0 deletions

diff --git a/internal/pkg/pkg_test.go b/internal/pkg/pkg_test.go
new file mode 100644
index 00000000..c73049e5
--- /dev/null
+++ b/internal/pkg/pkg_test.go
@@ -0,0 +1,327 @@
+package pkg_test
+
+import (
+	"bytes"
+	"crypto/sha512"
+	"encoding/base64"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"reflect"
+	"syscall"
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/container/check"
+	"hakurei.app/container/stub"
+	"hakurei.app/internal/pkg"
+)
+
+func TestCache(t *testing.T) {
+	t.Parallel()
+
+	const testdata = "" +
+		"\x00\x00\x00\x00" +
+		"\xad\x0b\x00" +
+		"\x04" +
+		"\xfe\xfe\x00\x00" +
+		"\xfe\xca\x00\x00"
+
+	testdataChecksum := func() pkg.Checksum {
+		h := sha512.New384()
+		h.Write([]byte(testdata))
+		return (pkg.Checksum)(h.Sum(nil))
+	}()
+
+	testdataChecksumString := base64.URLEncoding.EncodeToString(testdataChecksum[:])
+
+	testCases := []struct {
+		name  string
+		early func(t *testing.T, base *check.Absolute)
+		f     func(t *testing.T, base *check.Absolute, c *pkg.Cache)
+		check func(t *testing.T, base *check.Absolute)
+	}{
+		{"file", nil, func(t *testing.T, base *check.Absolute, c *pkg.Cache) {
+			wantErrNonexistent := &os.PathError{
+				Op: "open",
+				Path: base.Append(
+					"identifier",
+					testdataChecksumString,
+				).String(),
+				Err: syscall.ENOENT,
+			}
+			if _, _, err := c.LoadFile(testdataChecksum); !reflect.DeepEqual(err, wantErrNonexistent) {
+				t.Fatalf("LoadFile: error = %#v, want %#v", err, wantErrNonexistent)
+			}
+
+			identifier := (pkg.ID)(bytes.Repeat([]byte{
+				0x75, 0xe6, 0x9d, 0x6d, 0xe7, 0x9f,
+			}, 8))
+			wantPathname := base.Append(
+				"identifier",
+				"deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef",
+			)
+			identifier0 := (pkg.ID)(bytes.Repeat([]byte{
+				0x71, 0xa7, 0xde, 0x6d, 0xa6, 0xde,
+			}, 8))
+			wantPathname0 := base.Append(
+				"identifier",
+				"cafebabecafebabecafebabecafebabecafebabecafebabecafebabecafebabe",
+			)
+
+			// initial store
+			if pathname, err := c.StoreFile(
+				identifier,
+				[]byte(testdata),
+				&testdataChecksum,
+				true,
+			); err != nil {
+				t.Fatalf("StoreFile: error = %v", err)
+			} else if !pathname.Is(wantPathname) {
+				t.Fatalf("StoreFile: pathname = %q, want %q", pathname, wantPathname)
+			}
+
+			// load or store, identical content
+			if pathname, data, store, err := c.LoadOrStoreFile(identifier0, func() ([]byte, error) {
+				return []byte(testdata), nil
+			}, &testdataChecksum, true); err != nil {
+				t.Fatalf("LoadOrStoreFile: error = %v", err)
+			} else if !pathname.Is(wantPathname0) {
+				t.Fatalf("LoadOrStoreFile: pathname = %q, want %q", pathname, wantPathname0)
+			} else if string(data) != testdata {
+				t.Fatalf("LoadOrStoreFile: data = %x, want %x", data, testdata)
+			} else if !store {
+				t.Fatal("LoadOrStoreFile did not store nonpresent entry")
+			}
+
+			// load or store, existing entry
+			if pathname, data, store, err := c.LoadOrStoreFile(identifier, func() ([]byte, error) {
+				return []byte(testdata), nil
+			}, &testdataChecksum, true); err != nil {
+				t.Fatalf("LoadOrStoreFile: error = %v", err)
+			} else if !pathname.Is(wantPathname) {
+				t.Fatalf("LoadOrStoreFile: pathname = %q, want %q", pathname, wantPathname)
+			} else if string(data) != testdata {
+				t.Fatalf("LoadOrStoreFile: data = %x, want %x", data, testdata)
+			} else if store {
+				t.Fatal("LoadOrStoreFile stored over present entry")
+			}
+
+			// load, existing entry
+			if pathname, data, err := c.LoadFile(identifier0); err != nil {
+				t.Fatalf("LoadFile: error = %v", err)
+			} else if !pathname.Is(wantPathname0) {
+				t.Fatalf("LoadFile: pathname = %q, want %q", pathname, wantPathname0)
+			} else if string(data) != testdata {
+				t.Fatalf("LoadFile: data = %x, want %x", data, testdata)
+			}
+
+			// checksum mismatch
+			wantErrChecksum := &pkg.ChecksumMismatchError{
+				Got: testdataChecksum,
+			}
+			if _, err := c.StoreFile(
+				testdataChecksum,
+				[]byte(testdata),
+				new(pkg.Checksum),
+				true,
+			); !reflect.DeepEqual(err, wantErrChecksum) {
+				t.Fatalf("StoreFile: error = %#v, want %#v", err, wantErrChecksum)
+			}
+
+			// verify failed store
+			if _, _, err := c.LoadFile(testdataChecksum); !reflect.DeepEqual(err, wantErrNonexistent) {
+				t.Fatalf("LoadFile: error = %#v, want %#v", err, wantErrNonexistent)
+			}
+
+			// store, same identifier
+			wantPathnameF := base.Append(
+				"identifier",
+				testdataChecksumString,
+			)
+			if pathname, err := c.StoreFile(
+				testdataChecksum,
+				[]byte(testdata),
+				&testdataChecksum,
+				true,
+			); err != nil {
+				t.Fatalf("StoreFile: error = %v", err)
+			} else if !pathname.Is(wantPathnameF) {
+				t.Fatalf("StoreFile: pathname = %q, want %q", pathname, wantPathnameF)
+			}
+
+			// load, same identifier
+			if pathname, data, err := c.LoadFile(testdataChecksum); err != nil {
+				t.Fatalf("LoadFile: error = %v", err)
+			} else if !pathname.Is(wantPathnameF) {
+				t.Fatalf("LoadFile: pathname = %q, want %q", pathname, wantPathnameF)
+			} else if string(data) != testdata {
+				t.Fatalf("LoadFile: data = %x, want %x", data, testdata)
+			}
+
+			// store without validation
+			wantChecksum := pkg.Checksum{
+				0xbe, 0xc0, 0x21, 0xb4, 0xf3, 0x68,
+				0xe3, 0x06, 0x91, 0x34, 0xe0, 0x12,
+				0xc2, 0xb4, 0x30, 0x70, 0x83, 0xd3,
+				0xa9, 0xbd, 0xd2, 0x06, 0xe2, 0x4e,
+				0x5f, 0x0d, 0x86, 0xe1, 0x3d, 0x66,
+				0x36, 0x65, 0x59, 0x33, 0xec, 0x2b,
+				0x41, 0x34, 0x65, 0x96, 0x68, 0x17,
+				0xa9, 0xc2, 0x08, 0xa1, 0x17, 0x17,
+			}
+			var gotChecksum pkg.Checksum
+			wantPathnameG := base.Append(
+				"identifier",
+				base64.URLEncoding.EncodeToString(wantChecksum[:]),
+			)
+			if pathname, err := c.StoreFile(
+				wantChecksum,
+				[]byte{0},
+				&gotChecksum,
+				false,
+			); err != nil {
+				t.Fatalf("StoreFile: error = %#v", err)
+			} else if !pathname.Is(wantPathnameG) {
+				t.Fatalf("StoreFile: pathname = %q, want %q", pathname, wantPathnameG)
+			} else if gotChecksum != wantChecksum {
+				t.Fatalf("StoreFile: buf = %x, want %x", gotChecksum, wantChecksum)
+			}
+
+			// makeData passthrough
+			var zeroIdent pkg.ID
+			wantErrPassthrough := stub.UniqueError(0xcafe)
+			if _, _, _, err := c.LoadOrStoreFile(zeroIdent, func() ([]byte, error) {
+				return nil, wantErrPassthrough
+			}, new(pkg.Checksum), true); !reflect.DeepEqual(err, wantErrPassthrough) {
+				t.Fatalf("LoadOrStoreFile: error = %#v, want %#v", err, wantErrPassthrough)
+			}
+
+			// verify failed store
+			wantErrNonexistentZero := &os.PathError{
+				Op: "open",
+				Path: base.Append(
+					"identifier",
+					"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
+				).String(),
+				Err: syscall.ENOENT,
+			}
+			if _, _, err := c.LoadFile(zeroIdent); !reflect.DeepEqual(err, wantErrNonexistentZero) {
+				t.Fatalf("LoadFile: error = %#v, want %#v", err, wantErrNonexistentZero)
+			}
+		}, func(t *testing.T, base *check.Absolute) {
+			wantChecksum := pkg.MustDecode(
+				"lvK4lY9bQUFscHpxqHmiPvptjUwOgn3BFhzCXZMeupkY1n22WUPSuh7pswEvVZrx",
+			)
+			if checksum, err := pkg.HashDir(base); err != nil {
+				t.Fatalf("HashDir: error = %v", err)
+			} else if checksum != wantChecksum {
+				t.Fatalf("HashDir: %v", &pkg.ChecksumMismatchError{
+					Got:  checksum,
+					Want: wantChecksum,
+				})
+			}
+		}},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			base := check.MustAbs(t.TempDir())
+			if err := os.Chmod(base.String(), 0700); err != nil {
+				t.Fatal(err)
+			}
+			t.Cleanup(func() {
+				if err := filepath.WalkDir(base.String(), func(path string, d fs.DirEntry, err error) error {
+					if err != nil {
+						t.Error(err)
+						return nil
+					}
+					if !d.IsDir() {
+						return nil
+					}
+					return os.Chmod(path, 0700)
+				}); err != nil {
+					t.Fatal(err)
+				}
+			})
+
+			if c, err := pkg.New(base); err != nil {
+				t.Fatalf("New: error = %v", err)
+			} else {
+				if tc.early != nil {
+					tc.early(t, base)
+				}
+				tc.f(t, base, c)
+				tc.check(t, base)
+			}
+		})
+	}
+}
+
+func TestErrors(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name string
+		err  error
+		want string
+	}{
+		{"ChecksumMismatchError", &pkg.ChecksumMismatchError{
+			Want: (pkg.Checksum)(bytes.Repeat([]byte{
+				0x75, 0xe6, 0x9d, 0x6d, 0xe7, 0x9f,
+			}, 8)),
+		}, "got AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" +
+			" instead of deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef"},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			if got := tc.err.Error(); got != tc.want {
+				t.Errorf("Error: %q, want %q", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestNew(t *testing.T) {
+	t.Parallel()
+
+	t.Run("nonexistent", func(t *testing.T) {
+		t.Parallel()
+
+		wantErr := &os.PathError{
+			Op:   "mkdir",
+			Path: container.Nonexistent,
+			Err:  syscall.ENOENT,
+		}
+		if _, err := pkg.New(check.MustAbs(container.Nonexistent)); !reflect.DeepEqual(err, wantErr) {
+			t.Errorf("New: error = %#v, want %#v", err, wantErr)
+		}
+	})
+
+	t.Run("permission", func(t *testing.T) {
+		t.Parallel()
+
+		tempDir := check.MustAbs(t.TempDir())
+		if err := os.Chmod(tempDir.String(), 0); err != nil {
+			t.Fatal(err)
+		} else {
+			t.Cleanup(func() {
+				if err = os.Chmod(tempDir.String(), 0700); err != nil {
+					t.Fatal(err)
+				}
+			})
+		}
+
+		wantErr := &os.PathError{
+			Op:   "mkdir",
+			Path: tempDir.Append("cache").String(),
+			Err:  syscall.EACCES,
+		}
+		if _, err := pkg.New(tempDir.Append("cache")); !reflect.DeepEqual(err, wantErr) {
+			t.Errorf("New: error = %#v, want %#v", err, wantErr)
+		}
+	})
+}