One image request type instead of five (closes #307)

The new package internal/imagerequest holds the request type, its two
parts Source and Transform, the Format and Fit types, the dimension and
fit checks, the /v1/image/ path parsing and the variant key; it imports
no other package of pixa. imgcache.ParsedURL, imgcache.ImageRequest,
signature.Request, imageprocessor.Request, the second Size, format and
fit types and the conversions between them are gone. The image
processor takes a Transform only. encurl keeps a private struct with the
token's short CBOR field names. VariantKey moves with the function that
makes it. Tests follow the moved and renamed code; the tests of the
removed conversions go with them.

Model: opus-5-5

internal/imgcache/negative_cache_internal_test.go

@@ -6,6 +6,8 @@ import (
 	"strconv"
 	"testing"
 	"time"
+
+	"sneak.berlin/go/pixa/internal/imagerequest"
 )
 
 func TestNegativeCache_StoreAndCheck(t *testing.T) {
@@ -23,9 +25,11 @@ func TestNegativeCache_StoreAndCheck(t *testing.T) {
 	}
 
 	ctx := context.Background()
-	req := &ImageRequest{
-		SourceHost: testHostExample,
-		SourcePath: "/missing.jpg",
+	req := &imagerequest.Request{
+		Source: imagerequest.Source{
+			Host: testHostExample,
+			Path: "/missing.jpg",
+		},
 	}
 
 	// Initially should not be in negative cache
@@ -70,9 +74,11 @@ func TestNegativeCache_Expired(t *testing.T) {
 	}
 
 	ctx := context.Background()
-	req := &ImageRequest{
-		SourceHost: testHostExample,
-		SourcePath: "/expired.jpg",
+	req := &imagerequest.Request{
+		Source: imagerequest.Source{
+			Host: testHostExample,
+			Path: "/expired.jpg",
+		},
 	}
 
 	// Store a negative entry with very short TTL
@@ -106,20 +112,21 @@ func TestService_Get_ServesCachedVariantOfNegativeCachedURL(t *testing.T) {
 
 	svc, fixtures := SetupTestService(t)
 
-	resp, err := svc.Get(t.Context(), photoVariant(fixtures, 85, FitCover))
+	resp, err := svc.Get(t.Context(), photoVariant(fixtures, 85, imagerequest.FitCover))
 	if err != nil {
 		t.Fatalf("Get() first request error = %v", err)
 	}
 
 	_ = resp.Content.Close()
 
-	err = svc.cache.StoreNegative(t.Context(), photoVariant(fixtures, 85, FitCover),
+	err = svc.cache.StoreNegative(t.Context(),
+		photoVariant(fixtures, 85, imagerequest.FitCover),
 		httpStatusBadGateway, "upstream answered 503")
 	if err != nil {
 		t.Fatalf("StoreNegative() error = %v", err)
 	}
 
-	resp, err = svc.Get(t.Context(), photoVariant(fixtures, 85, FitCover))
+	resp, err = svc.Get(t.Context(), photoVariant(fixtures, 85, imagerequest.FitCover))
 	if err != nil {
 		t.Fatalf("Get() of the cached variant error = %v", err)
 	}
@@ -131,7 +138,7 @@ func TestService_Get_ServesCachedVariantOfNegativeCachedURL(t *testing.T) {
 			resp.CacheStatus, CacheHit)
 	}
 
-	resp, err = svc.Get(t.Context(), photoVariant(fixtures, 40, FitCover))
+	resp, err = svc.Get(t.Context(), photoVariant(fixtures, 40, imagerequest.FitCover))
 	t.Logf("Get() of a variant made from the cached source: error = %v", err)
 
 	if err != nil {
@@ -141,7 +148,7 @@ func TestService_Get_ServesCachedVariantOfNegativeCachedURL(t *testing.T) {
 	_ = resp.Content.Close()
 
 	contentHash, _, err := svc.cache.LookupSource(t.Context(),
-		photoVariant(fixtures, 85, FitCover))
+		photoVariant(fixtures, 85, imagerequest.FitCover))
 	if err != nil || contentHash == "" {
 		t.Fatalf("LookupSource() = %q, %v, want the cached source", contentHash, err)
 	}
@@ -151,7 +158,7 @@ func TestService_Get_ServesCachedVariantOfNegativeCachedURL(t *testing.T) {
 		t.Fatalf("evictSourceBlob() error = %v", err)
 	}
 
-	_, err = svc.Get(t.Context(), photoVariant(fixtures, 60, FitCover))
+	_, err = svc.Get(t.Context(), photoVariant(fixtures, 60, imagerequest.FitCover))
 	t.Logf("Get() of a variant whose source was evicted: error = %v", err)
 
 	if !errors.Is(err, ErrNegativeCached) {
@@ -190,8 +197,8 @@ func TestEvictionLoopRemovesExpiredNegativeCacheRows(t *testing.T) {
 				t.Fatalf("failed to create cache: %v", err)
 			}
 
-			expired := &ImageRequest{
-				SourceHost: testHostExample, SourcePath: "/gone.jpg",
+			expired := &imagerequest.Request{
+				Source: imagerequest.Source{Host: testHostExample, Path: "/gone.jpg"},
 			}
 
 			err = cache.StoreNegative(t.Context(), expired, 404, "not found")
@@ -215,7 +222,7 @@ func TestEvictionLoopRemovesExpiredNegativeCacheRows(t *testing.T) {
 			cache.StartEviction(100 * time.Millisecond)
 			defer func() { _ = cache.StopEviction(t.Context()) }()
 
-			for negativeCacheRowCount(t, cache, expired.SourcePath) > 0 {
+			for negativeCacheRowCount(t, cache, expired.Source.Path) > 0 {
 				if time.Since(started) > 10*time.Second {
 					t.Fatal("the expired row is still in negative_cache")
 				}