Keep this issue's TODO.md entry at the top of Completed Steps

The rebase onto next put the newer entry above it.

Model: opus-5-5

README.md

@@ -316,32 +316,12 @@ once, is refused with 400.
   both optional (values under Signature Specification). Both are part of what is
   cached, so each value of either is a separate cached image.
 
-A source URL's query follows its path after `%3F`, the encoded `?`:
-`/v1/image/<host>/<path>%3F<query>/<size>.<format>`. pixa decodes the
-percent-escapes in the image URL's path once, then reads the host up to the
-first `/`, the size and format after the last `/`, and between them the source
-path up to the first `?` and the source query after it. So the `?` before the
-query, any `?` in the query, and every `%` in the source path or query must be
-percent-encoded, as `%3F` and `%25`. Any other character may be written as
-itself or percent-encoded: `/`, `;`, `,`, `=` and `&` work either way. For
-example,
-`https://cdn.example.com/img?url=https://origin.example.com/my%20cat.jpg` at
-800x600 WebP is
-`/v1/image/cdn.example.com/img%3Furl=https://origin.example.com/my%2520cat.jpg/800x600.webp`,
-signed as shown under Signature Specification.
-
 A size with one side `0` has that side scaled to keep the source's proportions,
 and is refused with 400 when that side would come out above 8192, the most
 either side may be; so is a size with `fit=outside`, which scales the image to
 cover the size and so past it on one side, when that side would come out
 above 8192.
 
-An AVIF image of more than 16,777,216 pixels, the number 4096x4096 and 8192x2048
-have, is refused with 400 before anything is decoded, as its encode could take
-more than 40 seconds (see below). That includes `orig` of an AVIF source, and
-`auto` when it chooses AVIF, so a client whose `Accept` names `image/avif` but
-not `image/jxl` is refused such a size.
-
 The source image may be JPEG, PNG, GIF, WebP, AVIF or JPEG XL. The upstream's
 `Content-Type` must name its format, and the image's first bytes must match it.
 An upstream answering with any other `Content-Type`, SVG included, is refused
@@ -391,18 +371,14 @@ transcode that stops this way is answered 503 with the error
 ended. govips gives pixa no way to stop libvips once an encode has begun, so an
 encode keeps its slot until it finishes, which can be after
 `downstream_timeout`. The limit of 8192 on each side of the source and of the
-output, and for AVIF the limit of 16,777,216 pixels, bound how long that takes.
-With one libvips thread, as pixad runs it, encoding 8192x8192 random pixels
-takes up to about 1 second as JPEG, 15 as PNG and 16 as GIF, the slowest of 8 or
-16 bits per sample, with or without an alpha channel. The WebP and JPEG XL
-encoders run below libvips' default effort, and AVIF at the lowest effort govips
-can set, so that no encode takes more than 40 seconds of the default
-`downstream_timeout` of 60: at any quality and 8 or 16 bits per sample,
-8192x8192 random pixels with an alpha channel take up to about 23 seconds as
-WebP and 27 as JPEG XL, and 4096x4096, 8192x2048 or 2048x8192 up to about 34 as
-AVIF, which at quality 85 would take about 96 at 8192x8192. Without an alpha
-channel they take up to about 16, 13 and 22 seconds. Decoding such a source adds
-up to about 11 seconds.
+output bounds how long that takes. With one libvips thread, as pixad runs it,
+encoding 8192x8192 random pixels takes up to about 1 second as JPEG, 15 as PNG,
+16 as GIF, 63 as WebP, 110 as AVIF and 96 as JPEG XL, the slowest of 8 or 16
+bits per sample, with or without an alpha channel. WebP, AVIF and JPEG XL are
+that slow only with an alpha channel: 8-bit RGB takes about 44, 53 and 28
+seconds. Decoding such a source adds up to about 11 seconds. A WebP, AVIF or
+JPEG XL encode can therefore hold its slot past the default `downstream_timeout`
+of 60 seconds.
 
 The login form (`POST /`) is limited to 5 attempts per minute per client
 address, counting an IPv6 client by its /64; an attempt over the limit is
@@ -454,8 +430,7 @@ nor change what it asks for.
    sent with an empty format, or none, also makes a JPEG XL URL. Width and
    height both empty or `0` keep the original size; if only one of them is empty
    or `0`, that side is scaled to keep the image's proportions. A URL whose
-   scaled side would come out above 8192 answers 400, and so does an AVIF URL of
-   more than 16,777,216 pixels (see Routes).
+   scaled side would come out above 8192 answers 400.
 3. The page shows the URL, `https://<host>/v1/e/<token>/img.<format>`, and when
    it expires. `<host>` is the host the page was opened on, and the URL starts
    with `http` instead while `debug` is on. The name after the token is ignored
@@ -560,17 +535,6 @@ For the same image at quality 40 with fit `contain`, the input ends in
 and the URL is
 `/v1/image/cdn.example.com/photos/cat.jpg/800x600.webp?sig=5IwXUx6vf7yefhaUvFzgXZvG2o0Df4RJxPTK3pKq5VU=&exp=1704067200&q=40&fit=contain`.
 
-For a source URL with a query,
-`https://cdn.example.com/img?url=https://origin.example.com/my%20cat.jpg`, at
-800x600 WebP with the same key and expiration and the default quality and fit:
-
-1. Build input, with the query's `:` written as `%3A` and its `%` as `%25`:
-   `cdn.example.com:/img:url=https%3A//origin.example.com/my%2520cat.jpg:800:600:webp:1704067200:85:cover`
-2. The signature is `37aFa9GSVCZM1kRY9SzMOk2fOg_M7Wt5gKNR4xM-FYA=`
-3. URL, with the `?` before the query written as `%3F` and the query's `%` as
-   `%25` (see Routes):
-   `/v1/image/cdn.example.com/img%3Furl=https://origin.example.com/my%2520cat.jpg/800x600.webp?sig=37aFa9GSVCZM1kRY9SzMOk2fOg_M7Wt5gKNR4xM-FYA=&exp=1704067200`
-
 **Allowlist patterns:**
 
 - **Exact match**: `cdn.example.com` — matches only that host

TODO.md

@@ -30,32 +30,6 @@ P2: security: per-origin rate limiting
 
 # Completed Steps
 
-- 2026-10-15 a WebP, AVIF or JPEG XL encode at the limits takes at most about 34
-  seconds (closes #272): with one libvips thread, 8192x8192 random pixels with
-  an alpha channel took about 61 seconds to encode as WebP, 96 as AVIF and 81 as
-  JPEG XL, so with the default `downstream_timeout` of 60 seconds such an image
-  was never delivered, yet its encode held a processing slot to the end. WebP is
-  now saved at effort 2 and JPEG XL at effort 4, which take up to about 23 and
-  27 seconds. AVIF was already at the lowest effort govips can set, so an AVIF
-  output of more than 16,777,216 pixels is refused with 400 before anything is
-  decoded; 4096x4096, 8192x2048 or 2048x8192 takes up to about 34 seconds. Each
-  time is the slowest at any quality. Resizing with `fit=cover` already decodes
-  the input, so the output's dimensions are worked out before resizing.
-  `README.md` gives the limit and the new times.
-- 2026-10-15 the README says how a source URL with a query is written into an
-  image URL, and the image route accepts it (closes #255): the query follows the
-  source path after `%3F`. pixa now reads the image URL's path decoded once, so
-  the `?` before the query, any `?` in it and every `%` in the source path or
-  query must be percent-encoded, and any other character may be. The route used
-  to parse chi's wildcard, which holds the path as the client wrote it whenever
-  that is not Go's own encoding of it; a `/`, `;` or `,` in the query written as
-  `%2F`, `%3B` or `%2C`, as `GenerateSignedURL` wrote them, kept the `%3F` from
-  being read as `?`, and the request failed with 401. `GenerateSignedURL` now
-  writes Go's own encoding of the path. The README has an example with a query
-  and its signature. The path traversal check no longer reads the source query,
-  and keeps a `%` that does not start a percent-escape as it is instead of
-  refusing the URL, so a source path or query holding `%25` is accepted, while a
-  double-encoded `..` next to such a `%` is still refused.
 - 2026-10-15 `max_concurrent_processing` defaults to half the CPUs pixa sees,
   rounded down, and at least 1 (closes #242): it defaulted to one image per CPU,
   and a container with no CPU limit sees every CPU of the host, so on a 48-CPU

internal/handlers/avif_too_large_internal_test.go

@@ -1,49 +0,0 @@
-package handlers
-
-import (
-	"fmt"
-	"log/slog"
-	"net/http"
-	"net/http/httptest"
-	"strings"
-	"testing"
-
-	"sneak.berlin/go/pixa/internal/imageprocessor"
-	"sneak.berlin/go/pixa/internal/imgcache"
-)
-
-// TestAVIFOutputTooLargeAnswers400 checks that respondImageError and
-// handleImageError, which answer the errors of the two image routes, answer
-// 400 naming the AVIF pixel limit when the image processor refuses an AVIF
-// output above it, wrapped as the service wraps it. The request's source only
-// goes into a log line, so it is left empty.
-func TestAVIFOutputTooLargeAnswers400(t *testing.T) {
-	t.Parallel()
-
-	h := &Handlers{log: slog.New(slog.DiscardHandler)}
-	err := fmt.Errorf("image processing failed: %w: 4097x4096",
-		imageprocessor.ErrAVIFOutputTooLarge)
-	wantBody := fmt.Sprintf("above %d pixels", imageprocessor.MaxAVIFOutputPixels)
-
-	plain := httptest.NewRecorder()
-	h.respondImageError(plain, &imgcache.ImageRequest{}, err)
-
-	encrypted := httptest.NewRecorder()
-	h.handleImageError(encrypted, err)
-
-	for name, rec := range map[string]*httptest.ResponseRecorder{
-		"respondImageError": plain, "handleImageError": encrypted,
-	} {
-		t.Logf("%s: status = %d, body = %q", name, rec.Code, rec.Body.String())
-
-		if rec.Code != http.StatusBadRequest {
-			t.Errorf("%s: status = %d, want %d",
-				name, rec.Code, http.StatusBadRequest)
-		}
-
-		if !strings.Contains(rec.Body.String(), wantBody) {
-			t.Errorf("%s: body = %q, want it to say %q",
-				name, rec.Body.String(), wantBody)
-		}
-	}
-}

internal/handlers/image.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
 	"sneak.berlin/go/pixa/internal/encurl"
 	"sneak.berlin/go/pixa/internal/httpfetcher"
@@ -79,21 +80,20 @@ func (s *Handlers) HandleRobotsTxt() http.HandlerFunc {
 	}
 }
 
-// parseImageRequest parses the image URL's path and query parameters into
+// parseImageRequest parses the wildcard path and query parameters into
 // an ImageRequest. On invalid input it writes an error response and
 // returns false.
 func (s *Handlers) parseImageRequest(
 	w http.ResponseWriter, r *http.Request,
 ) (*imgcache.ImageRequest, bool) {
-	// The path is parsed decoded once, as r.URL.Path holds it, and not from
-	// chi's wildcard: chi routes on the path as the client wrote it whenever
-	// that is not Go's own encoding of it, so its wildcard would still hold
-	// the %3F before a source query when, say, a "/" in the query is written
-	// as %2F
-	parsed, err := imgcache.ParseImageURL(r.URL.Path)
+	// Get the wildcard path from chi
+	pathParam := chi.URLParam(r, "*")
+
+	// Parse the URL path
+	parsed, err := imgcache.ParseImagePath(pathParam)
 	if err != nil {
 		s.log.Warn("failed to parse image URL",
-			"path", r.URL.Path,
+			"path", pathParam,
 			"error", err,
 		)
 		s.respondError(w, "invalid image URL: "+err.Error(), http.StatusBadRequest)
@@ -264,14 +264,6 @@ func (s *Handlers) respondImageError(
 		return
 	}
 
-	if errors.Is(err, imageprocessor.ErrAVIFOutputTooLarge) {
-		s.respondError(w, fmt.Sprintf("size too large for AVIF: the output "+
-			"would be above %d pixels", imageprocessor.MaxAVIFOutputPixels),
-			http.StatusBadRequest)
-
-		return
-	}
-
 	s.respondError(w, "internal error", http.StatusInternalServerError)
 }
 

internal/handlers/image_signature_internal_test.go

@@ -169,166 +169,3 @@ func TestHandleImage_InvalidExp_Returns400(t *testing.T) {
 		})
 	}
 }
-
-// TestHandleImage_GeneratedSignedURLWithSourceQueryVerifies sends URLs built
-// by the service's signed-URL generator for source URLs with a query to the
-// route, through a chi router: chi routes on the path as the client wrote it
-// whenever that is not Go's own encoding of it. A 502 means the signature
-// passed, so the route read the source path and query that were signed.
-func TestHandleImage_GeneratedSignedURLWithSourceQueryVerifies(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name  string
-		query string
-	}{
-		{"slash and colon", "url=https://origin.example.com/cat.jpg"},
-		{"semicolon", "a=1;b=2"},
-		{"comma", "crop=0,0,50,50"},
-		{"equals and ampersand", "a=1&b=2"},
-		{"percent-escape", "name=my%20cat"},
-		{"question mark", "next=/a?b=1"},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			fix := setupTestHandler(t)
-
-			signedURL, err := fix.service.GenerateSignedURL("", &imgcache.ImageRequest{
-				SourceHost:  signedHost,
-				SourcePath:  photoPath,
-				SourceQuery: tt.query,
-				Size:        imgcache.Size{Width: 50, Height: 50},
-				Format:      imgcache.FormatJPEG,
-			}, time.Hour)
-			if err != nil {
-				t.Fatalf("GenerateSignedURL() error = %v", err)
-			}
-
-			status := getImage(t, fix, signedURL)
-			if status != http.StatusBadGateway {
-				t.Errorf("status = %d, want %d", status, http.StatusBadGateway)
-			}
-		})
-	}
-}
-
-// TestHandleImage_SourceQueryEncodedAnyWay signs one source URL with a query
-// and writes it into the image URL in ways the README allows: the "?" before
-// the query and each "%" in it percent-encoded, and every other character as
-// itself or percent-encoded. A 502 means the signature passed.
-func TestHandleImage_SourceQueryEncodedAnyWay(t *testing.T) {
-	t.Parallel()
-
-	expires := time.Now().Add(time.Hour)
-	signer := signature.New("test-signing-key-must-be-32-chars")
-	sig := signer.Sign(&signature.Request{
-		SourceHost:  signedHost,
-		SourcePath:  photoPath,
-		SourceQuery: "url=https://origin.example.com/my%20cat.jpg",
-		Width:       50,
-		Height:      50,
-		Format:      string(imgcache.FormatJPEG),
-		Quality:     85,
-		FitMode:     string(imgcache.FitCover),
-		Expires:     expires,
-	})
-
-	tests := []struct {
-		name         string
-		writtenQuery string
-	}{
-		{"only ? and % encoded",
-			"%3Furl=https://origin.example.com/my%2520cat.jpg"},
-		{"every reserved character encoded",
-			"%3Furl%3Dhttps%3A%2F%2Forigin.example.com%2Fmy%2520cat.jpg"},
-		{"lower-case hex digits",
-			"%3furl=https://origin.example.com/my%2520cat.jpg"},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			target := fmt.Sprintf("/v1/image/%s%s%s/50x50.jpeg?sig=%s&exp=%d",
-				signedHost, photoPath, tt.writtenQuery, sig, expires.Unix())
-
-			status := getImage(t, setupTestHandler(t), target)
-			if status != http.StatusBadGateway {
-				t.Errorf("status = %d, want %d", status, http.StatusBadGateway)
-			}
-		})
-	}
-}
-
-// TestHandleImage_SourceURLHoldingPercent25Verifies signs a source path and a
-// source query that each hold %25, the percent-escape of a literal "%", and
-// sends each to the route written as the README says, with that "%" written as
-// %25, and as GenerateSignedURL writes it. A 502 means the signature passed.
-func TestHandleImage_SourceURLHoldingPercent25Verifies(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name        string
-		sourcePath  string
-		sourceQuery string
-		// writtenPathAndQuery is the source path and query as the README says
-		// to write them into the image URL
-		writtenPathAndQuery string
-	}{
-		{"path", "/sale/50%25off.jpg", "", "/sale/50%2525off.jpg"},
-		{"query", photoPath, "discount=50%25", photoPath + "%3Fdiscount=50%2525"},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name+" written by the README rule", func(t *testing.T) {
-			t.Parallel()
-
-			expires := time.Now().Add(time.Hour)
-			signer := signature.New("test-signing-key-must-be-32-chars")
-			sig := signer.Sign(&signature.Request{
-				SourceHost:  signedHost,
-				SourcePath:  tt.sourcePath,
-				SourceQuery: tt.sourceQuery,
-				Width:       50,
-				Height:      50,
-				Format:      string(imgcache.FormatJPEG),
-				Quality:     85,
-				FitMode:     string(imgcache.FitCover),
-				Expires:     expires,
-			})
-
-			target := fmt.Sprintf("/v1/image/%s%s/50x50.jpeg?sig=%s&exp=%d",
-				signedHost, tt.writtenPathAndQuery, sig, expires.Unix())
-
-			status := getImage(t, setupTestHandler(t), target)
-			if status != http.StatusBadGateway {
-				t.Errorf("status = %d, want %d", status, http.StatusBadGateway)
-			}
-		})
-
-		t.Run(tt.name+" written by GenerateSignedURL", func(t *testing.T) {
-			t.Parallel()
-
-			fix := setupTestHandler(t)
-
-			signedURL, err := fix.service.GenerateSignedURL("", &imgcache.ImageRequest{
-				SourceHost:  signedHost,
-				SourcePath:  tt.sourcePath,
-				SourceQuery: tt.sourceQuery,
-				Size:        imgcache.Size{Width: 50, Height: 50},
-				Format:      imgcache.FormatJPEG,
-			}, time.Hour)
-			if err != nil {
-				t.Fatalf("GenerateSignedURL() error = %v", err)
-			}
-
-			status := getImage(t, fix, signedURL)
-			if status != http.StatusBadGateway {
-				t.Errorf("status = %d, want %d", status, http.StatusBadGateway)
-			}
-		})
-	}
-}

internal/handlers/imageenc.go

@@ -170,10 +170,6 @@ func (s *Handlers) handleImageError(w http.ResponseWriter, err error) {
 		s.respondError(w, fmt.Sprintf("size too large for the source: the side "+
 			"computed from its proportions is above %d",
 			imageprocessor.MaxOutputDimension), http.StatusBadRequest)
-	case errors.Is(err, imageprocessor.ErrAVIFOutputTooLarge):
-		s.respondError(w, fmt.Sprintf("size too large for AVIF: the output "+
-			"would be above %d pixels", imageprocessor.MaxAVIFOutputPixels),
-			http.StatusBadRequest)
 	default:
 		s.log.Error("image request failed", "error", err)
 		s.respondError(w, "internal error", http.StatusInternalServerError)

internal/imageprocessor/avif_too_large_internal_test.go

@@ -1,64 +0,0 @@
-package imageprocessor
-
-import (
-	"bytes"
-	"errors"
-	"testing"
-)
-
-// TestImageProcessor_RefusesAVIFAboveMaxPixels verifies that an AVIF output
-// of more than MaxAVIFOutputPixels is refused with ErrAVIFOutputTooLarge
-// before anything is decoded, whatever size and fit give it, and that an AVIF
-// output of at most that many pixels, or one in another format, is not. The
-// input is a 64x32 PNG cut off in its pixel data: libvips reads its size from
-// its header but fails when it decodes it, so a request that gets that failure
-// was not refused, and a refusal came before any decoding.
-func TestImageProcessor_RefusesAVIFAboveMaxPixels(t *testing.T) {
-	t.Parallel()
-
-	whole := createTestPNG(t, 64, 32)
-	cutOff := whole[:len(whole)/2]
-
-	tests := []struct {
-		name          string
-		format        Format
-		width, height int
-		fit           FitMode
-		refused       bool
-	}{
-		{"AVIF at the limit", FormatAVIF, 4096, 4096, FitCover, false},
-		{"AVIF above the limit", FormatAVIF, 4096, 4097, FitCover, true},
-		{"WebP above the AVIF limit", FormatWebP, 4096, 4097, FitCover, false},
-		// FitInside does not enlarge, so the output stays 64x32
-		{"AVIF inside a larger size", FormatAVIF, 8192, 8192, FitInside, false},
-		// FitOutside scales 64x32 by 128 to cover 8192x1: 8192x4096
-		{"AVIF outside a smaller size", FormatAVIF, 8192, 1, FitOutside, true},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			_, err := New(Params{}).Process(t.Context(), bytes.NewReader(cutOff),
-				&Request{
-					Size:    Size{Width: tt.width, Height: tt.height},
-					Format:  tt.format,
-					FitMode: tt.fit,
-				})
-			t.Logf("Process() error = %v", err)
-
-			if tt.refused {
-				if !errors.Is(err, ErrAVIFOutputTooLarge) {
-					t.Errorf("Process() error = %v, want %v", err, ErrAVIFOutputTooLarge)
-				}
-
-				return
-			}
-
-			if err == nil || errors.Is(err, ErrAVIFOutputTooLarge) {
-				t.Errorf("Process() error = %v, want the failure to decode "+
-					"the cut-off input", err)
-			}
-		})
-	}
-}

internal/imageprocessor/encoder_settings_internal_test.go

@@ -77,10 +77,10 @@ func TestImageProcessor_PNGIsCompressed(t *testing.T) {
 	}
 }
 
-// TestImageProcessor_WebPAtEffort2 verifies that WebP is saved at effort 2,
-// not libvips' default of 4: the output is the size of the same image saved
-// at effort 2.
-func TestImageProcessor_WebPAtEffort2(t *testing.T) {
+// TestImageProcessor_WebPAtDefaultEffort verifies that WebP is saved at
+// libvips' default effort, 4: the output is the size of the same image saved
+// at that effort.
+func TestImageProcessor_WebPAtDefaultEffort(t *testing.T) {
 	t.Parallel()
 
 	input := createTestJPEG(t, 200, 150)
@@ -90,14 +90,14 @@ func TestImageProcessor_WebPAtEffort2(t *testing.T) {
 	want, _, err := decode(t, input).ExportWebp(&vips.WebpExportParams{
 		StripMetadata:   true,
 		Quality:         85,
-		ReductionEffort: 2,
+		ReductionEffort: 4,
 	})
 	if err != nil {
 		t.Fatalf("ExportWebp() error = %v", err)
 	}
 
 	if size != int64(len(want)) {
-		t.Errorf("WebP output is %d bytes, want %d, the size at effort 2",
+		t.Errorf("WebP output is %d bytes, want %d, the size at effort 4",
 			size, len(want))
 	}
 }
@@ -143,29 +143,3 @@ func TestImageProcessor_AVIFAtEffort1(t *testing.T) {
 			"and 8 bits", size, len(want))
 	}
 }
-
-// TestImageProcessor_JPEGXLAtEffort4 verifies that JPEG XL is saved at
-// effort 4, not libvips' default of 7: the output is the size of the same
-// image saved at effort 4, with the distance exportJXL gives quality 85.
-func TestImageProcessor_JPEGXLAtEffort4(t *testing.T) {
-	t.Parallel()
-
-	input := createTestJPEG(t, 200, 150)
-
-	size := processedSize(t, input, &Request{Format: FormatJXL, Quality: 85})
-
-	params := vips.NewJxlExportParams()
-	params.Quality = 85
-	params.Distance = jxlDistance(85)
-	params.Effort = 4
-
-	want, _, err := decode(t, input).ExportJxl(params)
-	if err != nil {
-		t.Fatalf("ExportJxl() error = %v", err)
-	}
-
-	if size != int64(len(want)) {
-		t.Errorf("JPEG XL output is %d bytes, want %d, the size at effort 4",
-			size, len(want))
-	}
-}

internal/imageprocessor/imageprocessor.go

@@ -142,19 +142,6 @@ const MaxOutputDimension = 8192
 // requested size.
 var ErrOutputTooLarge = errors.New("output image dimensions exceed maximum")
 
-// MaxAVIFOutputPixels is the most pixels an AVIF output may have, so that an
-// encode takes at most 40 seconds of the default downstream_timeout of 60
-// seconds; AVIF is already at the lowest effort govips can set (avifEffort).
-// With one thread, as pixad runs libvips, saving 4096x4096, 8192x2048 or
-// 2048x8192 random pixels with an alpha channel takes up to about 34
-// seconds, the slowest at any quality and at 8 or 16 bits per sample, and
-// 5120x4096 at 8 bits already takes about 36.
-const MaxAVIFOutputPixels = 4096 * 4096
-
-// ErrAVIFOutputTooLarge is returned, before anything is decoded, when an AVIF
-// output would have more than MaxAVIFOutputPixels pixels.
-var ErrAVIFOutputTooLarge = errors.New("AVIF output has too many pixels")
-
 // ErrUnsupportedOutputFormat is returned when the requested output format is
 // not supported.
 var ErrUnsupportedOutputFormat = errors.New("unsupported output format")
@@ -223,8 +210,7 @@ func New(params Params) *ImageProcessor {
 // ErrTooManyImages. When ctx has ended once Process has a slot, or before it
 // encodes, it returns ctx's error and gives the slot back. govips gives pixa
 // no way to stop libvips once an encode has begun, so an encode keeps its
-// slot until it finishes. An AVIF output of more than MaxAVIFOutputPixels is
-// refused with ErrAVIFOutputTooLarge before anything is decoded.
+// slot until it finishes.
 func (p *ImageProcessor) Process(
 	ctx context.Context,
 	input io.Reader,
@@ -237,9 +223,18 @@ func (p *ImageProcessor) Process(
 
 	defer release()
 
-	data, err := p.readInput(input)
+	// Read input with a size limit to prevent unbounded memory consumption.
+	// We read at most maxInputBytes+1 so we can detect if the input exceeds
+	// the limit without consuming additional memory.
+	limited := io.LimitReader(input, p.maxInputBytes+1)
+
+	data, err := io.ReadAll(limited)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to read input: %w", err)
+	}
+
+	if int64(len(data)) > p.maxInputBytes {
+		return nil, ErrInputDataTooLarge
 	}
 
 	// govips picks the libvips loader from the input's first bytes with
@@ -282,28 +277,20 @@ func (p *ImageProcessor) Process(
 		return nil, err
 	}
 
+	// Resize if needed
+	if targetWidth != origWidth || targetHeight != origHeight {
+		err := p.resize(img, targetWidth, targetHeight, req.FitMode)
+		if err != nil {
+			return nil, fmt.Errorf("failed to resize: %w", err)
+		}
+	}
+
 	// orig is the source's own format; encode refuses an empty format
 	outputFormat := req.Format
 	if outputFormat == FormatOriginal {
 		outputFormat = sourceFormat
 	}
 
-	// Determine output dimensions; too large ones are refused before
-	// resizing, which with FitCover already decodes the input
-	outputWidth, outputHeight, err := outputDimensions(origWidth, origHeight,
-		targetWidth, targetHeight, req.FitMode, outputFormat)
-	if err != nil {
-		return nil, err
-	}
-
-	// Resize if needed
-	if targetWidth != origWidth || targetHeight != origHeight {
-		err := p.resize(img, outputWidth, outputHeight, req.FitMode)
-		if err != nil {
-			return nil, fmt.Errorf("failed to resize: %w", err)
-		}
-	}
-
 	// Encode to target format
 	output, err := p.encode(ctx, img, outputFormat, req.Quality)
 	if err != nil {
@@ -456,23 +443,6 @@ func (p *ImageProcessor) acquireSlot(ctx context.Context) (func(), error) {
 	return release, nil
 }
 
-// readInput reads input with a size limit to prevent unbounded memory
-// consumption, refusing more than maxInputBytes with ErrInputDataTooLarge. It
-// reads at most maxInputBytes+1 so it can detect if the input exceeds the
-// limit without consuming additional memory.
-func (p *ImageProcessor) readInput(input io.Reader) ([]byte, error) {
-	data, err := io.ReadAll(io.LimitReader(input, p.maxInputBytes+1))
-	if err != nil {
-		return nil, fmt.Errorf("failed to read input: %w", err)
-	}
-
-	if int64(len(data)) > p.maxInputBytes {
-		return nil, ErrInputDataTooLarge
-	}
-
-	return data, nil
-}
-
 // detectFormat returns the format string for a govips image type.
 func (p *ImageProcessor) detectFormat(imageType vips.ImageType) string {
 	switch imageType {
@@ -497,61 +467,9 @@ func (p *ImageProcessor) detectFormat(imageType vips.ImageType) string {
 	}
 }
 
-// outputDimensions returns the dimensions resize gives an image of imgWidth x
-// imgHeight for the target dimensions and fit mode, without resizing it, and
-// refuses an output too large for format. With FitOutside one side can come
-// out larger than the target; when it would be above MaxOutputDimension,
-// outputDimensions returns ErrOutputTooLarge. An AVIF output of more than
-// MaxAVIFOutputPixels is ErrAVIFOutputTooLarge.
-func outputDimensions(
-	imgWidth, imgHeight, width, height int, fit FitMode, format Format,
-) (int, int, error) {
-	scaleW := float64(width) / float64(imgWidth)
-	scaleH := float64(height) / float64(imgHeight)
-	outputWidth, outputHeight := width, height
-
-	switch fit {
-	case FitCover, FitFill, "":
-		// Cover crops, and fill stretches, to exactly the target dimensions
-
-	case FitContain:
-		// Fit within the target dimensions, maintaining aspect ratio
-		scale := min(scaleW, scaleH)
-		outputWidth = int(float64(imgWidth) * scale)
-		outputHeight = int(float64(imgHeight) * scale)
-
-	case FitInside:
-		// Same as contain, but only shrink
-		scale := min(scaleW, scaleH, 1)
-		outputWidth = int(float64(imgWidth) * scale)
-		outputHeight = int(float64(imgHeight) * scale)
-
-	case FitOutside:
-		// The smallest dimension fits, the other may exceed the target
-		scale := max(scaleW, scaleH)
-		outputWidth = int(float64(imgWidth) * scale)
-		outputHeight = int(float64(imgHeight) * scale)
-
-	default:
-		return 0, 0, fmt.Errorf("%w: %s", ErrInvalidFitMode, fit)
-	}
-
-	// The side FitOutside scales past the target is held to the maximum too
-	if max(outputWidth, outputHeight) > MaxOutputDimension {
-		return 0, 0, fmt.Errorf("%w: %dx%d is above %d", ErrOutputTooLarge,
-			outputWidth, outputHeight, MaxOutputDimension)
-	}
-
-	if format == FormatAVIF && outputWidth*outputHeight > MaxAVIFOutputPixels {
-		return 0, 0, fmt.Errorf("%w: %dx%d is above %d pixels",
-			ErrAVIFOutputTooLarge, outputWidth, outputHeight, MaxAVIFOutputPixels)
-	}
-
-	return outputWidth, outputHeight, nil
-}
-
-// resize resizes the image to width x height, the dimensions
-// outputDimensions gives for the fit mode.
+// resize resizes the image according to the fit mode. With FitOutside one
+// side can come out larger than requested; when it would be above
+// MaxOutputDimension, resize returns ErrOutputTooLarge without resizing.
 func (p *ImageProcessor) resize(
 	img *vips.ImageRef, width, height int, fit FitMode,
 ) error {
@@ -560,20 +478,52 @@ func (p *ImageProcessor) resize(
 		// Resize and crop to fill exact dimensions (default)
 		return img.Thumbnail(width, height, vips.InterestingCentre)
 
+	case FitContain:
+		// Resize to fit within dimensions, maintaining aspect ratio
+		imgW, imgH := img.Width(), img.Height()
+		scaleW := float64(width) / float64(imgW)
+		scaleH := float64(height) / float64(imgH)
+		scale := min(scaleW, scaleH)
+		newW := int(float64(imgW) * scale)
+		newH := int(float64(imgH) * scale)
+
+		return img.Thumbnail(newW, newH, vips.InterestingNone)
+
 	case FitFill:
 		// Resize to exact dimensions (may distort)
 		return img.ThumbnailWithSize(width, height, vips.InterestingNone, vips.SizeForce)
 
 	case FitInside:
-		// outputDimensions keeps the dimensions of an image that already fits
-		if img.Width() == width && img.Height() == height {
-			return nil
+		// Same as contain, but only shrink
+		if img.Width() <= width && img.Height() <= height {
+			return nil // Already fits
 		}
 
-		return img.Thumbnail(width, height, vips.InterestingNone)
+		imgW, imgH := img.Width(), img.Height()
+		scaleW := float64(width) / float64(imgW)
+		scaleH := float64(height) / float64(imgH)
+		scale := min(scaleW, scaleH)
+		newW := int(float64(imgW) * scale)
+		newH := int(float64(imgH) * scale)
 
-	case FitContain, FitOutside:
-		return img.Thumbnail(width, height, vips.InterestingNone)
+		return img.Thumbnail(newW, newH, vips.InterestingNone)
+
+	case FitOutside:
+		// Resize so smallest dimension fits, may exceed target on other dimension
+		imgW, imgH := img.Width(), img.Height()
+		scaleW := float64(width) / float64(imgW)
+		scaleH := float64(height) / float64(imgH)
+		scale := max(scaleW, scaleH)
+		newW := int(float64(imgW) * scale)
+		newH := int(float64(imgH) * scale)
+
+		// The dimension that exceeds the target is held to the maximum too
+		if newW > MaxOutputDimension || newH > MaxOutputDimension {
+			return fmt.Errorf("%w: %dx%d is above %d", ErrOutputTooLarge,
+				newW, newH, MaxOutputDimension)
+		}
+
+		return img.Thumbnail(newW, newH, vips.InterestingNone)
 
 	default:
 		return fmt.Errorf("%w: %s", ErrInvalidFitMode, fit)
@@ -677,16 +627,11 @@ func exportGIF(img *vips.ImageRef) ([]byte, error) {
 	return output, err
 }
 
-// webpEffort is the WebP effort, from 0 (fastest) to 6. It is below libvips'
-// default of 4 so that an encode takes at most 40 seconds of the default
-// downstream_timeout of 60 seconds. With one thread, as pixad runs libvips,
-// saving an 8192x8192 image of random pixels with an alpha channel takes up
-// to about 23 seconds at 2, and up to about 16 without one, at any quality;
-// with an alpha channel, 3 takes about 50 seconds and 4 about 61.
-const webpEffort = 2
+// webpEffort is libvips' default WebP effort, from 0 (fastest) to 6.
+const webpEffort = 4
 
-// exportWebP encodes img as lossy WebP at quality and webpEffort, without
-// metadata.
+// exportWebP encodes img as lossy WebP at quality and libvips' default
+// effort, without metadata.
 func exportWebP(img *vips.ImageRef, quality int) ([]byte, error) {
 	output, _, err := img.ExportWebp(&vips.WebpExportParams{
 		StripMetadata:   true,
@@ -698,13 +643,12 @@ func exportWebP(img *vips.ImageRef, quality int) ([]byte, error) {
 }
 
 // avifEffort is the AVIF effort, from 0 (fastest) to 9; 1 is the lowest
-// govips can set. With one thread, as pixad runs libvips, 1 takes about 52
-// seconds to save an 8192x8192 RGB image of random pixels at quality 85,
-// and about 96 with an alpha channel, against the default
-// downstream_timeout of 60 seconds, so an AVIF output is held to
-// MaxAVIFOutputPixels. On an image of milder noise, which 1 saves in about
-// 12 seconds, 2 takes nearly a minute and libvips' default, 4, takes
-// minutes.
+// govips can set. With one thread, as pixad runs libvips, 1 takes about 51
+// seconds to save an 8192x8192 RGB image of random pixels, and about 110
+// with an alpha channel, the worst case, against the default
+// downstream_timeout of 60 seconds. On an image of milder noise, which 1
+// saves in about 12 seconds, 2 takes nearly a minute and libvips' default,
+// 4, takes minutes.
 const avifEffort = 1
 
 // avifBitdepth is the AVIF bit depth, 8 bits per sample for every image.
@@ -731,18 +675,10 @@ func exportAVIF(img *vips.ImageRef, quality int) ([]byte, error) {
 // JPEG that names none.
 const jxlResolution = 72 / 25.4
 
-// jxlEffort is the JPEG XL effort, from 1 (fastest) to 9. It is below
-// libvips' default of 7 so that an encode takes at most 40 seconds of the
-// default downstream_timeout of 60 seconds. With one thread, as pixad runs
-// libvips, saving an 8192x8192 image of random pixels with an alpha channel
-// takes up to about 27 seconds at 4, and up to about 13 without one, at any
-// quality; with an alpha channel, 5 takes about 43 seconds and 7 about 81.
-const jxlEffort = 4
-
-// exportJXL encodes img as JPEG XL at quality and jxlEffort, without
-// metadata. govips sends libvips a distance, the JPEG XL encoder's own
-// measure of quality, along with the quality, and libvips then uses the
-// distance alone, so the quality is also given as a distance.
+// exportJXL encodes img as JPEG XL at quality, with libvips' default effort
+// and without metadata. govips sends libvips a distance, the JPEG XL
+// encoder's own measure of quality, along with the quality, and libvips then
+// uses the distance alone, so the quality is also given as a distance.
 func exportJXL(img *vips.ImageRef, quality int) ([]byte, error) {
 	// libvips converts a CMYK image to sRGB before it saves WebP, AVIF or
 	// PNG, but cannot save one as JPEG XL. encode has already converted
@@ -781,7 +717,6 @@ func exportJXL(img *vips.ImageRef, quality int) ([]byte, error) {
 	params := vips.NewJxlExportParams()
 	params.Quality = quality
 	params.Distance = jxlDistance(quality)
-	params.Effort = jxlEffort
 
 	output, _, err := toSave.ExportJxl(params)
 	if err != nil {

internal/imgcache/urlparser.go

@@ -47,9 +47,6 @@ func ValidateDimension(name string, value int) error {
 var sizeFormatRegex = regexp.MustCompile(
 	`^(\d+)x(\d+)(?:\.(\w+))?$|^(orig)(?:\.(\w+))?$`)
 
-// percentEscapeRegex matches one percent-escape, such as "%2e"
-var percentEscapeRegex = regexp.MustCompile(`%[0-9A-Fa-f]{2}`)
-
 // ParsedURL contains the parsed components of an image proxy URL.
 type ParsedURL struct {
 	// Host is the source origin host (e.g., "cdn.example.com")
@@ -64,8 +61,9 @@ type ParsedURL struct {
 	Format ImageFormat
 }
 
-// ParseImagePath parses an image URL's path after /v1/image/, decoded once:
-// <host>/<path>/<size>.<format>, or <host>/<path>/<size> for JPEG XL.
+// ParseImagePath parses the path captured by chi's wildcard:
+// <host>/<path>/<size>.<format>, or <host>/<path>/<size> for JPEG XL
+// This is the primary entry point when using chi routing.
 // Examples:
 //   - cdn.example.com/photos/cat.jpg/800x600.webp
 //   - cdn.example.com/photos/cat.jpg/0x0.jpeg
@@ -81,10 +79,9 @@ func ParseImagePath(path string) (*ParsedURL, error) {
 	return parseImageComponents(path)
 }
 
-// ParseImageURL parses an image URL's path, decoded once as r.URL.Path holds
-// it: /v1/image/<host>/<path>/<size>.<format>, or /v1/image/<host>/<path>/<size>
-// for JPEG XL. A source query follows the source path after a "?", which the
-// URL writes as %3F.
+// ParseImageURL parses a full URL path like /v1/image/<host>/<path>/<size>.<format>,
+// or /v1/image/<host>/<path>/<size> for JPEG XL
+// Use ParseImagePath instead when working with chi's wildcard capture.
 func ParseImageURL(urlPath string) (*ParsedURL, error) {
 	// Remove the /v1/image/ prefix
 	const prefix = "/v1/image/"
@@ -103,6 +100,12 @@ func ParseImageURL(urlPath string) (*ParsedURL, error) {
 // parseImageComponents parses <host>/<path>/<size>.<format>, or
 // <host>/<path>/<size> for JPEG XL.
 func parseImageComponents(remainder string) (*ParsedURL, error) {
+	// Check for path traversal before any other processing
+	err := checkPathTraversal(remainder)
+	if err != nil {
+		return nil, err
+	}
+
 	// Find the last path segment, which holds "size" or "size.format"
 	lastSlash := strings.LastIndex(remainder, "/")
 	if lastSlash == -1 {
@@ -158,13 +161,6 @@ func parseImageComponents(remainder string) (*ParsedURL, error) {
 		path = path[:qIndex]
 	}
 
-	// The source query names no file on the upstream, so only the host and
-	// the source path are checked for path traversal
-	err = checkPathTraversal(host + path)
-	if err != nil {
-		return nil, err
-	}
-
 	// Ensure path starts with /
 	if !strings.HasPrefix(path, "/") {
 		path = "/" + path
@@ -190,7 +186,12 @@ func checkPathTraversal(path string) error {
 	// Decode multiple times to catch double-encoding
 	decoded := path
 	for range 3 {
-		newDecoded := decodePercentEscapes(decoded)
+		newDecoded, err := url.PathUnescape(decoded)
+		if err != nil {
+			// Malformed encoding is suspicious
+			return ErrPathTraversal
+		}
+
 		if newDecoded == decoded {
 			break
 		}
@@ -231,18 +232,6 @@ func checkPathTraversal(path string) error {
 	return nil
 }
 
-// decodePercentEscapes decodes every percent-escape in s, such as %2e, and
-// keeps a "%" that does not start one as it is, where url.PathUnescape would
-// refuse the whole string. A source path holding %25, a literal "%", has such
-// a "%" after one more decoding.
-func decodePercentEscapes(s string) string {
-	return percentEscapeRegex.ReplaceAllStringFunc(s, func(escape string) string {
-		decoded, _ := url.PathUnescape(escape)
-
-		return decoded
-	})
-}
-
 // parseSizeFormat parses strings like "800x600.webp", "orig.png" or "800x600"
 func parseSizeFormat(s string) (Size, ImageFormat, error) {
 	matches := sizeFormatRegex.FindStringSubmatch(s)

internal/imgcache/urlparser_internal_test.go

@@ -407,71 +407,6 @@ func TestParseImagePath_PathTraversal(t *testing.T) {
 	}
 }
 
-// TestParseImageURL_SourceURLHoldingPercent25 verifies that a source path and
-// a source query holding %25, the percent-escape of a literal "%", are
-// accepted as they are, although decoding them once more leaves a "%" that
-// does not start a percent-escape.
-func TestParseImageURL_SourceURLHoldingPercent25(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name  string
-		input string
-		want  *ParsedURL
-	}{
-		{
-			name:  "path",
-			input: "/v1/image/cdn.example.com/sale/50%25off.jpg/800x600.webp",
-			want: &ParsedURL{
-				Host: testHostCDN, Path: "/sale/50%25off.jpg",
-				Size: Size{Width: 800, Height: 600}, Format: FormatWebP,
-			},
-		},
-		{
-			name:  "query",
-			input: "/v1/image/cdn.example.com/photos/cat.jpg?discount=50%25/800x600.webp",
-			want: &ParsedURL{
-				Host: testHostCDN, Path: testPathCat, Query: "discount=50%25",
-				Size: Size{Width: 800, Height: 600}, Format: FormatWebP,
-			},
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			got, err := ParseImageURL(tt.input)
-			if err != nil {
-				t.Fatalf("ParseImageURL() unexpected error = %v", err)
-			}
-
-			assertParsedURL(t, got, tt.want)
-		})
-	}
-}
-
-// TestParseImageURL_DoubleEncodedTraversalNextToPercent verifies that a
-// double-encoded ".." is still refused when the path also holds a "%" that
-// does not start a percent-escape, either as written or after one more
-// decoding.
-func TestParseImageURL_DoubleEncodedTraversalNextToPercent(t *testing.T) {
-	t.Parallel()
-
-	for _, input := range []string{
-		"/v1/image/cdn.example.com/photos/%252e%252e/secret/50%25off.jpg/800x600.jpeg",
-		"/v1/image/cdn.example.com/photos/%252e%252e/secret/100%/800x600.jpeg",
-	} {
-		_, err := ParseImageURL(input)
-		t.Logf("ParseImageURL(%q) error = %v", input, err)
-
-		if !errors.Is(err, ErrPathTraversal) {
-			t.Errorf("ParseImageURL(%q) error = %v, want ErrPathTraversal",
-				input, err)
-		}
-	}
-}
-
 // errorIs checks if err matches target (handles wrapped errors).
 func errorIs(err, target error) bool {
 	if errors.Is(err, target) {

internal/signature/signature.go

@@ -126,20 +126,31 @@ func (s *Signer) GenerateSignedURL(
 		sizeStr = fmt.Sprintf("%dx%d", req.Width, req.Height)
 	}
 
-	// Build the path. A source query follows the source path after a "?".
-	// The image route reads the path decoded once, so the whole path is
-	// written in Go's own percent-encoding of a URL path, which writes "?"
-	// as %3F and "%" as %25, and leaves "/", ";", ",", "=" and "&" as they
-	// are.
-	sourcePathAndQuery := req.SourcePath
+	// Build the path.
+	// When a source query is present, it is embedded as a path segment
+	// (e.g. /host/path?query/size.fmt) so that the URL parser can extract
+	// it from the last-slash split. The "?" inside a path segment is
+	// percent-encoded by clients but chi delivers it decoded, which is
+	// exactly what the URL parser expects.
+	var path string
 	if req.SourceQuery != "" {
-		sourcePathAndQuery += "?" + req.SourceQuery
+		path = fmt.Sprintf("/v1/image/%s%s%%3F%s/%s.%s",
+			req.SourceHost,
+			req.SourcePath,
+			url.PathEscape(req.SourceQuery),
+			sizeStr,
+			req.Format,
+		)
+	} else {
+		path = fmt.Sprintf("/v1/image/%s%s/%s.%s",
+			req.SourceHost,
+			req.SourcePath,
+			sizeStr,
+			req.Format,
+		)
 	}
 
-	unescapedPath := fmt.Sprintf("/v1/image/%s%s/%s.%s",
-		req.SourceHost, sourcePathAndQuery, sizeStr, req.Format)
-
-	return (&url.URL{Path: unescapedPath}).EscapedPath(), sig, exp
+	return path, sig, exp
 }
 
 // buildSignatureData creates the string to be signed.

internal/signature/signature_test.go

@@ -475,44 +475,6 @@ func TestGenerateSignedURL_WithoutQueryString(t *testing.T) {
 	}
 }
 
-// TestGenerateSignedURL_ReadmeQueryExample checks the README's example of a
-// source URL with a query, the image at
-// https://cdn.example.com/img?url=https://origin.example.com/my%20cat.jpg: its
-// signature with the README's key, and the path GenerateSignedURL writes for
-// it, with the "?" written as %3F and the "%" as %25.
-func TestGenerateSignedURL_ReadmeQueryExample(t *testing.T) {
-	t.Parallel()
-
-	signer := signature.New("example-signing-key-for-documentation")
-
-	req := signature.Request{
-		SourceHost:  testHost,
-		SourcePath:  "/img",
-		SourceQuery: "url=https://origin.example.com/my%20cat.jpg",
-		Width:       800,
-		Height:      600,
-		Format:      testFormatWebP,
-		Quality:     85,
-		FitMode:     testFitCover,
-		Expires:     time.Unix(1704067200, 0),
-	}
-
-	const wantSig = "37aFa9GSVCZM1kRY9SzMOk2fOg_M7Wt5gKNR4xM-FYA="
-
-	gotSig := signer.Sign(&req)
-	if gotSig != wantSig {
-		t.Errorf("Sign() = %q, want %q", gotSig, wantSig)
-	}
-
-	const wantPath = "/v1/image/cdn.example.com" +
-		"/img%3Furl=https://origin.example.com/my%2520cat.jpg/800x600.webp"
-
-	gotPath, _, _ := signer.GenerateSignedURL(&req, time.Hour)
-	if gotPath != wantPath {
-		t.Errorf("GenerateSignedURL() path = %q, want %q", gotPath, wantPath)
-	}
-}
-
 func TestParseParams(t *testing.T) {
 	t.Parallel()