Files
pixa/internal/httpfetcher/mock.go
T
sneak 98b79c2e27
check / check (push) Canceled after 0s
Support SVG sources (closes #68)
The fetcher accepts image/svg+xml again and internal/magic detects SVG.
A raster format renders the SVG at the least size that covers the
output, held to 8192 on a side, through libvips' thumbnail, which
renders at any scale, so an enlarged SVG stays sharp. An SVG's own size
is not limited; one with a side more than 8192 times the other is
ErrSVGTooThin, answered 415. orig of an SVG at the orig size is the SVG
unchanged, cached as a variant; at any other size it is
ErrSVGNotOriginalSize, answered 400. The cache reads up to 1024 first
bytes of a file to find its format. Render time and memory grow with
what the SVG draws; their bound is the owner's decision on #68. Tests that pinned SVG as refused now
expect it to be read.

Model: opus-5-5
2026-11-11 12:08:53 +00:00

96 lines
2.4 KiB
Go

package httpfetcher
import (
"context"
"errors"
"fmt"
"io/fs"
"net/http"
"strings"
"sneak.berlin/go/pixa/internal/imagerequest"
)
// MockFetcher implements Fetcher using an embedded filesystem.
// Files are organized as: hostname/path/to/file.ext
// The source with host example.com and path /images/photo.jpg maps to
// example.com/images/photo.jpg; the source query is ignored.
type MockFetcher struct {
fs fs.FS
}
// NewMock creates a new mock fetcher backed by the given filesystem.
func NewMock(fsys fs.FS) *MockFetcher {
return &MockFetcher{fs: fsys}
}
// Fetch retrieves the source's content from the mock filesystem.
func (m *MockFetcher) Fetch(
ctx context.Context, source imagerequest.Source,
) (*FetchResult, error) {
// Check context cancellation
select {
case <-ctx.Done():
return nil, ctx.Err()
default:
}
path := source.Host + source.Path
// Open the file
f, err := m.fs.Open(path)
if err != nil {
if errors.Is(err, fs.ErrNotExist) {
return nil, fmt.Errorf("%w: status 404", ErrUpstreamError)
}
return nil, fmt.Errorf("failed to open mock file: %w", err)
}
// Get file info for content length
stat, err := f.Stat()
if err != nil {
_ = f.Close()
return nil, fmt.Errorf("failed to stat mock file: %w", err)
}
// Detect content type from extension
contentType := detectContentTypeFromPath(path)
return &FetchResult{
Content: f,
ContentLength: stat.Size(),
ContentType: contentType,
Headers: make(http.Header),
}, nil
}
// contentTypeOctetStream is the content type the mock fetcher gives files in
// no format pixa reads.
const contentTypeOctetStream = "application/octet-stream"
// detectContentTypeFromPath returns the MIME type based on file extension.
func detectContentTypeFromPath(path string) string {
path = strings.ToLower(path)
switch {
case strings.HasSuffix(path, ".jpg"), strings.HasSuffix(path, ".jpeg"):
return imagerequest.FormatJPEG.MIMEType()
case strings.HasSuffix(path, ".png"):
return imagerequest.FormatPNG.MIMEType()
case strings.HasSuffix(path, ".gif"):
return imagerequest.FormatGIF.MIMEType()
case strings.HasSuffix(path, ".webp"):
return imagerequest.FormatWebP.MIMEType()
case strings.HasSuffix(path, ".avif"):
return imagerequest.FormatAVIF.MIMEType()
case strings.HasSuffix(path, ".jxl"):
return imagerequest.FormatJXL.MIMEType()
case strings.HasSuffix(path, ".svg"):
return imagerequest.FormatSVG.MIMEType()
default:
return contentTypeOctetStream
}
}