issue 1440: the scan module's eSCL client, settings and image density

2026-10-20 20:09:47 +02:00
parent a67f01963f
commit 36a34a49b8
12 changed files with 755 additions and 0 deletions
@@ -0,0 +1,201 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// eSCL (the AirScan protocol) over HTTP: POST <base>/ScanJobs answers 201 and the job's Location, GET
+// <Location>/NextDocument answers the image, and a second NextDocument answers 404 once the job is done.
+
+// maxImage bounds what a scanner may send: a 600 dpi A4 JPEG is a few tens of megabytes.
+const maxImage = 256 << 20
+
+// Client speaks eSCL to one scanner.
+type Client struct {
+	Base string
+	HTTP *http.Client
+}
+
+// NewClient is a client for the eSCL base URL, with a timeout that outlasts a slow scan.
+func NewClient(base string) *Client {
+	return &Client{Base: strings.TrimRight(base, "/"), HTTP: &http.Client{Timeout: 3 * time.Minute}}
+}
+
+// Capabilities are the platen's largest scan region, in the 300ths of an inch the region is asked in.
+type Capabilities struct {
+	MaxWidth, MaxHeight int
+}
+
+type capabilitiesXML struct {
+	MaxWidth  int `xml:"Platen>PlatenInputCaps>MaxWidth"`
+	MaxHeight int `xml:"Platen>PlatenInputCaps>MaxHeight"`
+}
+
+// Status is what /ScannerStatus says.
+type Status struct {
+	State    string `xml:"State" json:"state"`
+	AdfState string `xml:"AdfState" json:"adf-state"`
+}
+
+func (c *Client) get(ctx context.Context, rawURL string) (*http.Response, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
+	if err != nil {
+		return nil, err
+	}
+	return c.HTTP.Do(req)
+}
+
+func readBody(resp *http.Response, limit int64) ([]byte, error) {
+	defer resp.Body.Close()
+	return io.ReadAll(io.LimitReader(resp.Body, limit))
+}
+
+// Capabilities asks the scanner how large its glass is.
+func (c *Client) Capabilities(ctx context.Context) (Capabilities, error) {
+	resp, err := c.get(ctx, c.Base+"/ScannerCapabilities")
+	if err != nil {
+		return Capabilities{}, fmt.Errorf("the scanner does not answer: %w", err)
+	}
+	body, err := readBody(resp, 1<<20)
+	if err != nil {
+		return Capabilities{}, fmt.Errorf("the scanner's capabilities cannot be read: %w", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return Capabilities{}, fmt.Errorf("the scanner refused its capabilities: %s", resp.Status)
+	}
+	var x capabilitiesXML
+	if err := xml.Unmarshal(body, &x); err != nil {
+		return Capabilities{}, fmt.Errorf("the scanner's capabilities are not XML: %w", err)
+	}
+	if x.MaxWidth <= 0 || x.MaxHeight <= 0 {
+		return Capabilities{}, fmt.Errorf("the scanner's capabilities name no platen size")
+	}
+	return Capabilities{MaxWidth: x.MaxWidth, MaxHeight: x.MaxHeight}, nil
+}
+
+// Status asks what the scanner is doing.
+func (c *Client) Status(ctx context.Context) (Status, error) {
+	resp, err := c.get(ctx, c.Base+"/ScannerStatus")
+	if err != nil {
+		return Status{}, fmt.Errorf("the scanner does not answer: %w", err)
+	}
+	body, err := readBody(resp, 1<<20)
+	if err != nil {
+		return Status{}, fmt.Errorf("the scanner's status cannot be read: %w", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return Status{}, fmt.Errorf("the scanner refused its status: %s", resp.Status)
+	}
+	var s Status
+	if err := xml.Unmarshal(body, &s); err != nil {
+		return Status{}, fmt.Errorf("the scanner's status is not XML: %w", err)
+	}
+	return s, nil
+}
+
+// colorModes maps the config's words to eSCL's.
+var colorModes = map[string]string{"color": "RGB24", "gray": "Grayscale8"}
+
+// ScanSettings is the request body: the Platen, the whole glass, the colour mode and resolution, as a JPEG.
+func ScanSettings(c Capabilities, resolution int, colorMode string) (string, error) {
+	escl, ok := colorModes[colorMode]
+	if !ok {
+		return "", fmt.Errorf("color-mode %q is not color or gray", colorMode)
+	}
+	return fmt.Sprintf(`<?xml version="1.0" encoding="UTF-8"?>
+<scan:ScanSettings xmlns:scan="http://schemas.hp.com/imaging/escl/2011/05/03" xmlns:pwg="http://www.pwg.org/schemas/2010/12/sm">
+<pwg:Version>2.63</pwg:Version>
+<pwg:ScanRegions><pwg:ScanRegion><pwg:ContentRegionUnits>escl:ThreeHundredthsOfInches</pwg:ContentRegionUnits><pwg:XOffset>0</pwg:XOffset><pwg:YOffset>0</pwg:YOffset><pwg:Width>%d</pwg:Width><pwg:Height>%d</pwg:Height></pwg:ScanRegion></pwg:ScanRegions>
+<pwg:InputSource>Platen</pwg:InputSource>
+<scan:ColorMode>%s</scan:ColorMode>
+<scan:XResolution>%d</scan:XResolution><scan:YResolution>%d</scan:YResolution>
+<pwg:DocumentFormat>image/jpeg</pwg:DocumentFormat>
+</scan:ScanSettings>
+`, c.MaxWidth, c.MaxHeight, escl, resolution, resolution), nil
+}
+
+// Scan puts one job to the scanner and returns the JPEG it sends. The resolution asked is only a request: the
+// real one is the image's own density (Density), for the real scanner answered 300 with 200.
+func (c *Client) Scan(ctx context.Context, resolution int, colorMode string) ([]byte, error) {
+	caps, err := c.Capabilities(ctx)
+	if err != nil {
+		return nil, err
+	}
+	settings, err := ScanSettings(caps, resolution, colorMode)
+	if err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.Base+"/ScanJobs", bytes.NewReader([]byte(settings)))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "text/xml")
+	resp, err := c.HTTP.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("the scanner does not answer: %w", err)
+	}
+	reply, _ := readBody(resp, 1<<20)
+	if resp.StatusCode != http.StatusCreated {
+		return nil, fmt.Errorf("the scanner refused the scan job: %s %s", resp.Status, strings.TrimSpace(string(reply)))
+	}
+	loc := resp.Header.Get("Location")
+	if loc == "" {
+		return nil, fmt.Errorf("the scanner took the scan job but named no Location")
+	}
+	base, _ := url.Parse(c.Base + "/")
+	ref, err := url.Parse(loc)
+	if err != nil {
+		return nil, fmt.Errorf("the scan job's Location %q is not a URL: %w", loc, err)
+	}
+	doc := strings.TrimRight(base.ResolveReference(ref).String(), "/") + "/NextDocument"
+	got, err := c.get(ctx, doc)
+	if err != nil {
+		return nil, fmt.Errorf("the scanned page cannot be fetched: %w", err)
+	}
+	image, err := readBody(got, maxImage)
+	if err != nil {
+		return nil, fmt.Errorf("the scanned page cannot be read: %w", err)
+	}
+	if got.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("the scanner gave no page: %s", got.Status)
+	}
+	if ct := got.Header.Get("Content-Type"); !strings.HasPrefix(ct, "image/jpeg") {
+		return nil, fmt.Errorf("the scanner sent %q, not image/jpeg", ct)
+	}
+	return image, nil
+}
+
+// Density is the image's own resolution in dpi, from its JFIF header (units dpi, or dots per cm).
+func Density(jpegBytes []byte) (int, error) {
+	b := jpegBytes
+	if len(b) < 4 || b[0] != 0xFF || b[1] != 0xD8 {
+		return 0, fmt.Errorf("the image is not a JPEG")
+	}
+	for i := 2; i+4 <= len(b) && b[i] == 0xFF; {
+		marker, n := b[i+1], int(b[i+2])<<8|int(b[i+3])
+		if marker == 0xE0 && n >= 16 && i+4+12 <= len(b) && string(b[i+4:i+9]) == "JFIF\x00" {
+			units := b[i+11]
+			x := int(b[i+12])<<8 | int(b[i+13])
+			switch {
+			case units == 1 && x > 0:
+				return x, nil
+			case units == 2 && x > 0:
+				return int(float64(x)*2.54 + 0.5), nil
+			}
+			return 0, fmt.Errorf("the image's JFIF header gives no resolution")
+		}
+		if marker == 0xDA || n < 2 {
+			break
+		}
+		i += 2 + n
+	}
+	return 0, fmt.Errorf("the image has no JFIF header, so its resolution is unknown")
+}
@@ -0,0 +1,106 @@
+package main
+
+import (
+	"context"
+	"strings"
+	"testing"
+)
+
+func squeeze(s string) string { return strings.ReplaceAll(s, "\n", "") }
+
+// 1440/AC1: the captured capabilities, job creation, document and status replies, served by a test server.
+func TestScanPostsOnePlatenJobOverTheWholeGlassAndFetchesTheDocumentOnce(t *testing.T) {
+	f := newFakeScanner(t, fixture(t, "scan.jpg"))
+	image, err := NewClient(f.base()).Scan(context.Background(), 300, "color")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if f.posts != 1 {
+		t.Fatalf("%d ScanJobs posts, want 1", f.posts)
+	}
+	// The body is the request the real scanner accepted (testdata/escl/settings.xml): Platen, 2550x3507
+	// 300ths of an inch from the capabilities, RGB24, 300 dpi, image/jpeg.
+	if got, want := squeeze(f.postBody), squeeze(string(fixture(t, "settings.xml"))); got != want {
+		t.Fatalf("the job is not the captured request\n got: %s\nwant: %s", got, want)
+	}
+	if f.documents != 1 {
+		t.Fatalf("%d NextDocument requests, want exactly 1", f.documents)
+	}
+	if want := fixture(t, "scan.jpg"); string(image) != string(want) {
+		t.Fatalf("the returned image is %d bytes, want the scanner's %d", len(image), len(want))
+	}
+}
+
+// 1440/AC1: the colour mode and resolution asked are the configured ones.
+func TestScanAsksForTheConfiguredResolutionAndColourMode(t *testing.T) {
+	f := newFakeScanner(t, fixture(t, "scan.jpg"))
+	if _, err := NewClient(f.base()).Scan(context.Background(), 600, "gray"); err != nil {
+		t.Fatal(err)
+	}
+	for _, want := range []string{"<scan:ColorMode>Grayscale8</scan:ColorMode>", "<scan:XResolution>600</scan:XResolution>", "<scan:YResolution>600</scan:YResolution>"} {
+		if !strings.Contains(f.postBody, want) {
+			t.Errorf("the job lacks %s:\n%s", want, f.postBody)
+		}
+	}
+}
+
+// 1440/AC1: a job the scanner refuses is an error that says so, and no page is fetched.
+func TestScanSaysWhyAScannerRefusal(t *testing.T) {
+	f := newFakeScanner(t, fixture(t, "scan.jpg"))
+	f.refuse = 503
+	_, err := NewClient(f.base()).Scan(context.Background(), 300, "color")
+	if err == nil || !strings.Contains(err.Error(), "503") {
+		t.Fatalf("error = %v, want the refusal's 503", err)
+	}
+	if f.documents != 0 {
+		t.Fatalf("%d documents fetched after a refusal", f.documents)
+	}
+}
+
+// 1440/AC2: the image's own density, never the request's.
+func TestDensityIsTheImagesOwn(t *testing.T) {
+	dpi, err := Density(fixture(t, "scan.jpg"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if dpi != 200 {
+		t.Fatalf("density = %d dpi, want the captured scan's 200 (the request said 300)", dpi)
+	}
+}
+
+func TestDensityOfAnImageWithNoneIsAnError(t *testing.T) {
+	if _, err := Density([]byte{0xFF, 0xD8, 0xFF, 0xDA, 0, 2}); err == nil {
+		t.Fatal("an image with no JFIF header has a resolution")
+	}
+}
+
+// 1440/AC8: the captured status replies.
+func TestStatusReadsStateAndAdfState(t *testing.T) {
+	f := newFakeScanner(t, nil)
+	s, err := NewClient(f.base()).Status(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if s.State != "Idle" || s.AdfState != "ScannerAdfEmpty" {
+		t.Fatalf("status = %+v, want Idle / ScannerAdfEmpty", s)
+	}
+}
+
+// 1440/AC7: which value is unset is said by name.
+func TestMissingNamesWhatIsUnset(t *testing.T) {
+	for _, c := range []struct {
+		s    Settings
+		want string
+	}{
+		{Settings{Folder: "/x"}, "scanner"},
+		{Settings{Scanner: "http://192.0.2.10/eSCL"}, "scan-folder"},
+	} {
+		err := c.s.Missing()
+		if err == nil || !strings.Contains(err.Error(), c.want) {
+			t.Errorf("Missing(%+v) = %v, want it to name %s", c.s, err, c.want)
+		}
+	}
+	if err := (Settings{Scanner: "a", Folder: "/x"}).Missing(); err != nil {
+		t.Errorf("both set: %v", err)
+	}
+}
@@ -0,0 +1,81 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"sync"
+	"testing"
+)
+
+// fixture reads a capture of the real scanner's answers (testdata/escl, 2026-10-20). Tests never reach a real scanner.
+func fixture(t *testing.T, name string) []byte {
+	t.Helper()
+	b, err := os.ReadFile(filepath.Join("testdata", "escl", name))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return b
+}
+
+// fakeScanner serves the captured eSCL answers and records what it was asked.
+type fakeScanner struct {
+	*httptest.Server
+	mu        sync.Mutex
+	image     []byte
+	postBody  string
+	posts     int
+	documents int // NextDocument requests
+	refuse    int // when set, the status ScanJobs answers instead of 201
+	noPage    bool
+}
+
+func newFakeScanner(t *testing.T, image []byte) *fakeScanner {
+	t.Helper()
+	f := &fakeScanner{image: image}
+	mux := http.NewServeMux()
+	mux.HandleFunc("/eSCL/ScannerCapabilities", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/xml")
+		w.Write(fixture(t, "capabilities.xml"))
+	})
+	mux.HandleFunc("/eSCL/ScannerStatus", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/xml")
+		w.Write(fixture(t, "status-idle.xml"))
+	})
+	mux.HandleFunc("/eSCL/ScanJobs", func(w http.ResponseWriter, r *http.Request) {
+		f.mu.Lock()
+		defer f.mu.Unlock()
+		if r.Method != http.MethodPost {
+			http.Error(w, "post only", http.StatusMethodNotAllowed)
+			return
+		}
+		b := make([]byte, 1<<16)
+		n, _ := r.Body.Read(b)
+		f.postBody = string(b[:n])
+		f.posts++
+		if f.refuse != 0 {
+			http.Error(w, "busy", f.refuse)
+			return
+		}
+		// The captured Location names the real scanner's host; the test's own server stands in for it.
+		w.Header().Set("Location", f.URL+"/eSCL/ScanJobs/7320ead5")
+		w.WriteHeader(http.StatusCreated)
+	})
+	mux.HandleFunc("/eSCL/ScanJobs/7320ead5/NextDocument", func(w http.ResponseWriter, r *http.Request) {
+		f.mu.Lock()
+		defer f.mu.Unlock()
+		f.documents++
+		if f.documents > 1 || f.noPage {
+			http.NotFound(w, r)
+			return
+		}
+		w.Header().Set("Content-Type", "image/jpeg")
+		w.Write(f.image)
+	})
+	f.Server = httptest.NewServer(mux)
+	t.Cleanup(f.Close)
+	return f
+}
+
+func (f *fakeScanner) base() string { return f.URL + "/eSCL" }
@@ -0,0 +1,76 @@
+// Package main is the scan module's Go tools bundle (novox/hq ADR 0464, issue 1440): it scans the glass of a
+// network scanner over eSCL, crops the document, files it as a one-page PDF in a folder and says so on the bus.
+// A scan happens when a tool is called; the module runs no process of its own.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+)
+
+// Settings are the module's five config values, as the mesh writes them into settings.json (ADR 0348).
+type Settings struct {
+	// Scanner is the eSCL base URL, such as http://192.0.2.10/eSCL.
+	Scanner string
+	// Folder is the absolute path the PDFs are filed in. It is not a manifest resource: a directory's path
+	// cannot take a config value (issue 1441), so the code creates it.
+	Folder string
+	// Resolution is the dpi asked of the scanner: 100, 200, 300 or 600.
+	Resolution int
+	// ColorMode is "color" or "gray".
+	ColorMode string
+	// Crop says whether the document is cut out of the platen's white.
+	Crop bool
+}
+
+// LoadSettings reads settings.json (the file named by SCAN_SETTINGS) and lays the defaults under it. A missing
+// or unreadable file is an error that names it; an unset scanner or folder is Missing's to say.
+func LoadSettings(path string) (Settings, error) {
+	s := Settings{Resolution: 300, ColorMode: "color", Crop: true}
+	if path == "" {
+		return s, fmt.Errorf("SCAN_SETTINGS names no settings file: the module's config does not reach the code")
+	}
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return s, fmt.Errorf("settings cannot be read: %w", err)
+	}
+	var in map[string]any
+	if err := json.Unmarshal(raw, &in); err != nil {
+		return s, fmt.Errorf("settings are not JSON (%s): %w", path, err)
+	}
+	if v, ok := in["scanner"].(string); ok {
+		s.Scanner = strings.TrimSpace(v)
+	}
+	if v, ok := in["scan-folder"].(string); ok {
+		s.Folder = strings.TrimSpace(v)
+	}
+	if v, ok := in["resolution"].(float64); ok && v > 0 {
+		s.Resolution = int(v)
+	}
+	if v, ok := in["color-mode"].(string); ok && v != "" {
+		s.ColorMode = v
+	}
+	if v, ok := in["crop"].(bool); ok {
+		s.Crop = v
+	}
+	return s, nil
+}
+
+// Missing is nil when both required values are set, and otherwise says which is not: no tool writes or
+// asks anything before that (1440/AC7).
+func (s Settings) Missing() error {
+	var unset []string
+	if s.Scanner == "" {
+		unset = append(unset, "scanner")
+	}
+	if s.Folder == "" {
+		unset = append(unset, "scan-folder")
+	}
+	if len(unset) == 0 {
+		return nil
+	}
+	return fmt.Errorf("config value %s is not set: the operator gives it with the config verb for the scan module on this node",
+		strings.Join(unset, " and "))
+}
@@ -0,0 +1,261 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<scan:ScannerCapabilities
+xmlns:scan="http://schemas.hp.com/imaging/escl/2011/05/03"
+xmlns:pwg="http://www.pwg.org/schemas/2010/12/sm"
+xmlns:dest="http://schemas.hp.com/imaging/destination/2011/06/06"
+xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+xsi:schemaLocation="http://schemas.hp.com/imaging/escl/2011/05/03 ../../schemas/eSCL-1_92.xsd">
+<pwg:Version>2.93</pwg:Version>
+<pwg:MakeAndModel>Brother MFC-L8390CDW series</pwg:MakeAndModel>
+<pwg:SerialNumber>E82414G4N581626</pwg:SerialNumber>
+<scan:Manufacturer>Brother</scan:Manufacturer>
+<scan:UUID>e3248000-80ce-11db-8000-94ddf83ec78a</scan:UUID>
+<scan:AdminURI>http://BRW58CDC9DFC80B.local./net/net/airprint.html</scan:AdminURI>
+<scan:IconURI>http://BRW58CDC9DFC80B.local./icons/device-icons-128.png</scan:IconURI>
+<scan:Certifications>
+<scan:Certification>
+<scan:Name>mopria-certified-scan</scan:Name>
+<scan:Version>1.4</scan:Version>
+</scan:Certification>
+</scan:Certifications>
+<scan:Platen>
+<scan:PlatenInputCaps>
+<scan:MinWidth>64</scan:MinWidth>
+<scan:MaxWidth>2550</scan:MaxWidth>
+<scan:MinHeight>64</scan:MinHeight>
+<scan:MaxHeight>3507</scan:MaxHeight>
+<scan:MaxXOffset>2486</scan:MaxXOffset>
+<scan:MaxYOffset>3443</scan:MaxYOffset>
+<scan:MaxScanRegions>1</scan:MaxScanRegions>
+<scan:SettingProfiles>
+<scan:SettingProfile>
+<scan:ColorModes>
+<scan:ColorMode>BlackAndWhite1</scan:ColorMode>
+<scan:ColorMode>Grayscale8</scan:ColorMode>
+<scan:ColorMode>RGB24</scan:ColorMode>
+</scan:ColorModes>
+<scan:DocumentFormats>
+<pwg:DocumentFormat>application/pdf</pwg:DocumentFormat>
+<pwg:DocumentFormat>image/jpeg</pwg:DocumentFormat>
+<scan:DocumentFormatExt>application/pdf</scan:DocumentFormatExt>
+<scan:DocumentFormatExt>image/jpeg</scan:DocumentFormatExt>
+</scan:DocumentFormats>
+<scan:SupportedResolutions>
+<scan:DiscreteResolutions>
+<scan:DiscreteResolution>
+<scan:XResolution>100</scan:XResolution>
+<scan:YResolution>100</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>200</scan:XResolution>
+<scan:YResolution>200</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>300</scan:XResolution>
+<scan:YResolution>300</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>600</scan:XResolution>
+<scan:YResolution>600</scan:YResolution>
+</scan:DiscreteResolution>
+</scan:DiscreteResolutions>
+</scan:SupportedResolutions>
+<scan:ColorSpaces>
+<scan:ColorSpace>CMYK</scan:ColorSpace>
+<scan:ColorSpace>YCC</scan:ColorSpace>
+<scan:ColorSpace>sRGB</scan:ColorSpace>
+</scan:ColorSpaces>
+<scan:CcdChannels>
+<scan:CcdChannel>Red</scan:CcdChannel>
+<scan:CcdChannel>Green</scan:CcdChannel>
+<scan:CcdChannel>Blue</scan:CcdChannel>
+<scan:CcdChannel>NTSC</scan:CcdChannel>
+<scan:CcdChannel>GrayCcd</scan:CcdChannel>
+<scan:CcdChannel>GrayCcdEmulated</scan:CcdChannel>
+</scan:CcdChannels>
+<scan:BinaryRenderings>
+<scan:BinaryRendering>Halftone</scan:BinaryRendering>
+<scan:BinaryRendering>Threshold</scan:BinaryRendering>
+</scan:BinaryRenderings>
+</scan:SettingProfile>
+</scan:SettingProfiles>
+<scan:SupportedIntents>
+<scan:Intent>Document</scan:Intent>
+<scan:Intent>TextAndGraphic</scan:Intent>
+<scan:Intent>Photo</scan:Intent>
+<scan:Intent>Preview</scan:Intent>
+</scan:SupportedIntents>
+<scan:MaxOpticalXResolution>1200</scan:MaxOpticalXResolution>
+<scan:MaxOpticalYResolution>2400</scan:MaxOpticalYResolution>
+<scan:RiskyLeftMargin>0</scan:RiskyLeftMargin>
+<scan:RiskyRightMargin>0</scan:RiskyRightMargin>
+<scan:RiskyTopMargin>0</scan:RiskyTopMargin>
+<scan:RiskyBottomMargin>0</scan:RiskyBottomMargin>
+<scan:MaxPhysicalWidth>2550</scan:MaxPhysicalWidth>
+<scan:MaxPhysicalHeight>3507</scan:MaxPhysicalHeight>
+</scan:PlatenInputCaps>
+</scan:Platen>
+<scan:Adf>
+<scan:AdfSimplexInputCaps>
+<scan:MinWidth>64</scan:MinWidth>
+<scan:MaxWidth>2550</scan:MaxWidth>
+<scan:MinHeight>1740</scan:MinHeight>
+<scan:MaxHeight>4200</scan:MaxHeight>
+<scan:MaxXOffset>2486</scan:MaxXOffset>
+<scan:MaxYOffset>2460</scan:MaxYOffset>
+<scan:MaxScanRegions>1</scan:MaxScanRegions>
+<scan:SettingProfiles>
+<scan:SettingProfile>
+<scan:ColorModes>
+<scan:ColorMode>BlackAndWhite1</scan:ColorMode>
+<scan:ColorMode>Grayscale8</scan:ColorMode>
+<scan:ColorMode>RGB24</scan:ColorMode>
+</scan:ColorModes>
+<scan:DocumentFormats>
+<pwg:DocumentFormat>application/pdf</pwg:DocumentFormat>
+<pwg:DocumentFormat>image/jpeg</pwg:DocumentFormat>
+<scan:DocumentFormatExt>application/pdf</scan:DocumentFormatExt>
+<scan:DocumentFormatExt>image/jpeg</scan:DocumentFormatExt>
+</scan:DocumentFormats>
+<scan:SupportedResolutions>
+<scan:DiscreteResolutions>
+<scan:DiscreteResolution>
+<scan:XResolution>100</scan:XResolution>
+<scan:YResolution>100</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>200</scan:XResolution>
+<scan:YResolution>200</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>300</scan:XResolution>
+<scan:YResolution>300</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>600</scan:XResolution>
+<scan:YResolution>600</scan:YResolution>
+</scan:DiscreteResolution>
+</scan:DiscreteResolutions>
+</scan:SupportedResolutions>
+<scan:ColorSpaces>
+<scan:ColorSpace>CMYK</scan:ColorSpace>
+<scan:ColorSpace>YCC</scan:ColorSpace>
+<scan:ColorSpace>sRGB</scan:ColorSpace>
+</scan:ColorSpaces>
+<scan:CcdChannels>
+<scan:CcdChannel>Red</scan:CcdChannel>
+<scan:CcdChannel>Green</scan:CcdChannel>
+<scan:CcdChannel>Blue</scan:CcdChannel>
+<scan:CcdChannel>NTSC</scan:CcdChannel>
+<scan:CcdChannel>GrayCcd</scan:CcdChannel>
+<scan:CcdChannel>GrayCcdEmulated</scan:CcdChannel>
+</scan:CcdChannels>
+<scan:BinaryRenderings>
+<scan:BinaryRendering>Halftone</scan:BinaryRendering>
+<scan:BinaryRendering>Threshold</scan:BinaryRendering>
+</scan:BinaryRenderings>
+</scan:SettingProfile>
+</scan:SettingProfiles>
+<scan:SupportedIntents>
+<scan:Intent>Document</scan:Intent>
+<scan:Intent>TextAndGraphic</scan:Intent>
+<scan:Intent>Photo</scan:Intent>
+<scan:Intent>Preview</scan:Intent>
+</scan:SupportedIntents>
+<scan:MaxOpticalXResolution>1200</scan:MaxOpticalXResolution>
+<scan:MaxOpticalYResolution>600</scan:MaxOpticalYResolution>
+<scan:RiskyLeftMargin>0</scan:RiskyLeftMargin>
+<scan:RiskyRightMargin>0</scan:RiskyRightMargin>
+<scan:RiskyTopMargin>0</scan:RiskyTopMargin>
+<scan:RiskyBottomMargin>0</scan:RiskyBottomMargin>
+<scan:MaxPhysicalWidth>2550</scan:MaxPhysicalWidth>
+<scan:MaxPhysicalHeight>4200</scan:MaxPhysicalHeight>
+</scan:AdfSimplexInputCaps>
+<scan:AdfDuplexInputCaps>
+<scan:MinWidth>64</scan:MinWidth>
+<scan:MaxWidth>2550</scan:MaxWidth>
+<scan:MinHeight>1740</scan:MinHeight>
+<scan:MaxHeight>4200</scan:MaxHeight>
+<scan:MaxXOffset>2486</scan:MaxXOffset>
+<scan:MaxYOffset>2460</scan:MaxYOffset>
+<scan:MaxScanRegions>1</scan:MaxScanRegions>
+<scan:SettingProfiles>
+<scan:SettingProfile>
+<scan:ColorModes>
+<scan:ColorMode>BlackAndWhite1</scan:ColorMode>
+<scan:ColorMode>Grayscale8</scan:ColorMode>
+<scan:ColorMode>RGB24</scan:ColorMode>
+</scan:ColorModes>
+<scan:DocumentFormats>
+<pwg:DocumentFormat>application/pdf</pwg:DocumentFormat>
+<pwg:DocumentFormat>image/jpeg</pwg:DocumentFormat>
+<scan:DocumentFormatExt>application/pdf</scan:DocumentFormatExt>
+<scan:DocumentFormatExt>image/jpeg</scan:DocumentFormatExt>
+</scan:DocumentFormats>
+<scan:SupportedResolutions>
+<scan:DiscreteResolutions>
+<scan:DiscreteResolution>
+<scan:XResolution>100</scan:XResolution>
+<scan:YResolution>100</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>200</scan:XResolution>
+<scan:YResolution>200</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>300</scan:XResolution>
+<scan:YResolution>300</scan:YResolution>
+</scan:DiscreteResolution>
+<scan:DiscreteResolution>
+<scan:XResolution>600</scan:XResolution>
+<scan:YResolution>600</scan:YResolution>
+</scan:DiscreteResolution>
+</scan:DiscreteResolutions>
+</scan:SupportedResolutions>
+<scan:ColorSpaces>
+<scan:ColorSpace>CMYK</scan:ColorSpace>
+<scan:ColorSpace>YCC</scan:ColorSpace>
+<scan:ColorSpace>sRGB</scan:ColorSpace>
+</scan:ColorSpaces>
+<scan:CcdChannels>
+<scan:CcdChannel>Red</scan:CcdChannel>
+<scan:CcdChannel>Green</scan:CcdChannel>
+<scan:CcdChannel>Blue</scan:CcdChannel>
+<scan:CcdChannel>NTSC</scan:CcdChannel>
+<scan:CcdChannel>GrayCcd</scan:CcdChannel>
+<scan:CcdChannel>GrayCcdEmulated</scan:CcdChannel>
+</scan:CcdChannels>
+<scan:BinaryRenderings>
+<scan:BinaryRendering>Halftone</scan:BinaryRendering>
+<scan:BinaryRendering>Threshold</scan:BinaryRendering>
+</scan:BinaryRenderings>
+</scan:SettingProfile>
+</scan:SettingProfiles>
+<scan:SupportedIntents>
+<scan:Intent>Document</scan:Intent>
+<scan:Intent>TextAndGraphic</scan:Intent>
+<scan:Intent>Photo</scan:Intent>
+<scan:Intent>Preview</scan:Intent>
+</scan:SupportedIntents>
+<scan:MaxOpticalXResolution>600</scan:MaxOpticalXResolution>
+<scan:MaxOpticalYResolution>600</scan:MaxOpticalYResolution>
+<scan:RiskyLeftMargin>0</scan:RiskyLeftMargin>
+<scan:RiskyRightMargin>0</scan:RiskyRightMargin>
+<scan:RiskyTopMargin>0</scan:RiskyTopMargin>
+<scan:RiskyBottomMargin>0</scan:RiskyBottomMargin>
+<scan:MaxPhysicalWidth>2550</scan:MaxPhysicalWidth>
+<scan:MaxPhysicalHeight>4200</scan:MaxPhysicalHeight>
+</scan:AdfDuplexInputCaps>
+<scan:FeederCapacity>50</scan:FeederCapacity>
+<scan:AdfOptions>
+<scan:AdfOption>DetectPaperLoaded</scan:AdfOption>
+<scan:AdfOption>Duplex</scan:AdfOption>
+</scan:AdfOptions>
+</scan:Adf>
+<scan:CompressionFactorSupport>
+<scan:Min>1</scan:Min>
+<scan:Max>3</scan:Max>
+<scan:Normal>2</scan:Normal>
+<scan:Step>1</scan:Step>
+</scan:CompressionFactorSupport>
+</scan:ScannerCapabilities>
@@ -0,0 +1,6 @@
+HTTP/1.1 200 OK
+Content-Location: /eSCL/ScanJobs/7320ead5-ccb0-11f1-8ff9-94ddf83ec78a/doc-1
+Accept-Encoding: identity
+Content-Type: image/jpeg
+Transfer-Encoding: chunked
+
@@ -0,0 +1,10 @@
+HTTP/1.1 201 Created
+Cache-Control: no-store
+Accept-Encoding: identity
+X-Frame-Options: DENY
+Content-Length: 0
+Content-Type: text/xml
+Connection: close
+Pragma: no-cache
+Location: http://192.168.1.171/eSCL/ScanJobs/7320ead5-ccb0-11f1-8ff9-94ddf83ec78a
+
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<scan:ScanSettings xmlns:scan="http://schemas.hp.com/imaging/escl/2011/05/03" xmlns:pwg="http://www.pwg.org/schemas/2010/12/sm">
+<pwg:Version>2.63</pwg:Version>
+<pwg:ScanRegions><pwg:ScanRegion><pwg:ContentRegionUnits>escl:ThreeHundredthsOfInches</pwg:ContentRegionUnits><pwg:XOffset>0</pwg:XOffset><pwg:YOffset>0</pwg:YOffset><pwg:Width>2550</pwg:Width><pwg:Height>3507</pwg:Height></pwg:ScanRegion></pwg:ScanRegions>
+<pwg:InputSource>Platen</pwg:InputSource>
+<scan:ColorMode>RGB24</scan:ColorMode>
+<scan:XResolution>300</scan:XResolution><scan:YResolution>300</scan:YResolution>
+<pwg:DocumentFormat>image/jpeg</pwg:DocumentFormat>
+</scan:ScanSettings>
@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8"?><scan:ScannerStatus xmlns:pwg="http://www.pwg.org/schemas/2010/12/sm" xmlns:scan="http://schemas.hp.com/imaging/escl/2011/05/03" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schemas.hp.com/imaging/escl/2011/05/03 ../../schemas/eSCL-1_92.xsd"><pwg:Version>2.93</pwg:Version><pwg:State>Idle</pwg:State><scan:AdfState>ScannerAdfEmpty</scan:AdfState><scan:Jobs><scan:JobInfo><pwg:JobUri>/eSCL/ScanJobs/7320ead5-ccb0-11f1-8ff9-94ddf83ec78a</pwg:JobUri><pwg:JobUuid>urn:uuid:7320ead5-ccb0-11f1-8ff9-94ddf83ec78a</pwg:JobUuid><scan:Age>9291071</scan:Age><pwg:ImagesCompleted>1</pwg:ImagesCompleted><pwg:ImagesToTransfer>1</pwg:ImagesToTransfer><pwg:JobState>Completed</pwg:JobState><pwg:JobStateReasons><pwg:JobStateReason>JobCompletedSuccessfully</pwg:JobStateReason></pwg:JobStateReasons></scan:JobInfo></scan:Jobs></scan:ScannerStatus>
@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8"?><scan:ScannerStatus xmlns:pwg="http://www.pwg.org/schemas/2010/12/sm" xmlns:scan="http://schemas.hp.com/imaging/escl/2011/05/03" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schemas.hp.com/imaging/escl/2011/05/03 ../../schemas/eSCL-1_92.xsd"><pwg:Version>2.93</pwg:Version><pwg:State>Idle</pwg:State><scan:AdfState>ScannerAdfEmpty</scan:AdfState><scan:Jobs><scan:JobInfo><pwg:JobUri>/eSCL/ScanJobs/7320ead5-ccb0-11f1-8ff9-94ddf83ec78a</pwg:JobUri><pwg:JobUuid>urn:uuid:7320ead5-ccb0-11f1-8ff9-94ddf83ec78a</pwg:JobUuid><scan:Age>9292192</scan:Age><pwg:ImagesCompleted>1</pwg:ImagesCompleted><pwg:ImagesToTransfer>1</pwg:ImagesToTransfer><pwg:JobState>Completed</pwg:JobState><pwg:JobStateReasons><pwg:JobStateReason>JobCompletedSuccessfully</pwg:JobStateReason></pwg:JobStateReasons></scan:JobInfo></scan:Jobs></scan:ScannerStatus>
@@ -0,0 +1,3 @@
+module scan
+
+go 1.26.0
				`@@ -0,0 +1 @@`
				<?xml version="1.0" encoding="UTF-8"?><scan:ScannerStatus xmlns:pwg="http://www.pwg.org/schemas/2010/12/sm" xmlns:scan="http://schemas.hp.com/imaging/escl/2011/05/03" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schemas.hp.com/imaging/escl/2011/05/03 ../../schemas/eSCL-1_92.xsd"><pwg:Version>2.93</pwg:Version><pwg:State>Idle</pwg:State><scan:AdfState>ScannerAdfEmpty</scan:AdfState><scan:Jobs><scan:JobInfo><pwg:JobUri>/eSCL/ScanJobs/7320ead5-ccb0-11f1-8ff9-94ddf83ec78a</pwg:JobUri><pwg:JobUuid>urn:uuid:7320ead5-ccb0-11f1-8ff9-94ddf83ec78a</pwg:JobUuid><scan:Age>9291071</scan:Age><pwg:ImagesCompleted>1</pwg:ImagesCompleted><pwg:ImagesToTransfer>1</pwg:ImagesToTransfer><pwg:JobState>Completed</pwg:JobState><pwg:JobStateReasons><pwg:JobStateReason>JobCompletedSuccessfully</pwg:JobStateReason></pwg:JobStateReasons></scan:JobInfo></scan:Jobs></scan:ScannerStatus>