Diagnostics, source positions, limits & threads

32Diagnostics, source positions, limits & threads

Every ZplRenderResult has Diagnostics: ZplDiagnostic with a stable code, severity, message, command and position (offset, line, column). Warnings is kept and contains the messages of all warnings and errors.

Try it online on zplCloud.com: ZPL Linter

Code	Severity	Meaning
`ZPL1001`	Error	Command with invalid parameters ignored (the rest of the label is rendered)
`ZPL1002`	Warning	Field could not be drawn (e.g. invalid barcode data)
`ZPL1003`	Warning	Barcode data longer than any symbology can hold
`ZPL1101`	Warning	`^GF` larger than the label or `MaxGraphicBytes`
`ZPL1102`	Warning	`^GF` data cannot be decoded
`ZPL1103`	Warning	`^XG`/`^IM` references a graphic that is not stored
`ZPL1201`	Warning	`^A@` font not found – font A is used, as on a Zebra
`ZPL1301`	Warning	`FieldValues` key without a matching `^FN` (INVALID_FIELD_VALUE_KEY)
`ZPL2001`	Info	Accepted, no effect on the image (`^FE`, `^FA`, RFID operations other than writing)

With TraceElements, every element carries SourceOffset/SourceLength (its ^FO…^FS block); every parsed ZplCommand has Offset/Length, and ZplParser.LineColumn converts them. Missing ^A@ fonts can be supplied on demand by the FontProvider callback.

var renderer = new ZplRenderer(new ZplRenderSettings
{
    TraceElements = true,
    FontProvider = name => name == "E:BRAND.TTF" ? File.ReadAllBytes("fonts/Brand.ttf") : null,
});
foreach (var result in renderer.Render(zpl))
{
    foreach (ZplDiagnostic d in result.Diagnostics)          // e.g. "ZPL1201 warning (3:12): …"
        Console.WriteLine($"{d.Code} {d.Severity} {d.Command} Zeile {d.Line}, Spalte {d.Column}: {d.Message}");
    foreach (var e in result.Elements)                       // ^FO…^FS range in the source
        Console.WriteLine(zpl.Substring(e.SourceOffset, e.SourceLength));
    result.Bitmap.Dispose();
}

Limits for untrusted input & thread safety

Defaults: MaxLabelSide 32000, MaxLabelDots 64 million, MaxQuantity 10000, MaxLabels 100000, MaxGraphicBytes 32 MB (also the Z64 decompression limit against zip bombs), MaxFieldDataLength 1 million, ZplResourceStore.MaxTotalBytes 256 MB. ZplRenderer/EplRenderer hold printer state and are not thread-safe – use one renderer per thread; ZplResourceStore, FontManager, ZplCaches, PropertyPath and configured LabelBindings are. ConcurrencyTests compares the SHA-256 of all outputs from 16 threads with the single-threaded run; samples/FuzzRunner feeds the parser random and mutated input, samples/LeakTest renders 1 million labels and logs heap and RSS. Details: THREADING.md, DIAGNOSTICS.md.

var shared = new ZplResourceStore();                          // thread-safe, shareable by many renderers
var safe = new ZplRenderSettings
{
    MaxLabelSide = 8000, MaxLabelDots = 16_000_000, MaxQuantity = 100,
    MaxLabels = 1000, MaxGraphicBytes = 4 * 1024 * 1024, MaxFieldDataLength = 10_000,
};
Parallel.For(0, 8, _ =>
{
    var r = new ZplRenderer(safe) { Store = shared };         // one renderer per thread
    r.ProcessCommands(untrusted);
});