V1_commit_RGC

SuiviREForamteur/node_modules/fast-png/lib/helpers/signature.js

@@ -0,0 +1,27 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.writeSignature = writeSignature;
+exports.checkSignature = checkSignature;
+exports.hasPngSignature = hasPngSignature;
+// https://www.w3.org/TR/PNG/#5PNG-file-signature
+const pngSignature = Uint8Array.of(137, 80, 78, 71, 13, 10, 26, 10);
+function writeSignature(buffer) {
+    buffer.writeBytes(pngSignature);
+}
+function checkSignature(buffer) {
+    if (!hasPngSignature(buffer.readBytes(pngSignature.length))) {
+        throw new Error('wrong PNG signature');
+    }
+}
+function hasPngSignature(array) {
+    if (array.length < pngSignature.length) {
+        return false;
+    }
+    for (let i = 0; i < pngSignature.length; i++) {
+        if (array[i] !== pngSignature[i]) {
+            return false;
+        }
+    }
+    return true;
+}
+//# sourceMappingURL=signature.js.map