something is working

2022-09-15 01:55:36 -04:00
parent a0aa251c27
commit f38e69883c
1123 changed files with 251731 additions and 11 deletions
@@ -0,0 +1,47 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.validateUtf8 = void 0;
+var FIRST_BIT = 0x80;
+var FIRST_TWO_BITS = 0xc0;
+var FIRST_THREE_BITS = 0xe0;
+var FIRST_FOUR_BITS = 0xf0;
+var FIRST_FIVE_BITS = 0xf8;
+var TWO_BIT_CHAR = 0xc0;
+var THREE_BIT_CHAR = 0xe0;
+var FOUR_BIT_CHAR = 0xf0;
+var CONTINUING_CHAR = 0x80;
+/**
+ * Determines if the passed in bytes are valid utf8
+ * @param bytes - An array of 8-bit bytes. Must be indexable and have length property
+ * @param start - The index to start validating
+ * @param end - The index to end validating
+ */
+function validateUtf8(bytes, start, end) {
+    var continuation = 0;
+    for (var i = start; i < end; i += 1) {
+        var byte = bytes[i];
+        if (continuation) {
+            if ((byte & FIRST_TWO_BITS) !== CONTINUING_CHAR) {
+                return false;
+            }
+            continuation -= 1;
+        }
+        else if (byte & FIRST_BIT) {
+            if ((byte & FIRST_THREE_BITS) === TWO_BIT_CHAR) {
+                continuation = 1;
+            }
+            else if ((byte & FIRST_FOUR_BITS) === THREE_BIT_CHAR) {
+                continuation = 2;
+            }
+            else if ((byte & FIRST_FIVE_BITS) === FOUR_BIT_CHAR) {
+                continuation = 3;
+            }
+            else {
+                return false;
+            }
+        }
+    }
+    return !continuation;
+}
+exports.validateUtf8 = validateUtf8;
+//# sourceMappingURL=validate_utf8.js.map