Base UI

node_modules/axios/lib/helpers/estimateDataURLDecodedBytes.js

@@ -0,0 +1,105 @@
+/**
+ * Estimate decoded byte length of a data:// URL *without* allocating large buffers.
+ * - For base64: compute exact decoded size using length and padding;
+ *               handle %XX at the character-count level (no string allocation).
+ * - For non-base64: compute the exact percent-decoded UTF-8 byte length.
+ *
+ * @param {string} url
+ * @returns {number}
+ */
+const isHexDigit = (charCode) =>
+  (charCode >= 48 && charCode <= 57) ||
+  (charCode >= 65 && charCode <= 70) ||
+  (charCode >= 97 && charCode <= 102);
+
+const isPercentEncodedByte = (str, i, len) =>
+  i + 2 < len && isHexDigit(str.charCodeAt(i + 1)) && isHexDigit(str.charCodeAt(i + 2));
+
+export default function estimateDataURLDecodedBytes(url) {
+  if (!url || typeof url !== 'string') return 0;
+  if (!url.startsWith('data:')) return 0;
+
+  const comma = url.indexOf(',');
+  if (comma < 0) return 0;
+
+  const meta = url.slice(5, comma);
+  const body = url.slice(comma + 1);
+  const isBase64 = /;base64/i.test(meta);
+
+  if (isBase64) {
+    let effectiveLen = body.length;
+    const len = body.length; // cache length
+
+    for (let i = 0; i < len; i++) {
+      if (body.charCodeAt(i) === 37 /* '%' */ && i + 2 < len) {
+        const a = body.charCodeAt(i + 1);
+        const b = body.charCodeAt(i + 2);
+        const isHex = isHexDigit(a) && isHexDigit(b);
+
+        if (isHex) {
+          effectiveLen -= 2;
+          i += 2;
+        }
+      }
+    }
+
+    let pad = 0;
+    let idx = len - 1;
+
+    const tailIsPct3D = (j) =>
+      j >= 2 &&
+      body.charCodeAt(j - 2) === 37 && // '%'
+      body.charCodeAt(j - 1) === 51 && // '3'
+      (body.charCodeAt(j) === 68 || body.charCodeAt(j) === 100); // 'D' or 'd'
+
+    if (idx >= 0) {
+      if (body.charCodeAt(idx) === 61 /* '=' */) {
+        pad++;
+        idx--;
+      } else if (tailIsPct3D(idx)) {
+        pad++;
+        idx -= 3;
+      }
+    }
+
+    if (pad === 1 && idx >= 0) {
+      if (body.charCodeAt(idx) === 61 /* '=' */) {
+        pad++;
+      } else if (tailIsPct3D(idx)) {
+        pad++;
+      }
+    }
+
+    const groups = Math.floor(effectiveLen / 4);
+    const bytes = groups * 3 - (pad || 0);
+    return bytes > 0 ? bytes : 0;
+  }
+
+  // Compute UTF-8 byte length directly from UTF-16 code units without allocating
+  // a byte buffer (TextEncoder.encode would defeat the DoS guard on large bodies).
+  // Valid %XX triplets count as one decoded byte; this matches the bytes that
+  // decodeURIComponent(body) would produce before Buffer re-encodes the string.
+  let bytes = 0;
+  for (let i = 0, len = body.length; i < len; i++) {
+    const c = body.charCodeAt(i);
+    if (c === 37 /* '%' */ && isPercentEncodedByte(body, i, len)) {
+      bytes += 1;
+      i += 2;
+    } else if (c < 0x80) {
+      bytes += 1;
+    } else if (c < 0x800) {
+      bytes += 2;
+    } else if (c >= 0xd800 && c <= 0xdbff && i + 1 < len) {
+      const next = body.charCodeAt(i + 1);
+      if (next >= 0xdc00 && next <= 0xdfff) {
+        bytes += 4;
+        i++;
+      } else {
+        bytes += 3;
+      }
+    } else {
+      bytes += 3;
+    }
+  }
+  return bytes;
+}