work around missing tilde character in huffman tree

2026-08-14 09:57:21 +03:00
parent b12948bbef
commit bdc3c33026
1 changed files with 14 additions and 1 deletions
@@ -264,7 +264,20 @@ export function compress (input, alphabet) {
        huffmanNumber = huffmanEncode(huffmanNumber, pathEncode["%"]);
        i -= 2;
      } else {
-        huffmanNumber = huffmanEncode(huffmanNumber, pathEncode[segment.value[i]]);
+        if (segment.value[i] === "~") {
+          /**
+           * HACK HACK HACK!!!
+           * Our Huffman tree is missing the tilde character (whoops!)
+           * It's too late to change it now without bumping the version
+           * number, and that currently costs 1 bit. Tildes are so rare
+           * that it makes more sense to %-encode them instead.
+           */
+          huffmanNumber *= 256n;
+          huffmanNumber += BigInt(126);
+          huffmanNumber = huffmanEncode(huffmanNumber, pathEncode["%"]);
+        } else {
+          huffmanNumber = huffmanEncode(huffmanNumber, pathEncode[segment.value[i]]);
+        }
      }
    }
    // Encode segment variant as 0