Refactor continuation protocol buffers

5 files changed, 274 insertions, 276 deletions

diff --git a/src/invidious/channels.cr b/src/invidious/channels.cr
index 129ff192..988b39f4 100644
--- a/src/invidious/channels.cr
+++ b/src/invidious/channels.cr
@@ -441,53 +441,57 @@ def produce_channel_videos_url(ucid, page = 1, auto_generated = nil, sort_by = "
     switch = 0x00
   end
 
-  meta = IO::Memory.new
-  meta.write(Bytes[0x12, 0x06])
-  meta.print("videos")
-
-  meta.write(Bytes[0x30, 0x02])
-  meta.write(Bytes[0x38, 0x01])
-  meta.write(Bytes[0x60, 0x01])
-  meta.write(Bytes[0x6a, 0x00])
-  meta.write(Bytes[0xb8, 0x01, 0x00])
-
-  meta.write(Bytes[0x20, switch])
-  meta.write(Bytes[0x7a, page.size])
-  meta.print(page)
+  data = IO::Memory.new
+  data.write_byte 0x12
+  data.write_byte 0x06
+  data.print "videos"
+
+  data.write Bytes[0x30, 0x02]
+  data.write Bytes[0x38, 0x01]
+  data.write Bytes[0x60, 0x01]
+  data.write Bytes[0x6a, 0x00]
+  data.write Bytes[0xb8, 0x01, 0x00]
+
+  data.write Bytes[0x20, switch]
+  data.write_byte 0x7a
+  VarInt.to_io(data, page.bytesize)
+  data.print page
 
   case sort_by
   when "newest"
     # Empty tags can be omitted
     # meta.write(Bytes[0x18,0x00])
   when "popular"
-    meta.write(Bytes[0x18, 0x01])
+    data.write Bytes[0x18, 0x01]
   when "oldest"
-    meta.write(Bytes[0x18, 0x02])
+    data.write Bytes[0x18, 0x02]
   end
 
-  meta.rewind
-  meta = Base64.urlsafe_encode(meta.to_slice)
-  meta = URI.escape(meta)
+  data = Base64.urlsafe_encode(data)
+  cursor = URI.escape(data)
+
+  data = IO::Memory.new
 
-  continuation = IO::Memory.new
-  continuation.write(Bytes[0x12, ucid.size])
-  continuation.print(ucid)
+  data.write_byte 0x12
+  VarInt.to_io(data, ucid.bytesize)
+  data.print ucid
 
-  continuation.write(Bytes[0x1a, meta.size])
-  continuation.print(meta)
+  data.write_byte 0x1a
+  VarInt.to_io(data, cursor.bytesize)
+  data.print cursor
 
-  continuation.rewind
-  continuation = continuation.gets_to_end
+  data.rewind
 
-  wrapper = IO::Memory.new
-  wrapper.write(Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02, continuation.size])
-  wrapper.print(continuation)
-  wrapper.rewind
+  buffer = IO::Memory.new
+  buffer.write Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02]
+  VarInt.to_io(buffer, data.bytesize)
 
-  wrapper = Base64.urlsafe_encode(wrapper.to_slice)
-  wrapper = URI.escape(wrapper)
+  IO.copy data, buffer
 
-  url = "/browse_ajax?continuation=#{wrapper}&gl=US&hl=en"
+  continuation = Base64.urlsafe_encode(buffer)
+  continuation = URI.escape(continuation)
+
+  url = "/browse_ajax?continuation=#{continuation}&gl=US&hl=en"
 
   return url
 end
@@ -497,117 +501,108 @@ def produce_channel_playlists_url(ucid, cursor, sort = "newest", auto_generated
     cursor = Base64.urlsafe_encode(cursor, false)
   end
 
-  meta = IO::Memory.new
+  data = IO::Memory.new
 
   if auto_generated
-    meta.write(Bytes[0x08, 0x0a])
+    data.write Bytes[0x08, 0x0a]
   end
 
-  meta.write(Bytes[0x12, 0x09])
-  meta.print("playlists")
+  data.write Bytes[0x12, 0x09]
+  data.print "playlists"
 
   if auto_generated
-    meta.write(Bytes[0x20, 0x32])
+    data.write Bytes[0x20, 0x32]
   else
     # TODO: Look at 0x01, 0x00
     case sort
     when "oldest", "oldest_created"
-      meta.write(Bytes[0x18, 0x02])
+      data.write Bytes[0x18, 0x02]
     when "newest", "newest_created"
-      meta.write(Bytes[0x18, 0x03])
+      data.write Bytes[0x18, 0x03]
     when "last", "last_added"
-      meta.write(Bytes[0x18, 0x04])
+      data.write Bytes[0x18, 0x04]
     end
 
-    meta.write(Bytes[0x20, 0x01])
+    data.write Bytes[0x20, 0x01]
   end
 
-  meta.write(Bytes[0x30, 0x02])
-  meta.write(Bytes[0x38, 0x01])
-  meta.write(Bytes[0x60, 0x01])
-  meta.write(Bytes[0x6a, 0x00])
+  data.write Bytes[0x30, 0x02]
+  data.write Bytes[0x38, 0x01]
+  data.write Bytes[0x60, 0x01]
+  data.write Bytes[0x6a, 0x00]
 
-  meta.write(Bytes[0x7a, cursor.size])
-  meta.print(cursor)
+  data.write_byte 0x7a
+  VarInt.to_io(data, cursor.bytesize)
+  data.print cursor
 
-  meta.write(Bytes[0xb8, 0x01, 0x00])
+  data.write Bytes[0xb8, 0x01, 0x00]
 
-  meta.rewind
-  meta = Base64.urlsafe_encode(meta.to_slice)
-  meta = URI.escape(meta)
+  data.rewind
+  data = Base64.urlsafe_encode(data)
+  continuation = URI.escape(data)
 
-  continuation = IO::Memory.new
-  continuation.write(Bytes[0x12, ucid.size])
-  continuation.print(ucid)
+  data = IO::Memory.new
 
-  continuation.write(Bytes[0x1a])
-  continuation.write(write_var_int(meta.size))
-  continuation.print(meta)
+  data.write_byte 0x12
+  VarInt.to_io(data, ucid.bytesize)
+  data.print ucid
 
-  continuation.rewind
-  continuation = continuation.gets_to_end
+  data.write_byte 0x1a
+  VarInt.to_io(data, continuation.bytesize)
+  data.print continuation
 
-  wrapper = IO::Memory.new
-  wrapper.write(Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02])
-  wrapper.write(write_var_int(continuation.size))
-  wrapper.print(continuation)
-  wrapper.rewind
+  data.rewind
 
-  wrapper = Base64.urlsafe_encode(wrapper.to_slice)
-  wrapper = URI.escape(wrapper)
+  buffer = IO::Memory.new
+  buffer.write Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02]
+  VarInt.to_io(buffer, data.bytesize)
 
-  url = "/browse_ajax?continuation=#{wrapper}&gl=US&hl=en"
+  IO.copy data, buffer
+
+  continuation = Base64.urlsafe_encode(buffer)
+  continuation = URI.escape(continuation)
+
+  url = "/browse_ajax?continuation=#{continuation}&gl=US&hl=en"
 
   return url
 end
 
 def extract_channel_playlists_cursor(url, auto_generated)
-  wrapper = HTTP::Params.parse(URI.parse(url).query.not_nil!)["continuation"]
+  continuation = HTTP::Params.parse(URI.parse(url).query.not_nil!)["continuation"]
 
-  wrapper = URI.unescape(wrapper)
-  wrapper = Base64.decode(wrapper)
+  continuation = URI.unescape(continuation)
+  data = IO::Memory.new(Base64.decode(continuation))
 
   # 0xe2 0xa9 0x85 0xb2 0x02
-  wrapper += 5
-
-  continuation_size = read_var_int(wrapper[0, 4])
-  wrapper += write_var_int(continuation_size).size
-  continuation = wrapper[0, continuation_size]
-
-  # 0x12
-  continuation += 1
-  ucid_size = continuation[0]
-  continuation += 1
-  ucid = continuation[0, ucid_size]
-  continuation += ucid_size
-
-  # 0x1a
-  continuation += 1
-  meta_size = read_var_int(continuation[0, 4])
-  continuation += write_var_int(meta_size).size
-  meta = continuation[0, meta_size]
-  continuation += meta_size
-
-  meta = String.new(meta)
-  meta = URI.unescape(meta)
-  meta = Base64.decode(meta)
+  data.pos += 5
+
+  continuation = Bytes.new(data.read_bytes(VarInt))
+  data.read continuation
+  data = IO::Memory.new(continuation)
+
+  data.read_byte # => 0x12
+  ucid = Bytes.new(data.read_bytes(VarInt))
+  data.read ucid
+
+  data.read_byte # => 0x1a
+  inner_continuation = Bytes.new(data.read_bytes(VarInt))
+  data.read inner_continuation
+
+  continuation = String.new(inner_continuation)
+  continuation = URI.unescape(continuation)
+  data = IO::Memory.new(Base64.decode(continuation))
 
   # 0x12 0x09 playlists
-  meta += 11
+  data.pos += 11
 
-  until meta[0] == 0x7a
-    tag = read_var_int(meta[0, 4])
-    meta += write_var_int(tag).size
-    value = meta[0]
-    meta += 1
+  until data.peek[0] == 0x7a
+    key = data.read_bytes(VarInt)
+    value = data.read_bytes(VarInt)
   end
 
-  # 0x7a
-  meta += 1
-  cursor_size = meta[0]
-  meta += 1
-  cursor = meta[0, cursor_size]
-
+  data.pos += 1 # => 0x7a
+  cursor = Bytes.new(data.read_bytes(VarInt))
+  data.read cursor
   cursor = String.new(cursor)
 
   if !auto_generated
@@ -874,20 +869,26 @@ end
 
 def produce_channel_community_continuation(ucid, cursor)
   cursor = URI.escape(cursor)
-  continuation = IO::Memory.new
 
-  continuation.write(Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02])
-  continuation.write(write_var_int(3 + ucid.size + write_var_int(cursor.size).size + cursor.size))
+  data = IO::Memory.new
+
+  data.write_byte 0x12
+  VarInt.to_io(data, ucid.bytesize)
+  data.print ucid
 
-  continuation.write(Bytes[0x12, ucid.size])
-  continuation.print(ucid)
+  data.write_byte 0x1a
+  VarInt.to_io(data, cursor.bytesize)
+  data.print cursor
 
-  continuation.write(Bytes[0x1a])
-  continuation.write(write_var_int(cursor.size))
-  continuation.print(cursor)
-  continuation.rewind
+  data.rewind
 
-  continuation = Base64.urlsafe_encode(continuation.to_slice)
+  buffer = IO::Memory.new
+  buffer.write Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02]
+  VarInt.to_io(buffer, data.size)
+
+  IO.copy data, buffer
+
+  continuation = Base64.urlsafe_encode(buffer)
   continuation = URI.escape(continuation)
 
   return continuation
@@ -895,28 +896,25 @@ end
 
 def extract_channel_community_cursor(continuation)
   continuation = URI.unescape(continuation)
-  continuation = Base64.decode(continuation)
+  data = IO::Memory.new(Base64.decode(continuation))
 
   # 0xe2 0xa9 0x85 0xb2 0x02
-  continuation += 5
-
-  total_size = read_var_int(continuation[0, 4])
-  continuation += write_var_int(total_size).size
-
-  # 0x12
-  continuation += 1
-  ucid_size = continuation[0]
-  continuation += 1
-  ucid = continuation[0, ucid_size]
-  continuation += ucid_size
-
-  # 0x1a
-  continuation += 1
-  until continuation[0] == 'E'.ord
-    continuation += 1
+  data.pos += 5
+
+  continuation = Bytes.new(data.read_bytes(VarInt))
+  data.read continuation
+  data = IO::Memory.new(continuation)
+
+  data.read_byte # => 0x12
+  ucid = Bytes.new(data.read_bytes(VarInt))
+  data.read ucid
+
+  data.read_byte # => 0x1a
+  until data.peek[0] == 'E'.ord
+    data.read_byte
   end
 
-  return String.new(continuation)
+  return URI.unescape(data.gets_to_end)
 end
 
 def get_about_info(ucid, locale)
diff --git a/src/invidious/comments.cr b/src/invidious/comments.cr
index b72f8ec7..e060fe46 100644
--- a/src/invidious/comments.cr
+++ b/src/invidious/comments.cr
@@ -564,108 +564,105 @@ def content_to_comment_html(content)
 end
 
 def produce_comment_continuation(video_id, cursor = "", sort_by = "top")
-  continuation = IO::Memory.new
+  data = IO::Memory.new
 
-  continuation.write(Bytes[0x12, 0x26])
+  data.write Bytes[0x12, 0x26]
 
-  continuation.write(Bytes[0x12, video_id.size])
-  continuation.print(video_id)
+  data.write_byte 0x12
+  VarInt.to_io(data, video_id.bytesize)
+  data.print video_id
 
-  continuation.write(Bytes[0xc0, 0x01, 0x01])
-  continuation.write(Bytes[0xc8, 0x01, 0x01])
-  continuation.write(Bytes[0xe0, 0x01, 0x01])
+  data.write Bytes[0xc0, 0x01, 0x01]
+  data.write Bytes[0xc8, 0x01, 0x01]
+  data.write Bytes[0xe0, 0x01, 0x01]
 
-  continuation.write(Bytes[0xa2, 0x02, 0x0d])
-  continuation.write(Bytes[0x28, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01])
+  data.write Bytes[0xa2, 0x02, 0x0d]
+  data.write Bytes[0x28, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01]
 
-  continuation.write(Bytes[0x40, 0x00])
-  continuation.write(Bytes[0x18, 0x06])
+  data.write Bytes[0x40, 0x00]
+  data.write Bytes[0x18, 0x06]
 
   if cursor.empty?
-    continuation.write(Bytes[0x32])
-    continuation.write(write_var_int(video_id.size + 8))
+    data.write Bytes[0x32]
+    VarInt.to_io(data, cursor.bytesize + video_id.bytesize + 8)
 
-    continuation.write(Bytes[0x22, video_id.size + 4])
-    continuation.write(Bytes[0x22, video_id.size])
-    continuation.print(video_id)
+    data.write Bytes[0x22, video_id.bytesize + 4]
+    data.write Bytes[0x22, video_id.bytesize]
+    data.print video_id
 
     case sort_by
     when "top"
-      continuation.write(Bytes[0x30, 0x00])
+      data.write Bytes[0x30, 0x00]
     when "new", "newest"
-      continuation.write(Bytes[0x30, 0x01])
+      data.write Bytes[0x30, 0x01]
     end
 
-    continuation.write(Bytes[0x78, 0x02])
+    data.write(Bytes[0x78, 0x02])
   else
-    continuation.write(Bytes[0x32])
-    continuation.write(write_var_int(cursor.size + video_id.size + 11))
+    data.write Bytes[0x32]
+    VarInt.to_io(data, cursor.bytesize + video_id.bytesize + 11)
 
-    continuation.write(Bytes[0x0a])
-    continuation.write(write_var_int(cursor.size))
-    continuation.print(cursor)
+    data.write_byte 0x0a
+    VarInt.to_io(data, cursor.bytesize)
+    data.print cursor
 
-    continuation.write(Bytes[0x22, video_id.size + 4])
-    continuation.write(Bytes[0x22, video_id.size])
-    continuation.print(video_id)
+    data.write Bytes[0x22, video_id.bytesize + 4]
+    data.write Bytes[0x22, video_id.bytesize]
+    data.print video_id
 
     case sort_by
     when "top"
-      continuation.write(Bytes[0x30, 0x00])
+      data.write Bytes[0x30, 0x00]
     when "new", "newest"
-      continuation.write(Bytes[0x30, 0x01])
+      data.write Bytes[0x30, 0x01]
     end
 
-    continuation.write(Bytes[0x28, 0x14])
+    data.write Bytes[0x28, 0x14]
   end
 
-  continuation.rewind
-  continuation = continuation.gets_to_end
-
-  continuation = Base64.urlsafe_encode(continuation.to_slice)
+  continuation = Base64.urlsafe_encode(data)
   continuation = URI.escape(continuation)
 
   return continuation
 end
 
 def produce_comment_reply_continuation(video_id, ucid, comment_id)
-  continuation = IO::Memory.new
-
-  continuation.write(Bytes[0x12, 0x26])
+  data = IO::Memory.new
 
-  continuation.write(Bytes[0x12, video_id.size])
-  continuation.print(video_id)
+  data.write Bytes[0x12, 0x26]
 
-  continuation.write(Bytes[0xc0, 0x01, 0x01])
-  continuation.write(Bytes[0xc8, 0x01, 0x01])
-  continuation.write(Bytes[0xe0, 0x01, 0x01])
+  data.write_byte 0x12
+  VarInt.to_io(data, video_id.size)
+  data.print video_id
 
-  continuation.write(Bytes[0xa2, 0x02, 0x0d])
-  continuation.write(Bytes[0x28, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01])
+  data.write Bytes[0xc0, 0x01, 0x01]
+  data.write Bytes[0xc8, 0x01, 0x01]
+  data.write Bytes[0xe0, 0x01, 0x01]
 
-  continuation.write(Bytes[0x40, 0x00])
-  continuation.write(Bytes[0x18, 0x06])
+  data.write Bytes[0xa2, 0x02, 0x0d]
+  data.write Bytes[0x28, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01]
 
-  continuation.write(Bytes[0x32, ucid.size + video_id.size + comment_id.size + 16])
-  continuation.write(Bytes[0x1a, ucid.size + video_id.size + comment_id.size + 14])
+  data.write Bytes[0x40, 0x00]
+  data.write Bytes[0x18, 0x06]
 
-  continuation.write(Bytes[0x12, comment_id.size])
-  continuation.print(comment_id)
+  data.write(Bytes[0x32, ucid.size + video_id.size + comment_id.size + 16])
+  data.write(Bytes[0x1a, ucid.size + video_id.size + comment_id.size + 14])
 
-  continuation.write(Bytes[0x22, 0x02, 0x08, 0x00]) # ??
+  data.write_byte 0x12
+  VarInt.to_io(data, comment_id.size)
+  data.print comment_id
 
-  continuation.write(Bytes[ucid.size + video_id.size + 7])
-  continuation.write(Bytes[ucid.size])
-  continuation.print(ucid)
-  continuation.write(Bytes[0x32, video_id.size])
-  continuation.print(video_id)
-  continuation.write(Bytes[0x40, 0x01])
-  continuation.write(Bytes[0x48, 0x0a])
+  data.write(Bytes[0x22, 0x02, 0x08, 0x00]) # ??
 
-  continuation.rewind
-  continuation = continuation.gets_to_end
+  data.write(Bytes[ucid.size + video_id.size + 7])
+  data.write(Bytes[ucid.size])
+  data.print(ucid)
+  data.write(Bytes[0x32, video_id.size])
+  data.print(video_id)
+  data.write(Bytes[0x40, 0x01])
+  data.write(Bytes[0x48, 0x0a])
 
-  continuation = Base64.urlsafe_encode(continuation.to_slice)
+  continuation = Base64.urlsafe_encode(data.to_slice)
   continuation = URI.escape(continuation)
 
   return continuation
diff --git a/src/invidious/helpers/utils.cr b/src/invidious/helpers/utils.cr
index b7deae76..69aae839 100644
--- a/src/invidious/helpers/utils.cr
+++ b/src/invidious/helpers/utils.cr
@@ -266,50 +266,40 @@ def get_referer(env, fallback = "/", unroll = true)
   return referer
 end
 
-def read_var_int(bytes)
-  num_read = 0
-  result = 0
+struct VarInt
+  def self.from_io(io : IO, format = IO::ByteFormat::BigEndian) : Int32
+    result = 0_i32
+    num_read = 0
 
-  read = bytes[num_read]
-
-  if bytes.size == 1
-    result = bytes[0].to_i32
-  else
-    while ((read & 0b10000000) != 0)
-      read = bytes[num_read].to_u64
-      value = (read & 0b01111111)
-      result |= (value << (7 * num_read))
+    loop do
+      byte = io.read_byte
+      raise "Invalid VarInt" if !byte
+      value = byte & 0x7f
 
+      result |= value.to_i32 << (7 * num_read)
       num_read += 1
-      if num_read > 5
-        raise "VarInt is too big"
-      end
+
+      break if byte & 0x80 == 0
+      raise "Invalid VarInt" if num_read > 5
     end
-  end
 
-  return result
-end
+    result
+  end
 
-def write_var_int(value : Int)
-  bytes = [] of UInt8
-  value = value.to_u32
+  def self.to_io(io : IO, value : Int32)
+    io.write_byte 0x00 if value == 0x00
 
-  if value == 0
-    bytes = [0_u8]
-  else
     while value != 0
-      temp = (value & 0b01111111).to_u8
-      value = value >> 7
+      byte = (value & 0x7f).to_u8
+      value >>= 7
 
       if value != 0
-        temp |= 0b10000000
+        byte |= 0x80
       end
 
-      bytes << temp
+      io.write_byte byte
     end
   end
-
-  return Slice.new(bytes.to_unsafe, bytes.size)
 end
 
 def sha256(text)
diff --git a/src/invidious/playlists.cr b/src/invidious/playlists.cr
index 373d1fba..d28a4149 100644
--- a/src/invidious/playlists.cr
+++ b/src/invidious/playlists.cr
@@ -157,37 +157,44 @@ def produce_playlist_url(id, index)
   end
   ucid = "VL" + id
 
-  meta = IO::Memory.new
-  meta.write(Bytes[0x08])
-  meta.write(write_var_int(index))
+  data = IO::Memory.new
+  data.write_byte 0x08
+  VarInt.to_io(data, index)
 
-  meta.rewind
-  meta = Base64.urlsafe_encode(meta.to_slice, false)
-  meta = "PT:#{meta}"
+  data.rewind
+  data = Base64.urlsafe_encode(data, false)
+  data = "PT:#{data}"
 
   continuation = IO::Memory.new
-  continuation.write(Bytes[0x7a, meta.size])
-  continuation.print(meta)
+  continuation.write_byte 0x7a
+  VarInt.to_io(continuation, data.bytesize)
+  continuation.print data
 
-  continuation.rewind
-  meta = Base64.urlsafe_encode(continuation.to_slice)
-  meta = URI.escape(meta)
+  data = Base64.urlsafe_encode(continuation)
+  cursor = URI.escape(data)
 
-  continuation = IO::Memory.new
-  continuation.write(Bytes[0x12, ucid.size])
-  continuation.print(ucid)
-  continuation.write(Bytes[0x1a, meta.size])
-  continuation.print(meta)
+  data = IO::Memory.new
+
+  data.write_byte 0x12
+  VarInt.to_io(data, ucid.bytesize)
+  data.print ucid
+
+  data.write_byte 0x1a
+  VarInt.to_io(data, cursor.bytesize)
+  data.print cursor
+
+  data.rewind
+
+  buffer = IO::Memory.new
+  buffer.write Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02]
+  VarInt.to_io(buffer, data.bytesize)
 
-  wrapper = IO::Memory.new
-  wrapper.write(Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02, continuation.size])
-  wrapper.print(continuation)
-  wrapper.rewind
+  IO.copy data, buffer
 
-  wrapper = Base64.urlsafe_encode(wrapper.to_slice)
-  wrapper = URI.escape(wrapper)
+  continuation = Base64.urlsafe_encode(buffer)
+  continuation = URI.escape(continuation)
 
-  url = "/browse_ajax?continuation=#{wrapper}&gl=US&hl=en"
+  url = "/browse_ajax?continuation=#{continuation}&gl=US&hl=en"
 
   return url
 end
diff --git a/src/invidious/search.cr b/src/invidious/search.cr
index ebeb2236..79bfd55a 100644
--- a/src/invidious/search.cr
+++ b/src/invidious/search.cr
@@ -374,45 +374,51 @@ end
 def produce_channel_search_url(ucid, query, page)
   page = "#{page}"
 
-  meta = IO::Memory.new
-  meta.write(Bytes[0x12, 0x06])
-  meta.print("search")
+  data = IO::Memory.new
+  data.write_byte 0x12
+  data.write_byte 0x06
+  data.print "search"
 
-  meta.write(Bytes[0x30, 0x02])
-  meta.write(Bytes[0x38, 0x01])
-  meta.write(Bytes[0x60, 0x01])
-  meta.write(Bytes[0x6a, 0x00])
-  meta.write(Bytes[0xb8, 0x01, 0x00])
+  data.write Bytes[0x30, 0x02]
+  data.write Bytes[0x38, 0x01]
+  data.write Bytes[0x60, 0x01]
+  data.write Bytes[0x6a, 0x00]
+  data.write Bytes[0xb8, 0x01, 0x00]
 
-  meta.write(Bytes[0x7a, page.size])
-  meta.print(page)
+  data.write_byte 0x7a
+  VarInt.to_io(data, page.bytesize)
+  data.print page
 
-  meta.rewind
-  meta = Base64.urlsafe_encode(meta.to_slice)
-  meta = URI.escape(meta)
+  data.rewind
+  data = Base64.urlsafe_encode(data)
+  continuation = URI.escape(data)
 
-  continuation = IO::Memory.new
-  continuation.write(Bytes[0x12, ucid.size])
-  continuation.print(ucid)
+  data = IO::Memory.new
 
-  continuation.write(Bytes[0x1a, meta.size])
-  continuation.print(meta)
+  data.write_byte 0x12
+  VarInt.to_io(data, ucid.bytesize)
+  data.print ucid
 
-  continuation.write(Bytes[0x5a, query.size])
-  continuation.print(query)
+  data.write_byte 0x1a
+  VarInt.to_io(data, continuation.bytesize)
+  data.print continuation
 
-  continuation.rewind
-  continuation = continuation.gets_to_end
+  data.write_byte 0x5a
+  VarInt.to_io(data, query.bytesize)
+  data.print query
 
-  wrapper = IO::Memory.new
-  wrapper.write(Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02, continuation.size])
-  wrapper.print(continuation)
-  wrapper.rewind
+  data.rewind
 
-  wrapper = Base64.urlsafe_encode(wrapper.to_slice)
-  wrapper = URI.escape(wrapper)
+  buffer = IO::Memory.new
+  buffer.write Bytes[0xe2, 0xa9, 0x85, 0xb2, 0x02]
+  VarInt.to_io(buffer, data.bytesize)
 
-  url = "/browse_ajax?continuation=#{wrapper}&gl=US&hl=en"
+  IO.copy data, buffer
+
+  continuation = Base64.urlsafe_encode(buffer)
+  continuation = URI.escape(continuation)
+
+  url = "/browse_ajax?continuation=#{continuation}&gl=US&hl=en"
 
   return url
 end