HPACK: Add HpackHuffmanTable::EncodedSize()

net/spdy/hpack_huffman_table.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/spdy/hpack_huffman_table.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/logging.h"
@@ skipping 230 matching lines @@
       length = 8;
     }
     out->AppendBits(static_cast<uint8>(code), length);
   }
   if (bit_remnant != 0) {
     // Pad current byte as required.
     out->AppendBits(pad_bits_ >> bit_remnant, 8 - bit_remnant);
   }
 }
 
+size_t HpackHuffmanTable::EncodedSize(StringPiece in) const {
+  size_t bit_count = 0;
+  for (size_t i = 0; i != in.size(); i++) {
+    uint16 symbol_id = static_cast<uint8>(in[i]);
+    CHECK_GT(code_by_id_.size(), symbol_id);
+
+    bit_count += length_by_id_[symbol_id];
+  }
+  if (bit_count % 8 != 0) {
+    bit_count += 8 - bit_count % 8;
+  }
+  return bit_count / 8;
+}
+
 bool HpackHuffmanTable::DecodeString(HpackInputStream* in,
                                      size_t out_capacity,
                                      string* out) const {
   // Number of decode iterations required for a 32-bit code.
   const int kDecodeIterations = static_cast<int>(
       std::ceil((32.f - kDecodeTableRootBits) / kDecodeTableBranchBits));
 
   out->clear();
 
   // Current input, stored in the high |bits_available| bits of |bits|.
@@ skipping 39 matching lines @@
       bits = bits << entry.length;
       bits_available -= entry.length;
     }
     peeked_success = in->PeekBits(&bits_available, &bits);
   }
   NOTREACHED();
   return false;
 }
 
 }  // namespace net