Add HpackDecoderTables, static and dynamic tables for decoding HPACK.

net/http2/tools/random_util.cc

+// Copyright 2016 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/http2/tools/random_util.h"
+
+#include <cmath>
+
+#include "net/http2/tools/http2_random.h"
+
+using std::string;
+using base::StringPiece;
+
+namespace net {
+namespace test {
+
+const char kWebsafe64[] =
+    "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_";
+
+string RandomString(RandomBase* rng, int len, StringPiece alphabet) {
+  string random_string;
+  random_string.reserve(len);
+  for (int i = 0; i < len; ++i)
+    random_string.push_back(alphabet[rng->Uniform(alphabet.size())]);
+  return random_string;
+}
+
+size_t GenerateUniformInRange(size_t lo, size_t hi, RandomBase* rng) {
+  if (lo + 1 >= hi) {
+    return lo;
+  }
+  return lo + rng->Rand64() % (hi - lo);
+}
+
+// Here "word" means something that starts with a lower-case letter, and has
+// zero or more additional characters that are numbers or lower-case letters.
+string GenerateHttp2HeaderName(size_t len, RandomBase* rng) {
+  StringPiece alpha_lc = "abcdefghijklmnopqrstuvwxyz";
+  // If the name is short, just make it one word.
+  if (len < 8) {
+    return RandomString(rng, len, alpha_lc);
+  }
+  // If the name is longer, ensure it starts with a word, and after that may
+  // have any character in alphanumdash_lc. 4 is arbitrary, could be as low
+  // as 1.
+  StringPiece alphanumdash_lc = "abcdefghijklmnopqrstuvwxyz0123456789-";
+  return RandomString(rng, 4, alpha_lc) +
+         RandomString(rng, len - 4, alphanumdash_lc);
+}
+
+string GenerateWebSafeString(size_t len, RandomBase* rng) {
+  return RandomString(rng, len, kWebsafe64);
+}
+
+string GenerateWebSafeString(size_t lo, size_t hi, RandomBase* rng) {
+  return GenerateWebSafeString(GenerateUniformInRange(lo, hi, rng), rng);
+}
+
+}  // namespace test
+}  // namespace net