chrome/browser/browsing_data/canonical_cookie_hash.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // Provides utility structures for inserting a CanonicalCookie into a hash set.
   6 // Two cookies are considered equal if their names, domains, and paths are
   7 // equivalent.
   8
   9 #ifndef CHROME_BROWSER_BROWSING_DATA_CANONICAL_COOKIE_HASH_H_
  10 #define CHROME_BROWSER_BROWSING_DATA_CANONICAL_COOKIE_HASH_H_
  11
  12 #if defined(COMPILER_MSVC)
  13 #include <functional>
  14 #endif  // COMPILER_MSVC
  15
  16 #include "base/containers/hash_tables.h"
  17 #include "net/cookies/canonical_cookie.h"
  18
  19 namespace canonical_cookie {
  20
  21 // Returns a fast hash of a cookie, based on its name, domain, and path.
  22 size_t FastHash(const net::CanonicalCookie& cookie);
  23
  24 #if defined(COMPILER_MSVC)
  25 struct CanonicalCookieTraits {
  26   static const size_t bucket_size = 4;
  27
  28   // Returns a hash of |cookie|.
  29   size_t operator()(const net::CanonicalCookie& cookie) const {
  30     return FastHash(cookie);
  31   }
  32
  33   // The 'less' operator on cookies. We need to create a total ordering. We
  34   // order lexigraphically, first by name, then path, then domain. Name is most
  35   // likely to be distinct, so it is compared first, and domain is least likely
  36   // to be distinct, so it is compared last.
  37   bool operator()(const net::CanonicalCookie& cookie1,
  38                   const net::CanonicalCookie& cookie2) const {
  39     std::less<std::string> less_than;
  40     if (less_than(cookie1.Name(), cookie2.Name()))
  41       return true;
  42     if (less_than(cookie2.Name(), cookie1.Name()))
  43       return false;
  44     if (less_than(cookie1.Path(), cookie2.Path()))
  45       return true;
  46     if (less_than(cookie2.Path(), cookie1.Path()))
  47       return false;
  48     if (less_than(cookie1.Domain(), cookie2.Domain()))
  49       return true;
  50     if (less_than(cookie2.Domain(), cookie1.Domain()))
  51       return false;
  52
  53     // The cookies are equivalent.
  54     return false;
  55   }
  56 };
  57
  58 typedef base::hash_set<net::CanonicalCookie, CanonicalCookieTraits>
  59     CookieHashSet;
  60
  61 #else  // COMPILER_MSVC
  62
  63 struct CanonicalCookieHasher {
  64   std::size_t operator()(const net::CanonicalCookie& cookie) const {
  65     return FastHash(cookie);
  66   }
  67 };
  68
  69 struct CanonicalCookieComparer {
  70   bool operator()(const net::CanonicalCookie& cookie1,
  71                   const net::CanonicalCookie& cookie2) const {
  72     return cookie1.Name() == cookie2.Name() &&
  73            cookie1.Domain() == cookie2.Domain() &&
  74            cookie1.Path() == cookie2.Path();
  75   }
  76 };
  77
  78 typedef base::hash_set<net::CanonicalCookie,
  79                        CanonicalCookieHasher,
  80                        CanonicalCookieComparer> CookieHashSet;
  81
  82 #endif  // COMPILER_MSVC
  83
  84 };  // namespace canonical_cookie
  85
  86 #endif  // CHROME_BROWSER_BROWSING_DATA_CANONICAL_COOKIE_HASH_H_