gfx/2d/UserData.h@97036ab72558 (annotated)
gfx/2d/UserData.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
| michael@0 | 1 | /* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- |
| michael@0 | 2 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | #ifndef MOZILLA_GFX_USERDATA_H_ |
| michael@0 | 7 | #define MOZILLA_GFX_USERDATA_H_ |
| michael@0 | 8 | |
| michael@0 | 9 | #include <stdlib.h> |
| michael@0 | 10 | #include "Types.h" |
| michael@0 | 11 | #include "mozilla/Assertions.h" |
| michael@0 | 12 | |
| michael@0 | 13 | namespace mozilla { |
| michael@0 | 14 | namespace gfx { |
| michael@0 | 15 | |
| michael@0 | 16 | struct UserDataKey { |
| michael@0 | 17 | int unused; |
| michael@0 | 18 | }; |
| michael@0 | 19 | |
| michael@0 | 20 | /* this class is basically a clone of the user data concept from cairo */ |
| michael@0 | 21 | class UserData |
| michael@0 | 22 | { |
| michael@0 | 23 | typedef void (*destroyFunc)(void *data); |
| michael@0 | 24 | public: |
| michael@0 | 25 | UserData() : count(0), entries(nullptr) {} |
| michael@0 | 26 | |
| michael@0 | 27 | /* Attaches untyped userData associated with key. destroy is called on destruction */ |
| michael@0 | 28 | void Add(UserDataKey *key, void *userData, destroyFunc destroy) |
| michael@0 | 29 | { |
| michael@0 | 30 | for (int i=0; i<count; i++) { |
| michael@0 | 31 | if (key == entries[i].key) { |
| michael@0 | 32 | if (entries[i].destroy) { |
| michael@0 | 33 | entries[i].destroy(entries[i].userData); |
| michael@0 | 34 | } |
| michael@0 | 35 | entries[i].userData = userData; |
| michael@0 | 36 | entries[i].destroy = destroy; |
| michael@0 | 37 | return; |
| michael@0 | 38 | } |
| michael@0 | 39 | } |
| michael@0 | 40 | |
| michael@0 | 41 | // We could keep entries in a std::vector instead of managing it by hand |
| michael@0 | 42 | // but that would propagate an stl dependency out which we'd rather not |
| michael@0 | 43 | // do (see bug 666609). Plus, the entries array is expect to stay small |
| michael@0 | 44 | // so doing a realloc everytime we add a new entry shouldn't be too costly |
| michael@0 | 45 | entries = static_cast<Entry*>(realloc(entries, sizeof(Entry)*(count+1))); |
| michael@0 | 46 | |
| michael@0 | 47 | if (!entries) { |
| michael@0 | 48 | MOZ_CRASH(); |
| michael@0 | 49 | } |
| michael@0 | 50 | |
| michael@0 | 51 | entries[count].key = key; |
| michael@0 | 52 | entries[count].userData = userData; |
| michael@0 | 53 | entries[count].destroy = destroy; |
| michael@0 | 54 | |
| michael@0 | 55 | count++; |
| michael@0 | 56 | } |
| michael@0 | 57 | |
| michael@0 | 58 | /* Remove and return user data associated with key, without destroying it */ |
| michael@0 | 59 | void* Remove(UserDataKey *key) |
| michael@0 | 60 | { |
| michael@0 | 61 | for (int i=0; i<count; i++) { |
| michael@0 | 62 | if (key == entries[i].key) { |
| michael@0 | 63 | void *userData = entries[i].userData; |
| michael@0 | 64 | // decrement before looping so entries[i+1] doesn't read past the end: |
| michael@0 | 65 | --count; |
| michael@0 | 66 | for (;i<count; i++) { |
| michael@0 | 67 | entries[i] = entries[i+1]; |
| michael@0 | 68 | } |
| michael@0 | 69 | return userData; |
| michael@0 | 70 | } |
| michael@0 | 71 | } |
| michael@0 | 72 | return nullptr; |
| michael@0 | 73 | } |
| michael@0 | 74 | |
| michael@0 | 75 | /* Retrives the userData for the associated key */ |
| michael@0 | 76 | void *Get(UserDataKey *key) const |
| michael@0 | 77 | { |
| michael@0 | 78 | for (int i=0; i<count; i++) { |
| michael@0 | 79 | if (key == entries[i].key) { |
| michael@0 | 80 | return entries[i].userData; |
| michael@0 | 81 | } |
| michael@0 | 82 | } |
| michael@0 | 83 | return nullptr; |
| michael@0 | 84 | } |
| michael@0 | 85 | |
| michael@0 | 86 | bool Has(UserDataKey *key) |
| michael@0 | 87 | { |
| michael@0 | 88 | for (int i=0; i<count; i++) { |
| michael@0 | 89 | if (key == entries[i].key) { |
| michael@0 | 90 | return true; |
| michael@0 | 91 | } |
| michael@0 | 92 | } |
| michael@0 | 93 | return false; |
| michael@0 | 94 | } |
| michael@0 | 95 | |
| michael@0 | 96 | void Destroy() |
| michael@0 | 97 | { |
| michael@0 | 98 | for (int i=0; i<count; i++) { |
| michael@0 | 99 | if (entries[i].destroy) { |
| michael@0 | 100 | entries[i].destroy(entries[i].userData); |
| michael@0 | 101 | } |
| michael@0 | 102 | } |
| michael@0 | 103 | free(entries); |
| michael@0 | 104 | entries = nullptr; |
| michael@0 | 105 | count = 0; |
| michael@0 | 106 | } |
| michael@0 | 107 | |
| michael@0 | 108 | ~UserData() |
| michael@0 | 109 | { |
| michael@0 | 110 | Destroy(); |
| michael@0 | 111 | } |
| michael@0 | 112 | |
| michael@0 | 113 | private: |
| michael@0 | 114 | struct Entry { |
| michael@0 | 115 | const UserDataKey *key; |
| michael@0 | 116 | void *userData; |
| michael@0 | 117 | destroyFunc destroy; |
| michael@0 | 118 | }; |
| michael@0 | 119 | |
| michael@0 | 120 | int count; |
| michael@0 | 121 | Entry *entries; |
| michael@0 | 122 | |
| michael@0 | 123 | }; |
| michael@0 | 124 | |
| michael@0 | 125 | } |
| michael@0 | 126 | } |
| michael@0 | 127 | |
| michael@0 | 128 | #endif /* MOZILLA_GFX_USERDATA_H_ */ |
