1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/2d/UserData.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,128 @@
1.4 +/* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef MOZILLA_GFX_USERDATA_H_
1.10 +#define MOZILLA_GFX_USERDATA_H_
1.11 +
1.12 +#include <stdlib.h>
1.13 +#include "Types.h"
1.14 +#include "mozilla/Assertions.h"
1.15 +
1.16 +namespace mozilla {
1.17 +namespace gfx {
1.18 +
1.19 +struct UserDataKey {
1.20 + int unused;
1.21 +};
1.22 +
1.23 +/* this class is basically a clone of the user data concept from cairo */
1.24 +class UserData
1.25 +{
1.26 + typedef void (*destroyFunc)(void *data);
1.27 +public:
1.28 + UserData() : count(0), entries(nullptr) {}
1.29 +
1.30 + /* Attaches untyped userData associated with key. destroy is called on destruction */
1.31 + void Add(UserDataKey *key, void *userData, destroyFunc destroy)
1.32 + {
1.33 + for (int i=0; i<count; i++) {
1.34 + if (key == entries[i].key) {
1.35 + if (entries[i].destroy) {
1.36 + entries[i].destroy(entries[i].userData);
1.37 + }
1.38 + entries[i].userData = userData;
1.39 + entries[i].destroy = destroy;
1.40 + return;
1.41 + }
1.42 + }
1.43 +
1.44 + // We could keep entries in a std::vector instead of managing it by hand
1.45 + // but that would propagate an stl dependency out which we'd rather not
1.46 + // do (see bug 666609). Plus, the entries array is expect to stay small
1.47 + // so doing a realloc everytime we add a new entry shouldn't be too costly
1.48 + entries = static_cast<Entry*>(realloc(entries, sizeof(Entry)*(count+1)));
1.49 +
1.50 + if (!entries) {
1.51 + MOZ_CRASH();
1.52 + }
1.53 +
1.54 + entries[count].key = key;
1.55 + entries[count].userData = userData;
1.56 + entries[count].destroy = destroy;
1.57 +
1.58 + count++;
1.59 + }
1.60 +
1.61 + /* Remove and return user data associated with key, without destroying it */
1.62 + void* Remove(UserDataKey *key)
1.63 + {
1.64 + for (int i=0; i<count; i++) {
1.65 + if (key == entries[i].key) {
1.66 + void *userData = entries[i].userData;
1.67 + // decrement before looping so entries[i+1] doesn't read past the end:
1.68 + --count;
1.69 + for (;i<count; i++) {
1.70 + entries[i] = entries[i+1];
1.71 + }
1.72 + return userData;
1.73 + }
1.74 + }
1.75 + return nullptr;
1.76 + }
1.77 +
1.78 + /* Retrives the userData for the associated key */
1.79 + void *Get(UserDataKey *key) const
1.80 + {
1.81 + for (int i=0; i<count; i++) {
1.82 + if (key == entries[i].key) {
1.83 + return entries[i].userData;
1.84 + }
1.85 + }
1.86 + return nullptr;
1.87 + }
1.88 +
1.89 + bool Has(UserDataKey *key)
1.90 + {
1.91 + for (int i=0; i<count; i++) {
1.92 + if (key == entries[i].key) {
1.93 + return true;
1.94 + }
1.95 + }
1.96 + return false;
1.97 + }
1.98 +
1.99 + void Destroy()
1.100 + {
1.101 + for (int i=0; i<count; i++) {
1.102 + if (entries[i].destroy) {
1.103 + entries[i].destroy(entries[i].userData);
1.104 + }
1.105 + }
1.106 + free(entries);
1.107 + entries = nullptr;
1.108 + count = 0;
1.109 + }
1.110 +
1.111 + ~UserData()
1.112 + {
1.113 + Destroy();
1.114 + }
1.115 +
1.116 +private:
1.117 + struct Entry {
1.118 + const UserDataKey *key;
1.119 + void *userData;
1.120 + destroyFunc destroy;
1.121 + };
1.122 +
1.123 + int count;
1.124 + Entry *entries;
1.125 +
1.126 +};
1.127 +
1.128 +}
1.129 +}
1.130 +
1.131 +#endif /* MOZILLA_GFX_USERDATA_H_ */
