1 // Copyright 2013 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 #ifndef EXTENSIONS_BROWSER_PROCESS_MAP_H_ 6 #define EXTENSIONS_BROWSER_PROCESS_MAP_H_ 7 8 #include <set> 9 #include <string> 10 11 #include "base/basictypes.h" 12 13 namespace extensions { 14 15 // Contains information about which extensions are assigned to which processes. 16 // 17 // The relationship between extensions and processes is complex: 18 // 19 // - Extensions can be either "split" mode or "spanning" mode. 20 // - In spanning mode, extensions share a single process between all incognito 21 // and normal windows. This was the original mode for extensions. 22 // - In split mode, extensions have separate processes in incognito windows. 23 // - There are also hosted apps, which are a kind of extensions, and those 24 // usually have a process model similar to normal web sites: multiple 25 // processes per-profile. 26 // - A single hosted app can have more than one SiteInstance in the same process 27 // if we're over the process limit and force them to share a process. 28 // 29 // In general, we seem to play with the process model of extensions a lot, so 30 // it is safest to assume it is many-to-many in most places in the codebase. 31 // 32 // Note that because of content scripts, frames, and other edge cases in 33 // Chrome's process isolation, extension code can still end up running outside 34 // an assigned process. 35 // 36 // But we only allow high-privilege operations to be performed by an extension 37 // when it is running in an assigned process. 38 // 39 // =========================================================================== 40 // WARNINGS - PLEASE UNDERSTAND THESE BEFORE CALLING OR MODIFYING THIS CLASS 41 // =========================================================================== 42 // 43 // 1. This class contains the processes for hosted apps as well as extensions 44 // and packaged apps. Just because a process is present here *does not* mean 45 // it is an "extension process" (e.g., for UI purposes). It may contain only 46 // hosted apps. See crbug.com/102533. 47 // 48 // 2. An extension can show up in multiple processes. That is why there is no 49 // GetExtensionProcess() method here. There are two cases: a) The extension 50 // is actually a hosted app, in which case this is normal, or b) there is an 51 // incognito window open and the extension is "split mode". It is *not safe* 52 // to assume that there is one process per extension. If you only care about 53 // extensions (not hosted apps), and you are on the UI thread, and you don't 54 // care about incognito version of this extension (or vice versa if you're in 55 // an incognito profile) then use 56 // extensions::ProcessManager::GetSiteInstanceForURL()->[Has|Get]Process(). 57 // 58 // 3. The process ids contained in this class are *not limited* to the Profile 59 // you got this map from. They can also be associated with that profile's 60 // incognito/normal twin. If you care about this, use 61 // RenderProcessHost::FromID() and check the profile of the resulting object. 62 // 63 // TODO(aa): The above warnings suggest this class could use improvement :). 64 class ProcessMap { 65 public: 66 ProcessMap(); 67 ~ProcessMap(); 68 69 size_t size() const { return items_.size(); } 70 71 bool Insert(const std::string& extension_id, int process_id, 72 int site_instance_id); 73 74 bool Remove(const std::string& extension_id, int process_id, 75 int site_instance_id); 76 int RemoveAllFromProcess(int process_id); 77 78 bool Contains(const std::string& extension_id, int process_id) const; 79 bool Contains(int process_id) const; 80 81 std::set<std::string> GetExtensionsInProcess(int process_id) const; 82 83 private: 84 struct Item; 85 86 typedef std::set<Item> ItemSet; 87 ItemSet items_; 88 89 DISALLOW_COPY_AND_ASSIGN(ProcessMap); 90 }; 91 92 } // extensions 93 94 #endif // EXTENSIONS_BROWSER_PROCESS_MAP_H_ 95
