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.
5 #ifndef EXTENSIONS_BROWSER_USER_SCRIPT_LOADER_H_
6 #define EXTENSIONS_BROWSER_USER_SCRIPT_LOADER_H_
11 #include "base/compiler_specific.h"
12 #include "base/memory/scoped_ptr.h"
13 #include "base/memory/shared_memory.h"
14 #include "base/memory/weak_ptr.h"
15 #include "base/observer_list.h"
16 #include "base/scoped_observer.h"
17 #include "content/public/browser/notification_observer.h"
18 #include "content/public/browser/notification_registrar.h"
19 #include "extensions/common/host_id.h"
20 #include "extensions/common/user_script.h"
28 class RenderProcessHost
;
31 namespace extensions
{
33 // Manages one "logical unit" of user scripts in shared memory by constructing a
34 // new shared memory region when the set of scripts changes. Also notifies
35 // renderers of new shared memory region when new renderers appear, or when
36 // script reloading completes. Script loading lives on the UI thread. Instances
37 // of this class are embedded within classes with names ending in
38 // UserScriptMaster. These "master" classes implement the strategy for which
39 // scripts to load/unload on this logical unit of scripts.
40 class UserScriptLoader
: public content::NotificationObserver
{
42 using LoadScriptsCallback
=
43 base::Callback
<void(scoped_ptr
<UserScriptList
>,
44 scoped_ptr
<base::SharedMemory
>)>;
47 virtual void OnScriptsLoaded(UserScriptLoader
* loader
) = 0;
48 virtual void OnUserScriptLoaderDestroyed(UserScriptLoader
* loader
) = 0;
51 // Parses the includes out of |script| and returns them in |includes|.
52 static bool ParseMetadataHeader(const base::StringPiece
& script_text
,
55 UserScriptLoader(content::BrowserContext
* browser_context
,
56 const HostID
& host_id
);
57 ~UserScriptLoader() override
;
59 // Add |scripts| to the set of scripts managed by this loader.
60 void AddScripts(const std::set
<UserScript
>& scripts
);
62 // Add |scripts| to the set of scripts managed by this loader.
63 // The fetch of the content of the script starts URL request
64 // to the associated render specified by
65 // |render_process_id, render_view_id|.
66 // TODO(hanxi): The renderer information doesn't really belong in this base
67 // class, but it's not an easy fix.
68 virtual void AddScripts(const std::set
<UserScript
>& scripts
,
69 int render_process_id
,
72 // Remove |scripts| from the set of scripts managed by this loader.
73 void RemoveScripts(const std::set
<UserScript
>& scripts
);
75 // Clears the set of scripts managed by this loader.
78 // Initiates procedure to start loading scripts on the file thread.
81 // Returns true if we have any scripts ready.
82 bool scripts_ready() const { return shared_memory_
.get() != NULL
; }
84 // Pickle user scripts and return pointer to the shared memory.
85 static scoped_ptr
<base::SharedMemory
> Serialize(
86 const extensions::UserScriptList
& scripts
);
88 // Adds or removes observers.
89 void AddObserver(Observer
* observer
);
90 void RemoveObserver(Observer
* observer
);
93 // Allows the derived classes have different ways to load user scripts.
94 virtual void LoadScripts(scoped_ptr
<UserScriptList
> user_scripts
,
95 const std::set
<HostID
>& changed_hosts
,
96 const std::set
<int>& added_script_ids
,
97 LoadScriptsCallback callback
) = 0;
99 // Sets the flag if the initial set of hosts has finished loading; if it's
100 // set to be true, calls AttempLoad() to bootstrap.
101 void SetReady(bool ready
);
103 content::BrowserContext
* browser_context() const { return browser_context_
; }
104 const HostID
& host_id() const { return host_id_
; }
107 // content::NotificationObserver implementation.
108 void Observe(int type
,
109 const content::NotificationSource
& source
,
110 const content::NotificationDetails
& details
) override
;
112 // Returns whether or not it is possible that calls to AddScripts(),
113 // RemoveScripts(), and/or ClearScripts() have caused any real change in the
114 // set of scripts to be loaded.
115 bool ScriptsMayHaveChanged() const;
117 // Attempts to initiate a load.
120 // Called once we have finished loading the scripts on the file thread.
121 void OnScriptsLoaded(scoped_ptr
<UserScriptList
> user_scripts
,
122 scoped_ptr
<base::SharedMemory
> shared_memory
);
124 // Sends the renderer process a new set of user scripts. If
125 // |changed_hosts| is not empty, this signals that only the scripts from
126 // those hosts should be updated. Otherwise, all hosts will be
128 void SendUpdate(content::RenderProcessHost
* process
,
129 base::SharedMemory
* shared_memory
,
130 const std::set
<HostID
>& changed_hosts
);
132 bool is_loading() const {
133 // Ownership of |user_scripts_| is passed to the file thread when loading.
134 return user_scripts_
.get() == NULL
;
137 // Manages our notification registrations.
138 content::NotificationRegistrar registrar_
;
140 // Contains the scripts that were found the last time scripts were updated.
141 scoped_ptr
<base::SharedMemory
> shared_memory_
;
143 // List of scripts from currently-installed extensions we should load.
144 scoped_ptr
<UserScriptList
> user_scripts_
;
146 // The mutually-exclusive sets of scripts that were added or removed since the
148 std::set
<UserScript
> added_scripts_
;
149 std::set
<UserScript
> removed_scripts_
;
151 // Indicates whether the the collection of scripts should be cleared before
152 // additions and removals on the next script load.
155 // The IDs of the extensions which changed in the last update sent to the
157 std::set
<HostID
> changed_hosts_
;
159 // If the initial set of hosts has finished loading.
162 // If list of user scripts is modified while we're loading it, we note
163 // that we're currently mid-load and then start over again once the load
164 // finishes. This boolean tracks whether another load is pending.
167 // Whether or not we are currently loading.
170 // The browser_context for which the scripts managed here are installed.
171 content::BrowserContext
* browser_context_
;
173 // ID of the host that owns these scripts, if any. This is only set to a
174 // non-empty value for declarative user script shared memory regions.
177 // The associated observers.
178 ObserverList
<Observer
> observers_
;
180 base::WeakPtrFactory
<UserScriptLoader
> weak_factory_
;
182 DISALLOW_COPY_AND_ASSIGN(UserScriptLoader
);
185 } // namespace extensions
187 #endif // EXTENSIONS_BROWSER_USER_SCRIPT_LOADER_H_