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 COMPONENTS_INVALIDATION_PUBLIC_INVALIDATION_H_
6 #define COMPONENTS_INVALIDATION_PUBLIC_INVALIDATION_H_
10 #include "base/basictypes.h"
11 #include "base/memory/scoped_ptr.h"
12 #include "base/memory/weak_ptr.h"
13 #include "base/sequenced_task_runner.h"
14 #include "base/values.h"
15 #include "components/invalidation/public/ack_handle.h"
16 #include "components/invalidation/public/invalidation_export.h"
17 #include "google/cacheinvalidation/include/types.h"
21 class DroppedInvalidationTracker
;
24 // Represents a local invalidation, and is roughly analogous to
25 // invalidation::Invalidation. Unlike invalidation::Invalidation, this class
26 // supports "local" ack-tracking and simple serialization to pref values.
27 class INVALIDATION_EXPORT Invalidation
{
30 static Invalidation
Init(const invalidation::ObjectId
& id
,
32 const std::string
& payload
);
33 static Invalidation
InitUnknownVersion(const invalidation::ObjectId
& id
);
34 static Invalidation
InitFromDroppedInvalidation(const Invalidation
& dropped
);
35 static scoped_ptr
<Invalidation
> InitFromValue(
36 const base::DictionaryValue
& value
);
40 // Compares two invalidations. The comparison ignores ack-tracking state.
41 bool Equals(const Invalidation
& other
) const;
43 invalidation::ObjectId
object_id() const;
44 bool is_unknown_version() const;
46 // Safe to call only if is_unknown_version() returns false.
47 int64
version() const;
49 // Safe to call only if is_unknown_version() returns false.
50 const std::string
& payload() const;
52 const AckHandle
& ack_handle() const;
54 // Sets the AckHandler to be used to track this Invalidation.
56 // This should be set by the class that generates the invalidation. Clients
57 // of the Invalidations API should not need to call this.
59 // Note that some sources of invalidations do not support ack tracking, and do
60 // not set the ack_handler. This will be hidden from users of this class.
62 base::WeakPtr
<AckHandler
> handler
,
63 scoped_refptr
<base::SequencedTaskRunner
> handler_task_runner
);
65 // Returns whether or not this instance supports ack tracking. This will
66 // depend on whether or not the source of invaliadations supports
69 // Clients can safely ignore this flag. They can assume that all
70 // invalidations support ack tracking. If they're wrong, then invalidations
71 // will be less reliable, but their behavior will be no less correct.
72 bool SupportsAcknowledgement() const;
74 // Acknowledges the receipt of this invalidation.
76 // Clients should call this on a received invalidation when they have fully
77 // processed the invalidation and persisted the results to disk. Once this
78 // function is called, the invalidations system is under no obligation to
79 // re-deliver this invalidation in the event of a crash or restart.
80 void Acknowledge() const;
82 // Informs the ack tracker that this invalidation will not be serviced.
84 // If a client's buffer reaches its limit and it is forced to start dropping
85 // invalidations, it should call this function before dropping its
86 // invalidations in order to allow the ack tracker to drop the invalidation,
89 // To indicate recovery from a drop event, the client should call
90 // Acknowledge() on the most recently dropped inavlidation.
93 scoped_ptr
<base::DictionaryValue
> ToValue() const;
94 std::string
ToString() const;
97 Invalidation(const invalidation::ObjectId
& id
,
98 bool is_unknown_version
,
100 const std::string
& payload
,
101 AckHandle ack_handle
);
103 // The ObjectId to which this invalidation belongs.
104 invalidation::ObjectId id_
;
106 // This flag is set to true if this is an unknown version invalidation.
107 bool is_unknown_version_
;
109 // The version number of this invalidation. Should not be accessed if this is
110 // an unkown version invalidation.
113 // The payaload associated with this invalidation. Should not be accessed if
114 // this is an unknown version invalidation.
115 std::string payload_
;
117 // A locally generated unique ID used to manage local acknowledgements.
118 AckHandle ack_handle_
;
120 // The acknowledgement tracking handler and its thread.
121 base::WeakPtr
<AckHandler
> ack_handler_
;
122 scoped_refptr
<base::SequencedTaskRunner
> ack_handler_task_runner_
;
125 } // namespace syncer
127 #endif // COMPONENTS_INVALIDATION_PUBLIC_INVALIDATION_H_