1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/modules/mediasource/media_source_handle_impl.h"
#include "base/logging.h"
#include "third_party/blink/renderer/core/html/media/media_source_attachment.h"
#include "third_party/blink/renderer/modules/mediasource/handle_attachment_provider.h"
#include "third_party/blink/renderer/platform/bindings/script_wrappable.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace blink {
MediaSourceHandleImpl::MediaSourceHandleImpl(
scoped_refptr<HandleAttachmentProvider> attachment_provider,
String internal_blob_url)
: attachment_provider_(std::move(attachment_provider)),
internal_blob_url_(internal_blob_url) {
DCHECK(attachment_provider_);
DCHECK(!internal_blob_url.empty());
DVLOG(1) << __func__ << " this=" << this
<< ", attachment_provider_=" << attachment_provider_
<< ", internal_blob_url_=" << internal_blob_url_;
}
MediaSourceHandleImpl::~MediaSourceHandleImpl() {
DVLOG(1) << __func__ << " this=" << this;
}
scoped_refptr<HandleAttachmentProvider>
MediaSourceHandleImpl::TakeAttachmentProvider() {
DVLOG(1) << __func__ << " this=" << this;
return std::move(attachment_provider_);
}
scoped_refptr<MediaSourceAttachment> MediaSourceHandleImpl::TakeAttachment() {
DVLOG(1) << __func__ << " this=" << this;
if (!attachment_provider_) {
// Either this handle instance has already been serialized, has been
// transferred, or it has been assigned as srcObject on an HTMLMediaElement
// and used later to begin asynchronous attachment start.
DCHECK(is_serialized() || detached_ || is_used());
return nullptr;
}
// Otherwise, this handle instance must not yet have been serialized,
// transferred or used to begin an attachment. The only case we should be here
// is when this instance is being used to attempt asynchronous attachment
// start after it was set as srcObject on an HTMLMediaElement.
DCHECK(is_used() && !is_serialized() && !detached_);
scoped_refptr<MediaSourceAttachment> result =
attachment_provider_->TakeAttachment();
attachment_provider_ = nullptr;
// Note that |result| would be nullptr here if some other duplicated handle
// (due to postMessage's lack of true move-only semantics) has already started
// asynchronous attachment for the same underlying attachment (and
// MediaSource).
return result;
}
String MediaSourceHandleImpl::GetInternalBlobURL() {
DVLOG(1) << __func__ << " this=" << this;
return internal_blob_url_;
}
void MediaSourceHandleImpl::mark_serialized() {
DVLOG(1) << __func__ << " this=" << this;
DCHECK(!serialized_);
serialized_ = true;
// Before being serialized, the serialization must have retrieved our
// reference to the |attachment_provider_| precisely once. Note that
// immediately upon an instance of us being assigned to srcObject, that
// instance can no longer be serialized and there will be at most one async
// media element load that retrieves our provider's attachment reference.
DCHECK(!attachment_provider_);
}
void MediaSourceHandleImpl::mark_detached() {
DVLOG(1) << __func__ << " this=" << this;
DCHECK(!detached_);
detached_ = true;
attachment_provider_ = nullptr;
}
void MediaSourceHandleImpl::Trace(Visitor* visitor) const {
ScriptWrappable::Trace(visitor);
}
} // namespace blink
|
