Source/WebCore/Modules/mediastream/MediaDevicesRequest.cpp

/*
 * Copyright (C) 2015-2016 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 */

#include "config.h"
#include "MediaDevicesRequest.h"

#if ENABLE(MEDIA_STREAM)

#include "CaptureDevice.h"
#include "Document.h"
#include "Frame.h"
#include "JSMediaDeviceInfo.h"
#include "MediaDevicesEnumerationRequest.h"
#include "SecurityOrigin.h"
#include "UserMediaController.h"
#include <wtf/MainThread.h>
#include <wtf/SHA1.h>

namespace WebCore {

inline MediaDevicesRequest::MediaDevicesRequest(Document& document, MediaDevices::EnumerateDevicesPromise&& promise)
    : ContextDestructionObserver(&document)
    , m_promise(WTFMove(promise))
{
}

Ref<MediaDevicesRequest> MediaDevicesRequest::create(Document& document, MediaDevices::EnumerateDevicesPromise&& promise)
{
    return adoptRef(*new MediaDevicesRequest(document, WTFMove(promise)));
}

MediaDevicesRequest::~MediaDevicesRequest()
{
    if (m_enumerationRequest)
        m_enumerationRequest->cancel();
}

SecurityOrigin* MediaDevicesRequest::securityOrigin() const
{
    if (scriptExecutionContext())
        return scriptExecutionContext()->securityOrigin();

    return nullptr;
}

void MediaDevicesRequest::contextDestroyed()
{
    if (m_enumerationRequest) {
        m_enumerationRequest->cancel();
        m_enumerationRequest = nullptr;
    }
    ContextDestructionObserver::contextDestroyed();
}

void MediaDevicesRequest::start()
{
    RefPtr<MediaDevicesRequest> protectedThis = this;
    auto completion = [this, protectedThis = WTFMove(protectedThis)] (const Vector<CaptureDevice>& captureDevices, const String& deviceIdentifierHashSalt, bool originHasPersistentAccess) mutable {

        m_enumerationRequest = nullptr;

        if (!scriptExecutionContext())
            return;

        Document& document = downcast<Document>(*scriptExecutionContext());
        UserMediaController* controller = UserMediaController::from(document.page());
        if (!controller)
            return;

        m_idHashSalt = deviceIdentifierHashSalt;

        Vector<RefPtr<MediaDeviceInfo>> devices;
        for (auto& deviceInfo : captureDevices) {
            auto label = emptyString();
            if (originHasPersistentAccess || document.hasHadActiveMediaStreamTrack())
                label = deviceInfo.label();

            auto id = hashID(deviceInfo.persistentId());
            if (id.isEmpty())
                continue;

            auto groupId = hashID(deviceInfo.groupId());
            auto deviceType = deviceInfo.kind() == CaptureDevice::SourceKind::Audio ? MediaDeviceInfo::Kind::Audioinput : MediaDeviceInfo::Kind::Videoinput;
            devices.append(MediaDeviceInfo::create(scriptExecutionContext(), label, id, groupId, deviceType));
        }

        callOnMainThread([protectedThis = makeRef(*this), devices = WTFMove(devices)]() mutable {
            protectedThis->m_promise.resolve(devices);
        });
    };

    m_enumerationRequest = MediaDevicesEnumerationRequest::create(*downcast<Document>(scriptExecutionContext()), WTFMove(completion));
    m_enumerationRequest->start();
}

static void hashString(SHA1& sha1, const String& string)
{
    if (string.isEmpty())
        return;

    if (string.is8Bit() && string.containsOnlyASCII()) {
        const uint8_t nullByte = 0;
        sha1.addBytes(string.characters8(), string.length());
        sha1.addBytes(&nullByte, 1);
        return;
    }

    auto utf8 = string.utf8();
    sha1.addBytes(reinterpret_cast<const uint8_t*>(utf8.data()), utf8.length() + 1); // Include terminating null byte.
}

String MediaDevicesRequest::hashID(const String& id)
{
    if (id.isEmpty() || m_idHashSalt.isEmpty())
        return emptyString();

    SHA1 sha1;

    hashString(sha1, id);
    hashString(sha1, m_idHashSalt);

    SHA1::Digest digest;
    sha1.computeHash(digest);

    return SHA1::hexDigest(digest).data();
}

} // namespace WebCore

#endif // ENABLE(MEDIA_STREAM)