media/libdatasource/include/datasource/HTTPBase.h

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef HTTP_BASE_H_

#define HTTP_BASE_H_

#include <media/DataSource.h>
#include <media/stagefright/foundation/ABase.h>
#include <media/stagefright/MediaErrors.h>
#include <utils/List.h>
#include <utils/threads.h>

namespace android {

struct HTTPBase : public DataSource {
    enum Flags {
        // Don't log any URLs.
        kFlagIncognito = 1
    };

    HTTPBase();

    virtual status_t connect(
            const char *uri,
            const KeyedVector<String8, String8> *headers = NULL,
            off64_t offset = 0) = 0;

    virtual void disconnect() = 0;

    // Returns true if bandwidth could successfully be estimated,
    // false otherwise.
    virtual bool estimateBandwidth(int32_t *bandwidth_bps);

    virtual status_t getEstimatedBandwidthKbps(int32_t *kbps);

    virtual status_t setBandwidthStatCollectFreq(int32_t freqMs);

    virtual void setBandwidthHistorySize(size_t numHistoryItems);

    virtual String8 toString() {
        return mName;
    }

protected:
    virtual void addBandwidthMeasurement(size_t numBytes, int64_t delayUs);
    String8 mName;

private:
    struct BandwidthEntry {
        int64_t mDelayUs;
        size_t mNumBytes;
    };

    Mutex mLock;

    List<BandwidthEntry> mBandwidthHistory;
    size_t mNumBandwidthHistoryItems;
    int64_t mTotalTransferTimeUs;
    size_t mTotalTransferBytes;
    size_t mMaxBandwidthHistoryItems;

    enum {
        kMinBandwidthCollectFreqMs = 1000,   // 1 second
        kMaxBandwidthCollectFreqMs = 60000,  // one minute
    };

    int64_t mPrevBandwidthMeasureTimeUs;
    int32_t mPrevEstimatedBandWidthKbps;
    int32_t mBandWidthCollectFreqMs;

    DISALLOW_EVIL_CONSTRUCTORS(HTTPBase);
};

}  // namespace android

#endif  // HTTP_BASE_H_