/*
* Copyright (C) 2014 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.
*/
package android.alsa;
import android.util.Slog;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Vector;
/**
* @hide
* Retrieves information from an ALSA "devices" file.
*/
public class AlsaDevicesParser {
private static final String TAG = "AlsaDevicesParser";
private static final int kIndex_CardDeviceField = 5;
private static final int kStartIndex_CardNum = 6;
private static final int kEndIndex_CardNum = 8; // one past
private static final int kStartIndex_DeviceNum = 9;
private static final int kEndIndex_DeviceNum = 11; // one past
private static final int kStartIndex_Type = 14;
private static LineTokenizer mTokenizer = new LineTokenizer(" :[]-");
private boolean mHasCaptureDevices = false;
private boolean mHasPlaybackDevices = false;
private boolean mHasMIDIDevices = false;
public class AlsaDeviceRecord {
public static final int kDeviceType_Unknown = -1;
public static final int kDeviceType_Audio = 0;
public static final int kDeviceType_Control = 1;
public static final int kDeviceType_MIDI = 2;
public static final int kDeviceDir_Unknown = -1;
public static final int kDeviceDir_Capture = 0;
public static final int kDeviceDir_Playback = 1;
int mCardNum = -1;
int mDeviceNum = -1;
int mDeviceType = kDeviceType_Unknown;
int mDeviceDir = kDeviceDir_Unknown;
public AlsaDeviceRecord() {
}
public boolean parse(String line) {
// "0123456789012345678901234567890"
// " 2: [ 0-31]: digital audio playback"
// " 3: [ 0-30]: digital audio capture"
// " 35: [ 1] : control"
// " 36: [ 2- 0]: raw midi"
final int kToken_LineNum = 0;
final int kToken_CardNum = 1;
final int kToken_DeviceNum = 2;
final int kToken_Type0 = 3; // "digital", "control", "raw"
final int kToken_Type1 = 4; // "audio", "midi"
final int kToken_Type2 = 5; // "capture", "playback"
int tokenOffset = 0;
int delimOffset = 0;
int tokenIndex = kToken_LineNum;
while (true) {
tokenOffset = mTokenizer.nextToken(line, delimOffset);
if (tokenOffset == LineTokenizer.kTokenNotFound) {
break; // bail
}
delimOffset = mTokenizer.nextDelimiter(line, tokenOffset);
if (delimOffset == LineTokenizer.kTokenNotFound) {
delimOffset = line.length();
}
String token = line.substring(tokenOffset, delimOffset);
switch (tokenIndex) {
case kToken_LineNum:
// ignore
break;
case kToken_CardNum:
mCardNum = Integer.parseInt(token);
if (line.charAt(delimOffset) != '-') {
tokenIndex++; // no device # in the token stream
}
break;
case kToken_DeviceNum:
mDeviceNum = Integer.parseInt(token);
break;
case kToken_Type0:
if (token.equals("digital")) {
// NOP
} else if (token.equals("control")) {
mDeviceType = kDeviceType_Control;
} else if (token.equals("raw")) {
// NOP
}
break;
case kToken_Type1:
if (token.equals("audio")) {
mDeviceType = kDeviceType_Audio;
} else if (token.equals("midi")) {
mDeviceType = kDeviceType_MIDI;
mHasMIDIDevices = true;
}
break;
case kToken_Type2:
if (token.equals("capture")) {
mDeviceDir = kDeviceDir_Capture;
mHasCaptureDevices = true;
} else if (token.equals("playback")) {
mDeviceDir = kDeviceDir_Playback;
mHasPlaybackDevices = true;
}
break;
} // switch (tokenIndex)
tokenIndex++;
} // while (true)
return true;
} // parse()
public String textFormat() {
StringBuilder sb = new StringBuilder();
sb.append("[" + mCardNum + ":" + mDeviceNum + "]");
switch (mDeviceType) {
case kDeviceType_Unknown:
sb.append(" N/A");
break;
case kDeviceType_Audio:
sb.append(" Audio");
break;
case kDeviceType_Control:
sb.append(" Control");
break;
case kDeviceType_MIDI:
sb.append(" MIDI");
break;
}
switch (mDeviceDir) {
case kDeviceDir_Unknown:
sb.append(" N/A");
break;
case kDeviceDir_Capture:
sb.append(" Capture");
break;
case kDeviceDir_Playback:
sb.append(" Playback");
break;
}
return sb.toString();
}
}
private Vector<AlsaDeviceRecord>
deviceRecords_ = new Vector<AlsaDeviceRecord>();
private boolean isLineDeviceRecord(String line) {
return line.charAt(kIndex_CardDeviceField) == '[';
}
public AlsaDevicesParser() {
}
public int getNumDeviceRecords() {
return deviceRecords_.size();
}
public AlsaDeviceRecord getDeviceRecordAt(int index) {
return deviceRecords_.get(index);
}
public void Log() {
int numDevRecs = getNumDeviceRecords();
for (int index = 0; index < numDevRecs; ++index) {
Slog.w(TAG, "usb:" + getDeviceRecordAt(index).textFormat());
}
}
public boolean hasPlaybackDevices() {
return mHasPlaybackDevices;
}
public boolean hasPlaybackDevices(int card) {
for (int index = 0; index < deviceRecords_.size(); index++) {
AlsaDeviceRecord deviceRecord = deviceRecords_.get(index);
if (deviceRecord.mCardNum == card &&
deviceRecord.mDeviceType == AlsaDeviceRecord.kDeviceType_Audio &&
deviceRecord.mDeviceDir == AlsaDeviceRecord.kDeviceDir_Playback) {
return true;
}
}
return false;
}
public boolean hasCaptureDevices() {
return mHasCaptureDevices;
}
public boolean hasCaptureDevices(int card) {
for (int index = 0; index < deviceRecords_.size(); index++) {
AlsaDeviceRecord deviceRecord = deviceRecords_.get(index);
if (deviceRecord.mCardNum == card &&
deviceRecord.mDeviceType == AlsaDeviceRecord.kDeviceType_Audio &&
deviceRecord.mDeviceDir == AlsaDeviceRecord.kDeviceDir_Capture) {
return true;
}
}
return false;
}
public boolean hasMIDIDevices() {
return mHasMIDIDevices;
}
public boolean hasMIDIDevices(int card) {
for (int index = 0; index < deviceRecords_.size(); index++) {
AlsaDeviceRecord deviceRecord = deviceRecords_.get(index);
if (deviceRecord.mCardNum == card &&
deviceRecord.mDeviceType == AlsaDeviceRecord.kDeviceType_MIDI) {
return true;
}
}
return false;
}
public void scan() {
deviceRecords_.clear();
final String devicesFilePath = "/proc/asound/devices";
File devicesFile = new File(devicesFilePath);
try {
FileReader reader = new FileReader(devicesFile);
BufferedReader bufferedReader = new BufferedReader(reader);
String line = "";
while ((line = bufferedReader.readLine()) != null) {
if (isLineDeviceRecord(line)) {
AlsaDeviceRecord deviceRecord = new AlsaDeviceRecord();
deviceRecord.parse(line);
deviceRecords_.add(deviceRecord);
}
}
reader.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
} // class AlsaDevicesParser
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