Enrico Granata | 1d59008 | 2017-04-12 17:25:23 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.car.obd2; |
| 18 | |
| 19 | import android.os.SystemClock; |
| 20 | import android.util.JsonWriter; |
| 21 | import android.util.Log; |
| 22 | import com.android.car.obd2.Obd2Command.FreezeFrameCommand; |
| 23 | import com.android.car.obd2.Obd2Command.OutputSemanticHandler; |
| 24 | import java.io.IOException; |
| 25 | import java.util.ArrayList; |
| 26 | import java.util.List; |
| 27 | import java.util.Optional; |
| 28 | import java.util.Set; |
| 29 | |
| 30 | public class Obd2FreezeFrameGenerator { |
| 31 | public static final String FRAME_TYPE_FREEZE = "freeze"; |
| 32 | public static final String TAG = Obd2FreezeFrameGenerator.class.getSimpleName(); |
| 33 | |
| 34 | private final Obd2Connection mConnection; |
| 35 | private final List<OutputSemanticHandler<Integer>> mIntegerCommands = new ArrayList<>(); |
| 36 | private final List<OutputSemanticHandler<Float>> mFloatCommands = new ArrayList<>(); |
| 37 | |
| 38 | private List<String> mPreviousDtcs = new ArrayList<>(); |
| 39 | |
| 40 | public Obd2FreezeFrameGenerator(Obd2Connection connection) |
| 41 | throws IOException, InterruptedException { |
| 42 | mConnection = connection; |
| 43 | Set<Integer> connectionPids = connection.getSupportedPIDs(); |
| 44 | Set<Integer> apiIntegerPids = Obd2Command.getSupportedIntegerCommands(); |
| 45 | Set<Integer> apiFloatPids = Obd2Command.getSupportedFloatCommands(); |
| 46 | apiIntegerPids |
| 47 | .stream() |
| 48 | .filter(connectionPids::contains) |
| 49 | .forEach((Integer pid) -> mIntegerCommands.add(Obd2Command.getIntegerCommand(pid))); |
| 50 | apiFloatPids |
| 51 | .stream() |
| 52 | .filter(connectionPids::contains) |
| 53 | .forEach((Integer pid) -> mFloatCommands.add(Obd2Command.getFloatCommand(pid))); |
| 54 | Log.i( |
| 55 | TAG, |
| 56 | String.format( |
| 57 | "connectionPids = %s\napiIntegerPids=%s\napiFloatPids = %s\n" |
| 58 | + "mIntegerCommands = %s\nmFloatCommands = %s\n", |
| 59 | connectionPids, |
| 60 | apiIntegerPids, |
| 61 | apiFloatPids, |
| 62 | mIntegerCommands, |
| 63 | mFloatCommands)); |
| 64 | } |
| 65 | |
| 66 | public JsonWriter generate(JsonWriter jsonWriter) throws IOException, InterruptedException { |
| 67 | return generate(jsonWriter, SystemClock.elapsedRealtimeNanos()); |
| 68 | } |
| 69 | |
| 70 | // OBD2 does not have a notion of timestamping the fault codes |
| 71 | // As such, we need to perform additional magic in order to figure out |
| 72 | // whether a fault code we retrieved is the same as a fault code we already |
| 73 | // saw in a past iteration. The logic goes as follows: |
| 74 | // for every position i in currentDtcs, if mPreviousDtcs[i] is the same |
| 75 | // fault code, then assume they are identical. If they are not the same fault code, |
| 76 | // then everything in currentDtcs[i...size()) is assumed to be a new fault code as |
| 77 | // something in the list must have moved around; if currentDtcs is shorter than |
| 78 | // mPreviousDtcs then obviously exit at the end of currentDtcs; if currentDtcs |
| 79 | // is longer, however, anything in currentDtcs past the end of mPreviousDtcs is a new |
| 80 | // fault code and will be included |
| 81 | private final class FreezeFrameIdentity { |
| 82 | public final String dtc; |
| 83 | public final int id; |
| 84 | |
| 85 | FreezeFrameIdentity(String dtc, int id) { |
| 86 | this.dtc = dtc; |
| 87 | this.id = id; |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | private List<FreezeFrameIdentity> discoverNewDtcs(List<String> currentDtcs) { |
| 92 | List<FreezeFrameIdentity> newDtcs = new ArrayList<>(); |
| 93 | int currentIndex = 0; |
| 94 | boolean inCopyAllMode = false; |
| 95 | |
| 96 | for (; currentIndex < currentDtcs.size(); ++currentIndex) { |
| 97 | if (currentIndex == mPreviousDtcs.size()) { |
| 98 | // we have more current DTCs than previous DTCs, copy everything |
| 99 | inCopyAllMode = true; |
| 100 | break; |
| 101 | } |
| 102 | if (!currentDtcs.get(currentIndex).equals(mPreviousDtcs.get(currentIndex))) { |
| 103 | // we found a different DTC, copy everything |
| 104 | inCopyAllMode = true; |
| 105 | break; |
| 106 | } |
| 107 | // same DTC, not at end of either list yet, keep looping |
| 108 | } |
| 109 | |
| 110 | if (inCopyAllMode) { |
| 111 | for (; currentIndex < currentDtcs.size(); ++currentIndex) { |
| 112 | newDtcs.add(new FreezeFrameIdentity(currentDtcs.get(currentIndex), currentIndex)); |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | return newDtcs; |
| 117 | } |
| 118 | |
| 119 | public JsonWriter generate(JsonWriter jsonWriter, long timestamp) |
| 120 | throws IOException, InterruptedException { |
| 121 | List<String> currentDtcs = mConnection.getDiagnosticTroubleCodes(); |
| 122 | List<FreezeFrameIdentity> newDtcs = discoverNewDtcs(currentDtcs); |
| 123 | mPreviousDtcs = currentDtcs; |
| 124 | for (FreezeFrameIdentity freezeFrame : newDtcs) { |
| 125 | jsonWriter.beginObject(); |
| 126 | jsonWriter.name("type").value(FRAME_TYPE_FREEZE); |
| 127 | jsonWriter.name("timestamp").value(timestamp); |
| 128 | jsonWriter.name("stringValue").value(freezeFrame.dtc); |
| 129 | jsonWriter.name("intValues").beginArray(); |
| 130 | for (OutputSemanticHandler<Integer> handler : mIntegerCommands) { |
| 131 | FreezeFrameCommand<Integer> command = |
| 132 | Obd2Command.getFreezeFrameCommand(handler, freezeFrame.id); |
| 133 | try { |
| 134 | Optional<Integer> result = command.run(mConnection); |
| 135 | if (result.isPresent()) { |
| 136 | jsonWriter.beginObject(); |
| 137 | jsonWriter.name("id").value(command.getPid()); |
| 138 | jsonWriter.name("value").value(result.get()); |
| 139 | jsonWriter.endObject(); |
| 140 | } |
| 141 | } catch (IOException | InterruptedException e) { |
| 142 | Log.w( |
| 143 | TAG, |
| 144 | String.format( |
| 145 | "unable to retrieve OBD2 pid %d due to exception: %s", |
| 146 | command.getPid(), e)); |
| 147 | // skip this entry |
| 148 | } |
| 149 | } |
| 150 | jsonWriter.endArray(); |
| 151 | jsonWriter.name("floatValues").beginArray(); |
| 152 | for (OutputSemanticHandler<Float> handler : mFloatCommands) { |
| 153 | FreezeFrameCommand<Float> command = |
| 154 | Obd2Command.getFreezeFrameCommand(handler, freezeFrame.id); |
| 155 | try { |
| 156 | Optional<Float> result = command.run(mConnection); |
| 157 | if (result.isPresent()) { |
| 158 | jsonWriter.beginObject(); |
| 159 | jsonWriter.name("id").value(command.getPid()); |
| 160 | jsonWriter.name("value").value(result.get()); |
| 161 | jsonWriter.endObject(); |
| 162 | } |
| 163 | } catch (IOException | InterruptedException e) { |
| 164 | Log.w( |
| 165 | TAG, |
| 166 | String.format( |
| 167 | "unable to retrieve OBD2 pid %d due to exception: %s", |
| 168 | command.getPid(), e)); |
| 169 | // skip this entry |
| 170 | } |
| 171 | } |
| 172 | jsonWriter.endArray(); |
| 173 | jsonWriter.endObject(); |
| 174 | } |
| 175 | return jsonWriter; |
| 176 | } |
| 177 | } |