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      1 /*
      2  * Copyright (C) 2008 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.mail.utils;
     18 
     19 import android.util.Log;
     20 
     21 import java.io.FilterInputStream;
     22 import java.io.IOException;
     23 import java.io.InputStream;
     24 
     25 /**
     26  * Simple class used for debugging only that affords us a view of the raw IMAP or POP3 stream,
     27  * in addition to the tokenized version.
     28  *
     29  * Use of this class *MUST* be restricted to logging-enabled situations only.
     30  */
     31 public class LoggingInputStream extends FilterInputStream {
     32     private static final String LOG_TAG = new LogUtils().getLogTag();
     33     private StringBuilder mSb;
     34     private boolean mDumpEmptyLines;
     35     private final String mTag;
     36 
     37     public LoggingInputStream(InputStream in) {
     38         this(in, "RAW", false);
     39     }
     40 
     41     public LoggingInputStream(InputStream in, String tag, boolean dumpEmptyLines) {
     42         super(in);
     43         mTag = tag + " ";
     44         mDumpEmptyLines = dumpEmptyLines;
     45         initBuffer();
     46         Log.d(LOG_TAG, mTag + "dump start");
     47     }
     48 
     49     private void initBuffer() {
     50         mSb = new StringBuilder(mTag);
     51     }
     52 
     53     /**
     54      * Collect chars as read, and log them when EOL reached.
     55      */
     56     @Override
     57     public int read() throws IOException {
     58         int oneByte = super.read();
     59         logRaw(oneByte);
     60         return oneByte;
     61     }
     62 
     63     /**
     64      * Collect chars as read, and log them when EOL reached.
     65      */
     66     @Override
     67     public int read(byte[] b, int offset, int length) throws IOException {
     68         int bytesRead = super.read(b, offset, length);
     69         int copyBytes = bytesRead;
     70         while (copyBytes > 0) {
     71             logRaw(b[offset] & 0xFF);
     72             copyBytes--;
     73             offset++;
     74         }
     75 
     76         return bytesRead;
     77     }
     78 
     79     /**
     80      * Write and clear the buffer
     81      */
     82     private void logRaw(int oneByte) {
     83         if (oneByte == '\r') {
     84             // Don't log.
     85         } else if (oneByte == '\n') {
     86             flushLog();
     87         } else if (0x20 <= oneByte && oneByte <= 0x7e) { // Printable ASCII.
     88             mSb.append((char)oneByte);
     89         } else {
     90             // email protocols are supposed to be all 7bits, but there are wrong implementations
     91             // that do send 8 bit characters...
     92             mSb.append("\\x" + LogUtils.byteToHex(oneByte));
     93         }
     94     }
     95 
     96     private void flushLog() {
     97         if (mDumpEmptyLines || (mSb.length() > mTag.length())) {
     98             Log.d(LOG_TAG, mSb.toString());
     99             initBuffer();
    100         }
    101     }
    102 
    103     @Override
    104     public void close() throws IOException {
    105         super.close();
    106         flushLog();
    107     }
    108 }
    109