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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.emailcommon.utility;
     18 
     19 import com.android.emailcommon.Logging;
     20 
     21 import android.util.Log;
     22 
     23 import java.io.FilterInputStream;
     24 import java.io.IOException;
     25 import java.io.InputStream;
     26 
     27 /**
     28  * Simple class used for debugging only that affords us a view of the raw IMAP or POP3 stream,
     29  * in addition to the tokenized version.
     30  *
     31  * Use of this class *MUST* be restricted to logging-enabled situations only.
     32  */
     33 public class LoggingInputStream extends FilterInputStream {
     34     private StringBuilder mSb;
     35     private boolean mDumpEmptyLines;
     36     private final String mTag;
     37 
     38     public LoggingInputStream(InputStream in) {
     39         this(in, "RAW", false);
     40     }
     41 
     42     public LoggingInputStream(InputStream in, String tag, boolean dumpEmptyLines) {
     43         super(in);
     44         mTag = tag + " ";
     45         mDumpEmptyLines = dumpEmptyLines;
     46         initBuffer();
     47         Log.d(Logging.LOG_TAG, mTag + "dump start");
     48     }
     49 
     50     private void initBuffer() {
     51         mSb = new StringBuilder(mTag);
     52     }
     53 
     54     /**
     55      * Collect chars as read, and log them when EOL reached.
     56      */
     57     @Override
     58     public int read() throws IOException {
     59         int oneByte = super.read();
     60         logRaw(oneByte);
     61         return oneByte;
     62     }
     63 
     64     /**
     65      * Collect chars as read, and log them when EOL reached.
     66      */
     67     @Override
     68     public int read(byte[] b, int offset, int length) throws IOException {
     69         int bytesRead = super.read(b, offset, length);
     70         int copyBytes = bytesRead;
     71         while (copyBytes > 0) {
     72             logRaw(b[offset] & 0xFF);
     73             copyBytes--;
     74             offset++;
     75         }
     76 
     77         return bytesRead;
     78     }
     79 
     80     /**
     81      * Write and clear the buffer
     82      */
     83     private void logRaw(int oneByte) {
     84         if (oneByte == '\r') {
     85             // Don't log.
     86         } else if (oneByte == '\n') {
     87             flushLog();
     88         } else if (0x20 <= oneByte && oneByte <= 0x7e) { // Printable ASCII.
     89             mSb.append((char)oneByte);
     90         } else {
     91             // email protocols are supposed to be all 7bits, but there are wrong implementations
     92             // that do send 8 bit characters...
     93             mSb.append("\\x" + Utility.byteToHex(oneByte));
     94         }
     95     }
     96 
     97     private void flushLog() {
     98         if (mDumpEmptyLines || (mSb.length() > mTag.length())) {
     99             Log.d(Logging.LOG_TAG, mSb.toString());
    100             initBuffer();
    101         }
    102     }
    103 
    104     @Override
    105     public void close() throws IOException {
    106         super.close();
    107         flushLog();
    108     }
    109 }
    110