The Tor Browser: netwerk/base/public/nsReadLine.h@b8a032363ba2 (annotated)

netwerk/base/public/nsReadLine.h@b8a032363ba2 (annotated)

netwerk/base/public/nsReadLine.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef nsReadLine_h__
 #define nsReadLine_h__
 #include "nsIInputStream.h"
 #include "mozilla/Likely.h"
 /**
  * @file
  * Functions to read complete lines from an input stream.
  *
  * To properly use the helper function in here (NS_ReadLine) the caller should
  * create a nsLineBuffer<T> with new, and pass it to NS_ReadLine every time it
  * wants a line out.
  *
  * When done, the object should be deleted.
  */
 /**
  * @internal
  * Buffer size. This many bytes will be buffered. If a line is longer than this,
  * the partial line will be appended to the out parameter of NS_ReadLine and the
  * buffer will be emptied.
  * Note: if you change this constant, please update the regression test in
  * netwerk/test/unit/test_readline.js accordingly (bug 397850).
  */
 #define kLineBufferSize 4096
 /**
  * @internal
  * Line buffer structure, buffers data from an input stream.
  * The buffer is empty when |start| == |end|.
  * Invariant: |start| <= |end|
  */
 template<typename CharT>
 class nsLineBuffer {
   public:
     nsLineBuffer() : start(buf), end(buf) { }
   CharT buf[kLineBufferSize+1];
   CharT* start;
   CharT* end;
 };
 /**
  * Read a line from an input stream. Lines are separated by '\r' (0x0D) or '\n'
  * (0x0A), or "\r\n" or "\n\r".
  *
  * @param aStream
  *        The stream to read from
  * @param aBuffer
  *        The line buffer to use.  A single line buffer must not be used with
  *        different input streams.
  * @param aLine [out]
  *        The string where the line will be stored.
  * @param more [out]
  *        Whether more data is available in the buffer. If true, NS_ReadLine may
  *        be called again to read further lines. Otherwise, further calls to
  *        NS_ReadLine will return an error.
  *
  * @retval NS_OK
  *         Read successful
  * @retval error
  *         Input stream returned an error upon read. See
  *         nsIInputStream::read.
  */
 template<typename CharT, class StreamType, class StringType>
 nsresult
 NS_ReadLine (StreamType* aStream, nsLineBuffer<CharT> * aBuffer,
              StringType & aLine, bool *more)
 {
   CharT eolchar = 0; // the first eol char or 1 after \r\n or \n\r is found
   aLine.Truncate();
   while (1) { // will be returning out of this loop on eol or eof
     if (aBuffer->start == aBuffer->end) { // buffer is empty.  Read into it.
       uint32_t bytesRead;
       nsresult rv = aStream->Read(aBuffer->buf, kLineBufferSize, &bytesRead);
       if (NS_FAILED(rv) || MOZ_UNLIKELY(bytesRead == 0)) {
         *more = false;
         return rv;
       }
       aBuffer->start = aBuffer->buf;
       aBuffer->end = aBuffer->buf + bytesRead;
       *(aBuffer->end) = '\0';
     }
     /*
      * Walk the buffer looking for an end-of-line.
      * There are 3 cases to consider:
      *  1. the eol char is the last char in the buffer
      *  2. the eol char + one more char at the end of the buffer
      *  3. the eol char + two or more chars at the end of the buffer
      * we need at least one char after the first eol char to determine if
      * it's a \r\n or \n\r sequence (and skip over it), and we need one
      * more char after the end-of-line to set |more| correctly.
      */
     CharT* current = aBuffer->start;
     if (MOZ_LIKELY(eolchar == 0)) {
       for ( ; current < aBuffer->end; ++current) {
         if (*current == '\n' || *current == '\r') {
           eolchar = *current;
           *current++ = '\0';
           aLine.Append(aBuffer->start);
           break;
         }
       }
     }
     if (MOZ_LIKELY(eolchar != 0)) {
       for ( ; current < aBuffer->end; ++current) {
         if ((eolchar == '\r' && *current == '\n') ||
             (eolchar == '\n' && *current == '\r')) {
           eolchar = 1;
           continue;
         }
         aBuffer->start = current;
         *more = true;
         return NS_OK;
       }
     }
     if (eolchar == 0)
       aLine.Append(aBuffer->start);
     aBuffer->start = aBuffer->end; // mark the buffer empty
   }
 }
 #endif // nsReadLine_h__

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netwerk/base/public/nsReadLine.h@b8a032363ba2 (annotated)

netwerk/base/public/nsReadLine.h