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    41 

    42 #include "q3membuf_p.h"

    43 

    44 QT_BEGIN_NAMESPACE

    45 

    46 // *******************************************************************

    47 // QMembuf declaration and implementation

    48 // *******************************************************************

    49 

    50 /*  \internal

    51     This class implements an efficient buffering of data that is often used by

    52     asynchronous IO classes like QSocket, QHttp and QProcess.

    53 */

    54 

    55 Q3Membuf::Q3Membuf() : _size(0), _index(0)

    56 {

    57 }

    58 

    59 Q3Membuf::~Q3Membuf()

    60 {

    61     while (!buf.isEmpty())

    62         delete buf.takeFirst();

    63 }

    64 

    65 /*! \internal

    66     This function consumes \a nbytes bytes of data from the

    67     buffer and copies it into \a sink. If \a sink is a 0 pointer

    68     the data goes into the nirvana.

    69 */

    70 bool Q3Membuf::consumeBytes(Q_ULONG nbytes, char *sink)

    71 {

    72     if (nbytes <= 0 || (qint64)nbytes > _size)

    73         return false;

    74     _size -= nbytes;

    75     while (!buf.isEmpty()) {

    76         QByteArray *a = buf.first();

    77         if ((int)(_index + nbytes) >= a->size()) {

    78             // Here we skip the whole byte array and get the next later

    79             int len = a->size() - _index;

    80             if (sink) {

    81                 memcpy(sink, a->constData()+_index, len);

    82                 sink += len;

    83             }

    84             nbytes -= len;

    85             buf.removeFirst();

    86 	    delete a;

    87             _index = 0;

    88             if (nbytes == 0)

    89                 break;

    90         } else {

    91             // Here we skip only a part of the first byte array

    92             if (sink)

    93                 memcpy(sink, a->constData()+_index, nbytes);

    94             _index += nbytes;

    95             break;

    96         }

    97     }

    98     return true;

    99 }

   100 

   101 /*! \internal

   102     Scans for any occurrence of '\n' in the buffer. If \a store

   103     is not 0 the text up to the first '\n' (or terminating 0) is

   104     written to \a store, and a terminating 0 is appended to \a store

   105     if necessary. Returns true if a '\n' was found; otherwise returns

   106     false.

   107 */

   108 bool Q3Membuf::scanNewline(QByteArray *store)

   109 {

   110     if (_size == 0)

   111         return false;

   112     int i = 0; // index into 'store'

   113     QByteArray *a = 0;

   114     char *p;

   115     int n;

   116     bool retval = false;

   117     for (int j = 0; j < buf.size(); ++j) {

   118         a = buf.at(j);

   119         p = a->data();

   120         n = a->size();

   121         if (!j) {

   122             // first buffer

   123             p += _index;

   124             n -= _index;

   125         }

   126         if (store) {

   127             while (n-- > 0) {

   128                 *(store->data()+i) = *p;

   129                 if (++i == (int)store->size())

   130                     store->resize(store->size() < 256

   131                                    ? 1024 : store->size()*4);

   132                 if (*p == '\n') {

   133                     retval = true;

   134                     goto end;

   135                 }

   136                 p++;

   137             }

   138         } else {

   139             while (n-- > 0) {

   140                 if(*p == '\n')

   141                     return true;

   142                 p++;

   143             }

   144         }

   145     }

   146  end:

   147     if (store)

   148         store->resize(i);

   149     return retval;

   150 }

   151 

   152 int Q3Membuf::ungetch(int ch)

   153 {

   154     if (buf.isEmpty() || _index==0) {

   155         // we need a new QByteArray

   156         QByteArray *ba = new QByteArray;

   157         ba->resize(1);

   158         buf.prepend(ba);

   159         _size++;

   160         (*ba)[0] = ch;

   161     } else {

   162         // we can reuse a place in the buffer

   163         QByteArray *ba = buf.first();

   164         _index--;

   165         _size++;

   166         (*ba)[(int)_index] = ch;

   167     }

   168     return ch;

   169 }

   170 

   171 QT_END_NAMESPACE