rosapps/smartpdf/poppler/poppler/FlateStream.cc

   1 //========================================================================
   2 //
   3 // FlateStream.cc
   4 //
   5 // Copyright (C) 2005, Jeff Muizelaar
   6 //
   7 //========================================================================
   8 #include "FlateStream.h"
   9 FlateStream::FlateStream(Stream *strA, int predictor, int columns, int colors, int bits) :
  10   FilterStream(strA)
  11 {
  12   if (predictor != 1) {
  13     pred = new StreamPredictor(this, predictor, columns, colors, bits);
  14   } else {
  15     pred = NULL;
  16   }
  17   out_pos = 0;
  18   memset(&d_stream, 0, sizeof(d_stream));
  19   inflateInit(&d_stream);
  20 }
  21
  22 FlateStream::~FlateStream() {
  23   inflateEnd(&d_stream);
  24   delete pred;
  25   delete str;
  26 }
  27
  28 void FlateStream::reset() {
  29   //FIXME: what are the semantics of reset?
  30   //i.e. how much intialization has to happen in the constructor?
  31
  32   /* reinitialize zlib */
  33   inflateEnd(&d_stream);
  34   memset(&d_stream, 0, sizeof(d_stream));
  35   inflateInit(&d_stream);
  36
  37   str->reset();
  38   d_stream.avail_in = 0;
  39   status = Z_OK;
  40   out_pos = 0;
  41   out_buf_len = 0;
  42 }
  43
  44 int FlateStream::getChar() {
  45   if (pred)
  46     return pred->getChar();
  47   else
  48     return getRawChar();
  49 }
  50
  51 int FlateStream::lookChar() {
  52   if (pred)
  53     return pred->lookChar();
  54
  55   if (fill_buffer())
  56     return EOF;
  57
  58   return out_buf[out_pos];
  59 }
  60
  61 int FlateStream::fill_buffer() {
  62   /* only fill the buffer if it has all been used */
  63   if (out_pos >= out_buf_len) {
  64     /* check if the flatestream has been exhausted */
  65     if (status == Z_STREAM_END) {
  66       return -1;
  67     }
  68
  69     /* set to the begining of out_buf */
  70     d_stream.avail_out = sizeof(out_buf);
  71     d_stream.next_out = out_buf;
  72     out_pos = 0;
  73
  74     while (1) {
  75     /* buffer is empty so we need to fill it */
  76     if (d_stream.avail_in == 0) {
  77       int c;
  78       /* read from the source stream */
  79       while (d_stream.avail_in < sizeof(in_buf) && (c = str->getChar()) != EOF) {
  80         in_buf[d_stream.avail_in++] = c;
  81       }
  82       d_stream.next_in = in_buf;
  83     }
  84
  85       /* keep decompressing until we can't anymore */
  86       if (d_stream.avail_out == 0 || d_stream.avail_in == 0 || (status != Z_OK && status != Z_BUF_ERROR))
  87         break;
  88       status = inflate(&d_stream, Z_SYNC_FLUSH);
  89     }
  90
  91     out_buf_len = sizeof(out_buf) - d_stream.avail_out;
  92     if (status != Z_OK && status != Z_STREAM_END)
  93       return -1;
  94     if (!out_buf_len)
  95       return -1;
  96   }
  97
  98   return 0;
  99 }
 100
 101 GooString *FlateStream::getPSFilter(int psLevel, char *indent) {
 102   GooString *s;
 103
 104   if (psLevel < 3 || pred) {
 105     return NULL;
 106   }
 107   if (!(s = str->getPSFilter(psLevel, indent))) {
 108     return NULL;
 109   }
 110   s->append(indent)->append("<< >> /FlateDecode filter\n");
 111   return s;
 112 }
 113
 114 GBool FlateStream::isBinary(GBool last) {
 115   return str->isBinary(gTrue);
 116 }