1 //========================================================================
2 //
3 // FlateStream.cc
4 //
5 // Copyright (C) 2005, Jeff Muizelaar <jeff@infidigm.net>
6 // Copyright (C) 2010, Albert Astals Cid <aacid@kde.org>
7 //
8 // This file is under the GPLv2 or later license
9 //
10 //========================================================================
11 #include "FlateStream.h"
FlateStream(Stream * strA,int predictor,int columns,int colors,int bits)12 FlateStream::FlateStream(Stream *strA, int predictor, int columns, int colors, int bits) :
13 FilterStream(strA)
14 {
15 if (predictor != 1) {
16 pred = new StreamPredictor(this, predictor, columns, colors, bits);
17 } else {
18 pred = NULL;
19 }
20 out_pos = 0;
21 memset(&d_stream, 0, sizeof(d_stream));
22 inflateInit(&d_stream);
23 }
24
~FlateStream()25 FlateStream::~FlateStream() {
26 inflateEnd(&d_stream);
27 delete pred;
28 delete str;
29 }
30
reset()31 void FlateStream::reset() {
32 //FIXME: what are the semantics of reset?
33 //i.e. how much intialization has to happen in the constructor?
34
35 /* reinitialize zlib */
36 inflateEnd(&d_stream);
37 memset(&d_stream, 0, sizeof(d_stream));
38 inflateInit(&d_stream);
39
40 str->reset();
41 d_stream.avail_in = 0;
42 status = Z_OK;
43 out_pos = 0;
44 out_buf_len = 0;
45 }
46
getRawChar()47 int FlateStream::getRawChar() {
48 return doGetRawChar();
49 }
50
getRawChars(int nChars,int * buffer)51 void FlateStream::getRawChars(int nChars, int *buffer) {
52 for (int i = 0; i < nChars; ++i)
53 buffer[i] = doGetRawChar();
54 }
55
getChar()56 int FlateStream::getChar() {
57 if (pred)
58 return pred->getChar();
59 else
60 return getRawChar();
61 }
62
lookChar()63 int FlateStream::lookChar() {
64 if (pred)
65 return pred->lookChar();
66
67 if (fill_buffer())
68 return EOF;
69
70 return out_buf[out_pos];
71 }
72
fill_buffer()73 int FlateStream::fill_buffer() {
74 /* only fill the buffer if it has all been used */
75 if (out_pos >= out_buf_len) {
76 /* check if the flatestream has been exhausted */
77 if (status == Z_STREAM_END) {
78 return -1;
79 }
80
81 /* set to the begining of out_buf */
82 d_stream.avail_out = sizeof(out_buf);
83 d_stream.next_out = out_buf;
84 out_pos = 0;
85
86 while (1) {
87 /* buffer is empty so we need to fill it */
88 if (d_stream.avail_in == 0) {
89 int c;
90 /* read from the source stream */
91 while (d_stream.avail_in < sizeof(in_buf) && (c = str->getChar()) != EOF) {
92 in_buf[d_stream.avail_in++] = c;
93 }
94 d_stream.next_in = in_buf;
95 }
96
97 /* keep decompressing until we can't anymore */
98 if (d_stream.avail_out == 0 || d_stream.avail_in == 0 || (status != Z_OK && status != Z_BUF_ERROR))
99 break;
100 status = inflate(&d_stream, Z_SYNC_FLUSH);
101 }
102
103 out_buf_len = sizeof(out_buf) - d_stream.avail_out;
104 if (status != Z_OK && status != Z_STREAM_END)
105 return -1;
106 if (!out_buf_len)
107 return -1;
108 }
109
110 return 0;
111 }
112
getPSFilter(int psLevel,char * indent)113 GooString *FlateStream::getPSFilter(int psLevel, char *indent) {
114 GooString *s;
115
116 if (psLevel < 3 || pred) {
117 return NULL;
118 }
119 if (!(s = str->getPSFilter(psLevel, indent))) {
120 return NULL;
121 }
122 s->append(indent)->append("<< >> /FlateDecode filter\n");
123 return s;
124 }
125
isBinary(GBool last)126 GBool FlateStream::isBinary(GBool last) {
127 return str->isBinary(gTrue);
128 }
129