blob: 3ea4fb9d068cf63324c050e80c3c7f68f96b2a5a (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
#include <qpdf/OffsetInputSource.hh>
#include <limits>
#include <sstream>
#include <stdexcept>
OffsetInputSource::OffsetInputSource(
std::shared_ptr<InputSource> proxied, qpdf_offset_t global_offset) :
proxied(proxied),
global_offset(global_offset)
{
if (global_offset < 0) {
throw std::logic_error(
"OffsetInputSource constructed with negative offset");
}
this->max_safe_offset =
std::numeric_limits<qpdf_offset_t>::max() - global_offset;
}
qpdf_offset_t
OffsetInputSource::findAndSkipNextEOL()
{
return this->proxied->findAndSkipNextEOL() - this->global_offset;
}
std::string const&
OffsetInputSource::getName() const
{
return this->proxied->getName();
}
qpdf_offset_t
OffsetInputSource::tell()
{
return this->proxied->tell() - this->global_offset;
}
void
OffsetInputSource::seek(qpdf_offset_t offset, int whence)
{
if (whence == SEEK_SET) {
if (offset > this->max_safe_offset) {
std::ostringstream msg;
msg.imbue(std::locale::classic());
msg << "seeking to " << offset << " offset by " << global_offset
<< " would cause an overflow of the offset type";
throw std::range_error(msg.str());
}
this->proxied->seek(offset + global_offset, whence);
} else {
this->proxied->seek(offset, whence);
}
if (tell() < 0) {
throw std::runtime_error(
"offset input source: seek before beginning of file");
}
}
void
OffsetInputSource::rewind()
{
seek(0, SEEK_SET);
}
size_t
OffsetInputSource::read(char* buffer, size_t length)
{
size_t result = this->proxied->read(buffer, length);
this->setLastOffset(this->proxied->getLastOffset() - global_offset);
return result;
}
void
OffsetInputSource::unreadCh(char ch)
{
this->proxied->unreadCh(ch);
}
|
