83 lines
2.0 KiB
C++
83 lines
2.0 KiB
C++
#include <streambuf>
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#include <functional>
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#include <cassert>
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#include <cstring>
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using namespace std;
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namespace polyvox {
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class StreamBufferAdapter : public std::streambuf
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{
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public:
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StreamBufferAdapter(const char *begin, const char *end);
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~StreamBufferAdapter() {
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}
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streamsize size();
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private:
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int_type uflow() override;
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int_type underflow() override;
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int_type pbackfail(int_type ch) override;
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streampos seekoff(streamoff off, ios_base::seekdir way, ios_base::openmode which) override;
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streampos seekpos(streampos sp, ios_base::openmode which) override;
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std::streamsize showmanyc() override;
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};
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StreamBufferAdapter::StreamBufferAdapter(const char *begin, const char *end)
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{
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setg((char*)begin, (char*)begin, (char*)end);
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}
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streamsize StreamBufferAdapter::size() {
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return egptr() - eback();
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}
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streambuf::int_type StreamBufferAdapter::underflow()
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{
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if (gptr() == egptr()) {
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return traits_type::eof();
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}
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return *(gptr());
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}
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streambuf::int_type StreamBufferAdapter::uflow()
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{
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if (gptr() == egptr()) {
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return traits_type::eof();
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}
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gbump(1);
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return *(gptr());
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}
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streambuf::int_type StreamBufferAdapter::pbackfail(int_type ch)
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{
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if (gptr() == eback() || (ch != traits_type::eof() && ch != gptr()[-1]))
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return traits_type::eof();
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gbump(-ch);
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return *(gptr());
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}
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streamsize StreamBufferAdapter::showmanyc()
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{
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return egptr() - gptr();
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}
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streampos StreamBufferAdapter::seekoff(streamoff off, ios_base::seekdir way, ios_base::openmode which = ios_base::in) {
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if(way == ios_base::beg) {
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setg(eback(), eback()+off, egptr());
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} else if(way == ios_base::cur) {
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gbump(off);
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} else {
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setg(eback(), egptr()-off, egptr());
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}
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return gptr() - eback();
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}
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streampos StreamBufferAdapter::seekpos(streampos sp, ios_base::openmode which = ios_base::in) {
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return seekoff(sp - pos_type(off_type(0)), std::ios_base::beg, which);
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}
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} |