diff options
author | Hieu Hoang <hieuhoang@gmail.com> | 2012-11-12 23:56:18 +0400 |
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committer | Hieu Hoang <hieuhoang@gmail.com> | 2012-11-12 23:56:18 +0400 |
commit | 5e3ef23cef6101d2c098eb3445f562e8f595655b (patch) | |
tree | b8c332b6fa82bae84ea4910967a10ba1b08a7107 /moses/gzfilebuf.h | |
parent | 8c785cff2b1be3cccd76ea9026f71b649762dfc3 (diff) |
move moses/src/* to moses/
Diffstat (limited to 'moses/gzfilebuf.h')
-rw-r--r-- | moses/gzfilebuf.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/moses/gzfilebuf.h b/moses/gzfilebuf.h new file mode 100644 index 000000000..2376c2875 --- /dev/null +++ b/moses/gzfilebuf.h @@ -0,0 +1,88 @@ +#ifndef moses_gzfile_buf_h +#define moses_gzfile_buf_h + +#include <streambuf> +#include <zlib.h> +#include <cstring> + +/** wrapper around gzip input stream. Unknown parentage + * @todo replace with boost version - output stream already uses it + */ +class gzfilebuf : public std::streambuf +{ +public: + gzfilebuf(const char *filename) { + _gzf = gzopen(filename, "rb"); + setg (_buff+sizeof(int), // beginning of putback area + _buff+sizeof(int), // read position + _buff+sizeof(int)); // end position + } + ~gzfilebuf() { + gzclose(_gzf); + } +protected: + virtual int_type overflow (int_type /* c */) { + throw; + } + + // write multiple characters + virtual + std::streamsize xsputn (const char* /* s */, + std::streamsize /* num */) { + throw; + } + + virtual std::streampos seekpos ( std::streampos /* sp */, std::ios_base::openmode /* which = std::ios_base::in | std::ios_base::out */ ) { + throw; + } + + //read one character + virtual int_type underflow () { + // is read position before end of _buff? + if (gptr() < egptr()) { + return traits_type::to_int_type(*gptr()); + } + + /* process size of putback area + * - use number of characters read + * - but at most four + */ + unsigned int numPutback = gptr() - eback(); + if (numPutback > sizeof(int)) { + numPutback = sizeof(int); + } + + /* copy up to four characters previously read into + * the putback _buff (area of first four characters) + */ + std::memmove (_buff+(sizeof(int)-numPutback), gptr()-numPutback, + numPutback); + + // read new characters + int num = gzread(_gzf, _buff+sizeof(int), _buffsize-sizeof(int)); + if (num <= 0) { + // ERROR or EOF + return EOF; + } + + // reset _buff pointers + setg (_buff+(sizeof(int)-numPutback), // beginning of putback area + _buff+sizeof(int), // read position + _buff+sizeof(int)+num); // end of buffer + + // return next character + return traits_type::to_int_type(*gptr()); + } + + std::streamsize xsgetn (char* s, + std::streamsize num) { + return gzread(_gzf,s,num); + } + +private: + gzFile _gzf; + static const unsigned int _buffsize = 1024; + char _buff[_buffsize]; +}; + +#endif |