libbase/tu_file.cpp

   1 // tu_file.cpp  -- Ignacio Castaño, Thatcher Ulrich <tu@tulrich.com> 2003
   2
   3 // This source code has been donated to the Public Domain.  Do
   4 // whatever you want with it.
   5
   6 // A file class that can be customized with callbacks.
   7
   8 #include "tu_file.h"
   9
  10 #include <boost/format.hpp>
  11 #include <cerrno>
  12 #include <cstdio>
  13
  14 #include "GnashFileUtilities.h"
  15 #include "log.h"
  16
  17 namespace gnash {
  18
  19 //// Create a file from a standard file pointer.
  20 tu_file::tu_file(FILE* fp, bool autoclose = false)
  21     :
  22     _data(fp),
  23     _autoclose(autoclose)
  24 {
  25 }
  26
  27 tu_file::~tu_file()
  28 {
  29     // Close this file when destroyed unless not requested.
  30     if (_autoclose) close();
  31 }
  32
  33
  34 // Return the number of bytes actually read.  EOF or an error would
  35 // cause that to not be equal to "bytes".
  36 std::streamsize
  37 tu_file::read(void* dst, std::streamsize bytes)
  38 {
  39     assert(dst);
  40     return std::fread(dst, 1, bytes, _data);
  41 }
  42
  43 // Return the number of bytes actually written.
  44 std::streamsize
  45 tu_file::write(const void* src, std::streamsize bytes)
  46 {
  47     assert(src);
  48     return std::fwrite(src, 1, bytes, _data);
  49 }
  50
  51 bool
  52 tu_file::seek(std::streampos pos)
  53 {
  54     // TODO: optimize this by caching total stream size ?
  55     if (static_cast<size_t>(pos) > size()) return false;
  56
  57     std::clearerr(_data); // make sure EOF flag is cleared.
  58     const int result = std::fseek(_data, pos, SEEK_SET);
  59     if (result == EOF) {
  60         return false;
  61     }
  62
  63     assert (std::ftell(_data) == pos);
  64
  65     return true;
  66 }
  67
  68 void
  69 tu_file::go_to_end()
  70 {
  71     const int err = std::fseek(_data, 0, SEEK_END);
  72     if (err == -1) {
  73         boost::format fmt = boost::format(
  74                 _("Error while seeking to end: %1%")) % strerror(errno);
  75         throw IOException(fmt.str());
  76     }
  77 }
  78
  79 std::streampos
  80 tu_file::tell() const
  81 {
  82     std::streampos ret = std::ftell(_data);
  83     if (ret < 0) throw IOException("Error getting stream position");
  84
  85     assert(static_cast<size_t>(ret) <= size());
  86     return ret;
  87 }
  88
  89 bool
  90 tu_file::eof() const
  91 {
  92     return std::feof(_data);
  93 }
  94
  95 bool
  96 tu_file::bad() const
  97 {
  98     if (!_data) return true;
  99     return std::ferror(_data);
 100 }
 101
 102 size_t
 103 tu_file::size() const
 104 {
 105     assert(_data);
 106
 107     struct stat statbuf;
 108     if (fstat(fileno(_data), &statbuf) < 0)
 109     {
 110             log_error("Could not fstat file");
 111             return static_cast<size_t>(-1);
 112     }
 113     return statbuf.st_size;
 114 }
 115
 116
 117 void
 118 tu_file::close()
 119 {
 120     assert(_data);
 121     std::fclose(_data);
 122 }
 123
 124 } // end namespace gnash
 125
 126 // Local Variables:
 127 // mode: C++
 128 // indent-tabs-mode: t
 129 // End: