flower/memory-stream.cc

   1 /*
   2   memory-stream.cc --  implement Memory_out_stream
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2005--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include <cassert>
  10 #include <cstring>
  11 #include <cstdlib>
  12 using namespace std;
  13
  14 #include "memory-stream.hh"
  15
  16 /*
  17   TODO: add read support as well.
  18 */
  19 const int Memory_out_stream::block_size_ = 1024;
  20
  21 lily_cookie_io_functions_t
  22 Memory_out_stream::functions_
  23 = {
  24   Memory_out_stream::reader,
  25   Memory_out_stream::writer,
  26   Memory_out_stream::seeker,
  27   Memory_out_stream::cleaner
  28 };
  29
  30 int
  31 Memory_out_stream::cleaner (void *cookie)
  32 {
  33   Memory_out_stream *stream = (Memory_out_stream *) cookie;
  34
  35   stream->file_ = 0;
  36   return 0;
  37 }
  38
  39 Memory_out_stream::Memory_out_stream ()
  40 {
  41   size_ = 0;
  42   buffer_ = 0;
  43   buffer_blocks_ = 0;
  44   file_ = 0;
  45
  46 #if 0
  47   file_ = fopencookie ((void *) this, "w", functions_);
  48 #endif
  49 }
  50
  51 Memory_out_stream::~Memory_out_stream ()
  52 {
  53   if (file_)
  54     fclose (file_);
  55
  56   free (buffer_);
  57 }
  58
  59 FILE *
  60 Memory_out_stream::get_file () const
  61 {
  62   return file_;
  63 }
  64
  65 ssize_t
  66 Memory_out_stream::get_length () const
  67 {
  68   return size_;
  69 }
  70
  71 char const *
  72 Memory_out_stream::get_string () const
  73 {
  74   return buffer_;
  75 }
  76
  77 ssize_t
  78 Memory_out_stream::writer (void *cookie,
  79                            char const *buffer,
  80                            size_t size)
  81 {
  82   Memory_out_stream *stream = (Memory_out_stream *) cookie;
  83
  84   ssize_t newsize = stream->size_ + size;
  85
  86   bool change = false;
  87   while (newsize > stream->buffer_blocks_ * block_size_)
  88     {
  89       stream->buffer_blocks_ *= 2;
  90       stream->buffer_blocks_ += 1;
  91       change = true;
  92     }
  93
  94   if (change)
  95     stream->buffer_ = (char *) realloc (stream->buffer_,
  96                                         stream->buffer_blocks_ * block_size_);
  97
  98   memcpy (stream->buffer_ + stream->size_, buffer, size);
  99   stream->size_ = newsize;
 100
 101   return size;
 102 }
 103
 104 ssize_t
 105 Memory_out_stream::reader (void *cookie,
 106                            char *buffer,
 107                            size_t size)
 108 {
 109   (void) cookie;
 110   (void) buffer;
 111   (void) size;
 112
 113   assert (false);
 114   return 0;
 115 }
 116
 117 int
 118 Memory_out_stream::seeker (void *, off64_t *, int whence)
 119 {
 120   (void) whence;
 121
 122   assert (false);
 123   return 0;
 124 }