centralized classes for writing data

this allows global changes to how data is written with one change
currently, it only converts from big-endian to little-endian
in the future, this will allow an easy transition to writing 64-bit data


git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@4566 212acab6-be3b-0410-9dea-997c60f758d6

Source/writer.cpp

@@ -0,0 +1,73 @@
+#include "exehead/config.h"
+#include "writer.h"
+#include "growbuf.h"
+#include "util.h"
+#include <string.h>
+#include <stdlib.h>
+#include <stdexcept>
+
+void writer_sink::write_byte(const unsigned char b)
+{
+  write_data(&b, 1);
+}
+
+void writer_sink::write_short(const short s)
+{
+  short fs = FIX_ENDIAN_INT16(s);
+  write_data(&fs, sizeof(short));
+}
+
+void writer_sink::write_int(const int i)
+{
+  int fi = FIX_ENDIAN_INT32(i);
+  write_data(&fi, sizeof(int));
+}
+
+void writer_sink::write_int_array(const int i[], const size_t len)
+{
+  for (size_t l = 0; l < len; l++)
+  {
+    write_int(i[l]);
+  }
+}
+
+void writer_sink::write_string(const char *s)
+{
+  write_data(s, strlen(s) + 1);
+}
+
+void writer_sink::write_string(const char *s, const size_t size)
+{
+  char *wb = new char[size];
+  memset(wb, 0, size);
+  strncpy(wb, s, size);
+  write_data(wb, size);
+  delete [] wb;
+}
+
+void writer_sink::write_growbuf(const IGrowBuf *b)
+{
+  write_data(b->get(), b->getlen());
+}
+
+void growbuf_writer_sink::write_data(const void *data, const size_t size)
+{
+  m_buf->add(data, size);
+}
+
+void file_writer_sink::write_data(const void *data, const size_t size)
+{
+  if (fwrite(data, 1, size, m_fp) != size)
+  {
+    throw std::runtime_error("error writing");
+  }
+}
+
+#ifdef NSIS_CONFIG_CRC_SUPPORT
+extern "C" unsigned long NSISCALL CRC32(unsigned long crc, const unsigned char *buf, unsigned int len);
+
+void crc_writer_sink::write_data(const void *data, const size_t size)
+{
+  *m_crc = CRC32(*m_crc, (const unsigned char *) data, size);
+}
+#endif