lib/Support/circular_raw_ostream.cpp

   1 //===- circular_raw_ostream.cpp - Implement circular_raw_ostream ----------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This implements support for circular buffered streams.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Support/circular_raw_ostream.h"
  15 #include <algorithm>
  16 using namespace llvm;
  17
  18 void circular_raw_ostream::write_impl(const char *Ptr, size_t Size) {
  19   if (BufferSize == 0) {
  20     TheStream->write(Ptr, Size);
  21     return;
  22   }
  23
  24   // Write into the buffer, wrapping if necessary.
  25   while (Size != 0) {
  26     unsigned Bytes =
  27       std::min(unsigned(Size), unsigned(BufferSize - (Cur - BufferArray)));
  28     memcpy(Cur, Ptr, Bytes);
  29     Size -= Bytes;
  30     Cur += Bytes;
  31     if (Cur == BufferArray + BufferSize) {
  32       // Reset the output pointer to the start of the buffer.
  33       Cur = BufferArray;
  34       Filled = true;
  35     }
  36   }
  37 }
  38
  39 void circular_raw_ostream::flushBufferWithBanner() {
  40   if (BufferSize != 0) {
  41     // Write out the buffer
  42     TheStream->write(Banner, std::strlen(Banner));
  43     flushBuffer();
  44   }
  45 }