lib/Support/circular_raw_ostream.cpp

   1 //===- circular_raw_ostream.cpp - Implement circular_raw_ostream ----------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This implements support for circular buffered streams.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/Support/circular_raw_ostream.h"
  14 #include <algorithm>
  15 using namespace llvm;
  16
  17 void circular_raw_ostream::write_impl(const char *Ptr, size_t Size) {
  18   if (BufferSize == 0) {
  19     TheStream->write(Ptr, Size);
  20     return;
  21   }
  22
  23   // Write into the buffer, wrapping if necessary.
  24   while (Size != 0) {
  25     unsigned Bytes =
  26       std::min(unsigned(Size), unsigned(BufferSize - (Cur - BufferArray)));
  27     memcpy(Cur, Ptr, Bytes);
  28     Size -= Bytes;
  29     Cur += Bytes;
  30     if (Cur == BufferArray + BufferSize) {
  31       // Reset the output pointer to the start of the buffer.
  32       Cur = BufferArray;
  33       Filled = true;
  34     }
  35   }
  36 }
  37
  38 void circular_raw_ostream::flushBufferWithBanner() {
  39   if (BufferSize != 0) {
  40     // Write out the buffer
  41     TheStream->write(Banner, std::strlen(Banner));
  42     flushBuffer();
  43   }
  44 }