third_party/tcmalloc/chromium/src/raw_printer.cc

   1 // Copyright (c) 2008, Google Inc.
   2 // All rights reserved.
   3 //
   4 // Redistribution and use in source and binary forms, with or without
   5 // modification, are permitted provided that the following conditions are
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   9 // notice, this list of conditions and the following disclaimer.
  10 //     * Redistributions in binary form must reproduce the above
  11 // copyright notice, this list of conditions and the following disclaimer
  12 // in the documentation and/or other materials provided with the
  13 // distribution.
  14 //     * Neither the name of Google Inc. nor the names of its
  15 // contributors may be used to endorse or promote products derived from
  16 // this software without specific prior written permission.
  17 //
  18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 // ---
  31 // Author: sanjay@google.com (Sanjay Ghemawat)
  32
  33 #include <config.h>
  34 #include <stdarg.h>
  35 #include <stdio.h>
  36 #include "raw_printer.h"
  37 #include "base/logging.h"
  38
  39 namespace base {
  40
  41 RawPrinter::RawPrinter(char* buf, int length)
  42     : base_(buf),
  43       ptr_(buf),
  44       limit_(buf + length - 1) {
  45   RAW_DCHECK(length > 0, "");
  46   *ptr_ = '\0';
  47   *limit_ = '\0';
  48 }
  49
  50 void RawPrinter::Printf(const char* format, ...) {
  51   if (limit_ > ptr_) {
  52     va_list ap;
  53     va_start(ap, format);
  54     int avail = limit_ - ptr_;
  55     // We pass avail+1 to vsnprintf() since that routine needs room
  56     // to store the trailing \0.
  57     const int r = perftools_vsnprintf(ptr_, avail+1, format, ap);
  58     va_end(ap);
  59     if (r < 0) {
  60       // Perhaps an old glibc that returns -1 on truncation?
  61       ptr_ = limit_;
  62     } else if (r > avail) {
  63       // Truncation
  64       ptr_ = limit_;
  65     } else {
  66       ptr_ += r;
  67     }
  68   }
  69 }
  70
  71 }