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// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
// Copyright (c) 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// ---
// Author: Sanjay Ghemawat
//
// A printf() wrapper that writes into a fixed length buffer.
// Useful in low-level code that does not want to use allocating
// routines like StringPrintf().
//
// The implementation currently uses vsnprintf(). This seems to
// be fine for use in many low-level contexts, but we may need to
// rethink this decision if we hit a problem with it calling
// down into malloc() etc.
#ifndef BASE_RAW_PRINTER_H_
#define BASE_RAW_PRINTER_H_
#include <config.h>
#include "base/basictypes.h"
namespace base {
class RawPrinter {
public:
// REQUIRES: "length > 0"
// Will printf any data added to this into "buf[0,length-1]" and
// will arrange to always keep buf[] null-terminated.
RawPrinter(char* buf, int length);
// Return the number of bytes that have been appended to the string
// so far. Does not count any bytes that were dropped due to overflow.
int length() const { return (ptr_ - base_); }
// Return the number of bytes that can be added to this.
int space_left() const { return (limit_ - ptr_); }
// Format the supplied arguments according to the "format" string
// and append to this. Will silently truncate the output if it does
// not fit.
void Printf(const char* format, ...)
#ifdef HAVE___ATTRIBUTE__
__attribute__ ((__format__ (__printf__, 2, 3)))
#endif
;
private:
// We can write into [ptr_ .. limit_-1].
// *limit_ is also writable, but reserved for a terminating \0
// in case we overflow.
//
// Invariants: *ptr_ == \0
// Invariants: *limit_ == \0
char* base_; // Initial pointer
char* ptr_; // Where should we write next
char* limit_; // One past last non-\0 char we can write
DISALLOW_COPY_AND_ASSIGN(RawPrinter);
};
}
#endif // BASE_RAW_PRINTER_H_
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