15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2008, Google Inc. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// All rights reserved. 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Redistribution and use in source and binary forms, with or without 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// modification, are permitted provided that the following conditions are 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// met: 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Redistributions of source code must retain the above copyright 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// notice, this list of conditions and the following disclaimer. 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Redistributions in binary form must reproduce the above 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// copyright notice, this list of conditions and the following disclaimer 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// in the documentation and/or other materials provided with the 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// distribution. 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Neither the name of Google Inc. nor the names of its 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// contributors may be used to endorse or promote products derived from 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// this software without specific prior written permission. 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// --- 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Author: Sanjay Ghemawat 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A printf() wrapper that writes into a fixed length buffer. 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Useful in low-level code that does not want to use allocating 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// routines like StringPrintf(). 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The implementation currently uses vsnprintf(). This seems to 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// be fine for use in many low-level contexts, but we may need to 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// rethink this decision if we hit a problem with it calling 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// down into malloc() etc. 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef BASE_RAW_PRINTER_H_ 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define BASE_RAW_PRINTER_H_ 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <config.h> 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace base { 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class RawPrinter { 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // REQUIRES: "length > 0" 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Will printf any data added to this into "buf[0,length-1]" and 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // will arrange to always keep buf[] null-terminated. 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) RawPrinter(char* buf, int length); 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Return the number of bytes that have been appended to the string 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // so far. Does not count any bytes that were dropped due to overflow. 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int length() const { return (ptr_ - base_); } 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Return the number of bytes that can be added to this. 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int space_left() const { return (limit_ - ptr_); } 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Format the supplied arguments according to the "format" string 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // and append to this. Will silently truncate the output if it does 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // not fit. 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void Printf(const char* format, ...) 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifdef HAVE___ATTRIBUTE__ 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) __attribute__ ((__format__ (__printf__, 2, 3))) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles); 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // We can write into [ptr_ .. limit_-1]. 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // *limit_ is also writable, but reserved for a terminating \0 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // in case we overflow. 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Invariants: *ptr_ == \0 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Invariants: *limit_ == \0 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) char* base_; // Initial pointer 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) char* ptr_; // Where should we write next 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) char* limit_; // One past last non-\0 char we can write 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(RawPrinter); 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // BASE_RAW_PRINTER_H_ 90