1/* 2 * Copyright (c) 2015, Intel Corporation 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without modification, 6 * are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, this 9 * list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright notice, 12 * this list of conditions and the following disclaimer in the documentation and/or 13 * other materials provided with the distribution. 14 * 15 * 3. Neither the name of the copyright holder nor the names of its contributors 16 * may be used to endorse or promote products derived from this software without 17 * specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 22 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR 23 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 26 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include "FullIo.hpp" 32 33#include <cerrno> 34#include <unistd.h> 35 36namespace utility 37{ 38 39/** Workaround c++ `void *` arithmetic interdiction. */ 40template <class Ptr> 41Ptr *add(Ptr *ptr, size_t count) { 42 return (char *)ptr + count; 43} 44 45template <class Buff> 46static bool fullAccess(ssize_t (&accessor)(int, Buff, size_t), 47 bool (&accessFailed)(ssize_t), 48 int fd, Buff buf, size_t count) { 49 size_t done = 0; // Bytes already access in previous iterations 50 while (done < count) { 51 ssize_t accessed = accessor(fd, add(buf, done), count - done); 52 if (accessFailed(accessed)) { 53 return false; 54 } 55 done += accessed; 56 } 57 return true; 58} 59 60static bool accessFailed(ssize_t accessRes) { 61 return accessRes == -1 and errno != EAGAIN and errno != EINTR; 62} 63 64bool fullWrite(int fd, const void *buf, size_t count) { 65 return fullAccess(::write, accessFailed, fd, buf, count); 66} 67 68static bool readFailed(ssize_t readRes) { 69 if (readRes == 0) { // read should not return 0 (EOF) 70 errno = 0; 71 return true; 72 } 73 return accessFailed(readRes); 74} 75bool fullRead(int fd, void *buf, size_t count) { 76 return fullAccess(::read, readFailed, fd, buf, count); 77} 78 79} // namespace utility 80 81