1 /* 2 * Copyright 2013 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "SkOSFile.h" 9 10 #include "SkTFitsIn.h" 11 12 #include <stdio.h> 13 #include <sys/mman.h> 14 #include <sys/stat.h> 15 #include <sys/types.h> 16 #include <unistd.h> 17 18 bool sk_exists(const char *path, SkFILE_Flags flags) { 19 int mode = F_OK; 20 if (flags & kRead_SkFILE_Flag) { 21 mode |= R_OK; 22 } 23 if (flags & kWrite_SkFILE_Flag) { 24 mode |= W_OK; 25 } 26 return (0 == access(path, mode)); 27 } 28 29 typedef struct { 30 dev_t dev; 31 ino_t ino; 32 } SkFILEID; 33 34 static bool sk_ino(SkFILE* a, SkFILEID* id) { 35 int fd = fileno((FILE*)a); 36 if (fd < 0) { 37 return 0; 38 } 39 struct stat status; 40 if (0 != fstat(fd, &status)) { 41 return 0; 42 } 43 id->dev = status.st_dev; 44 id->ino = status.st_ino; 45 return true; 46 } 47 48 bool sk_fidentical(SkFILE* a, SkFILE* b) { 49 SkFILEID aID, bID; 50 return sk_ino(a, &aID) && sk_ino(b, &bID) 51 && aID.ino == bID.ino 52 && aID.dev == bID.dev; 53 } 54 55 void sk_fmunmap(const void* addr, size_t length) { 56 munmap(const_cast<void*>(addr), length); 57 } 58 59 void* sk_fdmmap(int fd, size_t* size) { 60 struct stat status; 61 if (0 != fstat(fd, &status)) { 62 return NULL; 63 } 64 if (!S_ISREG(status.st_mode)) { 65 return NULL; 66 } 67 if (!SkTFitsIn<size_t>(status.st_size)) { 68 return NULL; 69 } 70 size_t fileSize = static_cast<size_t>(status.st_size); 71 72 void* addr = mmap(NULL, fileSize, PROT_READ, MAP_PRIVATE, fd, 0); 73 if (MAP_FAILED == addr) { 74 return NULL; 75 } 76 77 *size = fileSize; 78 return addr; 79 } 80 81 int sk_fileno(SkFILE* f) { 82 return fileno((FILE*)f); 83 } 84 85 void* sk_fmmap(SkFILE* f, size_t* size) { 86 int fd = sk_fileno(f); 87 if (fd < 0) { 88 return NULL; 89 } 90 91 return sk_fdmmap(fd, size); 92 } 93
