michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkOSFile.h"
michael@0: 
michael@0: #include "SkTFitsIn.h"
michael@0: 
michael@0: #include <stdio.h>
michael@0: #include <sys/mman.h>
michael@0: #include <sys/stat.h>
michael@0: #include <sys/types.h>
michael@0: 
michael@0: typedef struct {
michael@0:     dev_t dev;
michael@0:     ino_t ino;
michael@0: } SkFILEID;
michael@0: 
michael@0: static bool sk_ino(SkFILE* a, SkFILEID* id) {
michael@0:     int fd = fileno((FILE*)a);
michael@0:     if (fd < 0) {
michael@0:         return 0;
michael@0:     }
michael@0:     struct stat status;
michael@0:     if (0 != fstat(fd, &status)) {
michael@0:         return 0;
michael@0:     }
michael@0:     id->dev = status.st_dev;
michael@0:     id->ino = status.st_ino;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool sk_fidentical(SkFILE* a, SkFILE* b) {
michael@0:     SkFILEID aID, bID;
michael@0:     return sk_ino(a, &aID) && sk_ino(b, &bID)
michael@0:            && aID.ino == bID.ino
michael@0:            && aID.dev == bID.dev;
michael@0: }
michael@0: 
michael@0: void sk_fmunmap(const void* addr, size_t length) {
michael@0:     munmap(const_cast<void*>(addr), length);
michael@0: }
michael@0: 
michael@0: void* sk_fdmmap(int fd, size_t* size) {
michael@0:     struct stat status;
michael@0:     if (0 != fstat(fd, &status)) {
michael@0:         return NULL;
michael@0:     }
michael@0:     if (!S_ISREG(status.st_mode)) {
michael@0:         return NULL;
michael@0:     }
michael@0:     if (!SkTFitsIn<size_t>(status.st_size)) {
michael@0:         return NULL;
michael@0:     }
michael@0:     size_t fileSize = static_cast<size_t>(status.st_size);
michael@0: 
michael@0:     void* addr = mmap(NULL, fileSize, PROT_READ, MAP_PRIVATE, fd, 0);
michael@0:     if (MAP_FAILED == addr) {
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     *size = fileSize;
michael@0:     return addr;
michael@0: }
michael@0: 
michael@0: int sk_fileno(SkFILE* f) {
michael@0:     return fileno((FILE*)f);
michael@0: }
michael@0: 
michael@0: void* sk_fmmap(SkFILE* f, size_t* size) {
michael@0:     int fd = sk_fileno(f);
michael@0:     if (fd < 0) {
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     return sk_fdmmap(fd, size);
michael@0: }