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
17typedef struct {
18    dev_t dev;
19    ino_t ino;
20} SkFILEID;
21
22static bool sk_ino(SkFILE* a, SkFILEID* id) {
23    int fd = fileno((FILE*)a);
24    if (fd < 0) {
25        return 0;
26    }
27    struct stat status;
28    if (0 != fstat(fd, &status)) {
29        return 0;
30    }
31    id->dev = status.st_dev;
32    id->ino = status.st_ino;
33    return true;
34}
35
36bool sk_fidentical(SkFILE* a, SkFILE* b) {
37    SkFILEID aID, bID;
38    return sk_ino(a, &aID) && sk_ino(b, &bID)
39           && aID.ino == bID.ino
40           && aID.dev == bID.dev;
41}
42
43void sk_fmunmap(const void* addr, size_t length) {
44    munmap(const_cast<void*>(addr), length);
45}
46
47void* sk_fdmmap(int fd, size_t* size) {
48    struct stat status;
49    if (0 != fstat(fd, &status)) {
50        return NULL;
51    }
52    if (!S_ISREG(status.st_mode)) {
53        return NULL;
54    }
55    if (!SkTFitsIn<size_t>(status.st_size)) {
56        return NULL;
57    }
58    size_t fileSize = static_cast<size_t>(status.st_size);
59
60    void* addr = mmap(NULL, fileSize, PROT_READ, MAP_PRIVATE, fd, 0);
61    if (MAP_FAILED == addr) {
62        return NULL;
63    }
64
65    *size = fileSize;
66    return addr;
67}
68
69int sk_fileno(SkFILE* f) {
70    return fileno((FILE*)f);
71}
72
73void* sk_fmmap(SkFILE* f, size_t* size) {
74    int fd = sk_fileno(f);
75    if (fd < 0) {
76        return NULL;
77    }
78
79    return sk_fdmmap(fd, size);
80}
81