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
18bool 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
29typedef struct {
30    dev_t dev;
31    ino_t ino;
32} SkFILEID;
33
34static 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
48bool 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
55void sk_fmunmap(const void* addr, size_t length) {
56    munmap(const_cast<void*>(addr), length);
57}
58
59void* 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
81int sk_fileno(SkFILE* f) {
82    return fileno((FILE*)f);
83}
84
85void* 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