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 <io.h>
13#include <stdio.h>
14#include <sys/stat.h>
15
16bool sk_exists(const char *path, SkFILE_Flags flags) {
17    int mode = 0; // existence
18    if (flags & kRead_SkFILE_Flag) {
19        mode |= 4; // read
20    }
21    if (flags & kWrite_SkFILE_Flag) {
22        mode |= 2; // write
23    }
24    return (0 == _access(path, mode));
25}
26
27typedef struct {
28    ULONGLONG fVolume;
29    ULONGLONG fLsbSize;
30    ULONGLONG fMsbSize;
31} SkFILEID;
32
33static bool sk_ino(SkFILE* f, SkFILEID* id) {
34    int fileno = _fileno((FILE*)f);
35    if (fileno < 0) {
36        return false;
37    }
38
39    HANDLE file = (HANDLE)_get_osfhandle(fileno);
40    if (INVALID_HANDLE_VALUE == file) {
41        return false;
42    }
43
44    //TODO: call GetFileInformationByHandleEx on Vista and later with FileIdInfo.
45    BY_HANDLE_FILE_INFORMATION info;
46    if (0 == GetFileInformationByHandle(file, &info)) {
47        return false;
48    }
49    id->fVolume = info.dwVolumeSerialNumber;
50    id->fLsbSize = info.nFileIndexLow + (((ULONGLONG)info.nFileIndexHigh) << 32);
51    id->fMsbSize = 0;
52
53    return true;
54}
55
56bool sk_fidentical(SkFILE* a, SkFILE* b) {
57    SkFILEID aID, bID;
58    return sk_ino(a, &aID) && sk_ino(b, &bID)
59           && aID.fLsbSize == bID.fLsbSize
60           && aID.fMsbSize == bID.fMsbSize
61           && aID.fVolume == bID.fVolume;
62}
63
64class SkAutoNullKernelHandle : SkNoncopyable {
65public:
66    SkAutoNullKernelHandle(const HANDLE handle) : fHandle(handle) { }
67    ~SkAutoNullKernelHandle() { CloseHandle(fHandle); }
68    operator HANDLE() const { return fHandle; }
69    bool isValid() const { return SkToBool(fHandle); }
70private:
71    HANDLE fHandle;
72};
73typedef SkAutoNullKernelHandle SkAutoWinMMap;
74
75void sk_fmunmap(const void* addr, size_t) {
76    UnmapViewOfFile(addr);
77}
78
79void* sk_fdmmap(int fileno, size_t* length) {
80    HANDLE file = (HANDLE)_get_osfhandle(fileno);
81    if (INVALID_HANDLE_VALUE == file) {
82        return NULL;
83    }
84
85    LARGE_INTEGER fileSize;
86    if (0 == GetFileSizeEx(file, &fileSize)) {
87        //TODO: use SK_TRACEHR(GetLastError(), "Could not get file size.") to report.
88        return NULL;
89    }
90    if (!SkTFitsIn<size_t>(fileSize.QuadPart)) {
91        return NULL;
92    }
93
94    SkAutoWinMMap mmap(CreateFileMapping(file, NULL, PAGE_READONLY, 0, 0, NULL));
95    if (!mmap.isValid()) {
96        //TODO: use SK_TRACEHR(GetLastError(), "Could not create file mapping.") to report.
97        return NULL;
98    }
99
100    // Eventually call UnmapViewOfFile
101    void* addr = MapViewOfFile(mmap, FILE_MAP_READ, 0, 0, 0);
102    if (NULL == addr) {
103        //TODO: use SK_TRACEHR(GetLastError(), "Could not map view of file.") to report.
104        return NULL;
105    }
106
107    *length = static_cast<size_t>(fileSize.QuadPart);
108    return addr;
109}
110
111int sk_fileno(SkFILE* f) {
112    return _fileno((FILE*)f);
113}
114
115void* sk_fmmap(SkFILE* f, size_t* length) {
116    int fileno = sk_fileno(f);
117    if (fileno < 0) {
118        return NULL;
119    }
120
121    return sk_fdmmap(fileno, length);
122}
123