xref: /aosp_15_r20/external/skia/src/ports/SkOSFile_posix.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
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 "include/core/SkString.h"
9 #include "include/core/SkTypes.h"
10 #include "include/private/base/SkTFitsIn.h"
11 #include "include/private/base/SkTemplates.h"
12 #include "src/core/SkOSFile.h"
13 
14 #include <dirent.h>
15 #include <new>
16 #include <stdio.h>
17 #include <string.h>
18 #include <sys/mman.h>
19 #include <sys/stat.h>
20 #include <sys/types.h>
21 #include <unistd.h>
22 
23 #ifdef SK_BUILD_FOR_IOS
24 #include "src/ports/SkOSFile_ios.h"
25 #endif
26 
sk_fsync(FILE * f)27 void sk_fsync(FILE* f) {
28 #if !defined(SK_BUILD_FOR_ANDROID) && !defined(__UCLIBC__) && !defined(_NEWLIB_VERSION)
29     int fd = fileno(f);
30     fsync(fd);
31 #endif
32 }
33 
sk_exists(const char * path,SkFILE_Flags flags)34 bool sk_exists(const char *path, SkFILE_Flags flags) {
35     int mode = F_OK;
36     if (flags & kRead_SkFILE_Flag) {
37         mode |= R_OK;
38     }
39     if (flags & kWrite_SkFILE_Flag) {
40         mode |= W_OK;
41     }
42 #ifdef SK_BUILD_FOR_IOS
43     // if the default path fails, check the bundle (but only if read-only)
44     if (0 == access(path, mode)) {
45         return true;
46     } else {
47         return (kRead_SkFILE_Flag == flags && ios_get_path_in_bundle(path, nullptr));
48     }
49 #else
50     return (0 == access(path, mode));
51 #endif
52 }
53 
54 typedef struct {
55     dev_t dev;
56     ino_t ino;
57 } SkFILEID;
58 
sk_ino(FILE * a,SkFILEID * id)59 static bool sk_ino(FILE* a, SkFILEID* id) {
60     int fd = fileno(a);
61     if (fd < 0) {
62         return 0;
63     }
64     struct stat status = {};
65     if (0 != fstat(fd, &status)) {
66         return 0;
67     }
68     id->dev = status.st_dev;
69     id->ino = status.st_ino;
70     return true;
71 }
72 
sk_fidentical(FILE * a,FILE * b)73 bool sk_fidentical(FILE* a, FILE* b) {
74     SkFILEID aID, bID;
75     return sk_ino(a, &aID) && sk_ino(b, &bID)
76            && aID.ino == bID.ino
77            && aID.dev == bID.dev;
78 }
79 
sk_fmunmap(const void * addr,size_t length)80 void sk_fmunmap(const void* addr, size_t length) {
81     munmap(const_cast<void*>(addr), length);
82 }
83 
sk_fdmmap(int fd,size_t * size)84 void* sk_fdmmap(int fd, size_t* size) {
85     struct stat status = {};
86     if (0 != fstat(fd, &status)) {
87         return nullptr;
88     }
89     if (!S_ISREG(status.st_mode)) {
90         return nullptr;
91     }
92     if (!SkTFitsIn<size_t>(status.st_size)) {
93         return nullptr;
94     }
95     size_t fileSize = static_cast<size_t>(status.st_size);
96 
97     void* addr = mmap(nullptr, fileSize, PROT_READ, MAP_PRIVATE, fd, 0);
98     if (MAP_FAILED == addr) {
99         return nullptr;
100     }
101 
102     *size = fileSize;
103     return addr;
104 }
105 
sk_fileno(FILE * f)106 int sk_fileno(FILE* f) {
107     return fileno(f);
108 }
109 
sk_fmmap(FILE * f,size_t * size)110 void* sk_fmmap(FILE* f, size_t* size) {
111     int fd = sk_fileno(f);
112     if (fd < 0) {
113         return nullptr;
114     }
115 
116     return sk_fdmmap(fd, size);
117 }
118 
sk_qread(FILE * file,void * buffer,size_t count,size_t offset)119 size_t sk_qread(FILE* file, void* buffer, size_t count, size_t offset) {
120     int fd = sk_fileno(file);
121     if (fd < 0) {
122         return SIZE_MAX;
123     }
124     ssize_t bytesRead = pread(fd, buffer, count, offset);
125     if (bytesRead < 0) {
126         return SIZE_MAX;
127     }
128     return bytesRead;
129 }
130 
131 ////////////////////////////////////////////////////////////////////////////
132 
133 struct SkOSFileIterData {
SkOSFileIterDataSkOSFileIterData134     SkOSFileIterData() : fDIR(nullptr) { }
135     DIR* fDIR;
136     SkString fPath, fSuffix;
137 };
138 static_assert(sizeof(SkOSFileIterData) <= SkOSFile::Iter::kStorageSize, "not_enough_space");
139 
Iter()140 SkOSFile::Iter::Iter() { new (fSelf) SkOSFileIterData; }
141 
Iter(const char path[],const char suffix[])142 SkOSFile::Iter::Iter(const char path[], const char suffix[]) {
143     new (fSelf) SkOSFileIterData;
144     this->reset(path, suffix);
145 }
146 
~Iter()147 SkOSFile::Iter::~Iter() {
148     SkOSFileIterData& self = *reinterpret_cast<SkOSFileIterData*>(fSelf);
149     if (self.fDIR) {
150         ::closedir(self.fDIR);
151     }
152     self.~SkOSFileIterData();
153 }
154 
reset(const char path[],const char suffix[])155 void SkOSFile::Iter::reset(const char path[], const char suffix[]) {
156     SkOSFileIterData& self = *reinterpret_cast<SkOSFileIterData*>(fSelf);
157     if (self.fDIR) {
158         ::closedir(self.fDIR);
159         self.fDIR = nullptr;
160     }
161     self.fPath.set(path);
162 
163     if (path) {
164         self.fDIR = ::opendir(path);
165 #ifdef SK_BUILD_FOR_IOS
166         // check bundle for directory
167         if (!self.fDIR && ios_get_path_in_bundle(path, &self.fPath)) {
168             self.fDIR = ::opendir(self.fPath.c_str());
169         }
170 #endif
171         self.fSuffix.set(suffix);
172     } else {
173         self.fSuffix.reset();
174     }
175 }
176 
177 // returns true if suffix is empty, or if str ends with suffix
issuffixfor(const SkString & suffix,const char str[])178 static bool issuffixfor(const SkString& suffix, const char str[]) {
179     size_t  suffixLen = suffix.size();
180     size_t  strLen = strlen(str);
181 
182     return  strLen >= suffixLen &&
183             memcmp(suffix.c_str(), str + strLen - suffixLen, suffixLen) == 0;
184 }
185 
next(SkString * name,bool getDir)186 bool SkOSFile::Iter::next(SkString* name, bool getDir) {
187     SkOSFileIterData& self = *reinterpret_cast<SkOSFileIterData*>(fSelf);
188     if (self.fDIR) {
189         dirent* entry;
190 
191         while ((entry = ::readdir(self.fDIR)) != nullptr) {
192             struct stat s = {};
193             SkString str(self.fPath);
194 
195             if (!str.endsWith("/") && !str.endsWith("\\")) {
196                 str.append("/");
197             }
198             str.append(entry->d_name);
199 
200             if (0 == stat(str.c_str(), &s)) {
201                 if (getDir) {
202                     if (s.st_mode & S_IFDIR) {
203                         break;
204                     }
205                 } else {
206                     if (!(s.st_mode & S_IFDIR) && issuffixfor(self.fSuffix, entry->d_name)) {
207                         break;
208                     }
209                 }
210             }
211         }
212         if (entry) { // we broke out with a file
213             if (name) {
214                 name->set(entry->d_name);
215             }
216             return true;
217         }
218     }
219     return false;
220 }
221