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1 //===-- Implementation of fopencookie -------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/stdio/fopencookie.h"
10 #include "src/__support/CPP/new.h"
11 #include "src/__support/File/file.h"
12 
13 #include "src/errno/libc_errno.h"
14 #include <stdio.h>
15 #include <stdlib.h>
16 
17 namespace LIBC_NAMESPACE {
18 
19 namespace {
20 
21 class CookieFile : public LIBC_NAMESPACE::File {
22   void *cookie;
23   cookie_io_functions_t ops;
24 
25   static FileIOResult cookie_write(File *f, const void *data, size_t size);
26   static FileIOResult cookie_read(File *f, void *data, size_t size);
27   static ErrorOr<long> cookie_seek(File *f, long offset, int whence);
28   static int cookie_close(File *f);
29 
30 public:
CookieFile(void * c,cookie_io_functions_t cops,uint8_t * buffer,size_t bufsize,File::ModeFlags mode)31   CookieFile(void *c, cookie_io_functions_t cops, uint8_t *buffer,
32              size_t bufsize, File::ModeFlags mode)
33       : File(&cookie_write, &cookie_read, &CookieFile::cookie_seek,
34              &cookie_close, buffer, bufsize, 0 /* default buffering mode */,
35              true /* File owns buffer */, mode),
36         cookie(c), ops(cops) {}
37 };
38 
cookie_write(File * f,const void * data,size_t size)39 FileIOResult CookieFile::cookie_write(File *f, const void *data, size_t size) {
40   auto cookie_file = reinterpret_cast<CookieFile *>(f);
41   if (cookie_file->ops.write == nullptr)
42     return 0;
43   return cookie_file->ops.write(cookie_file->cookie,
44                                 reinterpret_cast<const char *>(data), size);
45 }
46 
cookie_read(File * f,void * data,size_t size)47 FileIOResult CookieFile::cookie_read(File *f, void *data, size_t size) {
48   auto cookie_file = reinterpret_cast<CookieFile *>(f);
49   if (cookie_file->ops.read == nullptr)
50     return 0;
51   return cookie_file->ops.read(cookie_file->cookie,
52                                reinterpret_cast<char *>(data), size);
53 }
54 
cookie_seek(File * f,long offset,int whence)55 ErrorOr<long> CookieFile::cookie_seek(File *f, long offset, int whence) {
56   auto cookie_file = reinterpret_cast<CookieFile *>(f);
57   if (cookie_file->ops.seek == nullptr) {
58     return Error(EINVAL);
59   }
60   off64_t offset64 = offset;
61   int result = cookie_file->ops.seek(cookie_file->cookie, &offset64, whence);
62   if (result == 0)
63     return offset64;
64   else
65     return -1;
66 }
67 
cookie_close(File * f)68 int CookieFile::cookie_close(File *f) {
69   auto cookie_file = reinterpret_cast<CookieFile *>(f);
70   if (cookie_file->ops.close == nullptr)
71     return 0;
72   int retval = cookie_file->ops.close(cookie_file->cookie);
73   if (retval != 0)
74     return retval;
75   delete cookie_file;
76   return 0;
77 }
78 
79 } // anonymous namespace
80 
81 LLVM_LIBC_FUNCTION(::FILE *, fopencookie,
82                    (void *cookie, const char *mode,
83                     cookie_io_functions_t ops)) {
84   uint8_t *buffer;
85   {
86     AllocChecker ac;
87     buffer = new (ac) uint8_t[File::DEFAULT_BUFFER_SIZE];
88     if (!ac)
89       return nullptr;
90   }
91   AllocChecker ac;
92   auto *file = new (ac) CookieFile(
93       cookie, ops, buffer, File::DEFAULT_BUFFER_SIZE, File::mode_flags(mode));
94   if (!ac)
95     return nullptr;
96   return reinterpret_cast<::FILE *>(file);
97 }
98 
99 } // namespace LIBC_NAMESPACE
100