1 /* Copyright 2022 The TensorFlow Authors. All Rights Reserved.
2
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15
16 #include "tensorflow_lite_support/metadata/cc/utils/zip_readonly_mem_file.h"
17
18 #include <algorithm>
19 #include <cstdio>
20
21 #include "absl/strings/string_view.h"
22 #include "contrib/minizip/ioapi.h"
23
24 namespace tflite {
25 namespace metadata {
26
ZipReadOnlyMemFile(const char * buffer,size_t size)27 ZipReadOnlyMemFile::ZipReadOnlyMemFile(const char* buffer, size_t size)
28 : data_(buffer, size), offset_(0) {
29 zlib_filefunc64_def_.zopen64_file = OpenFile;
30 zlib_filefunc64_def_.zread_file = ReadFile;
31 zlib_filefunc64_def_.zwrite_file = WriteFile;
32 zlib_filefunc64_def_.ztell64_file = TellFile;
33 zlib_filefunc64_def_.zseek64_file = SeekFile;
34 zlib_filefunc64_def_.zclose_file = CloseFile;
35 zlib_filefunc64_def_.zerror_file = ErrorFile;
36 zlib_filefunc64_def_.opaque = this;
37 }
38
GetFileFunc64Def()39 zlib_filefunc64_def& ZipReadOnlyMemFile::GetFileFunc64Def() {
40 return zlib_filefunc64_def_;
41 }
42
43 /* static */
OpenFile(voidpf opaque,const void * filename,int mode)44 voidpf ZipReadOnlyMemFile::OpenFile(voidpf opaque, const void* filename,
45 int mode) {
46 // Result is never used, but needs to be non-null for `zipOpen2` not to fail.
47 return opaque;
48 }
49
50 /* static */
ReadFile(voidpf opaque,voidpf stream,void * buf,uLong size)51 uLong ZipReadOnlyMemFile::ReadFile(voidpf opaque, voidpf stream, void* buf,
52 uLong size) {
53 auto* mem_file = static_cast<ZipReadOnlyMemFile*>(opaque);
54 if (mem_file->offset_ < 0 || mem_file->Size() < mem_file->offset_) {
55 return 0;
56 }
57 if (mem_file->offset_ + size > mem_file->Size()) {
58 size = mem_file->Size() - mem_file->offset_;
59 }
60 memcpy(buf,
61 static_cast<const char*>(mem_file->data_.data()) + mem_file->offset_,
62 size);
63 mem_file->offset_ += size;
64 return size;
65 }
66
67 /* static */
WriteFile(voidpf opaque,voidpf stream,const void * buf,uLong size)68 uLong ZipReadOnlyMemFile::WriteFile(voidpf opaque, voidpf stream,
69 const void* buf, uLong size) {
70 // File is not writable.
71 return 0;
72 }
73
74 /* static */
TellFile(voidpf opaque,voidpf stream)75 ZPOS64_T ZipReadOnlyMemFile::TellFile(voidpf opaque, voidpf stream) {
76 return static_cast<ZipReadOnlyMemFile*>(opaque)->offset_;
77 }
78
79 /* static */
SeekFile(voidpf opaque,voidpf stream,ZPOS64_T offset,int origin)80 long ZipReadOnlyMemFile::SeekFile // NOLINT
81 (voidpf opaque, voidpf stream, ZPOS64_T offset, int origin) {
82 auto* mem_file = static_cast<ZipReadOnlyMemFile*>(opaque);
83 switch (origin) {
84 case SEEK_SET:
85 mem_file->offset_ = offset;
86 return 0;
87 case SEEK_CUR:
88 if (mem_file->offset_ + offset < 0 ||
89 mem_file->offset_ + offset > mem_file->Size()) {
90 return -1;
91 }
92 mem_file->offset_ += offset;
93 return 0;
94 case SEEK_END:
95 if (mem_file->Size() - offset < 0 ||
96 mem_file->Size() - offset > mem_file->Size()) {
97 return -1;
98 }
99 mem_file->offset_ = offset + mem_file->Size();
100 return 0;
101 default:
102 return -1;
103 }
104 }
105
106 /* static */
CloseFile(voidpf opaque,voidpf stream)107 int ZipReadOnlyMemFile::CloseFile(voidpf opaque, voidpf stream) {
108 // Nothing to do.
109 return 0;
110 }
111
112 /* static */
ErrorFile(voidpf opaque,voidpf stream)113 int ZipReadOnlyMemFile::ErrorFile(voidpf opaque, voidpf stream) {
114 // Unused.
115 return 0;
116 }
117
118 } // namespace metadata
119 } // namespace tflite