1 /*
2  * Copyright (C) 2013 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef LIBJPEG_HOOK_H_
18 #define LIBJPEG_HOOK_H_
19 
20 extern "C" {
21 #include "jinclude.h"
22 #include "jpeglib.h"
23 #include "jerror.h"
24 }
25 
26 #include "inputstream_wrapper.h"
27 #include "outputstream_wrapper.h"
28 
29 #include <stdint.h>
30 
31 /**
32  * DestManager holds the libjpeg destination manager struct and
33  * a holder with a java OutputStream.
34  */
35 typedef struct {
36     struct jpeg_destination_mgr mgr;
37     OutputStreamWrapper *outStream;
38 } DestManager;
39 
40 // Initializes the DestManager struct, sets up the jni refs
41 int32_t MakeDst(j_compress_ptr cinfo, JNIEnv *env, jobject outStream);
42 
43 /**
44  * Updates the jni env pointer. This should be called in the beginning of any
45  * JNI method in jpegstream.cpp before CleanDst or any of the libjpeg functions
46  * that can trigger a call to an OutputStreamWrapper method.
47  */
48 void UpdateDstEnv(j_compress_ptr cinfo, JNIEnv* env);
49 
50 // Cleans the jni refs.  To wipe the compress object call jpeg_destroy_compress
51 void CleanDst(j_compress_ptr cinfo);
52 
53 /**
54  * SourceManager holds the libjpeg source manager struct and a
55  * holder with a java InputStream.
56  */
57 typedef struct {
58     struct jpeg_source_mgr mgr;
59     boolean start_of_file;
60     InputStreamWrapper *inStream;
61 } SourceManager;
62 
63 // Initializes the SourceManager struct, sets up the jni refs
64 int32_t MakeSrc(j_decompress_ptr cinfo, JNIEnv *env, jobject inStream);
65 
66 /**
67  * Updates the jni env pointer. This should be called in the beginning of any
68  * JNI method in jpegstream.cpp before CleanSrc or any of the libjpeg functions
69  * that can trigger a call to an InputStreamWrapper method.
70  */
71 void UpdateSrcEnv(j_decompress_ptr cinfo, JNIEnv* env);
72 
73 // Cleans the jni refs.  To wipe the decompress object, call jpeg_destroy_decompress
74 void CleanSrc(j_decompress_ptr cinfo);
75 
76 #endif // LIBJPEG_HOOK_H_
77