jpeg_hook.h revision a8221bbdb8ece9b02dbf7b72565f9fbc5b314f7c 
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
20extern "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 */
35typedef struct {
36    struct jpeg_destination_mgr mgr;
37    OutputStreamWrapper *outStream;
38} DestManager;
39
40// Initializes the DestManager struct, sets up the jni refs
41int32_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 */
48void UpdateDstEnv(j_compress_ptr cinfo, JNIEnv* env);
49
50// Cleans the jni refs.  To wipe the compress object call jpeg_destroy_compress
51void CleanDst(j_compress_ptr cinfo);
52
53/**
54 * SourceManager holds the libjpeg source manager struct and a
55 * holder with a java InputStream.
56 */
57typedef 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
64int32_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 */
71void UpdateSrcEnv(j_decompress_ptr cinfo, JNIEnv* env);
72
73// Cleans the jni refs.  To wipe the decompress object, call jpeg_destroy_decompress
74void CleanSrc(j_decompress_ptr cinfo);
75
76#endif // LIBJPEG_HOOK_H_
77