android_backup_BackupDataInput.cpp revision 4528186e0d65fc68ef0dd1941aa2ac8aefcd55a3 
1/*
2 * Copyright (C) 2009 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#define LOG_TAG "FileBackupHelper_native"
18#include <utils/Log.h>
19
20#include "JNIHelp.h"
21#include <android_runtime/AndroidRuntime.h>
22
23#include <utils/BackupHelpers.h>
24
25namespace android
26{
27
28// java.io.FileDescriptor
29static jfieldID s_descriptorField = 0;
30
31// android.app.backup.BackupDataInput$EntityHeader
32static jfieldID s_keyField = 0;
33static jfieldID s_dataSizeField = 0;
34
35static int
36ctor_native(JNIEnv* env, jobject clazz, jobject fileDescriptor)
37{
38    int err;
39
40    int fd = env->GetIntField(fileDescriptor, s_descriptorField);
41    if (fd == -1) {
42        return NULL;
43    }
44
45    return (int)new BackupDataReader(fd);
46}
47
48static void
49dtor_native(JNIEnv* env, jobject clazz, int r)
50{
51    delete (BackupDataReader*)r;
52}
53
54static jint
55readNextHeader_native(JNIEnv* env, jobject clazz, int r, jobject entity)
56{
57    int err;
58    bool done;
59    BackupDataReader* reader = (BackupDataReader*)r;
60
61    int type = 0;
62
63    err = reader->ReadNextHeader(&done, &type);
64    if (done) {
65        return 1;
66    }
67
68    if (err != 0) {
69        return err < 0 ? err : -1;
70    }
71
72    switch (type) {
73    case BACKUP_HEADER_ENTITY_V1:
74    {
75        String8 key;
76        size_t dataSize;
77        err = reader->ReadEntityHeader(&key, &dataSize);
78        if (err != 0) {
79            return err < 0 ? err : -1;
80        }
81        // TODO: Set the fields in the entity object
82        jstring keyStr = env->NewStringUTF(key.string());
83        env->SetObjectField(entity, s_keyField, keyStr);
84        env->SetIntField(entity, s_dataSizeField, dataSize);
85        return 0;
86    }
87    default:
88        LOGD("Unknown header type: 0x%08x\n", type);
89        return -1;
90    }
91
92    // done
93    return 1;
94}
95
96static jint
97readEntityData_native(JNIEnv* env, jobject clazz, int r, jbyteArray data, int offset, int size)
98{
99    int err;
100    BackupDataReader* reader = (BackupDataReader*)r;
101
102    if (env->GetArrayLength(data) < (size+offset)) {
103        // size mismatch
104        return -1;
105    }
106
107    jbyte* dataBytes = env->GetByteArrayElements(data, NULL);
108    if (dataBytes == NULL) {
109        return -2;
110    }
111
112    err = reader->ReadEntityData(dataBytes+offset, size);
113
114    env->ReleaseByteArrayElements(data, dataBytes, 0);
115
116    return err;
117}
118
119static jint
120skipEntityData_native(JNIEnv* env, jobject clazz, int r)
121{
122    int err;
123    BackupDataReader* reader = (BackupDataReader*)r;
124
125    err = reader->SkipEntityData();
126
127    return err;
128}
129
130static const JNINativeMethod g_methods[] = {
131    { "ctor", "(Ljava/io/FileDescriptor;)I", (void*)ctor_native },
132    { "dtor", "(I)V", (void*)dtor_native },
133    { "readNextHeader_native", "(ILandroid/app/backup/BackupDataInput$EntityHeader;)I",
134            (void*)readNextHeader_native },
135    { "readEntityData_native", "(I[BII)I", (void*)readEntityData_native },
136    { "skipEntityData_native", "(I)I", (void*)skipEntityData_native },
137};
138
139int register_android_backup_BackupDataInput(JNIEnv* env)
140{
141    //LOGD("register_android_backup_BackupDataInput");
142
143    jclass clazz;
144
145    clazz = env->FindClass("java/io/FileDescriptor");
146    LOG_FATAL_IF(clazz == NULL, "Unable to find class java.io.FileDescriptor");
147    s_descriptorField = env->GetFieldID(clazz, "descriptor", "I");
148    LOG_FATAL_IF(s_descriptorField == NULL,
149            "Unable to find descriptor field in java.io.FileDescriptor");
150
151    clazz = env->FindClass("android/app/backup/BackupDataInput$EntityHeader");
152    LOG_FATAL_IF(clazz == NULL, "Unable to find class android.app.backup.BackupDataInput.EntityHeader");
153    s_keyField = env->GetFieldID(clazz, "key", "Ljava/lang/String;");
154    LOG_FATAL_IF(s_keyField == NULL,
155            "Unable to find key field in android.app.backup.BackupDataInput.EntityHeader");
156    s_dataSizeField = env->GetFieldID(clazz, "dataSize", "I");
157    LOG_FATAL_IF(s_dataSizeField == NULL,
158            "Unable to find dataSize field in android.app.backup.BackupDataInput.EntityHeader");
159
160    return AndroidRuntime::registerNativeMethods(env, "android/app/backup/BackupDataInput",
161            g_methods, NELEM(g_methods));
162}
163
164}
165