1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
/*
* Copyright (C) 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "core_jni_helpers.h"
#include "nativehelper/scoped_primitive_array.h"
namespace android {
static jint android_util_CharsetUtils_toModifiedUtf8Bytes(JNIEnv *env, jobject clazz,
jstring src, jint srcLen, jlong dest, jint destOff, jint destLen) {
char *destPtr = reinterpret_cast<char*>(dest);
// Quickly check if destination has plenty of room for worst-case
// 4-bytes-per-char encoded size
const size_t worstLen = (srcLen * 4);
if (destOff >= 0 && destOff + worstLen < destLen) {
env->GetStringUTFRegion(src, 0, srcLen, destPtr + destOff);
return strlen(destPtr + destOff + srcLen) + srcLen;
}
// String still might fit in destination, but we need to measure
// its actual encoded size to be sure
const size_t encodedLen = env->GetStringUTFLength(src);
if (destOff >= 0 && destOff + encodedLen < destLen) {
env->GetStringUTFRegion(src, 0, srcLen, destPtr + destOff);
return encodedLen;
}
return -encodedLen;
}
static jstring android_util_CharsetUtils_fromModifiedUtf8Bytes(JNIEnv *env, jobject clazz,
jlong src, jint srcOff, jint srcLen) {
char *srcPtr = reinterpret_cast<char*>(src);
// This is funky, but we need to temporarily swap a null byte so that
// JNI knows where the string ends; we'll put it back, we promise
char tmp = srcPtr[srcOff + srcLen];
srcPtr[srcOff + srcLen] = '\0';
jstring res = env->NewStringUTF(srcPtr + srcOff);
srcPtr[srcOff + srcLen] = tmp;
return res;
}
static const JNINativeMethod methods[] = {
// @FastNative
{"toModifiedUtf8Bytes", "(Ljava/lang/String;IJII)I",
(void*)android_util_CharsetUtils_toModifiedUtf8Bytes},
// @FastNative
{"fromModifiedUtf8Bytes", "(JII)Ljava/lang/String;",
(void*)android_util_CharsetUtils_fromModifiedUtf8Bytes},
};
int register_android_util_CharsetUtils(JNIEnv *env) {
return RegisterMethodsOrDie(env, "android/util/CharsetUtils", methods, NELEM(methods));
}
}
|
