1 /*
2  * Copyright (C) 2010 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 #include "Utils.h"
18 #include "SkUtils.h"
19 #include "SkData.h"
20 
21 #include <log/log.h>
22 
23 using namespace android;
24 
AssetStreamAdaptor(Asset * asset)25 AssetStreamAdaptor::AssetStreamAdaptor(Asset* asset)
26     : fAsset(asset)
27 {
28 }
29 
rewind()30 bool AssetStreamAdaptor::rewind() {
31     off64_t pos = fAsset->seek(0, SEEK_SET);
32     if (pos == (off64_t)-1) {
33         SkDebugf("----- fAsset->seek(rewind) failed\n");
34         return false;
35     }
36     return true;
37 }
38 
getLength() const39 size_t AssetStreamAdaptor::getLength() const {
40     return fAsset->getLength();
41 }
42 
isAtEnd() const43 bool AssetStreamAdaptor::isAtEnd() const {
44     return fAsset->getRemainingLength() == 0;
45 }
46 
onDuplicate() const47 SkStreamRewindable* AssetStreamAdaptor::onDuplicate() const {
48     // Cannot create a duplicate, since each AssetStreamAdaptor
49     // would be modifying the Asset.
50     //return new AssetStreamAdaptor(fAsset);
51     return NULL;
52 }
53 
hasPosition() const54 bool AssetStreamAdaptor::hasPosition() const {
55     return fAsset->seek(0, SEEK_CUR) != -1;
56 }
57 
getPosition() const58 size_t AssetStreamAdaptor::getPosition() const {
59     const off64_t offset = fAsset->seek(0, SEEK_CUR);
60     if (offset == -1) {
61         SkDebugf("---- fAsset->seek(0, SEEK_CUR) failed\n");
62         return 0;
63     }
64 
65     return offset;
66 }
67 
seek(size_t position)68 bool AssetStreamAdaptor::seek(size_t position) {
69     if (fAsset->seek(position, SEEK_SET) == -1) {
70         SkDebugf("---- fAsset->seek(0, SEEK_SET) failed\n");
71         return false;
72     }
73 
74     return true;
75 }
76 
move(long offset)77 bool AssetStreamAdaptor::move(long offset) {
78     if (fAsset->seek(offset, SEEK_CUR) == -1) {
79         SkDebugf("---- fAsset->seek(%i, SEEK_CUR) failed\n", offset);
80         return false;
81     }
82 
83     return true;
84 }
85 
read(void * buffer,size_t size)86 size_t AssetStreamAdaptor::read(void* buffer, size_t size) {
87     ssize_t amount;
88 
89     if (NULL == buffer) {
90         if (0 == size) {
91             return 0;
92         }
93         // asset->seek returns new total offset
94         // we want to return amount that was skipped
95 
96         off64_t oldOffset = fAsset->seek(0, SEEK_CUR);
97         if (-1 == oldOffset) {
98             SkDebugf("---- fAsset->seek(oldOffset) failed\n");
99             return 0;
100         }
101         off64_t newOffset = fAsset->seek(size, SEEK_CUR);
102         if (-1 == newOffset) {
103             SkDebugf("---- fAsset->seek(%d) failed\n", size);
104             return 0;
105         }
106         amount = newOffset - oldOffset;
107     } else {
108         amount = fAsset->read(buffer, size);
109     }
110 
111     if (amount < 0) {
112         amount = 0;
113     }
114     return amount;
115 }
116 
CopyAssetToStream(Asset * asset)117 SkMemoryStream* android::CopyAssetToStream(Asset* asset) {
118     if (NULL == asset) {
119         return NULL;
120     }
121 
122     const off64_t seekReturnVal = asset->seek(0, SEEK_SET);
123     if ((off64_t)-1 == seekReturnVal) {
124         SkDebugf("---- copyAsset: asset rewind failed\n");
125         return NULL;
126     }
127 
128     const off64_t size = asset->getLength();
129     if (size <= 0) {
130         SkDebugf("---- copyAsset: asset->getLength() returned %d\n", size);
131         return NULL;
132     }
133 
134     sk_sp<SkData> data(SkData::MakeUninitialized(size));
135     const off64_t len = asset->read(data->writable_data(), size);
136     if (len != size) {
137         SkDebugf("---- copyAsset: asset->read(%d) returned %d\n", size, len);
138         return NULL;
139     }
140 
141     return new SkMemoryStream(std::move(data));
142 }
143 
nullObjectReturn(const char msg[])144 jobject android::nullObjectReturn(const char msg[]) {
145     if (msg) {
146         SkDebugf("--- %s\n", msg);
147     }
148     return NULL;
149 }
150 
isSeekable(int descriptor)151 bool android::isSeekable(int descriptor) {
152     return ::lseek64(descriptor, 0, SEEK_CUR) != -1;
153 }
154 
get_env_or_die(JavaVM * jvm)155 JNIEnv* android::get_env_or_die(JavaVM* jvm) {
156     JNIEnv* env;
157     if (jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
158         LOG_ALWAYS_FATAL("Failed to get JNIEnv for JavaVM: %p", jvm);
159     }
160     return env;
161 }
162 
requireEnv(JavaVM * jvm)163 JNIEnv* android::requireEnv(JavaVM* jvm) {
164     JNIEnv* env;
165     if (jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
166         if (jvm->AttachCurrentThreadAsDaemon(&env, nullptr) != JNI_OK) {
167             LOG_ALWAYS_FATAL("Failed to AttachCurrentThread!");
168         }
169     }
170     return env;
171 }
172