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 using namespace android;
22
AssetStreamAdaptor(Asset * asset)23 AssetStreamAdaptor::AssetStreamAdaptor(Asset* asset)
24 : fAsset(asset)
25 {
26 }
27
rewind()28 bool AssetStreamAdaptor::rewind() {
29 off64_t pos = fAsset->seek(0, SEEK_SET);
30 if (pos == (off64_t)-1) {
31 SkDebugf("----- fAsset->seek(rewind) failed\n");
32 return false;
33 }
34 return true;
35 }
36
getLength() const37 size_t AssetStreamAdaptor::getLength() const {
38 return fAsset->getLength();
39 }
40
isAtEnd() const41 bool AssetStreamAdaptor::isAtEnd() const {
42 return fAsset->getRemainingLength() == 0;
43 }
44
duplicate() const45 SkStreamRewindable* AssetStreamAdaptor::duplicate() const {
46 // Cannot create a duplicate, since each AssetStreamAdaptor
47 // would be modifying the Asset.
48 //return new AssetStreamAdaptor(fAsset);
49 return NULL;
50 }
51
read(void * buffer,size_t size)52 size_t AssetStreamAdaptor::read(void* buffer, size_t size) {
53 ssize_t amount;
54
55 if (NULL == buffer) {
56 if (0 == size) {
57 return 0;
58 }
59 // asset->seek returns new total offset
60 // we want to return amount that was skipped
61
62 off64_t oldOffset = fAsset->seek(0, SEEK_CUR);
63 if (-1 == oldOffset) {
64 SkDebugf("---- fAsset->seek(oldOffset) failed\n");
65 return 0;
66 }
67 off64_t newOffset = fAsset->seek(size, SEEK_CUR);
68 if (-1 == newOffset) {
69 SkDebugf("---- fAsset->seek(%d) failed\n", size);
70 return 0;
71 }
72 amount = newOffset - oldOffset;
73 } else {
74 amount = fAsset->read(buffer, size);
75 if (amount <= 0) {
76 SkDebugf("---- fAsset->read(%d) returned %d\n", size, amount);
77 }
78 }
79
80 if (amount < 0) {
81 amount = 0;
82 }
83 return amount;
84 }
85
CopyAssetToStream(Asset * asset)86 SkMemoryStream* android::CopyAssetToStream(Asset* asset) {
87 if (NULL == asset) {
88 return NULL;
89 }
90
91 const off64_t seekReturnVal = asset->seek(0, SEEK_SET);
92 if ((off64_t)-1 == seekReturnVal) {
93 SkDebugf("---- copyAsset: asset rewind failed\n");
94 return NULL;
95 }
96
97 const off64_t size = asset->getLength();
98 if (size <= 0) {
99 SkDebugf("---- copyAsset: asset->getLength() returned %d\n", size);
100 return NULL;
101 }
102
103 SkAutoTUnref<SkData> data(SkData::NewUninitialized(size));
104 const off64_t len = asset->read(data->writable_data(), size);
105 if (len != size) {
106 SkDebugf("---- copyAsset: asset->read(%d) returned %d\n", size, len);
107 return NULL;
108 }
109
110 return new SkMemoryStream(data);
111 }
112
nullObjectReturn(const char msg[])113 jobject android::nullObjectReturn(const char msg[]) {
114 if (msg) {
115 SkDebugf("--- %s\n", msg);
116 }
117 return NULL;
118 }
119
isSeekable(int descriptor)120 bool android::isSeekable(int descriptor) {
121 return ::lseek64(descriptor, 0, SEEK_CUR) != -1;
122 }
123