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
21using namespace android;
22
23AssetStreamAdaptor::AssetStreamAdaptor(Asset* asset)
24    : fAsset(asset)
25{
26}
27
28bool 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
37size_t AssetStreamAdaptor::getLength() const {
38    return fAsset->getLength();
39}
40
41bool AssetStreamAdaptor::isAtEnd() const {
42    return fAsset->getRemainingLength() == 0;
43}
44
45SkStreamRewindable* AssetStreamAdaptor::onDuplicate() 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
52bool AssetStreamAdaptor::hasPosition() const {
53    return fAsset->seek(0, SEEK_CUR) != -1;
54}
55
56size_t AssetStreamAdaptor::getPosition() const {
57    const off64_t offset = fAsset->seek(0, SEEK_CUR);
58    if (offset == -1) {
59        SkDebugf("---- fAsset->seek(0, SEEK_CUR) failed\n");
60        return 0;
61    }
62
63    return offset;
64}
65
66bool AssetStreamAdaptor::seek(size_t position) {
67    if (fAsset->seek(position, SEEK_SET) == -1) {
68        SkDebugf("---- fAsset->seek(0, SEEK_SET) failed\n");
69        return false;
70    }
71
72    return true;
73}
74
75bool AssetStreamAdaptor::move(long offset) {
76    if (fAsset->seek(offset, SEEK_CUR) == -1) {
77        SkDebugf("---- fAsset->seek(%i, SEEK_CUR) failed\n", offset);
78        return false;
79    }
80
81    return true;
82}
83
84size_t AssetStreamAdaptor::read(void* buffer, size_t size) {
85    ssize_t amount;
86
87    if (NULL == buffer) {
88        if (0 == size) {
89            return 0;
90        }
91        // asset->seek returns new total offset
92        // we want to return amount that was skipped
93
94        off64_t oldOffset = fAsset->seek(0, SEEK_CUR);
95        if (-1 == oldOffset) {
96            SkDebugf("---- fAsset->seek(oldOffset) failed\n");
97            return 0;
98        }
99        off64_t newOffset = fAsset->seek(size, SEEK_CUR);
100        if (-1 == newOffset) {
101            SkDebugf("---- fAsset->seek(%d) failed\n", size);
102            return 0;
103        }
104        amount = newOffset - oldOffset;
105    } else {
106        amount = fAsset->read(buffer, size);
107    }
108
109    if (amount < 0) {
110        amount = 0;
111    }
112    return amount;
113}
114
115SkMemoryStream* android::CopyAssetToStream(Asset* asset) {
116    if (NULL == asset) {
117        return NULL;
118    }
119
120    const off64_t seekReturnVal = asset->seek(0, SEEK_SET);
121    if ((off64_t)-1 == seekReturnVal) {
122        SkDebugf("---- copyAsset: asset rewind failed\n");
123        return NULL;
124    }
125
126    const off64_t size = asset->getLength();
127    if (size <= 0) {
128        SkDebugf("---- copyAsset: asset->getLength() returned %d\n", size);
129        return NULL;
130    }
131
132    sk_sp<SkData> data(SkData::MakeUninitialized(size));
133    const off64_t len = asset->read(data->writable_data(), size);
134    if (len != size) {
135        SkDebugf("---- copyAsset: asset->read(%d) returned %d\n", size, len);
136        return NULL;
137    }
138
139    return new SkMemoryStream(std::move(data));
140}
141
142jobject android::nullObjectReturn(const char msg[]) {
143    if (msg) {
144        SkDebugf("--- %s\n", msg);
145    }
146    return NULL;
147}
148
149bool android::isSeekable(int descriptor) {
150    return ::lseek64(descriptor, 0, SEEK_CUR) != -1;
151}
152
153JNIEnv* android::get_env_or_die(JavaVM* jvm) {
154    JNIEnv* env;
155    if (jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
156        LOG_ALWAYS_FATAL("Failed to get JNIEnv for JavaVM: %p", jvm);
157    }
158    return env;
159}
160