Utils.cpp revision 2d5cf4f6db75d00285306b2d53bc6c0c6532d86e 
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
20using namespace android;
21
22AssetStreamAdaptor::AssetStreamAdaptor(Asset* asset, OwnAsset ownAsset,
23                                       HasMemoryBase hasMemoryBase)
24    : fAsset(asset)
25    , fMemoryBase(kYes_HasMemoryBase == hasMemoryBase ?
26                  asset->getBuffer(false) : NULL)
27    , fOwnAsset(ownAsset)
28{
29}
30
31AssetStreamAdaptor::~AssetStreamAdaptor() {
32    if (kYes_OwnAsset == fOwnAsset) {
33        delete fAsset;
34    }
35}
36
37bool AssetStreamAdaptor::rewind() {
38    off64_t pos = fAsset->seek(0, SEEK_SET);
39    if (pos == (off64_t)-1) {
40        SkDebugf("----- fAsset->seek(rewind) failed\n");
41        return false;
42    }
43    return true;
44}
45
46size_t AssetStreamAdaptor::getLength() const {
47    return fAsset->getLength();
48}
49
50bool AssetStreamAdaptor::isAtEnd() const {
51    return fAsset->getRemainingLength() == 0;
52}
53
54SkStreamRewindable* AssetStreamAdaptor::duplicate() const {
55    // Cannot create a duplicate, since each AssetStreamAdaptor
56    // would be modifying the Asset.
57    //return new AssetStreamAdaptor(fAsset);
58    return NULL;
59}
60
61size_t AssetStreamAdaptor::read(void* buffer, size_t size) {
62    ssize_t amount;
63
64    if (NULL == buffer) {
65        if (0 == size) {
66            return 0;
67        }
68        // asset->seek returns new total offset
69        // we want to return amount that was skipped
70
71        off64_t oldOffset = fAsset->seek(0, SEEK_CUR);
72        if (-1 == oldOffset) {
73            SkDebugf("---- fAsset->seek(oldOffset) failed\n");
74            return 0;
75        }
76        off64_t newOffset = fAsset->seek(size, SEEK_CUR);
77        if (-1 == newOffset) {
78            SkDebugf("---- fAsset->seek(%d) failed\n", size);
79            return 0;
80        }
81        amount = newOffset - oldOffset;
82    } else {
83        amount = fAsset->read(buffer, size);
84        if (amount <= 0) {
85            SkDebugf("---- fAsset->read(%d) returned %d\n", size, amount);
86        }
87    }
88
89    if (amount < 0) {
90        amount = 0;
91    }
92    return amount;
93}
94
95SkMemoryStream* android::CopyAssetToStream(Asset* asset) {
96    if (NULL == asset) {
97        return NULL;
98    }
99
100    off64_t size = asset->seek(0, SEEK_SET);
101    if ((off64_t)-1 == size) {
102        SkDebugf("---- copyAsset: asset rewind failed\n");
103        return NULL;
104    }
105
106    size = asset->getLength();
107    if (size <= 0) {
108        SkDebugf("---- copyAsset: asset->getLength() returned %d\n", size);
109        return NULL;
110    }
111
112    SkMemoryStream* stream = new SkMemoryStream(size);
113    void* data = const_cast<void*>(stream->getMemoryBase());
114    off64_t len = asset->read(data, size);
115    if (len != size) {
116        SkDebugf("---- copyAsset: asset->read(%d) returned %d\n", size, len);
117        delete stream;
118        stream = NULL;
119    }
120    return stream;
121}
122
123jobject android::nullObjectReturn(const char msg[]) {
124    if (msg) {
125        SkDebugf("--- %s\n", msg);
126    }
127    return NULL;
128}
129