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