1 /*
2  * Copyright (C) 2006 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 //
18 // Provide access to a read-only asset.
19 //
20 
21 #define LOG_TAG "asset"
22 //#define NDEBUG 0
23 
24 #include <androidfw/Asset.h>
25 #include <androidfw/StreamingZipInflater.h>
26 #include <androidfw/Util.h>
27 #include <androidfw/ZipFileRO.h>
28 #include <androidfw/ZipUtils.h>
29 #include <cutils/atomic.h>
30 #include <utils/FileMap.h>
31 #include <utils/Log.h>
32 #include <utils/threads.h>
33 
34 #include <assert.h>
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <memory.h>
38 #include <string.h>
39 #include <sys/stat.h>
40 #include <sys/types.h>
41 #include <unistd.h>
42 
43 using namespace android;
44 
45 #ifndef O_BINARY
46 # define O_BINARY 0
47 #endif
48 
49 static const bool kIsDebug = false;
50 
51 static Mutex gAssetLock;
52 static int32_t gCount = 0;
53 static Asset* gHead = NULL;
54 static Asset* gTail = NULL;
55 
registerAsset(Asset * asset)56 void Asset::registerAsset(Asset* asset)
57 {
58     AutoMutex _l(gAssetLock);
59     gCount++;
60     asset->mNext = asset->mPrev = NULL;
61     if (gTail == NULL) {
62         gHead = gTail = asset;
63     } else {
64         asset->mPrev = gTail;
65         gTail->mNext = asset;
66         gTail = asset;
67     }
68 
69     if (kIsDebug) {
70         ALOGI("Creating Asset %p #%d\n", asset, gCount);
71     }
72 }
73 
unregisterAsset(Asset * asset)74 void Asset::unregisterAsset(Asset* asset)
75 {
76     AutoMutex _l(gAssetLock);
77     gCount--;
78     if (gHead == asset) {
79         gHead = asset->mNext;
80     }
81     if (gTail == asset) {
82         gTail = asset->mPrev;
83     }
84     if (asset->mNext != NULL) {
85         asset->mNext->mPrev = asset->mPrev;
86     }
87     if (asset->mPrev != NULL) {
88         asset->mPrev->mNext = asset->mNext;
89     }
90     asset->mNext = asset->mPrev = NULL;
91 
92     if (kIsDebug) {
93         ALOGI("Destroying Asset in %p #%d\n", asset, gCount);
94     }
95 }
96 
getGlobalCount()97 int32_t Asset::getGlobalCount()
98 {
99     AutoMutex _l(gAssetLock);
100     return gCount;
101 }
102 
getAssetAllocations()103 String8 Asset::getAssetAllocations()
104 {
105     AutoMutex _l(gAssetLock);
106     String8 res;
107     Asset* cur = gHead;
108     while (cur != NULL) {
109         if (cur->isAllocated()) {
110             res.append("    ");
111             res.append(cur->getAssetSource());
112             off64_t size = (cur->getLength()+512)/1024;
113             char buf[64];
114             snprintf(buf, sizeof(buf), ": %dK\n", (int)size);
115             res.append(buf);
116         }
117         cur = cur->mNext;
118     }
119 
120     return res;
121 }
122 
Asset(void)123 Asset::Asset(void)
124     : mAccessMode(ACCESS_UNKNOWN), mNext(NULL), mPrev(NULL)
125 {
126 }
127 
128 /*
129  * Create a new Asset from a file on disk.  There is a fair chance that
130  * the file doesn't actually exist.
131  *
132  * We can use "mode" to decide how we want to go about it.
133  */
createFromFile(const char * fileName,AccessMode mode)134 /*static*/ Asset* Asset::createFromFile(const char* fileName, AccessMode mode)
135 {
136     return createFromFd(open(fileName, O_RDONLY | O_BINARY), fileName, mode);
137 }
138 
139 /*
140  * Create a new Asset from a file on disk.  There is a fair chance that
141  * the file doesn't actually exist.
142  *
143  * We can use "mode" to decide how we want to go about it.
144  */
createFromFd(const int fd,const char * fileName,AccessMode mode)145 /*static*/ Asset* Asset::createFromFd(const int fd, const char* fileName, AccessMode mode)
146 {
147     if (fd < 0) {
148         return NULL;
149     }
150 
151     _FileAsset* pAsset;
152     status_t result;
153     off64_t length;
154 
155     /*
156      * Under Linux, the lseek fails if we actually opened a directory.  To
157      * be correct we should test the file type explicitly, but since we
158      * always open things read-only it doesn't really matter, so there's
159      * no value in incurring the extra overhead of an fstat() call.
160      */
161     // TODO(kroot): replace this with fstat despite the plea above.
162 #if 1
163     length = lseek64(fd, 0, SEEK_END);
164     if (length < 0) {
165         ::close(fd);
166         return NULL;
167     }
168     (void) lseek64(fd, 0, SEEK_SET);
169 #else
170     struct stat st;
171     if (fstat(fd, &st) < 0) {
172         ::close(fd);
173         return NULL;
174     }
175 
176     if (!S_ISREG(st.st_mode)) {
177         ::close(fd);
178         return NULL;
179     }
180 #endif
181 
182     pAsset = new _FileAsset;
183     result = pAsset->openChunk(fileName, fd, 0, length);
184     if (result != NO_ERROR) {
185         delete pAsset;
186         return NULL;
187     }
188 
189     pAsset->mAccessMode = mode;
190     return pAsset;
191 }
192 
193 
194 /*
195  * Create a new Asset from a compressed file on disk.  There is a fair chance
196  * that the file doesn't actually exist.
197  *
198  * We currently support gzip files.  We might want to handle .bz2 someday.
199  */
createFromCompressedFile(const char * fileName,AccessMode mode)200 /*static*/ Asset* Asset::createFromCompressedFile(const char* fileName,
201     AccessMode mode)
202 {
203     _CompressedAsset* pAsset;
204     status_t result;
205     off64_t fileLen;
206     bool scanResult;
207     long offset;
208     int method;
209     long uncompressedLen, compressedLen;
210     int fd;
211 
212     fd = open(fileName, O_RDONLY | O_BINARY);
213     if (fd < 0)
214         return NULL;
215 
216     fileLen = lseek(fd, 0, SEEK_END);
217     if (fileLen < 0) {
218         ::close(fd);
219         return NULL;
220     }
221     (void) lseek(fd, 0, SEEK_SET);
222 
223     /* want buffered I/O for the file scan; must dup so fclose() is safe */
224     FILE* fp = fdopen(dup(fd), "rb");
225     if (fp == NULL) {
226         ::close(fd);
227         return NULL;
228     }
229 
230     unsigned long crc32;
231     scanResult = ZipUtils::examineGzip(fp, &method, &uncompressedLen,
232                     &compressedLen, &crc32);
233     offset = ftell(fp);
234     fclose(fp);
235     if (!scanResult) {
236         ALOGD("File '%s' is not in gzip format\n", fileName);
237         ::close(fd);
238         return NULL;
239     }
240 
241     pAsset = new _CompressedAsset;
242     result = pAsset->openChunk(fd, offset, method, uncompressedLen,
243                 compressedLen);
244     if (result != NO_ERROR) {
245         delete pAsset;
246         return NULL;
247     }
248 
249     pAsset->mAccessMode = mode;
250     return pAsset;
251 }
252 
253 
254 #if 0
255 /*
256  * Create a new Asset from part of an open file.
257  */
258 /*static*/ Asset* Asset::createFromFileSegment(int fd, off64_t offset,
259     size_t length, AccessMode mode)
260 {
261     _FileAsset* pAsset;
262     status_t result;
263 
264     pAsset = new _FileAsset;
265     result = pAsset->openChunk(NULL, fd, offset, length);
266     if (result != NO_ERROR) {
267         delete pAsset;
268         return NULL;
269     }
270 
271     pAsset->mAccessMode = mode;
272     return pAsset;
273 }
274 
275 /*
276  * Create a new Asset from compressed data in an open file.
277  */
278 /*static*/ Asset* Asset::createFromCompressedData(int fd, off64_t offset,
279     int compressionMethod, size_t uncompressedLen, size_t compressedLen,
280     AccessMode mode)
281 {
282     _CompressedAsset* pAsset;
283     status_t result;
284 
285     pAsset = new _CompressedAsset;
286     result = pAsset->openChunk(fd, offset, compressionMethod,
287                 uncompressedLen, compressedLen);
288     if (result != NO_ERROR) {
289         delete pAsset;
290         return NULL;
291     }
292 
293     pAsset->mAccessMode = mode;
294     return pAsset;
295 }
296 #endif
297 
298 /*
299  * Create a new Asset from a memory mapping.
300  */
createFromUncompressedMap(incfs::IncFsFileMap && dataMap,AccessMode mode,base::unique_fd fd)301 /*static*/ std::unique_ptr<Asset> Asset::createFromUncompressedMap(incfs::IncFsFileMap&& dataMap,
302                                                                    AccessMode mode,
303                                                                    base::unique_fd fd)
304 {
305     auto pAsset = util::make_unique<_FileAsset>();
306 
307     status_t result = pAsset->openChunk(std::move(dataMap), std::move(fd));
308     if (result != NO_ERROR) {
309         return NULL;
310     }
311 
312     // We succeeded, so relinquish control of dataMap
313     pAsset->mAccessMode = mode;
314     return std::move(pAsset);
315 }
316 
317 /*
318  * Create a new Asset from compressed data in a memory mapping.
319  */
createFromCompressedMap(incfs::IncFsFileMap && dataMap,size_t uncompressedLen,AccessMode mode)320 /*static*/ std::unique_ptr<Asset> Asset::createFromCompressedMap(incfs::IncFsFileMap&& dataMap,
321                                                                  size_t uncompressedLen,
322                                                                  AccessMode mode)
323 {
324   auto pAsset = util::make_unique<_CompressedAsset>();
325 
326   status_t result = pAsset->openChunk(std::move(dataMap), uncompressedLen);
327   if (result != NO_ERROR) {
328       return NULL;
329   }
330 
331   // We succeeded, so relinquish control of dataMap
332   pAsset->mAccessMode = mode;
333   return std::move(pAsset);
334 }
335 
336 /*
337  * Do generic seek() housekeeping.  Pass in the offset/whence values from
338  * the seek request, along with the current chunk offset and the chunk
339  * length.
340  *
341  * Returns the new chunk offset, or -1 if the seek is illegal.
342  */
handleSeek(off64_t offset,int whence,off64_t curPosn,off64_t maxPosn)343 off64_t Asset::handleSeek(off64_t offset, int whence, off64_t curPosn, off64_t maxPosn)
344 {
345     off64_t newOffset;
346 
347     switch (whence) {
348     case SEEK_SET:
349         newOffset = offset;
350         break;
351     case SEEK_CUR:
352         newOffset = curPosn + offset;
353         break;
354     case SEEK_END:
355         newOffset = maxPosn + offset;
356         break;
357     default:
358         ALOGW("unexpected whence %d\n", whence);
359         // this was happening due to an off64_t size mismatch
360         assert(false);
361         return (off64_t) -1;
362     }
363 
364     if (newOffset < 0 || newOffset > maxPosn) {
365         ALOGW("seek out of range: want %ld, end=%ld\n",
366             (long) newOffset, (long) maxPosn);
367         return (off64_t) -1;
368     }
369 
370     return newOffset;
371 }
372 
373 
374 /*
375  * ===========================================================================
376  *      _FileAsset
377  * ===========================================================================
378  */
379 
380 /*
381  * Constructor.
382  */
_FileAsset(void)383 _FileAsset::_FileAsset(void)
384     : mStart(0), mLength(0), mOffset(0), mFp(NULL), mFileName(NULL), mFd(-1), mBuf(NULL)
385 {
386     // Register the Asset with the global list here after it is fully constructed and its
387     // vtable pointer points to this concrete type. b/31113965
388     registerAsset(this);
389 }
390 
391 /*
392  * Destructor.  Release resources.
393  */
~_FileAsset(void)394 _FileAsset::~_FileAsset(void)
395 {
396     close();
397 
398     // Unregister the Asset from the global list here before it is destructed and while its vtable
399     // pointer still points to this concrete type. b/31113965
400     unregisterAsset(this);
401 }
402 
403 /*
404  * Operate on a chunk of an uncompressed file.
405  *
406  * Zero-length chunks are allowed.
407  */
openChunk(const char * fileName,int fd,off64_t offset,size_t length)408 status_t _FileAsset::openChunk(const char* fileName, int fd, off64_t offset, size_t length)
409 {
410     assert(mFp == NULL);    // no reopen
411     assert(!mMap.has_value());
412     assert(fd >= 0);
413     assert(offset >= 0);
414 
415     /*
416      * Seek to end to get file length.
417      */
418     off64_t fileLength;
419     fileLength = lseek64(fd, 0, SEEK_END);
420     if (fileLength == (off64_t) -1) {
421         // probably a bad file descriptor
422         ALOGD("failed lseek (errno=%d)\n", errno);
423         return UNKNOWN_ERROR;
424     }
425 
426     if ((off64_t) (offset + length) > fileLength) {
427         ALOGD("start (%ld) + len (%ld) > end (%ld)\n",
428             (long) offset, (long) length, (long) fileLength);
429         return BAD_INDEX;
430     }
431 
432     /* after fdopen, the fd will be closed on fclose() */
433     mFp = fdopen(fd, "rb");
434     if (mFp == NULL)
435         return UNKNOWN_ERROR;
436 
437     mStart = offset;
438     mLength = length;
439     assert(mOffset == 0);
440 
441     /* seek the FILE* to the start of chunk */
442     if (fseek(mFp, mStart, SEEK_SET) != 0) {
443         assert(false);
444     }
445 
446     mFileName = fileName != NULL ? strdup(fileName) : NULL;
447 
448     return NO_ERROR;
449 }
450 
451 /*
452  * Create the chunk from the map.
453  */
openChunk(incfs::IncFsFileMap && dataMap,base::unique_fd fd)454 status_t _FileAsset::openChunk(incfs::IncFsFileMap&& dataMap, base::unique_fd fd)
455 {
456     assert(mFp == NULL);    // no reopen
457     assert(!mMap.has_value());
458     assert(dataMap != NULL);
459 
460     mMap = std::move(dataMap);
461     mStart = -1;            // not used
462     mLength = mMap->length();
463     mFd = std::move(fd);
464     assert(mOffset == 0);
465 
466     return NO_ERROR;
467 }
468 
469 /*
470  * Read a chunk of data.
471  */
read(void * buf,size_t count)472 ssize_t _FileAsset::read(void* buf, size_t count)
473 {
474     size_t maxLen;
475     size_t actual;
476 
477     assert(mOffset >= 0 && mOffset <= mLength);
478 
479     if (getAccessMode() == ACCESS_BUFFER) {
480         /*
481          * On first access, read or map the entire file.  The caller has
482          * requested buffer access, either because they're going to be
483          * using the buffer or because what they're doing has appropriate
484          * performance needs and access patterns.
485          */
486         if (mBuf == NULL)
487             getBuffer(false);
488     }
489 
490     /* adjust count if we're near EOF */
491     maxLen = mLength - mOffset;
492     if (count > maxLen)
493         count = maxLen;
494 
495     if (!count)
496         return 0;
497 
498     if (mMap.has_value()) {
499         /* copy from mapped area */
500         //printf("map read\n");
501         const auto readPos = mMap->data().offset(mOffset).convert<char>();
502         if (!readPos.verify(count)) {
503             return -1;
504         }
505 
506         memcpy(buf, readPos.unsafe_ptr(), count);
507         actual = count;
508     } else if (mBuf != NULL) {
509         /* copy from buffer */
510         //printf("buf read\n");
511         memcpy(buf, (char*)mBuf + mOffset, count);
512         actual = count;
513     } else {
514         /* read from the file */
515         //printf("file read\n");
516         if (ftell(mFp) != mStart + mOffset) {
517             ALOGE("Hosed: %ld != %ld+%ld\n",
518                 ftell(mFp), (long) mStart, (long) mOffset);
519             assert(false);
520         }
521 
522         /*
523          * This returns 0 on error or eof.  We need to use ferror() or feof()
524          * to tell the difference, but we don't currently have those on the
525          * device.  However, we know how much data is *supposed* to be in the
526          * file, so if we don't read the full amount we know something is
527          * hosed.
528          */
529         actual = fread(buf, 1, count, mFp);
530         if (actual == 0)        // something failed -- I/O error?
531             return -1;
532 
533         assert(actual == count);
534     }
535 
536     mOffset += actual;
537     return actual;
538 }
539 
540 /*
541  * Seek to a new position.
542  */
seek(off64_t offset,int whence)543 off64_t _FileAsset::seek(off64_t offset, int whence)
544 {
545     off64_t newPosn;
546     off64_t actualOffset;
547 
548     // compute new position within chunk
549     newPosn = handleSeek(offset, whence, mOffset, mLength);
550     if (newPosn == (off64_t) -1)
551         return newPosn;
552 
553     actualOffset = mStart + newPosn;
554 
555     if (mFp != NULL) {
556         if (fseek(mFp, (long) actualOffset, SEEK_SET) != 0)
557             return (off64_t) -1;
558     }
559 
560     mOffset = actualOffset - mStart;
561     return mOffset;
562 }
563 
564 /*
565  * Close the asset.
566  */
close(void)567 void _FileAsset::close(void)
568 {
569     if (mBuf != NULL) {
570         delete[] mBuf;
571         mBuf = NULL;
572     }
573 
574     if (mFileName != NULL) {
575         free(mFileName);
576         mFileName = NULL;
577     }
578 
579     if (mFp != NULL) {
580         // can only be NULL when called from destructor
581         // (otherwise we would never return this object)
582         fclose(mFp);
583         mFp = NULL;
584     }
585 }
586 
587 /*
588  * Return a read-only pointer to a buffer.
589  *
590  * We can either read the whole thing in or map the relevant piece of
591  * the source file.  Ideally a map would be established at a higher
592  * level and we'd be using a different object, but we didn't, so we
593  * deal with it here.
594  */
getBuffer(bool aligned)595 const void* _FileAsset::getBuffer(bool aligned)
596 {
597     auto buffer = getIncFsBuffer(aligned);
598     if (mBuf != NULL)
599         return mBuf;
600     if (!buffer.convert<uint8_t>().verify(mLength))
601         return NULL;
602     return buffer.unsafe_ptr();
603 }
604 
getIncFsBuffer(bool aligned)605 incfs::map_ptr<void> _FileAsset::getIncFsBuffer(bool aligned)
606 {
607     /* subsequent requests just use what we did previously */
608     if (mBuf != NULL)
609         return mBuf;
610     if (mMap.has_value()) {
611         if (!aligned) {
612             return mMap->data();
613         }
614         return ensureAlignment(*mMap);
615     }
616 
617     assert(mFp != NULL);
618 
619     if (mLength < kReadVsMapThreshold) {
620         unsigned char* buf;
621         long allocLen;
622 
623         /* zero-length files are allowed; not sure about zero-len allocs */
624         /* (works fine with gcc + x86linux) */
625         allocLen = mLength;
626         if (mLength == 0)
627             allocLen = 1;
628 
629         buf = new unsigned char[allocLen];
630         if (buf == NULL) {
631             ALOGE("alloc of %ld bytes failed\n", (long) allocLen);
632             return NULL;
633         }
634 
635         ALOGV("Asset %p allocating buffer size %d (smaller than threshold)", this, (int)allocLen);
636         if (mLength > 0) {
637             long oldPosn = ftell(mFp);
638             fseek(mFp, mStart, SEEK_SET);
639             if (fread(buf, 1, mLength, mFp) != (size_t) mLength) {
640                 ALOGE("failed reading %ld bytes\n", (long) mLength);
641                 delete[] buf;
642                 return NULL;
643             }
644             fseek(mFp, oldPosn, SEEK_SET);
645         }
646 
647         ALOGV(" getBuffer: loaded into buffer\n");
648 
649         mBuf = buf;
650         return mBuf;
651     } else {
652         incfs::IncFsFileMap map;
653         if (!map.Create(fileno(mFp), mStart, mLength, NULL /* file_name */ )) {
654             return NULL;
655         }
656 
657         ALOGV(" getBuffer: mapped\n");
658 
659         mMap = std::move(map);
660         if (!aligned) {
661             return mMap->data();
662         }
663         return ensureAlignment(*mMap);
664     }
665 }
666 
openFileDescriptor(off64_t * outStart,off64_t * outLength) const667 int _FileAsset::openFileDescriptor(off64_t* outStart, off64_t* outLength) const
668 {
669     if (mMap.has_value()) {
670         if (mFd.ok()) {
671             *outStart = mMap->offset();
672             *outLength = mMap->length();
673             const int fd = dup(mFd);
674             if (fd < 0) {
675                 ALOGE("Unable to dup fd (%d).", mFd.get());
676                 return -1;
677             }
678             lseek64(fd, 0, SEEK_SET);
679             return fd;
680         }
681         const char* fname = mMap->file_name();
682         if (fname == NULL) {
683             fname = mFileName;
684         }
685         if (fname == NULL) {
686             return -1;
687         }
688         *outStart = mMap->offset();
689         *outLength = mMap->length();
690         return open(fname, O_RDONLY | O_BINARY);
691     }
692     if (mFileName == NULL) {
693         return -1;
694     }
695     *outStart = mStart;
696     *outLength = mLength;
697     return open(mFileName, O_RDONLY | O_BINARY);
698 }
699 
ensureAlignment(const incfs::IncFsFileMap & map)700 incfs::map_ptr<void> _FileAsset::ensureAlignment(const incfs::IncFsFileMap& map)
701 {
702     const auto data = map.data();
703     if (util::IsFourByteAligned(data)) {
704         // We can return this directly if it is aligned on a word
705         // boundary.
706         ALOGV("Returning aligned FileAsset %p (%s).", this,
707                 getAssetSource());
708         return data;
709     }
710 
711      if (!data.convert<uint8_t>().verify(mLength)) {
712         return NULL;
713     }
714 
715     // If not aligned on a word boundary, then we need to copy it into
716     // our own buffer.
717     ALOGV("Copying FileAsset %p (%s) to buffer size %d to make it aligned.", this,
718             getAssetSource(), (int)mLength);
719     unsigned char* buf = new unsigned char[mLength];
720     if (buf == NULL) {
721         ALOGE("alloc of %ld bytes failed\n", (long) mLength);
722         return NULL;
723     }
724 
725     memcpy(buf, data.unsafe_ptr(), mLength);
726     mBuf = buf;
727     return buf;
728 }
729 
730 /*
731  * ===========================================================================
732  *      _CompressedAsset
733  * ===========================================================================
734  */
735 
736 /*
737  * Constructor.
738  */
_CompressedAsset(void)739 _CompressedAsset::_CompressedAsset(void)
740     : mStart(0), mCompressedLen(0), mUncompressedLen(0), mOffset(0),
741       mFd(-1), mZipInflater(NULL), mBuf(NULL)
742 {
743     // Register the Asset with the global list here after it is fully constructed and its
744     // vtable pointer points to this concrete type. b/31113965
745     registerAsset(this);
746 }
747 
748 /*
749  * Destructor.  Release resources.
750  */
~_CompressedAsset(void)751 _CompressedAsset::~_CompressedAsset(void)
752 {
753     close();
754 
755     // Unregister the Asset from the global list here before it is destructed and while its vtable
756     // pointer still points to this concrete type. b/31113965
757     unregisterAsset(this);
758 }
759 
760 /*
761  * Open a chunk of compressed data inside a file.
762  *
763  * This currently just sets up some values and returns.  On the first
764  * read, we expand the entire file into a buffer and return data from it.
765  */
openChunk(int fd,off64_t offset,int compressionMethod,size_t uncompressedLen,size_t compressedLen)766 status_t _CompressedAsset::openChunk(int fd, off64_t offset,
767     int compressionMethod, size_t uncompressedLen, size_t compressedLen)
768 {
769     assert(mFd < 0);        // no re-open
770     assert(!mMap.has_value());
771     assert(fd >= 0);
772     assert(offset >= 0);
773     assert(compressedLen > 0);
774 
775     if (compressionMethod != ZipFileRO::kCompressDeflated) {
776         assert(false);
777         return UNKNOWN_ERROR;
778     }
779 
780     mStart = offset;
781     mCompressedLen = compressedLen;
782     mUncompressedLen = uncompressedLen;
783     assert(mOffset == 0);
784     mFd = fd;
785     assert(mBuf == NULL);
786 
787     if (uncompressedLen > StreamingZipInflater::OUTPUT_CHUNK_SIZE) {
788         mZipInflater = new StreamingZipInflater(mFd, offset, uncompressedLen, compressedLen);
789     }
790 
791     return NO_ERROR;
792 }
793 
794 /*
795  * Open a chunk of compressed data in a mapped region.
796  *
797  * Nothing is expanded until the first read call.
798  */
openChunk(incfs::IncFsFileMap && dataMap,size_t uncompressedLen)799 status_t _CompressedAsset::openChunk(incfs::IncFsFileMap&& dataMap, size_t uncompressedLen)
800 {
801     assert(mFd < 0);        // no re-open
802     assert(!mMap.has_value());
803     assert(dataMap != NULL);
804 
805     mMap = std::move(dataMap);
806     mStart = -1;        // not used
807     mCompressedLen = mMap->length();
808     mUncompressedLen = uncompressedLen;
809     assert(mOffset == 0);
810 
811     if (uncompressedLen > StreamingZipInflater::OUTPUT_CHUNK_SIZE) {
812         mZipInflater = new StreamingZipInflater(&(*mMap), uncompressedLen);
813     }
814     return NO_ERROR;
815 }
816 
817 /*
818  * Read data from a chunk of compressed data.
819  *
820  * [For now, that's just copying data out of a buffer.]
821  */
read(void * buf,size_t count)822 ssize_t _CompressedAsset::read(void* buf, size_t count)
823 {
824     size_t maxLen;
825     size_t actual;
826 
827     assert(mOffset >= 0 && mOffset <= mUncompressedLen);
828 
829     /* If we're relying on a streaming inflater, go through that */
830     if (mZipInflater) {
831         actual = mZipInflater->read(buf, count);
832     } else {
833         if (mBuf == NULL) {
834             if (getBuffer(false) == NULL)
835                 return -1;
836         }
837         assert(mBuf != NULL);
838 
839         /* adjust count if we're near EOF */
840         maxLen = mUncompressedLen - mOffset;
841         if (count > maxLen)
842             count = maxLen;
843 
844         if (!count)
845             return 0;
846 
847         /* copy from buffer */
848         //printf("comp buf read\n");
849         memcpy(buf, (char*)mBuf + mOffset, count);
850         actual = count;
851     }
852 
853     mOffset += actual;
854     return actual;
855 }
856 
857 /*
858  * Handle a seek request.
859  *
860  * If we're working in a streaming mode, this is going to be fairly
861  * expensive, because it requires plowing through a bunch of compressed
862  * data.
863  */
seek(off64_t offset,int whence)864 off64_t _CompressedAsset::seek(off64_t offset, int whence)
865 {
866     off64_t newPosn;
867 
868     // compute new position within chunk
869     newPosn = handleSeek(offset, whence, mOffset, mUncompressedLen);
870     if (newPosn == (off64_t) -1)
871         return newPosn;
872 
873     if (mZipInflater) {
874         mZipInflater->seekAbsolute(newPosn);
875     }
876     mOffset = newPosn;
877     return mOffset;
878 }
879 
880 /*
881  * Close the asset.
882  */
close(void)883 void _CompressedAsset::close(void)
884 {
885     delete[] mBuf;
886     mBuf = NULL;
887 
888     delete mZipInflater;
889     mZipInflater = NULL;
890 
891     if (mFd > 0) {
892         ::close(mFd);
893         mFd = -1;
894     }
895 }
896 
897 /*
898  * Get a pointer to a read-only buffer of data.
899  *
900  * The first time this is called, we expand the compressed data into a
901  * buffer.
902  */
getBuffer(bool)903 const void* _CompressedAsset::getBuffer(bool)
904 {
905     unsigned char* buf = NULL;
906 
907     if (mBuf != NULL)
908         return mBuf;
909 
910     /*
911      * Allocate a buffer and read the file into it.
912      */
913     buf = new unsigned char[mUncompressedLen];
914     if (buf == NULL) {
915         ALOGW("alloc %ld bytes failed\n", (long) mUncompressedLen);
916         goto bail;
917     }
918 
919     if (mMap.has_value()) {
920         if (!ZipUtils::inflateToBuffer(mMap->data(), buf,
921                 mUncompressedLen, mCompressedLen))
922             goto bail;
923     } else {
924         assert(mFd >= 0);
925 
926         /*
927          * Seek to the start of the compressed data.
928          */
929         if (lseek(mFd, mStart, SEEK_SET) != mStart)
930             goto bail;
931 
932         /*
933          * Expand the data into it.
934          */
935         if (!ZipUtils::inflateToBuffer(mFd, buf, mUncompressedLen,
936                 mCompressedLen))
937             goto bail;
938     }
939 
940     /*
941      * Success - now that we have the full asset in RAM we
942      * no longer need the streaming inflater
943      */
944     delete mZipInflater;
945     mZipInflater = NULL;
946 
947     mBuf = buf;
948     buf = NULL;
949 
950 bail:
951     delete[] buf;
952     return mBuf;
953 }
954 
getIncFsBuffer(bool aligned)955 incfs::map_ptr<void> _CompressedAsset::getIncFsBuffer(bool aligned) {
956     return incfs::map_ptr<void>(getBuffer(aligned));
957 }
958