ZipFile.h

   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 // General-purpose Zip archive access.  This class allows both reading and
  19 // writing to Zip archives, including deletion of existing entries.
  20 //
  21 #ifndef __LIBS_ZIPFILE_H
  22 #define __LIBS_ZIPFILE_H
  23
  24 #include <utils/Vector.h>
  25 #include <utils/Errors.h>
  26 #include <stdio.h>
  27
  28 #include "ZipEntry.h"
  29
  30 namespace android {
  31
  32 /*
  33  * Manipulate a Zip archive.
  34  *
  35  * Some changes will not be visible in the until until "flush" is called.
  36  *
  37  * The correct way to update a file archive is to make all changes to a
  38  * copy of the archive in a temporary file, and then unlink/rename over
  39  * the original after everything completes.  Because we're only interested
  40  * in using this for packaging, we don't worry about such things.  Crashing
  41  * after making changes and before flush() completes could leave us with
  42  * an unusable Zip archive.
  43  */
  44 class ZipFile {
  45 public:
  46     ZipFile(void)
  47       : mZipFp(NULL), mReadOnly(false), mNeedCDRewrite(false)
  48       {}
  49     ~ZipFile(void) {
  50         if (!mReadOnly)
  51             flush();
  52         if (mZipFp != NULL)
  53             fclose(mZipFp);
  54         discardEntries();
  55     }
  56
  57     /*
  58      * Open a new or existing archive.
  59      */
  60     enum {
  61         kOpenReadOnly   = 0x01,
  62         kOpenReadWrite  = 0x02,
  63         kOpenCreate     = 0x04,     // create if it doesn't exist
  64         kOpenTruncate   = 0x08,     // if it exists, empty it
  65     };
  66     status_t open(const char* zipFileName, int flags);
  67
  68     /*
  69      * Add a file to the end of the archive.  Specify whether you want the
  70      * library to try to store it compressed.
  71      *
  72      * If "storageName" is specified, the archive will use that instead
  73      * of "fileName".
  74      *
  75      * If there is already an entry with the same name, the call fails.
  76      * Existing entries with the same name must be removed first.
  77      *
  78      * If "ppEntry" is non-NULL, a pointer to the new entry will be returned.
  79      */
  80     status_t add(const char* fileName, int compressionMethod,
  81         ZipEntry** ppEntry)
  82     {
  83         return add(fileName, fileName, compressionMethod, ppEntry);
  84     }
  85     status_t add(const char* fileName, const char* storageName,
  86         int compressionMethod, ZipEntry** ppEntry)
  87     {
  88         return addCommon(fileName, NULL, 0, storageName,
  89                          ZipEntry::kCompressStored,
  90                          compressionMethod, ppEntry);
  91     }
  92
  93     /*
  94      * Add a file that is already compressed with gzip.
  95      *
  96      * If "ppEntry" is non-NULL, a pointer to the new entry will be returned.
  97      */
  98     status_t addGzip(const char* fileName, const char* storageName,
  99         ZipEntry** ppEntry)
 100     {
 101         return addCommon(fileName, NULL, 0, storageName,
 102                          ZipEntry::kCompressDeflated,
 103                          ZipEntry::kCompressDeflated, ppEntry);
 104     }
 105
 106     /*
 107      * Add a file from an in-memory data buffer.
 108      *
 109      * If "ppEntry" is non-NULL, a pointer to the new entry will be returned.
 110      */
 111     status_t add(const void* data, size_t size, const char* storageName,
 112         int compressionMethod, ZipEntry** ppEntry)
 113     {
 114         return addCommon(NULL, data, size, storageName,
 115                          ZipEntry::kCompressStored,
 116                          compressionMethod, ppEntry);
 117     }
 118
 119     /*
 120      * Add an entry by copying it from another zip file.  If "padding" is
 121      * nonzero, the specified number of bytes will be added to the "extra"
 122      * field in the header.
 123      *
 124      * If "ppEntry" is non-NULL, a pointer to the new entry will be returned.
 125      */
 126     status_t add(const ZipFile* pSourceZip, const ZipEntry* pSourceEntry,
 127         int padding, ZipEntry** ppEntry);
 128
 129     /*
 130      * Mark an entry as having been removed.  It is not actually deleted
 131      * from the archive or our internal data structures until flush() is
 132      * called.
 133      */
 134     status_t remove(ZipEntry* pEntry);
 135
 136     /*
 137      * Flush changes.  If mNeedCDRewrite is set, this writes the central dir.
 138      */
 139     status_t flush(void);
 140
 141     /*
 142      * Expand the data into the buffer provided.  The buffer must hold
 143      * at least <uncompressed len> bytes.  Variation expands directly
 144      * to a file.
 145      *
 146      * Returns "false" if an error was encountered in the compressed data.
 147      */
 148     //bool uncompress(const ZipEntry* pEntry, void* buf) const;
 149     //bool uncompress(const ZipEntry* pEntry, FILE* fp) const;
 150     void* uncompress(const ZipEntry* pEntry);
 151
 152     /*
 153      * Get an entry, by name.  Returns NULL if not found.
 154      *
 155      * Does not return entries pending deletion.
 156      */
 157     ZipEntry* getEntryByName(const char* fileName) const;
 158
 159     /*
 160      * Get the Nth entry in the archive.
 161      *
 162      * This will return an entry that is pending deletion.
 163      */
 164     int getNumEntries(void) const { return mEntries.size(); }
 165     ZipEntry* getEntryByIndex(int idx) const;
 166
 167 private:
 168     /* these are private and not defined */
 169     ZipFile(const ZipFile& src);
 170     ZipFile& operator=(const ZipFile& src);
 171
 172     class EndOfCentralDir {
 173     public:
 174         EndOfCentralDir(void) :
 175             mDiskNumber(0),
 176             mDiskWithCentralDir(0),
 177             mNumEntries(0),
 178             mTotalNumEntries(0),
 179             mCentralDirSize(0),
 180             mCentralDirOffset(0),
 181             mCommentLen(0),
 182             mComment(NULL)
 183             {}
 184         virtual ~EndOfCentralDir(void) {
 185             delete[] mComment;
 186         }
 187
 188         status_t readBuf(const unsigned char* buf, int len);
 189         status_t write(FILE* fp);
 190
 191         //unsigned long   mSignature;
 192         unsigned short  mDiskNumber;
 193         unsigned short  mDiskWithCentralDir;
 194         unsigned short  mNumEntries;
 195         unsigned short  mTotalNumEntries;
 196         unsigned long   mCentralDirSize;
 197         unsigned long   mCentralDirOffset;      // offset from first disk
 198         unsigned short  mCommentLen;
 199         unsigned char*  mComment;
 200
 201         enum {
 202             kSignature      = 0x06054b50,
 203             kEOCDLen        = 22,       // EndOfCentralDir len, excl. comment
 204
 205             kMaxCommentLen  = 65535,    // longest possible in ushort
 206             kMaxEOCDSearch  = kMaxCommentLen + EndOfCentralDir::kEOCDLen,
 207
 208         };
 209
 210         void dump(void) const;
 211     };
 212
 213
 214     /* read all entries in the central dir */
 215     status_t readCentralDir(void);
 216
 217     /* crunch deleted entries out */
 218     status_t crunchArchive(void);
 219
 220     /* clean up mEntries */
 221     void discardEntries(void);
 222
 223     /* common handler for all "add" functions */
 224     status_t addCommon(const char* fileName, const void* data, size_t size,
 225         const char* storageName, int sourceType, int compressionMethod,
 226         ZipEntry** ppEntry);
 227
 228     /* copy all of "srcFp" into "dstFp" */
 229     status_t copyFpToFp(FILE* dstFp, FILE* srcFp, unsigned long* pCRC32);
 230     /* copy all of "data" into "dstFp" */
 231     status_t copyDataToFp(FILE* dstFp,
 232         const void* data, size_t size, unsigned long* pCRC32);
 233     /* copy some of "srcFp" into "dstFp" */
 234     status_t copyPartialFpToFp(FILE* dstFp, FILE* srcFp, long length,
 235         unsigned long* pCRC32);
 236     /* like memmove(), but on parts of a single file */
 237     status_t filemove(FILE* fp, off_t dest, off_t src, size_t n);
 238     /* compress all of "srcFp" into "dstFp", using Deflate */
 239     status_t compressFpToFp(FILE* dstFp, FILE* srcFp,
 240         const void* data, size_t size, unsigned long* pCRC32);
 241
 242     /* get modification date from a file descriptor */
 243     time_t getModTime(int fd);
 244
 245     /*
 246      * We use stdio FILE*, which gives us buffering but makes dealing
 247      * with files >2GB awkward.  Until we support Zip64, we're fine.
 248      */
 249     FILE*           mZipFp;             // Zip file pointer
 250
 251     /* one of these per file */
 252     EndOfCentralDir mEOCD;
 253
 254     /* did we open this read-only? */
 255     bool            mReadOnly;
 256
 257     /* set this when we trash the central dir */
 258     bool            mNeedCDRewrite;
 259
 260     /*
 261      * One ZipEntry per entry in the zip file.  I'm using pointers instead
 262      * of objects because it's easier than making operator= work for the
 263      * classes and sub-classes.
 264      */
 265     Vector<ZipEntry*>   mEntries;
 266 };
 267
 268 }; // namespace android
 269
 270 #endif // __LIBS_ZIPFILE_H