include/library/zip.hpp

   1 #ifndef _library__zip__hpp__included__
   2 #define _library__zip__hpp__included__
   3
   4 #include <boost/iostreams/filtering_stream.hpp>
   5 #include <iostream>
   6 #include <iterator>
   7 #include <string>
   8 #include <map>
   9 #include <fstream>
  10 #include <zlib.h>
  11
  12 /**
  13  * This class opens ZIP archive and offers methods to read members off it.
  14  */
  15 class zip_reader
  16 {
  17 public:
  18 /**
  19  * This iterator iterates members of ZIP archive.
  20  */
  21         template<typename T, typename V>
  22         class iterator_class
  23         {
  24         public:
  25 /**
  26  * C++ iterators stuff.
  27  */
  28                 typedef std::bidirectional_iterator_tag iterator_category;
  29                 typedef V value_type;
  30                 typedef int difference_type;
  31                 typedef const V& reference;
  32                 typedef const V* pointer;
  33
  34 /**
  35  * This constructs new iteration sequence. Only the first component (keys) are taken into
  36  * account, the second component (values) are ignored.
  37  *
  38  * parameter _itr: The underlying map iterator.
  39  * throws std::bad_alloc: Not enough memory.
  40  */
  41                 iterator_class(T _itr) throw(std::bad_alloc)
  42                         : itr(_itr)
  43                 {
  44                 }
  45
  46 /**
  47  * Get name of current member.
  48  *
  49  * returns: Name of member.
  50  * throws std::bad_alloc: Not enough memory.
  51  */
  52                 reference operator*() throw(std::bad_alloc)
  53                 {
  54                         return itr->first;
  55                 }
  56
  57 /**
  58  * Get name of current member.
  59  *
  60  * returns: Name of member.
  61  * throws std::bad_alloc: Not enough memory.
  62  */
  63                 pointer operator->() throw(std::bad_alloc)
  64                 {
  65                         return &(itr->first);
  66                 }
  67
  68 /**
  69  * Are these two iterators the same?
  70  *
  71  * parameter i: The another iterator
  72  * returns: True if iterators are the same, false otherwise.
  73  */
  74                 bool operator==(const iterator_class<T, V>& i) const throw()
  75                 {
  76                         return itr == i.itr;
  77                 }
  78
  79 /**
  80  * Are these two iterators diffrent?
  81  *
  82  * paramer i: The another iterator
  83  * returns: True if iterators are diffrent, false otherwise.
  84  */
  85                 bool operator!=(const iterator_class<T, V>& i) const throw()
  86                 {
  87                         return itr != i.itr;
  88                 }
  89
  90 /**
  91  * Advance iterator one step.
  92  *
  93  * returns: The old value of iterator.
  94  * throws std::bad_alloc: Not enough memory.
  95  */
  96                 const iterator_class<T, V> operator++(int) throw(std::bad_alloc)
  97                 {
  98                         iterator_class<T, V> c(*this);
  99                         ++itr;
 100                         return c;
 101                 }
 102
 103 /**
 104  * Regress iterator one step.
 105  *
 106  * returns: The old value of iterator.
 107  * throws std::bad_alloc: Not enough memory.
 108  */
 109                 const iterator_class<T, V> operator--(int) throw(std::bad_alloc)
 110                 {
 111                         iterator_class<T, V> c(*this);
 112                         --itr;
 113                         return c;
 114                 }
 115
 116 /**
 117  * Advance iterator one step.
 118  *
 119  * returns: Reference to this iterator.
 120  */
 121                 iterator_class<T, V>& operator++() throw()
 122                 {
 123                         ++itr;
 124                         return *this;
 125                 }
 126
 127 /**
 128  * Regress iterator one step.
 129  *
 130  * returns: Reference to this iterator.
 131  */
 132                 iterator_class<T, V>& operator--() throw()
 133                 {
 134                         --itr;
 135                         return *this;
 136                 }
 137         private:
 138                 T itr;
 139         };
 140
 141 /**
 142  * This iterator iterates members of ZIP archive in forward order.
 143  */
 144         typedef iterator_class<std::map<std::string, unsigned long long>::iterator, std::string> iterator;
 145
 146 /**
 147  * This iterator iterates members of ZIP archive in reverse order
 148  */
 149         typedef iterator_class<std::map<std::string, unsigned long long>::reverse_iterator, std::string>
 150                 riterator;
 151
 152 /**
 153  * Opens specified ZIP archive for reading.
 154  *
 155  * parameter zipfile: The name of ZIP file to open.
 156  * throws std::bad_alloc: Not enough memory.
 157  * throws std::runtime_error: Can't open the ZIP file.
 158  */
 159         zip_reader(const std::string& zipfile) throw(std::bad_alloc, std::runtime_error);
 160
 161 /**
 162  * Destroy the ZIP reader. Opened input streams continue to be valid.
 163  */
 164         ~zip_reader() throw();
 165
 166 /**
 167  * Gives the name of the first member, or "" if empty archive.
 168  *
 169  * returns: The member name
 170  * throws std::bad_alloc: Not enough memory.
 171  */
 172         std::string find_first() throw(std::bad_alloc);
 173
 174 /**
 175  * Gives the name of the next member after specified, or "" if that member is the last.
 176  *
 177  * parameter name: The name to start the search from.
 178  * returns: The member name
 179  * throws std::bad_alloc: Not enough memory.
 180  */
 181         std::string find_next(const std::string& name) throw(std::bad_alloc);
 182
 183 /**
 184  * Starting iterator
 185  *
 186  * returns: The iterator pointing to first name.
 187  * throws std::bad_alloc: Not enough memory.
 188  */
 189         iterator begin() throw(std::bad_alloc);
 190
 191 /**
 192  * Ending iterator (one past the end).
 193  *
 194  * returns: The iterator pointing to one past the last name.
 195  * throws std::bad_alloc: Not enough memory.
 196  */
 197         iterator end() throw(std::bad_alloc);
 198
 199 /**
 200  * Starting reverse iterator
 201  *
 202  * returns: The iterator pointing to last name and acting in reverse.
 203  * throws std::bad_alloc: Not enough memory.
 204  */
 205         riterator rbegin() throw(std::bad_alloc);
 206
 207 /**
 208  * Ending reverse iterator (one past the start).
 209  * returrns: The iterator pointing to one before the first name and acting in reverse.
 210  * throws std::bad_alloc: Not enough memory.
 211  */
 212         riterator rend() throw(std::bad_alloc);
 213
 214 /**
 215  * Check if member with specified name exists.
 216  *
 217  * parameter name: The name of the member to check
 218  * returns: True if specified member exists, false otherwise.
 219  */
 220         bool has_member(const std::string& name) throw();
 221
 222 /**
 223  * Opens specified member. The resulting stream is not seekable, allocated using new and continues to be valid
 224  * after ZIP reader has been destroyed.
 225  *
 226  * parameter name: The name of member to open.
 227  * returns: The stream corresponding to member.
 228  * throws std::bad_alloc: Not enough memory.
 229  * throws std::runtime_error: The specified member does not exist
 230  */
 231         std::istream& operator[](const std::string& name) throw(std::bad_alloc, std::runtime_error);
 232 private:
 233         zip_reader(zip_reader&);
 234         zip_reader& operator=(zip_reader&);
 235         std::map<std::string, unsigned long long> offsets;
 236         std::ifstream* zipstream;
 237         size_t* refcnt;
 238 };
 239
 240 /**
 241  * Opens the file named by name parameter, which is interpretted relative to file designated by referencing_path.
 242  * The file can be inside ZIP archive. The resulting stream may or may not be seekable.
 243  *
 244  * If referencing_path is "", then name is traditional relative/absolute path. Otherwise if name is relative,
 245  * it is relative to directory containing referencing_path, not current directory.
 246  *
 247  * parameter name: The name of file to open.
 248  * parameter referencing_path: The path to file name is interpretted against.
 249  * returns: The new stream, allocated by new.
 250  * throw std::bad_alloc: Not enough memory.
 251  * throw std::runtime_error: The file does not exist or can't be opened.
 252  */
 253 std::istream& open_file_relative(const std::string& name, const std::string& referencing_path) throw(std::bad_alloc,
 254         std::runtime_error);
 255
 256 /**
 257  * As open_file_relative, but instead of returning handle to file, reads the entiere contents of the file and returns
 258  * that.
 259  *
 260  * parameter name: As in open_file_relative
 261  * parameter referencing_path: As in open_file_relative.
 262  * returns: The file contents.
 263  * throws std::bad_alloc: Not enough memory.
 264  * throws std::runtime_error: The file does not exist or can't be opened.
 265  */
 266 std::vector<char> read_file_relative(const std::string& name, const std::string& referencing_path)
 267         throw(std::bad_alloc, std::runtime_error);
 268
 269 /**
 270  * Resolves the final file path that open_file_relative/read_file_relative would open.
 271  *
 272  * parameter name: As in open_file_relative
 273  * parameter referencing_path: As in open_file_relative
 274  * returns: The file absolute path.
 275  * throws std::bad_alloc: Not enough memory.
 276  * throws std::runtime_error: Bad path.
 277  */
 278 std::string resolve_file_relative(const std::string& name, const std::string& referencing_path) throw(std::bad_alloc,
 279         std::runtime_error);
 280
 281 /**
 282  * This class handles writing a ZIP archives.
 283  */
 284 class zip_writer
 285 {
 286 public:
 287 /**
 288  * Creates new empty ZIP archive. The members will be compressed according to specified compression.
 289  *
 290  * parameter zipfile: The zipfile to create.
 291  * parameter _compression: Compression. 0 is uncompressed, 1-9 are deflate compression levels.
 292  * throws std::bad_alloc: Not enough memory.
 293  * throws std::runtime_error: Can't open archive or invalid argument.
 294  */
 295         zip_writer(const std::string& zipfile, unsigned _compression) throw(std::bad_alloc, std::runtime_error);
 296
 297 /**
 298  * Destroys ZIP writer, aborting the transaction (unless commit() has been called).
 299  */
 300         ~zip_writer() throw();
 301
 302 /**
 303  * Commits the ZIP file. Does atomic replace of existing file if possible.
 304  *
 305  * throws std::bad_alloc: Not enough memory.
 306  * throws std::logic_error: Existing file open.
 307  * throws std::runtime_error: Can't commit archive (OS error or member open).
 308  */
 309         void commit() throw(std::bad_alloc, std::logic_error, std::runtime_error);
 310
 311 /**
 312  * Create a new member inside ZIP file. No existing member may be open.
 313  *
 314  * parameter name: The name for new member.
 315  * returns: Writing stream for the file (don't free).
 316  * throws std::bad_alloc: Not enough memory.
 317  * throws std::logic_error: Existing file open.
 318  * throws std::runtime_error: Illegal name.
 319  */
 320         std::ostream& create_file(const std::string& name) throw(std::bad_alloc, std::logic_error, std::runtime_error);
 321
 322 /**
 323  * Closes open member and destroys stream corresponding to it.
 324  *
 325  * throws std::bad_alloc: Not enough memory.
 326  * throws std::logic_error: No file open.
 327  * throws std::runtime_error: Error from operating system.
 328  */
 329         void close_file() throw(std::bad_alloc, std::logic_error, std::runtime_error);
 330 private:
 331         struct zip_file_info
 332         {
 333                 unsigned long crc;
 334                 unsigned long uncompressed_size;
 335                 unsigned long compressed_size;
 336                 unsigned long offset;
 337         };
 338
 339         zip_writer(zip_writer&);
 340         zip_writer& operator=(zip_writer&);
 341         std::ofstream zipstream;
 342         std::string temp_path;
 343         std::string zipfile_path;
 344         std::string open_file;
 345         uint32_t base_offset;
 346         std::vector<char> current_compressed_file;
 347         std::map<std::string, zip_file_info> files;
 348         unsigned compression;
 349         boost::iostreams::filtering_ostream* s;
 350         uint32_t basepos;
 351         bool committed;
 352 };
 353
 354 #endif