zipios++  2.0.2 Zipios++ – a small C++ library that provides easy access to .zip files.
zipios::FileEntry Class Referenceabstract

A FileEntry represents an entry in a FileCollection. More...

#include <fileentry.hpp>

Inheritance diagram for zipios::FileEntry:
[legend]
Collaboration diagram for zipios::FileEntry:
[legend]

## Public Types

typedef std::vector< unsigned
char >
buffer_t

typedef int CompressionLevel
The compression level to be used to save an entry. More...

typedef uint32_t crc32_t

typedef uint32_t dostime_t

typedef std::shared_ptr
< FileEntry
pointer_t

typedef std::vector< pointer_tvector_t

## Public Member Functions

FileEntry (FilePath const &filename, std::string const &comment=std::string())
Initialize a FileEntry object. More...

virtual ~FileEntry ()
Clean up a FileEntry object. More...

virtual pointer_t clone () const =0
Create a clone of a file entry. More...

virtual std::string getComment () const
Retrieve the comment of the file entry. More...

virtual size_t getCompressedSize () const
Retrive the size of the file when compressed. More...

virtual crc32_t getCrc () const
Return the CRC of the entry. More...

std::streampos getEntryOffset () const
Get the offset of this entry in a Zip archive. More...

virtual buffer_t getExtra () const
Some extra data to be stored along the entry. More...

virtual std::string getFileName () const
Return the basename of this entry. More...

Retrieve the size of the header. More...

virtual CompressionLevel getLevel () const
Retrieve the compression level. More...

virtual StorageMethod getMethod () const
Return the method used to create this entry. More...

virtual std::string getName () const
Return the filename of the entry. More...

virtual size_t getSize () const
Retrieve the size of the file when uncompressed. More...

virtual dostime_t getTime () const
Get the MS-DOS date/time of this entry. More...

virtual std::time_t getUnixTime () const
Get the Unix date/time of this entry. More...

bool hasCrc () const
Check whether the CRC32 was defined. More...

virtual bool isDirectory () const
Check whether the filename represents a directory. More...

virtual bool isEqual (FileEntry const &file_entry) const
Compare two file entries for equality. More...

virtual bool isValid () const
Check whether this entry is valid. More...

Read this FileEntry from the input stream. More...

virtual void setComment (std::string const &comment)
Set the comment field for the FileEntry. More...

virtual void setCompressedSize (size_t size)
Set the size when the file is compressed. More...

virtual void setCrc (crc32_t crc)
Save the CRC of the entry. More...

void setEntryOffset (std::streampos offset)
Defines the position of the entry in a Zip archive. More...

virtual void setExtra (buffer_t const &extra)
Set the extra field buffer. More...

virtual void setLevel (CompressionLevel level)
Define the level of compression to use by this FileEntry. More...

virtual void setMethod (StorageMethod method)
Sets the storage method field for the entry. More...

virtual void setSize (size_t size)
Sets the size field for the entry. More...

virtual void setTime (dostime_t time)
Set the FileEntry time using a DOS time. More...

virtual void setUnixTime (std::time_t time)
Sets the time field in Unix time format for the entry. More...

virtual std::string toString () const
Returns a human-readable string representation of the entry. More...

virtual void write (std::ostream &os)
Write this FileEntry to the output stream. More...

## Static Public Attributes

static CompressionLevel const COMPRESSION_LEVEL_DEFAULT = -3

static CompressionLevel const COMPRESSION_LEVEL_FASTEST = -1

static CompressionLevel const COMPRESSION_LEVEL_MAXIMUM = 100

static CompressionLevel const COMPRESSION_LEVEL_MINIMUM = 1

static CompressionLevel const COMPRESSION_LEVEL_NONE = 0

static CompressionLevel const COMPRESSION_LEVEL_SMALLEST = -2

## Protected Attributes

std::string m_comment

StorageMethod m_compress_method = StorageMethod::STORED

CompressionLevel m_compression_level = COMPRESSION_LEVEL_DEFAULT

uint32_t m_crc_32 = 0

std::streampos m_entry_offset = 0

buffer_t m_extra_field

FilePath m_filename

bool m_has_crc_32 = false

size_t m_uncompressed_size = 0

time_t m_unix_time = 0

bool m_valid = false

## Detailed Description

The interface is a copy of the ZipEntry interface from the java.util.zip package. The name has been changed to FileEntry, as FileCollection is a more general abstraction, that covers other types of file collections than just zip files.

Note
The hashCode() supported in Java is not included as we do not have an equivalent in this library.

Definition at line 74 of file fileentry.hpp.

## Member Typedef Documentation

 typedef std::vector zipios::FileEntry::buffer_t

Definition at line 79 of file fileentry.hpp.

Values defined using this time represent the compression level to be used when compressing an entry.

If unchanged, use the DEFAULT_COMPRESSION value.

It is possible to change the compression level to NO_COMPRESSION or use the setMethod() with STORED to avoid any compression (i.e. create a zip file which awfully looks like a tarball).

Todo:
These values are one to one mapped to zlib compression values. This is likely to change once we start offering other compression scheme for a number defined between 0 and 100 instead.

Definition at line 85 of file fileentry.hpp.

 typedef uint32_t zipios::FileEntry::crc32_t

Definition at line 80 of file fileentry.hpp.

 typedef uint32_t zipios::FileEntry::dostime_t

Definition at line 81 of file fileentry.hpp.

 typedef std::shared_ptr zipios::FileEntry::pointer_t

Definition at line 77 of file fileentry.hpp.

 typedef std::vector zipios::FileEntry::vector_t

Definition at line 78 of file fileentry.hpp.

## Constructor & Destructor Documentation

 zipios::FileEntry::FileEntry ( FilePath const & filename, std::string const & comment = std::string() )

This funciton initializes a FileEntry object. By default you may define the filename of the FileEntry object.

In case of an on disk directory, the filename should be the path to the file that can be read from disk, otherwise the FileEntry object will be viewed as invalid. There is, otherwise, no restriction to the filename.

Parameters
 [in] filename The file entry filename. [in] comment The comment attached to the file.

Definition at line 100 of file fileentry.cpp.

 zipios::FileEntry::~FileEntry ( )
virtual

The destructor is defined as it has to be virtual.

It will eventually clean up resources used by the FileEntry class.

Definition at line 134 of file fileentry.cpp.

## Member Function Documentation

 FileEntry::pointer_t zipios::FileEntry::clone ( ) const
pure virtual

This function creates a heap allocated clone of the object this method is called for.

Note that the object is expected to overload this function in order to create a clone of the correct type.

Returns
A smart pointer to the clone.

Implemented in zipios::ZipLocalEntry, zipios::ZipCentralDirectoryEntry, and zipios::DirectoryEntry.

 std::string zipios::FileEntry::getComment ( ) const
virtual

This function returns the comment of this entry.

If the entry was not assigned a comment, this function returns an empty string. All entries can be given a comment, although for most it will be ignored unless you save the file to a Zip archive.

Returns
The comment associated with this entry, if there is one.

Definition at line 150 of file fileentry.cpp.

References m_comment.

 size_t zipios::FileEntry::getCompressedSize ( ) const
virtual

This function returns the compressed size of the entry. If the entry is not stored in a compressed format, the uncompressed size is returned.

Returns
The compressed size of the entry.

Reimplemented in zipios::ZipLocalEntry.

Definition at line 164 of file fileentry.cpp.

References getSize().

Referenced by toString().

 FileEntry::crc32_t zipios::FileEntry::getCrc ( ) const
virtual

This function returns the CRC 32 of this entry, if it has one.

The CRC is set only after the file is compressed so it may not always be available. The hasCrc() function can be used to know whether it was set before.

Returns
The CRC32 for the entry, if it has one.
Todo:
Should we throw if m_has_crc_32 is false?

Definition at line 182 of file fileentry.cpp.

References m_crc_32.

 std::streampos zipios::FileEntry::getEntryOffset ( ) const

This function retrieves the offset at which this FileEntry resides in the Zip archive it is attached to.

Note that in case of a Zip archive embedded in another file, the offset is virtual (relative to the start of the Zip archive in the larger file.)

Returns
The position in the Zip archive.

Definition at line 202 of file fileentry.cpp.

References m_entry_offset.

 FileEntry::buffer_t zipios::FileEntry::getExtra ( ) const
virtual

This function returns a copy of the vector of bytes of extra data that are stored with the entry.

This buffer should be generated using the still non-existant ZipExtra class. This includes definitions of additional meta data necessary on various operating systems. For example, Linux makes use of the "UT" (Universal Time) to save the atime, ctime, and mtime parameters, and "ux" (Unix) to save the Unix permissions and user identifier (uid) and group identifier (gid).

Returns
A buffer_t of extra bytes that are associated with this entry.

Definition at line 222 of file fileentry.cpp.

References m_extra_field.

 std::string zipios::FileEntry::getFileName ( ) const
virtual

This function returns the filename only of the entry.

Warning
The function returns the last segment of the filename whether it is a regular file or a directory so one can search for a directory with the MATCH or IGNORE search options.
Returns
The filename of the entry.

Definition at line 320 of file fileentry.cpp.

References zipios::FilePath::filename(), and m_filename.

virtual

This function determines the size of the Zip archive header necessary for that file.

By default the function returns zero meaning that no header is defined.

Returns
The size of the header in bytes.

Reimplemented in zipios::ZipLocalEntry, and zipios::ZipCentralDirectoryEntry.

Definition at line 237 of file fileentry.cpp.

 FileEntry::CompressionLevel zipios::FileEntry::getLevel ( ) const
virtual

Use this function to read the compression level to use to compress a file.

Note that the compression level is rarely saved in the destination file, so after reading a file from a Zip archive this parameter is set to the default compression level which does not represent the level used to create the file.

The compression level is a number between 1 and 100 if compression is wanted. 0 for no compression. A few negative numbers represent various default compression levels.

Returns
The compression level to use to write this entry to a Zip archive.
CompressionLevel
setLevel()

Definition at line 262 of file fileentry.cpp.

References COMPRESSION_LEVEL_NONE, isDirectory(), and m_compression_level.

 StorageMethod zipios::FileEntry::getMethod ( ) const
virtual

This function returns the method used to store the entry data in the FileCollection it is attached to.

Returns
the storage method used to store the entry in a collection.
StorageMethod
setMethod()

Definition at line 282 of file fileentry.cpp.

References isDirectory(), m_compress_method, and zipios::STORED.

 std::string zipios::FileEntry::getName ( ) const
virtual

The function returns the full filename of the entry, including a path if the entry is stored in a sub-folder.

Returns
The filename of the entry including its path.

Definition at line 303 of file fileentry.cpp.

References m_filename.

 size_t zipios::FileEntry::getSize ( ) const
virtual

This function returns the uncompressed size of the entry data.

Returns
Returns the uncompressed size of the entry.

Definition at line 332 of file fileentry.cpp.

References m_uncompressed_size.

Referenced by getCompressedSize(), and zipios::ZipInputStreambuf::ZipInputStreambuf().

 FileEntry::dostime_t zipios::FileEntry::getTime ( ) const
virtual

This function returns the date and time of the entry in MSDOS date/time format.

Note
An MS-DOS date is limited to 127 years starting on 1980. So it will be over after Dec 31, 2107.
Returns
The date and time of the entry in MS-DOS format.

Definition at line 349 of file fileentry.cpp.

References m_unix_time, and unix2dostime().

 std::time_t zipios::FileEntry::getUnixTime ( ) const
virtual

This function returns the date and time of the entry in Unix date/time format (see time()).

Note
The FileEntry object saves the time as a Unix time_t value, however, the Zip file format uses the DOS time format. So for a Zip file, the precision of the date is to the next even second. Yet, this function may return a value which is odd when the time comes from a file on disk.
Unless you have an old 32 bit system that defines time_t as a 32 bit value, a Unix date can be considered infinite. Otherwise it is limited to some time in 2068.
Returns
The date and time of the entry as a time_t value.

Definition at line 374 of file fileentry.cpp.

References m_unix_time.

 bool zipios::FileEntry::hasCrc ( ) const

This function returns true if the setCrc() function was called earlier with a valid CRC32 and the FileEntry implementation supports a CRC (i.e. a DirectoryEntry does not have a CRC).

Returns
true if a CRC32 is defined in this class.

Definition at line 388 of file fileentry.cpp.

References m_has_crc_32.

 bool zipios::FileEntry::isDirectory ( ) const
virtual

This function checks the last character of the filename, if it is a separator ('/') then the function returns true meaning that the file represents a directory.

Returns
true if the entry represents a directory.

Reimplemented in zipios::ZipLocalEntry.

Definition at line 402 of file fileentry.cpp.

References zipios::FilePath::isDirectory(), and m_filename.

Referenced by getLevel(), getMethod(), setLevel(), setMethod(), and toString().

 bool zipios::FileEntry::isEqual ( FileEntry const & file_entry ) const
virtual

This function compares most of the fields between two file entries to see whether they are equal or not.

Warning
The Extra buffer is ignored in the comparison. There are two reasons for this: (1) it is unlikely that such a parameter should could in the comparison (just like the compressed size of the file) and (2) the comparison is not trivial as each chunk in the buffer needs to be separately compared (we may offer that capability once we have a ZipExtra class.)
Parameters
 [in] file_entry The file entry to compare this against.
Returns
true if both FileEntry objects are considered equal.

Reimplemented in zipios::ZipLocalEntry, and zipios::DirectoryEntry.

Definition at line 425 of file fileentry.cpp.

Referenced by zipios::DirectoryEntry::isEqual(), and zipios::ZipLocalEntry::isEqual().

 bool zipios::FileEntry::isValid ( ) const
virtual

Any method or operator that initializes a FileEntry may set a flag that specifies whether the file entry is valid or not. If it is not this method returns false.

Returns
true if the FileEntry has been parsed succesfully.

Definition at line 447 of file fileentry.cpp.

References m_valid.

Referenced by zipios::ZipInputStreambuf::ZipInputStreambuf().

 void zipios::FileEntry::read ( std::istream & is )
virtual

This function is called when the FileEntry should be initialized from the specified input stream.

Exceptions
 IOException The default implementation raise an IOException error because there is no reading the FileEntry from anywhere.
Parameters
 [in,out] is The input stream.

Reimplemented in zipios::ZipLocalEntry, and zipios::ZipCentralDirectoryEntry.

Definition at line 724 of file fileentry.cpp.

 void zipios::FileEntry::setComment ( std::string const & comment )
virtual

This function sets the comment of this FileEntry. Note that all implementations of the FileEntry may not include support for a comment. In that case this function does nothing.

Parameters
 [in] comment A string with the new comment.

Definition at line 461 of file fileentry.cpp.

References m_comment.

 void zipios::FileEntry::setCompressedSize ( size_t size )
virtual

This function saves the compressed size of the entry in this object.

By default the compressed size is viewed as the same as the uncompressed size (i.e. as if STORED was used for the compression method.)

Parameters
 [in] size Value to set the compressed size field of the entry to.

Reimplemented in zipios::ZipLocalEntry.

Definition at line 480 of file fileentry.cpp.

 void zipios::FileEntry::setCrc ( crc32_t crc )
virtual

This funciton savees the CRC field in this FileEntry field.

Parameters
 crc value to set the crc field to.

Reimplemented in zipios::ZipLocalEntry.

Definition at line 492 of file fileentry.cpp.

 void zipios::FileEntry::setEntryOffset ( std::streampos offset )

This function defines the position of the FileEntry in a Zip archive. By default the position is set to zero.

The offset is generally read from a Zip directory entry.

When used to seek in a file, the FileCollection will add the start offset defined in the VirtualSeeker. In other words this is the position in the Zip archive itself, not the final position in the file you are reading the archive from.

Parameters
 [in] offset The new archive entry offset.

Definition at line 512 of file fileentry.cpp.

References m_entry_offset.

 void zipios::FileEntry::setExtra ( buffer_t const & extra )
virtual

This function is used to set the extra field.

Only one type of file entry supports an extra field buffer. The others do nothing when this function is called.

Parameters
 [in] extra The extra field is set to this value.

Definition at line 527 of file fileentry.cpp.

References m_extra_field.

 void zipios::FileEntry::setLevel ( CompressionLevel level )
virtual

This function saves the level of compression the library should use to compress the file before saving it in the output file.

Note
If the StorageMethod is set to STORED, then the compression level is ignored, but it is left unchanged.
Exceptions
 InvalidStateException This function raises this exception if the specified level is out of the allowed range.
Parameters
 [in] level The compression level to use to compress the file data.

Definition at line 548 of file fileentry.cpp.

 void zipios::FileEntry::setMethod ( StorageMethod method )
virtual

This function sets the method with which the file data is to be compressed.

The method is ignored in a file entry which cannot be compressed. (or more precisly, the method is forced as STORED.)

Exceptions
 InvalidStateException This exception is raised if the method parameter does not represent a supported method. At this time the library only supports STORED and DEFLATED. The getMethod() may return more types as read from a Zip archive, but it is not possible to set such types using this function.
Parameters
 [in] method The method field is set to the specified value.

Definition at line 585 of file fileentry.cpp.

References zipios::DEFLATED, isDirectory(), m_compress_method, and zipios::STORED.

 void zipios::FileEntry::setSize ( size_t size )
virtual

This function is used to save the size of this file on disk when uncompressed.

Parameters
 [in] size The size field is set to this value.

Definition at line 637 of file fileentry.cpp.

References m_uncompressed_size.

 void zipios::FileEntry::setTime ( dostime_t dostime )
virtual

This function saves the specified dostime value as the last modification date and time of this entry. This is generally used when reading that information from a Zip archive. Otherwise you probably want to use the setUnixTime() instead since it is one to one compatible with the value handle by time(), stat(), and other OS functions.

Parameters
 [in] dostime Set time field as is using this MSDOS date/time value.

Definition at line 653 of file fileentry.cpp.

References dos2unixtime(), and setUnixTime().

 void zipios::FileEntry::setUnixTime ( std::time_t time )
virtual

This function is used to set the last modification time of this entry. In most cases this comes from the stat structure field named st_mtime. If you are creating a file directly in memory, you may use the return value of time(nullptr);.

Parameters
 [in] time The time field is set to the specified value.

Definition at line 668 of file fileentry.cpp.

References m_unix_time.

Referenced by setTime().

 std::string zipios::FileEntry::toString ( ) const
virtual

This function transforms the basic information of the entry in a string. Note that most of the information is lost as the function is likely to only display the filename and the size of the file, nothing more.

Returns
A human-readable string representation of the entry.

Definition at line 683 of file fileentry.cpp.

References getCompressedSize(), isDirectory(), m_filename, and m_uncompressed_size.

Referenced by zipios::operator<<().

 void zipios::FileEntry::write ( std::ostream & os )
virtual

This function is called when the FileEntry should be saved in the specified output stream.

Exceptions
 IOException The default implementation raise an IOException error because there is no writing the FileEntry anywhere.
Parameters
 [in,out] os The output stream.

Reimplemented in zipios::ZipLocalEntry, and zipios::ZipCentralDirectoryEntry.

Definition at line 742 of file fileentry.cpp.

## Member Data Documentation

 CompressionLevel const zipios::FileEntry::COMPRESSION_LEVEL_DEFAULT = -3
static

Definition at line 87 of file fileentry.hpp.

Referenced by zipios::DeflateOutputStreambuf::init().

 CompressionLevel const zipios::FileEntry::COMPRESSION_LEVEL_FASTEST = -1
static

Definition at line 89 of file fileentry.hpp.

Referenced by zipios::DeflateOutputStreambuf::init().

 CompressionLevel const zipios::FileEntry::COMPRESSION_LEVEL_MAXIMUM = 100
static

Definition at line 92 of file fileentry.hpp.

Referenced by zipios::DeflateOutputStreambuf::init(), and setLevel().

 CompressionLevel const zipios::FileEntry::COMPRESSION_LEVEL_MINIMUM = 1
static

Definition at line 91 of file fileentry.hpp.

Referenced by zipios::DeflateOutputStreambuf::init(), and setLevel().

 CompressionLevel const zipios::FileEntry::COMPRESSION_LEVEL_NONE = 0
static
 CompressionLevel const zipios::FileEntry::COMPRESSION_LEVEL_SMALLEST = -2
static

Definition at line 88 of file fileentry.hpp.

Referenced by zipios::DeflateOutputStreambuf::init().

 std::string zipios::FileEntry::m_comment
protected

Definition at line 132 of file fileentry.hpp.

 StorageMethod zipios::FileEntry::m_compress_method = StorageMethod::STORED
protected

Definition at line 136 of file fileentry.hpp.

 CompressionLevel zipios::FileEntry::m_compression_level = COMPRESSION_LEVEL_DEFAULT
protected

Definition at line 137 of file fileentry.hpp.

 uint32_t zipios::FileEntry::m_crc_32 = 0
protected

Definition at line 138 of file fileentry.hpp.

 std::streampos zipios::FileEntry::m_entry_offset = 0
protected

Definition at line 135 of file fileentry.hpp.

 buffer_t zipios::FileEntry::m_extra_field
protected
 FilePath zipios::FileEntry::m_filename
protected
 bool zipios::FileEntry::m_has_crc_32 = false
protected

Definition at line 140 of file fileentry.hpp.

Referenced by hasCrc(), isEqual(), and zipios::ZipLocalEntry::setCrc().

 size_t zipios::FileEntry::m_uncompressed_size = 0
protected

Definition at line 133 of file fileentry.hpp.

 time_t zipios::FileEntry::m_unix_time = 0
protected

Definition at line 134 of file fileentry.hpp.

 bool zipios::FileEntry::m_valid = false
protected

Definition at line 141 of file fileentry.hpp.

The documentation for this class was generated from the following files: