Zipper unit

Unit implementing zip/unzip compression/decompression functionality.

zipper implements zip compression/decompression compatible with the popular .ZIP format. The zip file format is documented at:

http://www.pkware.com/documents/casestudies/APPNOTE.TXT.

The Pascal conversion of the standard zlib library was implemented by Jacques Nomssi Nzali. It is used in the FCL to implement the TCompressionStream class.

Classes and records

`Central_File_Header_Type`	record	Record structure containing central file header.
`CodeRec`	record	Small LZW compression helper type.
`End_of_Central_Dir_Type`	record	Record storing end of central directory information.
`Extensible_Data_Field_Header_Type`	record	Extra fields marker.
`EZipError`	class	Exception raised for errors in TZipper and TUnZipper.
`Local_File_Header_Type`	record	Record structure containing local file header.
`TCompressor`	class	Compressor object.
`TDeCompressor`	class	Decompressor object.
`TDeflater`	class	Child of TCompressor that implements the Deflate compression method.
`TFullZipFileEntries`	class	Collection of TFullZipFileEntry items.
`TFullZipFileEntry`	class	Extended zip file entry.
`TInflater`	class	Child of TDeCompressor that implements the Inflate decompression method.
`TShrinker`	class	Child of TCompressor that implements the Shrink compression method.
`TUnZipper`	class	Extracts and decompresses files and directories in a .ZIP archive file.
`TZipFileEntries`	class	Collection used to store information about files and directories in the .zip archive.
`TZipFileEntry`	class	Represents a file or directory added to a .ZIP file.
`TZipper`	class	Creates a .ZIP archive file.
`Zip64_End_of_Central_Dir_Locator_type`	record	Locator type.
`Zip64_End_of_Central_Dir_type`	record	Record at end of central directory.
`Zip64_Extended_Info_Field_Type`	record

Types

`BufPtr`	type	Implement the output buffer in TShrinker.
`CodeArray`	type	Array of CodeRec.
`FreeListArray`	type	Array of words.
`FreeListPtr`	type	Pointer to FreeListArray.
`TablePtr`	type	Pointer to CodeArray.
`TCustomInputStreamEvent`	procedure type	Specifies an event handler signalled for actions to an input stream.
`TOnCustomStreamEvent`	procedure type	Specifies an event handler signalled for stream actions in TUnZipper.
`TOnEndOfFileEvent`	procedure type	Event procedure for an end of file (de)compression event.
`TOnStartFileEvent`	procedure type	Event procedure for a start of file (de)compression event.
`TProgressEvent`	procedure type	Event procedure for capturing compression/decompression progress.
`TProgressEventEx`	procedure type	Specifies an event handler signalled to indicate compression/decompression progress.

Constants

`CENTRAL_FILE_HEADER_SIGNATURE`	constant	Marker specifying a file entry within the zip directory.
`Crc_32_Tab`	constant	Table used in calculating CRC-32.
`EFS_LANGUAGE_ENCODING_FLAG`	constant	Language encoding flag (EFS). When set the file name and comment fields must use UTF-8 encoding.
`END_OF_CENTRAL_DIR_SIGNATURE`	constant	Marker specifying end of directory within zip file.
`FIRSTENTRY`	constant	Offset of First entry in table.
`INFOZIP_UNICODE_PATH_ID`	constant
`LOCAL_FILE_HEADER_SIGNATURE`	constant	Marker specifying a file entry within the zip file.
`OS_FAT`	constant	MS-DOS and OS/2 (FAT/VFAT/FAT32).
`OS_NTFS`	constant	NTFS.
`OS_OS2`	constant	OS/2 HPFS.
`OS_OSX`	constant	Mac OSX.
`OS_UNIX`	constant	UNIX-like platforms.
`OS_VFAT`	constant	VFAT.
`TABLESIZE`	constant	Size for the code table used in LZW compression.
`UNIX_BLK`	constant	Unix block device.
`UNIX_CHAR`	constant	Unix character device.
`UNIX_DEFAULT`	constant	Unix default attributes.
`UNIX_DIR`	constant	Unix directory.
`UNIX_FIFO`	constant	Unix FIFO file type.
`UNIX_FILE`	constant	Unix regular file.
`UNIX_LINK`	constant	Unix symbolic link.
`UNIX_MASK`	constant	Unix permission mask.
`UNIX_RGRP`	constant	Unix group read permission.
`UNIX_ROTH`	constant	Unix other users read permission.
`UNIX_RUSR`	constant	Unix user read permission.
`UNIX_SOCK`	constant	Unix sockets.
`UNIX_WGRP`	constant	Unix group write permission.
`UNIX_WOTH`	constant	Unix other users write permission.
`UNIX_WUSR`	constant	Unix user write permission.
`UNIX_XGRP`	constant	Unix group execute permission.
`UNIX_XOTH`	constant	Unix other users execute permission.
`UNIX_XUSR`	constant	Unix user execute permission.
`ZIP64_END_OF_CENTRAL_DIR_LOCATOR_SIGNATURE`	constant
`ZIP64_END_OF_CENTRAL_DIR_SIGNATURE`	constant	Marker specifying end of the directory within a 64-bit zip file.
`ZIP64_HEADER_ID`	constant

Uses

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.