Struct ipworkszip::ZCompress

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The ZCompress struct implements an LZC compressor and decompressor. It is compatible with the UNIX compress utility.

Syntax

ipworkszip::ZCompress

Remarks

The LZC file format is used only to archive a single file. Accordingly, the operation of the struct is simpler than that of the other structs.

To compress with the struct, set archive_file to the name of the LZC compressed file to be created, and file_decompressed_name to the name of the file to be compressed. Finally, invoke compress. To extract the file, first set archive_file. file_decompressed_name may then be set; if not, it will automatically be set based on the archive_file name. Finally, invoke the extract method.

Example (Creating an LZC File)

ZipControl.ArchiveFile = "c:\test.Z" ZipControl.FileDecompressedName = "c:\test.txt" ZipControl.Compress() Example (Extracting from an LZC File)

ZipControl.ArchiveFile = "c:\test.Z" ZipControl.FileDecompressedName = "c:\test.txt" ZipControl.Extract()

Object Lifetime

The new() method returns a mutable reference to a struct instance. The object itself is kept in the global list maintained by IPWorksZip. Due to this, the ZCompress struct cannot be disposed of automatically. Please, call the dispose(&mut self) method of ZCompress when you have finished using the instance.

Property List

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The following is the full list of the properties of the struct with short descriptions. Click on the links for further details.

Method List

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The following is the full list of the methods of the struct with short descriptions. Click on the links for further details.

Event List

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The following is the full list of the events fired by the struct with short descriptions. Click on the links for further details.

Config Settings

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The following is a list of config settings for the struct with short descriptions. Click on the links for further details.

archive_file property (ZCompress Struct)

The name of the zip, gzip, tar, or jar archive.

Syntax

fn archive_file(&self ) -> Result<String, IPWorksZipError> 
fn set_archive_file(&self, value : &str) ->  Option<IPWorksZipError> 
fn set_archive_file_ref(&self, value : &String) ->  Option<IPWorksZipError> 

Default Value

""

Remarks

This property specifies the name of the archive to be read or written. This property is required when extracting files.

When scan, extract, or extract_all is invoked, the file specified by archive_file will be opened for read. If the file does not exist, a trappable error will be generated.

When compress is called, the file named by archive_file will be written; if a file of this name already exists the on_overwrite event will be fired. If archive_file is set to the empty string (""), the archive will not be written to disk, and will be provided only through the on_progress event.

The filename may be specified with or without a path. Paths may be relative or absolute, and should be specified in the format native to the host operating system. The filename should be specified with the appropriate extension (such as "zip"); an extension will not automatically be appended by the struct.

If the file cannot be read, or written, as appropriate, a trappable error will be generated.

Example (Creating an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Compress()

NOTE: an archive already open for read may be closed by setting archive_file to the empty string ("").

Data Type

String

file_decompressed_name property (ZCompress Struct)

File name to decompress to, or compress from.

Syntax

fn file_decompressed_name(&self ) -> Result<String, IPWorksZipError> 
fn set_file_decompressed_name(&self, value : &str) ->  Option<IPWorksZipError> 
fn set_file_decompressed_name_ref(&self, value : &String) ->  Option<IPWorksZipError> 

Default Value

""

Remarks

file_decompressed_name contains the name of the file in the archive, as stored on the file system, outside the archive.

When compressing a file and set_file_input_stream has not been called with a valid input stream, this property should be specified with a path, if necessary, to allow the file to be found by the struct. If the file cannot be found when compress is called, a trappable error will be generated, and the archive will not be correctly written.

When decompressing files, this property may be set prior to calling extract. If this property is set to the empty string when extract is called, extract will automatically set this property to an appropriate value.

Paths on the local file system should be specified in the format native to the host operating system. They may also be specified in standard (UNIX) format, in which case they will be immediately converted.

Data Type

String

file_input_data property (ZCompress Struct)

The data of the file to be compressed.

Syntax

fn file_input_data(&self ) -> Result<Vec<u8>, IPWorksZipError> 
fn set_file_input_data(&self, value : Vec<u8>) ->  Option<IPWorksZipError> 
fn set_file_input_data_ref(&self, value : &[u8]) ->  Option<IPWorksZipError> 

Default Value

""

Remarks

When this property is set, the struct will read in the data from this property instead of reading from the file contained in the file_decompressed_name property.

Data Type

Vec

z_compress_data property (ZCompress Struct)

(Decompression only) The LZC compressed file contents as a byte array.

Syntax

fn set_z_compress_data(&self, value : Vec<u8>) ->  Option<IPWorksZipError> 
fn set_z_compress_data_ref(&self, value : &[u8]) ->  Option<IPWorksZipError> 

Default Value

""

Remarks

Normally you should set archive_file before invoking extract. If you prefer to read the LZC compressed file from memory you may set z_compress_data instead. z_compress_data should be set to the entire contents of the LZC compressed file; this will allow you to read from the archive without writing any temporary files to disk.

If you would like to extract data from the archive without ever writing to disk you should also set WriteToProgressEvent to true, and you should set the value of file_decompressed_name to an empty string. Then, when you invoke extract the data will be provided in the on_progress event.

This property is write-only. Note that modifying a LZC compressed file stored in z_compress_data is not supported.

This property is write-only.

Data Type

Vec

abort method (ZCompress Struct)

Aborts the current operation.

Syntax

fn abort(&self) -> Result<(), IPWorksZipError>

Remarks

abort may be used to immediately interrupt compression or decompression. Any files partially written by the struct will be deleted.

compress method (ZCompress Struct)

Creates the compressed archive.

Syntax

fn compress(&self) -> Result<(), IPWorksZipError>

Remarks

Invoking compress creates the archive specified by archive_file. When the method is called, the file specified by file_decompressed_name will be opened, and the file specified by archive_file will contain the compressed output.

config method (ZCompress Struct)

Sets or retrieves a configuration setting.

Syntax

fn config(&self, configuration_string : &str) ->  Result<String, IPWorksZipError>

Remarks

config is a generic method available in every struct. It is used to set and retrieve configuration settings for the struct.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, access to these internal properties is provided through the config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

extract method (ZCompress Struct)

Extracts the compressed file from the archive.

Syntax

fn extract(&self) -> Result<(), IPWorksZipError>

Remarks

Invoking extract decompresses the archive specified by archive_file. The compressed file will be extracted, and written to disk.

If file_decompressed_name is set to a nonempty string the file will be written there. Otherwise the struct will automatically set file_decompressed_name to an appropriate value:

If file_decompressed_name is empty and archive_file ends in ".Z", this filename, less the ".Z" extension will be used. Otherwise the extension ".uncompressed" will be appended to the file name.

reset method (ZCompress Struct)

Resets the struct.

Syntax

fn reset(&self) -> Result<(), IPWorksZipError>

Remarks

reset resets the state of the struct. All properties will be set to their default values, and any files open will be closed.

on_begin_file event (ZCompress Struct)

Fired before a file is processed.

Syntax

// ZCompressBeginFileEventArgs carries the ZCompress BeginFile event's parameters.
pub struct ZCompressBeginFileEventArgs {
  fn index(&self) -> i32
  fn skip(&self) -> bool
  fn set_skip(&self, value : bool)
}

// ZCompressBeginFileEvent defines the signature of the ZCompress BeginFile event's handler function.
pub trait ZCompressBeginFileEvent {
  fn on_begin_file(&self, sender : ZCompress, e : &mut ZCompressBeginFileEventArgs);
}

impl <'a> ZCompress<'a> {
  pub fn on_begin_file(&self) -> &'a dyn ZCompressBeginFileEvent;
  pub fn set_on_begin_file(&mut self, value : &'a dyn ZCompressBeginFileEvent);
  ...
}

Remarks

on_begin_file is fired before compression or decompression begins. index will contain 0.

You may use the skip parameter to tell the component to skip the file when compressing or decompressing.

on_end_file event (ZCompress Struct)

Fired after a file is processed.

Syntax

// ZCompressEndFileEventArgs carries the ZCompress EndFile event's parameters.
pub struct ZCompressEndFileEventArgs {
  fn index(&self) -> i32
}

// ZCompressEndFileEvent defines the signature of the ZCompress EndFile event's handler function.
pub trait ZCompressEndFileEvent {
  fn on_end_file(&self, sender : ZCompress, e : &mut ZCompressEndFileEventArgs);
}

impl <'a> ZCompress<'a> {
  pub fn on_end_file(&self) -> &'a dyn ZCompressEndFileEvent;
  pub fn set_on_end_file(&mut self, value : &'a dyn ZCompressEndFileEvent);
  ...
}

Remarks

on_end_file is fired when compression or decompression finishes. index will contain 0.

on_error event (ZCompress Struct)

Information about non-fatal errors.

Syntax

// ZCompressErrorEventArgs carries the ZCompress Error event's parameters.
pub struct ZCompressErrorEventArgs {
  fn description(&self) -> &String
  fn error_code(&self) -> i32
  fn index(&self) -> i32
  fn file_name(&self) -> &String
  fn ignore(&self) -> bool
  fn set_ignore(&self, value : bool)
}

// ZCompressErrorEvent defines the signature of the ZCompress Error event's handler function.
pub trait ZCompressErrorEvent {
  fn on_error(&self, sender : ZCompress, e : &mut ZCompressErrorEventArgs);
}

impl <'a> ZCompress<'a> {
  pub fn on_error(&self) -> &'a dyn ZCompressErrorEvent;
  pub fn set_on_error(&mut self, value : &'a dyn ZCompressErrorEvent);
  ...
}

Remarks

The on_error event is fired when non-fatal errors occur during compression or decompression. Note that if this event is fired during decompression this may indicate that the archive is corrupt.

By default these errors will cause the component to fail with an exception. The exception may be overridden by setting ignore to true. This will cause the error to be ignored, the file will be skipped if necessary, and the struct will continue operation.

error_code will correspond to one of the following errors:

description contains a textual description of the error. index and file_name contain the array index (where appropriate) and filename of the file being processed at the time of the error.

on_overwrite event (ZCompress Struct)

Fired whenever a file exists and may be overwritten.

Syntax

// ZCompressOverwriteEventArgs carries the ZCompress Overwrite event's parameters.
pub struct ZCompressOverwriteEventArgs {
  fn file_name(&self) -> &String
  fn set_file_name(&self, value : &str)
  fn set_file_name_ref(&self, value : &String)
  fn overwrite(&self) -> bool
  fn set_overwrite(&self, value : bool)
}

// ZCompressOverwriteEvent defines the signature of the ZCompress Overwrite event's handler function.
pub trait ZCompressOverwriteEvent {
  fn on_overwrite(&self, sender : ZCompress, e : &mut ZCompressOverwriteEventArgs);
}

impl <'a> ZCompress<'a> {
  pub fn on_overwrite(&self) -> &'a dyn ZCompressOverwriteEvent;
  pub fn set_on_overwrite(&mut self, value : &'a dyn ZCompressOverwriteEvent);
  ...
}

Remarks

on_overwrite is fired when a file is about to be overwritten, and would overwrite an existing file. The event is fired during decompression.

file_name contains the full name of the file, specified with its pathname.

overwrite specifies whether or not the file will be overwritten. For Zip, Jar, and Tar, this is equal by default to the value of the overwrite_files property. For Gzip, this value defaults to true.

Either of the parameters may be changed when the event is fired. Changing the value of overwrite will override the default behavior of the struct, and cause the file to be overwritten or not overwritten, depending on the value set. If file_name is changed, the value of overwrite will be ignored, and the file will be written with the specified name. If a file of the new name also exists this file will be silently overwritten.

on_progress event (ZCompress Struct)

Fired as progress is made.

Syntax

// ZCompressProgressEventArgs carries the ZCompress Progress event's parameters.
pub struct ZCompressProgressEventArgs {
  fn data(&self) -> &[u8]
  fn file_name(&self) -> &String
  fn bytes_processed(&self) -> i64
  fn percent_processed(&self) -> i32
}

// ZCompressProgressEvent defines the signature of the ZCompress Progress event's handler function.
pub trait ZCompressProgressEvent {
  fn on_progress(&self, sender : ZCompress, e : &mut ZCompressProgressEventArgs);
}

impl <'a> ZCompress<'a> {
  pub fn on_progress(&self) -> &'a dyn ZCompressProgressEvent;
  pub fn set_on_progress(&mut self, value : &'a dyn ZCompressProgressEvent);
  ...
}

Remarks

The on_progress event is automatically fired as compression or decompression is performed. When WriteToProgressEvent is true, the output data is provided through the data parameter, allowing for it to be streamed out.

file_name contains the name of the file being written. If no file is being written, file_name will contain an empty string, and the output data will be provided exclusively through this event.

bytes_processed contains the total number of uncompressed bytes processed. percent_processed contains the percent of uncompressed bytes processed, corresponding roughly to the running time of the operation.

For Gzip extraction only, bytes_processed and percent_processed will reflect the number of compressed bytes extracted, as it is generally impossible to predetermine the total uncompressed size.

If WriteToProgressEvent is false, data will contain null.

Config Settings (ZCompress Struct)

The struct accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, access to these internal properties is provided through the config method.

ZCompress Config Settings

Base Config Settings

Trappable Errors (ZCompress Struct)

Errors

The following errors may be generated by the struct. Note that frequently the error message will contain more specific information than what is listed here.

Note that some non-fatal errors may be trapped and explicitly ignored in the on_error event. This will allow the struct to continue operation even in case of error.

ZCompress Errors