DecompressingInputStream Class Reference

Decompresses gzip or bzip2 data read from another InputStream, e.g. a remote object. More...

#include <OpenMS/FORMAT/DecompressingInputStream.h>

Inheritance diagram for DecompressingInputStream:

Public Types
enum class	Format { GZIP , BZIP2 }

Public Member Functions
	DecompressingInputStream (std::unique_ptr< InputStream > source, Format format, const std::string &name)
	Decompresses source, which holds data in format.
	~DecompressingInputStream () override
UInt64	curPos () const override
	The number of decompressed bytes read so far.
Size	readBytes (unsigned char *to_fill, Size max_to_read) override
	Reads up to max_to_read decompressed bytes into to_fill; 0 at the end of the data.
void	cancel () override
	Cancels a blocking read of the source stream.
	DecompressingInputStream (const DecompressingInputStream &)=delete
DecompressingInputStream &	operator= (const DecompressingInputStream &)=delete
Public Member Functions inherited from InputStream
virtual	~InputStream ()=default

Static Public Member Functions
static std::optional< Format >	detect (const unsigned char *head, Size size)
	The format whose magic bytes start head (1F 8B: gzip, "BZh": bzip2), if any.

Private Attributes
std::unique_ptr< Impl >	impl_
	zlib/bzip2 state (their headers stay out of this one)

Detailed Description

Decompresses gzip or bzip2 data read from another InputStream, e.g. a remote object.

Unlike GzipInputStream and Bzip2InputStream, which open local files, this decompresses an arbitrary stream on the fly. Concatenated members (as written by pigz or pbzip2) are read in sequence. Bytes after the last member that do not start another member are ignored, as gzread() does.

Errors of the source stream propagate. Corrupt or truncated compressed data throws Exception::ParseError.

Member Enumeration Documentation

Format

enum class Format

strong

Enumerator
GZIP
BZIP2

Constructor & Destructor Documentation

DecompressingInputStream() [1/2]

DecompressingInputStream	(	std::unique_ptr< InputStream >	source,
		Format	format,
		const std::string &	name
	)

Decompresses source, which holds data in format.

Parameters

[in]	source	The compressed stream; it is read from its current position
[in]	format	The compression format of source
[in]	name	The name of the data, for error messages (e.g. its URI)

~DecompressingInputStream()

~DecompressingInputStream ( )

override

DecompressingInputStream() [2/2]

DecompressingInputStream ( const DecompressingInputStream &  )

delete

Member Function Documentation

cancel()

void cancel ( )

overridevirtual

Cancels a blocking read of the source stream.

Reimplemented from InputStream.

curPos()

UInt64 curPos ( ) const

overridevirtual

The number of decompressed bytes read so far.

Implements InputStream.

detect()

static std::optional< Format > detect ( const unsigned char *  head, Size  size  )

static

The format whose magic bytes start head (1F 8B: gzip, "BZh": bzip2), if any.

operator=()

DecompressingInputStream & operator= ( const DecompressingInputStream &  )

delete

readBytes()

Size readBytes ( unsigned char *  to_fill, Size  max_to_read  )

overridevirtual

Reads up to max_to_read decompressed bytes into to_fill; 0 at the end of the data.

Implements InputStream.

Member Data Documentation

impl_

std::unique_ptr<Impl> impl_

private

zlib/bzip2 state (their headers stay out of this one)