package zlib

Import Path
	compress/zlib (on go.dev)

Dependency Relation
	imports 8 packages, and imported by 4 packages


Involved Source Files

	
		Package zlib implements reading and writing of zlib format compressed data,
		as specified in RFC 1950.
		
		The implementation provides filters that uncompress during reading
		and compress during writing.  For example, to write compressed data
		to a buffer:
		
			var b bytes.Buffer
			w := zlib.NewWriter(&b)
			w.Write([]byte("hello, world\n"))
			w.Close()
		
		and to read that data back:
		
			r, err := zlib.NewReader(&b)
			io.Copy(os.Stdout, r)
			r.Close()

	    writer.go


Code Examples

	
		package main
		
		import (
			"bytes"
			"compress/zlib"
			"io"
			"os"
		)
		
		func main() {
			buff := []byte{120, 156, 202, 72, 205, 201, 201, 215, 81, 40, 207,
				47, 202, 73, 225, 2, 4, 0, 0, 255, 255, 33, 231, 4, 147}
			b := bytes.NewReader(buff)
		
			r, err := zlib.NewReader(b)
			if err != nil {
				panic(err)
			}
			io.Copy(os.Stdout, r)
		
			r.Close()
		}

	
		package main
		
		import (
			"bytes"
			"compress/zlib"
			"fmt"
		)
		
		func main() {
			var b bytes.Buffer
		
			w := zlib.NewWriter(&b)
			w.Write([]byte("hello, world\n"))
			w.Close()
			fmt.Println(b.Bytes())
		}




Package-Level Type Names (total 2)


	/* sort by:  |  */
	
		Resetter resets a ReadCloser returned by [NewReader] or [NewReaderDict]
		to switch to a new underlying Reader. This permits reusing a ReadCloser
		instead of allocating a new one.

		
			
				Reset discards any buffered data and resets the Resetter as if it was
				newly initialized with the given reader.

		
			 compress/flate.Resetter (interface)
		
			 Resetter : compress/flate.Resetter


	
		A Writer takes data written to it and writes the compressed
		form of that data to an underlying writer (see [NewWriter]).

		
			
				Close closes the Writer, flushing any unwritten data to the underlying
				[io.Writer], but does not close the underlying io.Writer.

			
				Flush flushes the Writer to its underlying [io.Writer].

			
				Reset clears the state of the [Writer] z such that it is equivalent to its
				initial state from [NewWriterLevel] or [NewWriterLevelDict], but instead writing
				to w.

			
				Write writes a compressed form of p to the underlying [io.Writer]. The
				compressed bytes are not necessarily flushed until the [Writer] is closed or
				explicitly flushed.

		
			*Writer : internal/bisect.Writer
			*Writer : io.Closer
			*Writer : io.WriteCloser
			*Writer : io.Writer
		
			func NewWriter(w io.Writer) *Writer
			func NewWriterLevel(w io.Writer, level int) (*Writer, error)
			func NewWriterLevelDict(w io.Writer, level int, dict []byte) (*Writer, error)




Package-Level Functions (total 5)


	
		NewReader creates a new ReadCloser.
		Reads from the returned ReadCloser read and decompress data from r.
		If r does not implement [io.ByteReader], the decompressor may read more
		data than necessary from r.
		It is the caller's responsibility to call Close on the ReadCloser when done.
		
		The [io.ReadCloser] returned by NewReader also implements [Resetter].


	
		NewReaderDict is like [NewReader] but uses a preset dictionary.
		NewReaderDict ignores the dictionary if the compressed data does not refer to it.
		If the compressed data refers to a different dictionary, NewReaderDict returns [ErrDictionary].
		
		The ReadCloser returned by NewReaderDict also implements [Resetter].


	
		NewWriter creates a new [Writer].
		Writes to the returned Writer are compressed and written to w.
		
		It is the caller's responsibility to call Close on the Writer when done.
		Writes may be buffered and not flushed until Close.


	
		NewWriterLevel is like [NewWriter] but specifies the compression level instead
		of assuming [DefaultCompression].
		
		The compression level can be [DefaultCompression], [NoCompression], [HuffmanOnly]
		or any integer value between [BestSpeed] and [BestCompression] inclusive.
		The error returned will be nil if the level is valid.


	
		NewWriterLevelDict is like [NewWriterLevel] but specifies a dictionary to
		compress with.
		
		The dictionary may be nil. If not, its contents should not be modified until
		the Writer is closed.




Package-Level Variables (total 3)


	
		ErrChecksum is returned when reading ZLIB data that has an invalid checksum.


	
		ErrDictionary is returned when reading ZLIB data that has an invalid dictionary.


	
		ErrHeader is returned when reading ZLIB data that has an invalid header.




Package-Level Constants (total 5)


	
		These constants are copied from the [flate] package, so that code that imports
		[compress/zlib] does not also have to import [compress/flate].


	
		These constants are copied from the [flate] package, so that code that imports
		[compress/zlib] does not also have to import [compress/flate].


	
		These constants are copied from the [flate] package, so that code that imports
		[compress/zlib] does not also have to import [compress/flate].


	
		These constants are copied from the [flate] package, so that code that imports
		[compress/zlib] does not also have to import [compress/flate].


	
		These constants are copied from the [flate] package, so that code that imports
		[compress/zlib] does not also have to import [compress/flate].