Documentation
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Overview ¶
Package gzip implements reading and writing of gzip format compressed files, as specified in RFC 1952.
Index ¶
Constants ¶
const ( NoCompression = flate.NoCompression BestSpeed = flate.BestSpeed BestCompression = flate.BestCompression DefaultCompression = flate.DefaultCompression )
These constants are copied from the flate package, so that code that imports "compress/gzip" does not also have to import "compress/flate".
Variables ¶
var ChecksumError = os.NewError("gzip checksum error")
var HeaderError = os.NewError("invalid gzip header")
Functions ¶
This section is empty.
Types ¶
type Compressor ¶
type Compressor struct {
Header
// contains filtered or unexported fields
}
A Compressor is an io.WriteCloser that satisfies writes by compressing data written to its wrapped io.Writer.
func NewWriter ¶
func NewWriter(w io.Writer) (*Compressor, os.Error)
NewWriter calls NewWriterLevel with the default compression level.
func NewWriterLevel ¶
NewWriterLevel creates a new Compressor writing to the given writer. Writes may be buffered and not flushed until Close. Callers that wish to set the fields in Compressor.Header must do so before the first call to Write or Close. It is the caller's responsibility to call Close on the WriteCloser when done. level is the compression level, which can be DefaultCompression, NoCompression, or any integer value between BestSpeed and BestCompression (inclusive).
func (*Compressor) Close ¶
func (z *Compressor) Close() os.Error
Calling Close does not close the wrapped io.Writer originally passed to NewWriter.
type Decompressor ¶
type Decompressor struct {
Header
// contains filtered or unexported fields
}
An Decompressor is an io.Reader that can be read to retrieve uncompressed data from a gzip-format compressed file.
In general, a gzip file can be a concatenation of gzip files, each with its own header. Reads from the Decompressor return the concatenation of the uncompressed data of each. Only the first header is recorded in the Decompressor fields.
Gzip files store a length and checksum of the uncompressed data. The Decompressor will return a ChecksumError when Read reaches the end of the uncompressed data if it does not have the expected length or checksum. Clients should treat data returned by Read as tentative until they receive the successful (zero length, nil error) Read marking the end of the data.
func NewReader ¶
func NewReader(r io.Reader) (*Decompressor, os.Error)
NewReader creates a new Decompressor reading the given reader. The implementation buffers input and may read more data than necessary from r. It is the caller's responsibility to call Close on the Decompressor when done.
func (*Decompressor) Close ¶
func (z *Decompressor) Close() os.Error
Calling Close does not close the wrapped io.Reader originally passed to NewReader.
type Header ¶
type Header struct {
Comment string // comment
Extra []byte // "extra data"
Mtime uint32 // modification time (seconds since January 1, 1970)
Name string // file name
OS byte // operating system type
}
The gzip file stores a header giving metadata about the compressed file. That header is exposed as the fields of the Compressor and Decompressor structs.
Notes ¶
Bugs ¶
Comments and Names don't properly map UTF-8 character codes outside of the 0x00-0x7f range to ISO 8859-1 (Latin-1).
Source Files