httpbuffer - options.go

     1  package httpbuffer
     2  
     3  import (
     4  	"compress/flate"
     5  	"compress/gzip"
     6  	"io"
     7  
     8  	"github.com/klauspost/compress/zstd"
     9  	"github.com/molecule-man/go-brrr"
    10  )
    11  
    12  // Option represents a type that can be passed to the New function to specify
    13  // which compressors can be used to compress the buffered data.
    14  type Option func(*Handler)
    15  
    16  type gzipEncoding int
    17  
    18  func (g gzipEncoding) Open(w io.Writer) io.Writer {
    19  	gw, _ := gzip.NewWriterLevel(w, int(g))
    20  
    21  	return gw
    22  }
    23  
    24  func (gzipEncoding) Close(w io.Writer) {
    25  	w.(*gzip.Writer).Close()
    26  }
    27  
    28  func (gzipEncoding) Name() string {
    29  	return "gzip"
    30  }
    31  
    32  // Gzip enables the use of gzip to compress the data that will be sent to the
    33  // client when gzip is allowed in the Accept-Encoding header.
    34  func Gzip(compressionLevel int) Option {
    35  	if compressionLevel < gzip.HuffmanOnly || compressionLevel > gzip.BestCompression {
    36  		compressionLevel = gzip.DefaultCompression
    37  	}
    38  
    39  	return func(h *Handler) {
    40  		h.encodings = append(h.encodings, "gzip")
    41  		h.compressors["gzip"] = gzipEncoding(compressionLevel)
    42  	}
    43  }
    44  
    45  type deflateEncoding int
    46  
    47  func (d deflateEncoding) Open(w io.Writer) io.Writer {
    48  	dw, _ := flate.NewWriter(w, int(d))
    49  
    50  	return dw
    51  }
    52  
    53  func (deflateEncoding) Close(w io.Writer) {
    54  	w.(*flate.Writer).Close()
    55  }
    56  
    57  func (deflateEncoding) Name() string {
    58  	return "deflate"
    59  }
    60  
    61  // Deflate enables the use of flate to compress the data that will be sent to
    62  // the client when deflate is allowed in the Accept-Encoding header.
    63  func Deflate(compressionLevel int) Option {
    64  	if compressionLevel < flate.HuffmanOnly || compressionLevel > flate.BestCompression {
    65  		compressionLevel = flate.DefaultCompression
    66  	}
    67  
    68  	return func(h *Handler) {
    69  		h.encodings = append(h.encodings, "deflate")
    70  		h.compressors["deflate"] = deflateEncoding(compressionLevel)
    71  	}
    72  }
    73  
    74  type brotliEncoding int
    75  
    76  func (b brotliEncoding) Open(w io.Writer) io.Writer {
    77  	dw, _ := brrr.NewWriter(w, int(b))
    78  
    79  	return dw
    80  }
    81  
    82  func (brotliEncoding) Close(w io.Writer) {
    83  	w.(*brrr.Writer).Close()
    84  }
    85  
    86  func (brotliEncoding) Name() string {
    87  	return "br"
    88  }
    89  
    90  // Brotli enables the use of brotli to compress the data that will be sent to
    91  // the client when br is allowed in the Accept-Encoding header.
    92  func Brotli(compressionLevel int) Option {
    93  	if compressionLevel < 0 {
    94  		compressionLevel = brrr.BestSpeed
    95  	} else if compressionLevel > 11 {
    96  		compressionLevel = brrr.BestCompression
    97  	}
    98  
    99  	return func(h *Handler) {
   100  		h.encodings = append(h.encodings, "br")
   101  		h.compressors["br"] = brotliEncoding(compressionLevel)
   102  	}
   103  }
   104  
   105  type zstdEncoding int
   106  
   107  func (z zstdEncoding) Open(w io.Writer) io.Writer {
   108  	dw, _ := zstd.NewWriter(w, zstd.WithEncoderLevel(zstd.EncoderLevel(z)))
   109  
   110  	return dw
   111  }
   112  
   113  func (zstdEncoding) Close(w io.Writer) {
   114  	w.(*zstd.Encoder).Close()
   115  }
   116  
   117  func (zstdEncoding) Name() string {
   118  	return "zstd"
   119  }
   120  
   121  // Zstd enables the use of zstandard to compress the data that will be sent to
   122  // the client when zstd is allowed in the Accept-Encoding header.
   123  func Zstd(compressionLevel zstd.EncoderLevel) Option {
   124  	if compressionLevel < zstd.SpeedFastest {
   125  		compressionLevel = zstd.SpeedFastest
   126  	} else if compressionLevel > zstd.SpeedBestCompression {
   127  		compressionLevel = zstd.SpeedBestCompression
   128  	}
   129  
   130  	return func(h *Handler) {
   131  		h.encodings = append(h.encodings, "zstd")
   132  		h.compressors["zstd"] = zstdEncoding(compressionLevel)
   133  	}
   134  }
   135