Documentation
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Overview ¶
Package gzip provides an HTTP middleware for compressing response bodies using the gzip algorithm. It automatically adds the "Content-Encoding: gzip" header and compresses the payload for clients that support it (indicated by the "Accept-Encoding" request header).
Usage ¶
The middleware is designed to be efficient. It pools gzip writers to reduce memory allocations and gracefully skips compression for responses tha already have a "Content-Encoding" header set.
Example:
// Create the final handler.
handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/plain")
w.Write([]byte("This is a long string that will be compressed."))
})
// Create a gzip middleware pipe with the highest level if compression.
pipe := gzip.New(
gzip.WithCompressionLevel(gzip.BestCompression),
gzip.WithExcludeMimeTypes("text/*", "application/font-woff"),
)
// Apply the CORS middleware as one of the first layers.
chainedHandler := middleware.Chain(handler, pipe)
http.ListenAndServe(":8080", chainedHandler)
Index ¶
Constants ¶
const ( BestCompression = gzip.BestCompression BestSpeed = gzip.BestSpeed DefaultCompression = gzip.DefaultCompression NoCompression = gzip.NoCompression )
Mirror constants from the compress/gzip package for easy access without requiring an extra import.
Variables ¶
This section is empty.
Functions ¶
func New ¶
func New(opts ...Option) middleware.Pipe
New creates a middleware Pipe that compresses HTTP responses using gzip with the specified options.
The middleware is a no-op if the client does not send an Accept-Encoding header including "gzip" or if the response already has a non-empty Content-Encoding header. It adds the "Vary: Accept-Encoding" header to responses to prevent cache poisoning.
Types ¶
type Option ¶
type Option func(*config)
Option is a function that configures the middleware.
func WithCompressionLevel ¶
WithCompressionLevel sets the compression level. It accepts values ranging from BestSpeed (1) to BestCompression (9). For other values, it will fall back to DefaultCompression, a good balance between speed and compression ratio.
func WithExcludeMimeTypes ¶
WithExcludeMimeTypes adds MIME types to the list of content types that should not be compressed. This option is additive and can be called multiple times; it appends to the default exclusion list rather than replacing it.
The matching logic supports two formats:
- Exact: Provide the full MIME type (e.g., "application/pdf").
- Prefix: End the MIME type with a wildcard "*" (e.g., "image/*") to exclude all subtypes for that primary type.
Source Files