[#754] blobstor: Estimate compressability

Now it is possible to enable compressability estimation.
If data is likely uncompressable, it should reduce CPU time and memory.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/blobstor/blobstor.go

@@ -107,6 +107,27 @@ func WithCompressObjects(comp bool) Option {
 	}
 }
 
+// WithCompressibilityEstimate returns an option to use
+// normilized compressibility estimate to decide compress
+// data or not.
+//
+// See https://github.com/klauspost/compress/blob/v1.17.2/compressible.go#L5
+func WithCompressibilityEstimate(v bool) Option {
+	return func(c *cfg) {
+		c.compression.UseCompressEstimation = v
+	}
+}
+
+// WithCompressibilityEstimateThreshold returns an option to set
+// normilized compressibility estimate threshold.
+//
+// See https://github.com/klauspost/compress/blob/v1.17.2/compressible.go#L5
+func WithCompressibilityEstimateThreshold(threshold float64) Option {
+	return func(c *cfg) {
+		c.compression.CompressEstimationThreshold = threshold
+	}
+}
+
 // WithUncompressableContentTypes returns option to disable decompression
 // for specific content types as seen by object.AttributeContentType attribute.
 func WithUncompressableContentTypes(values []string) Option {