[#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>

cmd/frostfs-node/config.go

@@ -105,7 +105,10 @@ type applicationConfiguration struct {
 }
 
 type shardCfg struct {
-	compress                  bool
+	compress                         bool
+	estimateCompressibility          bool
+	estimateCompressibilityThreshold float64
+
 	smallSizeObjectLimit      uint64
 	uncompressableContentType []string
 	refillMetabase            bool
@@ -217,6 +220,8 @@ func (a *applicationConfiguration) updateShardConfig(c *config.Config, oldConfig
 	newConfig.refillMetabase = oldConfig.RefillMetabase()
 	newConfig.mode = oldConfig.Mode()
 	newConfig.compress = oldConfig.Compress()
+	newConfig.estimateCompressibility = oldConfig.EstimateCompressibility()
+	newConfig.estimateCompressibilityThreshold = oldConfig.EstimateCompressibilityThreshold()
 	newConfig.uncompressableContentType = oldConfig.UncompressableContentTypes()
 	newConfig.smallSizeObjectLimit = oldConfig.SmallSizeLimit()
 
@@ -830,6 +835,8 @@ func (c *cfg) getShardOpts(shCfg shardCfg) shardOptsWithID {
 	blobstoreOpts := []blobstor.Option{
 		blobstor.WithCompressObjects(shCfg.compress),
 		blobstor.WithUncompressableContentTypes(shCfg.uncompressableContentType),
+		blobstor.WithCompressibilityEstimate(shCfg.estimateCompressibility),
+		blobstor.WithCompressibilityEstimateThreshold(shCfg.estimateCompressibilityThreshold),
 		blobstor.WithStorages(ss),
 		blobstor.WithLogger(c.log),
 	}