Add opt-in zstd page compression to reduce database size

bucket.go

@@ -884,6 +884,11 @@ func (b *Bucket) node(pgId common.Pgid, parent *node) *node {
 		})
 	}
 
+	// If the page is compressed, decompress it before reading.
+	if p.IsCompressed() {
+		p = b.tx.decompressedPage(p)
+	}
+
 	// Read the page into the node and cache it.
 	n.read(p)
 	b.nodes[pgId] = n
@@ -945,7 +950,14 @@ func (b *Bucket) pageNode(id common.Pgid) (*common.Page, *node) {
 	}
 
 	// Finally lookup the page from the transaction if no node is materialized.
-	return b.tx.page(id), nil
+	p := b.tx.page(id)
+
+	// If the page is compressed, decompress it transparently.
+	if p.IsCompressed() {
+		p = b.tx.decompressedPage(p)
+	}
+
+	return p, nil
 }
 
 // BucketStats records statistics about resources used by a bucket.

cmd/bbolt/command/command_bench.go

@@ -41,6 +41,7 @@ type benchOptions struct {
 	pageSize        int
 	initialMmapSize int
 	deleteFraction  float64 // Fraction of keys of last tx to delete during writes. works only with "seq-del" write mode.
+	compression     bool
 }
 
 func (o *benchOptions) AddFlags(fs *pflag.FlagSet) {
@@ -61,6 +62,7 @@ func (o *benchOptions) AddFlags(fs *pflag.FlagSet) {
 	fs.BoolVar(&o.goBenchOutput, "gobench-output", false, "")
 	fs.IntVar(&o.pageSize, "page-size", common.DefaultPageSize, "Set page size in bytes.")
 	fs.IntVar(&o.initialMmapSize, "initial-mmap-size", 0, "Set initial mmap size in bytes for database file.")
+	fs.BoolVar(&o.compression, "compression", false, "Enables compression.")
 }
 
 // Returns an error if `bench` options are not valid.
@@ -145,6 +147,7 @@ func benchFunc(cmd *cobra.Command, options *benchOptions) error {
 	dbOptions := *bolt.DefaultOptions
 	dbOptions.PageSize = options.pageSize
 	dbOptions.InitialMmapSize = options.initialMmapSize
+	dbOptions.Compression = options.compression
 	db, err := bolt.Open(options.path, 0600, &dbOptions)
 	if err != nil {
 		return err

cmd/bbolt/command/command_bench_test.go

@@ -38,8 +38,9 @@ func TestBenchCommand_Run(t *testing.T) {
 	tests := map[string]struct {
 		args []string
 	}{
-		"no-args":    {},
-		"100k count": {[]string{"--count", "100000"}},
+		"no-args":     {},
+		"100k count":  {[]string{"--count", "100000"}},
+		"compression": {[]string{"--compression"}},
 	}
 
 	for name, test := range tests {