summaryrefslogtreecommitdiffstats
path: root/vendor/github.com/couchbase/vellum/pack.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/couchbase/vellum/pack.go')
-rw-r--r--vendor/github.com/couchbase/vellum/pack.go55
1 files changed, 55 insertions, 0 deletions
diff --git a/vendor/github.com/couchbase/vellum/pack.go b/vendor/github.com/couchbase/vellum/pack.go
new file mode 100644
index 0000000000..78f3dcd588
--- /dev/null
+++ b/vendor/github.com/couchbase/vellum/pack.go
@@ -0,0 +1,55 @@
+// Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vellum
+
+func deltaAddr(base, trans uint64) uint64 {
+ // transition dest of 0 is special case
+ if trans == 0 {
+ return 0
+ }
+ return base - trans
+}
+
+const packOutMask = 1<<4 - 1
+
+func encodePackSize(transSize, outSize int) byte {
+ var rv byte
+ rv = byte(transSize << 4)
+ rv |= byte(outSize)
+ return rv
+}
+
+func decodePackSize(pack byte) (transSize int, packSize int) {
+ transSize = int(pack >> 4)
+ packSize = int(pack & packOutMask)
+ return
+}
+
+const maxNumTrans = 1<<6 - 1
+
+func encodeNumTrans(n int) byte {
+ if n <= maxNumTrans {
+ return byte(n)
+ }
+ return 0
+}
+
+func readPackedUint(data []byte) (rv uint64) {
+ for i := range data {
+ shifted := uint64(data[i]) << uint(i*8)
+ rv |= shifted
+ }
+ return
+}