[VOL-4291] Rw-core updates for gRPC migration

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/go.uber.org/zap/zapcore/increase_level.go b/vendor/go.uber.org/zap/zapcore/increase_level.go
new file mode 100644
index 0000000..5a17492
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/increase_level.go
@@ -0,0 +1,66 @@
+// Copyright (c) 2020 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import "fmt"
+
+type levelFilterCore struct {
+	core  Core
+	level LevelEnabler
+}
+
+// NewIncreaseLevelCore creates a core that can be used to increase the level of
+// an existing Core. It cannot be used to decrease the logging level, as it acts
+// as a filter before calling the underlying core. If level decreases the log level,
+// an error is returned.
+func NewIncreaseLevelCore(core Core, level LevelEnabler) (Core, error) {
+	for l := _maxLevel; l >= _minLevel; l-- {
+		if !core.Enabled(l) && level.Enabled(l) {
+			return nil, fmt.Errorf("invalid increase level, as level %q is allowed by increased level, but not by existing core", l)
+		}
+	}
+
+	return &levelFilterCore{core, level}, nil
+}
+
+func (c *levelFilterCore) Enabled(lvl Level) bool {
+	return c.level.Enabled(lvl)
+}
+
+func (c *levelFilterCore) With(fields []Field) Core {
+	return &levelFilterCore{c.core.With(fields), c.level}
+}
+
+func (c *levelFilterCore) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
+	if !c.Enabled(ent.Level) {
+		return ce
+	}
+
+	return c.core.Check(ent, ce)
+}
+
+func (c *levelFilterCore) Write(ent Entry, fields []Field) error {
+	return c.core.Write(ent, fields)
+}
+
+func (c *levelFilterCore) Sync() error {
+	return c.core.Sync()
+}