Implement size estimation function for structs used in history event cache

common/constants.go

@@ -309,3 +309,7 @@ const (
 	ShardModeHashRing         = "hash-ring"
 	ShardModeShardDistributor = "shard-distributor"
 )
+
+const (
+	StringSizeOverheadBytes = 16
+)

common/definition/workflowIdentifier.go

@@ -20,6 +20,8 @@
 
 package definition
 
+import "github.com/uber/cadence/common"
+
 type (
 	// WorkflowIdentifier is the combinations which represent a workflow
 	WorkflowIdentifier struct {
@@ -29,6 +31,15 @@ type (
 	}
 )
 
+// Size calculates the size in bytes of the WorkflowIdentifier struct.
+func (wi *WorkflowIdentifier) Size() uint64 {
+	// Calculate the size of strings in bytes, we assume that all those fields are using ASCII which is 1 byte per char
+	size := len(wi.DomainID) + len(wi.WorkflowID) + len(wi.RunID)
+	// Each string internally holds a reference pointer and a length, which are 8 bytes each
+	stringOverhead := 3 * common.StringSizeOverheadBytes
+	return uint64(size + stringOverhead)
+}
+
 // NewWorkflowIdentifier create a new WorkflowIdentifier
 func NewWorkflowIdentifier(domainID string, workflowID string, runID string) WorkflowIdentifier {
 	return WorkflowIdentifier{

common/definition/workflowidentifier_test.go

@@ -0,0 +1,71 @@
+// The MIT License (MIT)
+
+// Copyright (c) 2017-2020 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 definition
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+// WorkflowIdentifierTestSuite is a test suite for the WorkflowIdentifier struct.
+type WorkflowIdentifierTestSuite struct {
+	suite.Suite
+}
+
+// SetupTest runs before each test function in the suite.
+func (suite *WorkflowIdentifierTestSuite) SetupTest() {
+	// Any necessary setup would go here, but it's not required in this case.
+}
+
+// TestSize verifies the Size method of WorkflowIdentifier.
+func (suite *WorkflowIdentifierTestSuite) TestSize() {
+	tests := []struct {
+		wi       WorkflowIdentifier
+		expected uint64
+	}{
+		{
+			wi:       NewWorkflowIdentifier("domain", "workflow", "run"),
+			expected: uint64(len("domain") + len("workflow") + len("run") + 3*16),
+		},
+		{
+			wi:       NewWorkflowIdentifier("", "", ""),
+			expected: uint64(3 * 16),
+		},
+		{
+			wi:       NewWorkflowIdentifier("a", "b", "c"),
+			expected: uint64(3 + 3*16),
+		},
+	}
+
+	for _, test := range tests {
+		size := test.wi.Size()
+		assert.Equal(suite.T(), test.expected, size)
+	}
+}
+
+// TestWorkflowIdentifierTestSuite runs the test suite.
+func TestWorkflowIdentifierTestSuite(t *testing.T) {
+	suite.Run(t, new(WorkflowIdentifierTestSuite))
+}