From 8ecaf4cfd52086a08ec5af3d4c07938436df1eda Mon Sep 17 00:00:00 2001
From: Chris Heppell <chris.john.heppell@gmail.com>
Date: Tue, 29 Dec 2020 20:47:57 +0000
Subject: [PATCH] create an in-memory store implementation

---
 storage/memory.go | 99 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 storage/memory.go

diff --git a/storage/memory.go b/storage/memory.go
new file mode 100644
index 00000000..9b4ec448
--- /dev/null
+++ b/storage/memory.go
@@ -0,0 +1,99 @@
+package storage
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/TwinProduction/gatus/core"
+)
+
+var (
+	serviceStatuses = make(map[string]*core.ServiceStatus)
+
+	// serviceResultsMutex is used to prevent concurrent map access
+	serviceResultsMutex sync.RWMutex
+)
+
+// InMemoryStore implements an in-memory store
+type InMemoryStore struct{}
+
+// NewInMemoryStore returns an in-memory store. Note that the store acts as a singleton, so although new-ing
+// up in-memory stores will give you a unique reference to a struct each time, all structs returned
+// by this function will act on the same in-memory store.
+func NewInMemoryStore() InMemoryStore {
+	return InMemoryStore{}
+}
+
+// GetAll returns all the observed results for all services from the in memory store
+func (ims *InMemoryStore) GetAll() map[string]*core.ServiceStatus {
+	results := make(map[string]*core.ServiceStatus)
+	serviceResultsMutex.RLock()
+	for key, svcStatus := range serviceStatuses {
+		copiedResults := copyResults(svcStatus.Results)
+		results[key] = &core.ServiceStatus{
+			Name:    svcStatus.Name,
+			Group:   svcStatus.Group,
+			Results: copiedResults,
+		}
+	}
+	serviceResultsMutex.RUnlock()
+
+	return results
+}
+
+// Insert inserts the observed result for the specified service into the in memory store
+func (ims *InMemoryStore) Insert(service *core.Service, result *core.Result) {
+	key := fmt.Sprintf("%s_%s", service.Group, service.Name)
+	serviceResultsMutex.Lock()
+	serviceStatus, exists := serviceStatuses[key]
+	if !exists {
+		serviceStatus = core.NewServiceStatus(service)
+		serviceStatuses[key] = serviceStatus
+	}
+	serviceStatus.AddResult(result)
+	serviceResultsMutex.Unlock()
+}
+
+func copyResults(results []*core.Result) []*core.Result {
+	copiedResults := []*core.Result{}
+	for _, result := range results {
+		copiedErrors := copyErrors(result.Errors)
+		copiedConditionResults := copyConditionResults(result.ConditionResults)
+
+		copiedResults = append(copiedResults, &core.Result{
+			HTTPStatus:            result.HTTPStatus,
+			DNSRCode:              result.DNSRCode,
+			Body:                  result.Body,
+			Hostname:              result.Hostname,
+			IP:                    result.IP,
+			Connected:             result.Connected,
+			Duration:              result.Duration,
+			Errors:                copiedErrors,
+			ConditionResults:      copiedConditionResults,
+			Success:               result.Connected,
+			Timestamp:             result.Timestamp,
+			CertificateExpiration: result.CertificateExpiration,
+		})
+	}
+	return copiedResults
+}
+
+func copyConditionResults(crs []*core.ConditionResult) []*core.ConditionResult {
+	copiedConditionResults := []*core.ConditionResult{}
+	for _, conditionResult := range crs {
+		copiedConditionResults = append(copiedConditionResults, &core.ConditionResult{
+			Condition: conditionResult.Condition,
+			Success:   conditionResult.Success,
+		})
+	}
+
+	return copiedConditionResults
+}
+
+func copyErrors(errors []string) []string {
+	copiedErrors := []string{}
+	for _, error := range errors {
+		copiedErrors = append(copiedErrors, error)
+	}
+	return copiedErrors
+}