Add insert link to cache

Add DisableLinkCaching config

cache.go

@@ -2,15 +2,72 @@ package proton_api_bridge
 
 import (
 	"context"
+	"sync"
 
 	"github.com/henrybear327/go-proton-api"
 )
 
+type cacheEntry struct {
+	link *proton.Link
+}
+
+type cache struct {
+	data           map[string]*cacheEntry
+	disableCaching bool
+
+	sync.RWMutex
+}
+
+func newCache(disableCaching bool) *cache {
+	return &cache{
+		data:           make(map[string]*cacheEntry),
+		disableCaching: disableCaching,
+	}
+}
+
+func (linkCache *cache) _getLink(linkID string) *proton.Link {
+	if linkCache.disableCaching {
+		return nil
+	}
+
+	linkCache.RLock()
+	defer linkCache.RUnlock()
+
+	if data, ok := linkCache.data[linkID]; ok && data.link != nil {
+		return data.link
+	}
+	return nil
+}
+
+func (linkCache *cache) _insertLink(linkID string, link *proton.Link) {
+	if linkCache.disableCaching {
+		return
+	}
+
+	linkCache.Lock()
+	defer linkCache.Unlock()
+
+	linkCache.data[linkID] = &cacheEntry{
+		link: link,
+	}
+}
+
 func (protonDrive *ProtonDrive) getLink(ctx context.Context, linkID string) (*proton.Link, error) {
+	// attempt to get from cache first
+	if link := protonDrive.cache._getLink(linkID); link != nil {
+		// log.Println("From cache")
+		return link, nil
+	}
+
+	// log.Println("Not from cache")
+	// no cached data, fetch
 	link, err := protonDrive.c.GetLink(ctx, protonDrive.MainShare.ShareID, linkID)
 	if err != nil {
 		return nil, err
 	}
 
+	// populate cache
+	protonDrive.cache._insertLink(linkID, &link)
+
 	return &link, nil
 }

common/config.go

@@ -17,6 +17,7 @@ type Config struct {
 	DestructiveIntegrationTest     bool // CAUTION: the integration test requires a clean proton drive
 	EmptyTrashAfterIntegrationTest bool // CAUTION: the integration test will clean up all the data in the trash
 	ReplaceExistingDraft           bool // for the file upload replace or keep it as-is option
+	DisableCaching                 bool // link node caching
 
 	/* Drive */
 	DataFolderName string
@@ -57,6 +58,7 @@ func NewConfigWithDefaultValues() *Config {
 		DestructiveIntegrationTest:     false,
 		EmptyTrashAfterIntegrationTest: false,
 		ReplaceExistingDraft:           false,
+		DisableCaching:                 true,
 
 		DataFolderName: "data",
 	}
@@ -102,6 +104,7 @@ func NewConfigForIntegrationTests() *Config {
 		DestructiveIntegrationTest:     true,
 		EmptyTrashAfterIntegrationTest: true,
 		ReplaceExistingDraft:           false,
+		DisableCaching:                 false,
 
 		DataFolderName: "data",
 	}

drive.go

@@ -25,6 +25,8 @@ type ProtonDrive struct {
 	addrKRs          map[string]*crypto.KeyRing
 	addrData         []proton.Address
 	signatureAddress string
+
+	cache *cache
 }
 
 func NewDefaultConfig() *common.Config {
@@ -140,6 +142,8 @@ func NewProtonDrive(ctx context.Context, config *common.Config, authHandler prot
 		addrKRs:          addrKRs,
 		addrData:         addrData,
 		signatureAddress: mainShare.Creator,
+
+		cache: newCache(config.DisableCaching),
 	}, credentials, nil
 }