From 9b4d46a6ed0b0a673d1e806ec3df251eda347f1d Mon Sep 17 00:00:00 2001
From: poornas <poornas@users.noreply.github.com>
Date: Fri, 7 Feb 2020 14:36:46 -0800
Subject: [PATCH] evict cached entry for server side copy (#8947)

Fixes #8942
---
 cmd/disk-cache.go      | 29 +++++++++++++++++++++++++++++
 cmd/object-handlers.go |  6 +++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/cmd/disk-cache.go b/cmd/disk-cache.go
index 3ad56b4db..e677b37e6 100644
--- a/cmd/disk-cache.go
+++ b/cmd/disk-cache.go
@@ -56,6 +56,7 @@ type CacheObjectLayer interface {
 	DeleteObject(ctx context.Context, bucket, object string) error
 	DeleteObjects(ctx context.Context, bucket string, objects []string) ([]error, error)
 	PutObject(ctx context.Context, bucket, object string, data *PutObjReader, opts ObjectOptions) (objInfo ObjectInfo, err error)
+	CopyObject(ctx context.Context, srcBucket, srcObject, destBucket, destObject string, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions) (objInfo ObjectInfo, err error)
 	// Storage operations.
 	StorageInfo(ctx context.Context) CacheStorageInfo
 	CacheStats() *CacheStats
@@ -82,6 +83,7 @@ type cacheObjects struct {
 	DeleteObjectFn   func(ctx context.Context, bucket, object string) error
 	DeleteObjectsFn  func(ctx context.Context, bucket string, objects []string) ([]error, error)
 	PutObjectFn      func(ctx context.Context, bucket, object string, data *PutObjReader, opts ObjectOptions) (objInfo ObjectInfo, err error)
+	CopyObjectFn     func(ctx context.Context, srcBucket, srcObject, destBucket, destObject string, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions) (objInfo ObjectInfo, err error)
 }
 
 func (c *cacheObjects) incHitsToMeta(ctx context.Context, dcache *diskCache, bucket, object string, size int64, eTag string) error {
@@ -373,6 +375,30 @@ func (c *cacheObjects) GetObjectInfo(ctx context.Context, bucket, object string,
 	return objInfo, nil
 }
 
+// CopyObject reverts to backend after evicting any stale cache entries
+func (c *cacheObjects) CopyObject(ctx context.Context, srcBucket, srcObject, dstBucket, dstObject string, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions) (objInfo ObjectInfo, err error) {
+	copyObjectFn := c.CopyObjectFn
+	if c.isCacheExclude(srcBucket, srcObject) || c.skipCache() {
+		return copyObjectFn(ctx, srcBucket, srcObject, dstBucket, dstObject, srcInfo, srcOpts, dstOpts)
+	}
+	if srcBucket != dstBucket || srcObject != dstObject {
+		return copyObjectFn(ctx, srcBucket, srcObject, dstBucket, dstObject, srcInfo, srcOpts, dstOpts)
+	}
+	// fetch diskCache if object is currently cached or nearest available cache drive
+	dcache, err := c.getCacheToLoc(ctx, srcBucket, srcObject)
+	if err != nil {
+		return copyObjectFn(ctx, srcBucket, srcObject, dstBucket, dstObject, srcInfo, srcOpts, dstOpts)
+	}
+	// if currently cached, evict old entry and revert to backend.
+	if cachedObjInfo, _, cerr := dcache.Stat(ctx, srcBucket, srcObject); cerr == nil {
+		cc := cacheControlOpts(cachedObjInfo)
+		if !cc.isStale(cachedObjInfo.ModTime) {
+			dcache.Delete(ctx, srcBucket, srcObject)
+		}
+	}
+	return copyObjectFn(ctx, srcBucket, srcObject, dstBucket, dstObject, srcInfo, srcOpts, dstOpts)
+}
+
 // StorageInfo - returns underlying storage statistics.
 func (c *cacheObjects) StorageInfo(ctx context.Context) (cInfo CacheStorageInfo) {
 	var total, free uint64
@@ -663,6 +689,9 @@ func newServerCacheObjects(ctx context.Context, config cache.Config) (CacheObjec
 		PutObjectFn: func(ctx context.Context, bucket, object string, data *PutObjReader, opts ObjectOptions) (objInfo ObjectInfo, err error) {
 			return newObjectLayerFn().PutObject(ctx, bucket, object, data, opts)
 		},
+		CopyObjectFn: func(ctx context.Context, srcBucket, srcObject, destBucket, destObject string, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions) (objInfo ObjectInfo, err error) {
+			return newObjectLayerFn().CopyObject(ctx, srcBucket, srcObject, destBucket, destObject, srcInfo, srcOpts, dstOpts)
+		},
 	}
 
 	if migrateSw {
diff --git a/cmd/object-handlers.go b/cmd/object-handlers.go
index 653b41b60..fae7a222f 100644
--- a/cmd/object-handlers.go
+++ b/cmd/object-handlers.go
@@ -1077,9 +1077,13 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 		objInfo.ETag = remoteObjInfo.ETag
 		objInfo.ModTime = remoteObjInfo.LastModified
 	} else {
+		copyObjectFn := objectAPI.CopyObject
+		if api.CacheAPI() != nil {
+			copyObjectFn = api.CacheAPI().CopyObject
+		}
 		// Copy source object to destination, if source and destination
 		// object is same then only metadata is updated.
-		objInfo, err = objectAPI.CopyObject(ctx, srcBucket, srcObject, dstBucket, dstObject, srcInfo, srcOpts, dstOpts)
+		objInfo, err = copyObjectFn(ctx, srcBucket, srcObject, dstBucket, dstObject, srcInfo, srcOpts, dstOpts)
 		if err != nil {
 			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL, guessIsBrowserReq(r))
 			return