[performance] add optional S3 object info caching (#4546)

This adds an optional S3 object info cache to the S3 storage driver backend (see [here](https://codeberg.org/gruf/go-storage/releases/tag/v0.4.0)) to reduce S3 calls largely during media cleanup operations, but it should also help in other situations cutting back on S3 calls when for example a key is already known to not exist.

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4546
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

1 files changed, 94 insertions, 0 deletions

diff --git a/vendor/codeberg.org/gruf/go-storage/s3/cache.go b/vendor/codeberg.org/gruf/go-storage/s3/cache.go
new file mode 100644
index 000000000..37ff9f321
--- /dev/null
+++ b/vendor/codeberg.org/gruf/go-storage/s3/cache.go
@@ -0,0 +1,94 @@
+package s3
+
+import (
+	"time"
+
+	"github.com/minio/minio-go/v7"
+)
+
+// EntryCache should provide a cache of
+// S3 object information for speeding up
+// Get(), Stat() and Remove() operations.
+type EntryCache interface {
+
+	// Get should return 'found' = true when information is cached,
+	// with 'info' optionally being nilable to allow caching errors.
+	Get(key string) (info *CachedObjectInfo, found bool)
+
+	// Put should cache the given information under key, with
+	// nil CachedObjectInfo{} meaning a 'not found' response.
+	Put(key string, info *CachedObjectInfo)
+}
+
+// CachedObjectInfo provides the minimum cacheable
+// set of S3 object information that may be returned
+// from a Get() or Stat() operation, or on Put().
+type CachedObjectInfo struct {
+	Key          string
+	ETag         string
+	Size         int64
+	ContentType  string
+	LastModified time.Time
+	VersionID    string
+}
+
+// ToObjectInfo converts CachedObjectInfo to returnable minio.ObjectInfo.
+func (info *CachedObjectInfo) ToObjectInfo() minio.ObjectInfo {
+	return minio.ObjectInfo{
+		Key:          info.Key,
+		ETag:         info.ETag,
+		Size:         info.Size,
+		ContentType:  info.ContentType,
+		LastModified: info.LastModified,
+		VersionID:    info.VersionID,
+	}
+}
+
+// cacheGet wraps cache.Get() operations to check if cache is nil.
+func cacheGet(cache EntryCache, key string) (*CachedObjectInfo, bool) {
+	if cache != nil {
+		return cache.Get(key)
+	}
+	return nil, false
+}
+
+// objectToCachedObjectInfo converts minio.ObjectInfo to CachedObjectInfo for caching.
+func objectToCachedObjectInfo(info minio.ObjectInfo) *CachedObjectInfo {
+	return &CachedObjectInfo{
+		Key:          info.Key,
+		ETag:         info.ETag,
+		Size:         info.Size,
+		ContentType:  info.ContentType,
+		LastModified: info.LastModified,
+		VersionID:    info.VersionID,
+	}
+}
+
+// cacheObject wraps cache.Put() operations to check if cache is nil.
+func cacheObject(cache EntryCache, key string, info minio.ObjectInfo) {
+	if cache != nil {
+		cache.Put(key, objectToCachedObjectInfo(info))
+	}
+}
+
+// cacheUpload wraps cache.Put() operations to check if cache is nil, uses ContentType from given opts.
+func cacheUpload(cache EntryCache, key string, info minio.UploadInfo, opts minio.PutObjectOptions) {
+	if cache != nil {
+		cache.Put(key, &CachedObjectInfo{
+			Key:          info.Key,
+			ETag:         info.ETag,
+			Size:         info.Size,
+			ContentType:  opts.ContentType,
+			LastModified: info.LastModified,
+			VersionID:    info.VersionID,
+		})
+	}
+}
+
+// cacheNotFound wraps cache.Put() to check if cache is
+// nil, storing a nil entry (i.e. not found) in cache.
+func cacheNotFound(cache EntryCache, key string) {
+	if cache != nil {
+		cache.Put(key, nil)
+	}
+}