X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/eae1286badb67ee63888633ff59bda9cb736131e..127e916894bcd16f6978aa6488c81e79a9ca2812:/sdk/go/keepclient/block_cache.go

diff --git a/sdk/go/keepclient/block_cache.go b/sdk/go/keepclient/block_cache.go
index e841a00fa1..539975e161 100644
--- a/sdk/go/keepclient/block_cache.go
+++ b/sdk/go/keepclient/block_cache.go
@@ -49,6 +49,19 @@ func (c *BlockCache) Sweep() {
 	}
 }
 
+// ReadAt returns data from the cache, first retrieving it from Keep if
+// necessary.
+func (c *BlockCache) ReadAt(kc *KeepClient, locator string, p []byte, off int) (int, error) {
+	buf, err := c.Get(kc, locator)
+	if err != nil {
+		return 0, err
+	}
+	if off > len(buf) {
+		return 0, io.ErrUnexpectedEOF
+	}
+	return copy(p, buf[off:]), nil
+}
+
 // Get returns data from the cache, first retrieving it from Keep if
 // necessary.
 func (c *BlockCache) Get(kc *KeepClient, locator string) ([]byte, error) {