X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/6eb3d1fb8fe71623fa63da46c250184cf2e4fbb8..816764a283c2cbf2d41b4582113065922b99bd52:/sdk/go/blockdigest/blockdigest.go

diff --git a/sdk/go/blockdigest/blockdigest.go b/sdk/go/blockdigest/blockdigest.go
index 5c29b902f2..b9ecc45abc 100644
--- a/sdk/go/blockdigest/blockdigest.go
+++ b/sdk/go/blockdigest/blockdigest.go
@@ -1,12 +1,20 @@
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+
 // Stores a Block Locator Digest compactly. Can be used as a map key.
 package blockdigest
 
 import (
 	"fmt"
-	"log"
+	"regexp"
 	"strconv"
+	"strings"
 )
 
+var LocatorPattern = regexp.MustCompile(
+	"^[0-9a-fA-F]{32}\\+[0-9]+(\\+[A-Z][A-Za-z0-9@_-]*)*$")
+
 // Stores a Block Locator Digest compactly, up to 128 bits.
 // Can be used as a map key.
 type BlockDigest struct {
@@ -14,10 +22,25 @@ type BlockDigest struct {
 	L uint64
 }
 
+type DigestWithSize struct {
+	Digest BlockDigest
+	Size   uint32
+}
+
+type BlockLocator struct {
+	Digest BlockDigest
+	Size   int
+	Hints  []string
+}
+
 func (d BlockDigest) String() string {
 	return fmt.Sprintf("%016x%016x", d.H, d.L)
 }
 
+func (w DigestWithSize) String() string {
+	return fmt.Sprintf("%s+%d", w.Digest.String(), w.Size)
+}
+
 // Will create a new BlockDigest unless an error is encountered.
 func FromString(s string) (dig BlockDigest, err error) {
 	if len(s) != 32 {
@@ -38,11 +61,33 @@ func FromString(s string) (dig BlockDigest, err error) {
 	return
 }
 
-// Will fatal with the error if an error is encountered
-func AssertFromString(s string) BlockDigest {
-	d, err := FromString(s)
-	if err != nil {
-		log.Fatalf("Error creating BlockDigest from %s: %v", s, err)
+func IsBlockLocator(s string) bool {
+	return LocatorPattern.MatchString(s)
+}
+
+func ParseBlockLocator(s string) (b BlockLocator, err error) {
+	if !LocatorPattern.MatchString(s) {
+		err = fmt.Errorf("String \"%s\" does not match BlockLocator pattern "+
+			"\"%s\".",
+			s,
+			LocatorPattern.String())
+	} else {
+		tokens := strings.Split(s, "+")
+		var blockSize int64
+		var blockDigest BlockDigest
+		// We expect both of the following to succeed since LocatorPattern
+		// restricts the strings appropriately.
+		blockDigest, err = FromString(tokens[0])
+		if err != nil {
+			return
+		}
+		blockSize, err = strconv.ParseInt(tokens[1], 10, 0)
+		if err != nil {
+			return
+		}
+		b.Digest = blockDigest
+		b.Size = int(blockSize)
+		b.Hints = tokens[2:]
 	}
-	return d
+	return
 }