diff --git a/report/id.go b/report/id.go index b0a9aa323..f0d3dec9b 100644 --- a/report/id.go +++ b/report/id.go @@ -166,11 +166,11 @@ func makeSingleComponentID(tag string) func(string) string { // parseSingleComponentID makes a single-component node id decoder func parseSingleComponentID(tag string) func(string) (string, bool) { return func(id string) (string, bool) { - fields := strings.SplitN(id, ScopeDelim, 2) - if len(fields) != 2 || fields[1] != "<"+tag+">" { + field0, field1, ok := split2(id, ScopeDelim) + if !ok || field1 != "<"+tag+">" { return "", false } - return fields[0], true + return field0, true } } @@ -197,48 +197,54 @@ func ParseOverlayNodeID(id string) (overlayPrefix string, peerName string) { return WeaveOverlayPeerPrefix, id } +// Split a string s into to parts separated by sep. +func split2(s, sep string) (s1, s2 string, ok bool) { + // Not using strings.SplitN() to avoid a heap allocation + pos := strings.Index(s, sep) + if pos == -1 { + return "", "", false + } + return s[:pos], s[pos+1:], true +} + // ParseNodeID produces the host ID and remainder (typically an address) from // a node ID. Note that hostID may be blank. func ParseNodeID(nodeID string) (hostID string, remainder string, ok bool) { - fields := strings.SplitN(nodeID, ScopeDelim, 2) - if len(fields) != 2 { - return "", "", false - } - return fields[0], fields[1], true + return split2(nodeID, ScopeDelim) } // ParseEndpointNodeID produces the scope, address, and port and remainder. -// Note that hostID may be blank. +// Note that scope may be blank. func ParseEndpointNodeID(endpointNodeID string) (scope, address, port string, ok bool) { - fields := strings.SplitN(endpointNodeID, ScopeDelim, 3) - if len(fields) != 3 { + // Not using strings.SplitN() to avoid a heap allocation + first := strings.Index(endpointNodeID, ScopeDelim) + if first == -1 { return "", "", "", false } - - return fields[0], fields[1], fields[2], true + second := strings.Index(endpointNodeID[first+1:], ScopeDelim) + if second == -1 { + return "", "", "", false + } + return endpointNodeID[:first], endpointNodeID[first+1 : first+1+second], endpointNodeID[first+1+second+1:], true } // ParseAddressNodeID produces the host ID, address from an address node ID. func ParseAddressNodeID(addressNodeID string) (hostID, address string, ok bool) { - fields := strings.SplitN(addressNodeID, ScopeDelim, 2) - if len(fields) != 2 { - return "", "", false - } - return fields[0], fields[1], true + return split2(addressNodeID, ScopeDelim) } // ParseECSServiceNodeID produces the cluster, service name from an ECS Service node ID func ParseECSServiceNodeID(ecsServiceNodeID string) (cluster, serviceName string, ok bool) { - fields := strings.SplitN(ecsServiceNodeID, ScopeDelim, 2) - if len(fields) != 2 { + cluster, serviceName, ok = split2(ecsServiceNodeID, ScopeDelim) + if !ok { return "", "", false } // In previous versions, ECS Service node IDs were of form serviceName + "". // For backwards compatibility, we should still return a sensical serviceName for these cases. - if fields[1] == "" { - return "unknown", fields[0], true + if serviceName == "" { + return "unknown", cluster, true } - return fields[0], fields[1], true + return cluster, serviceName, true } // ExtractHostID extracts the host id from Node