From 4bec8f23c6ea21bf4aafc1fcd52448a0c9988b3b Mon Sep 17 00:00:00 2001 From: Gina Yeh Date: Fri, 9 Jun 2023 09:39:02 -0700 Subject: [PATCH] cleanup - wrap block comments @ 80 columns --- internal/resolver/dns/dns_resolver.go | 62 ++++++++++++++++----------- 1 file changed, 37 insertions(+), 25 deletions(-) diff --git a/internal/resolver/dns/dns_resolver.go b/internal/resolver/dns/dns_resolver.go index 5fe4a1d83c1..99e1e5b36c8 100644 --- a/internal/resolver/dns/dns_resolver.go +++ b/internal/resolver/dns/dns_resolver.go @@ -62,7 +62,8 @@ const ( defaultPort = "443" defaultDNSSvrPort = "53" golang = "GO" - // txtPrefix is the prefix string to be prepended to the host name for txt record lookup. + // txtPrefix is the prefix string to be prepended to the host name for txt + // record lookup. txtPrefix = "_grpc_config." // In DNS, service config is encoded in a TXT record via the mechanism // described in RFC-1464 using the attribute name grpc_config. @@ -114,7 +115,8 @@ func NewBuilder() resolver.Builder { type dnsBuilder struct{} -// Build creates and starts a DNS resolver that watches the name resolution of the target. +// Build creates and starts a DNS resolver that watches the name resolution of +// the target. func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) { host, port, err := parseTarget(target.Endpoint(), defaultPort) if err != nil { @@ -180,19 +182,22 @@ type dnsResolver struct { ctx context.Context cancel context.CancelFunc cc resolver.ClientConn - // rn channel is used by ResolveNow() to force an immediate resolution of the target. + // rn channel is used by ResolveNow() to force an immediate resolution of the + // target. rn chan struct{} - // wg is used to enforce Close() to return after the watcher() goroutine has finished. - // Otherwise, data race will be possible. [Race Example] in dns_resolver_test we - // replace the real lookup functions with mocked ones to facilitate testing. - // If Close() doesn't wait for watcher() goroutine finishes, race detector sometimes - // will warns lookup (READ the lookup function pointers) inside watcher() goroutine - // has data race with replaceNetFunc (WRITE the lookup function pointers). + // wg is used to enforce Close() to return after the watcher() goroutine has + // finished. Otherwise, data race will be possible. [Race Example] in + // dns_resolver_test we replace the real lookup functions with mocked ones to + // facilitate testing. If Close() doesn't wait for watcher() goroutine + // finishes, race detector sometimes will warns lookup (READ the lookup + // function pointers) inside watcher() goroutine has data race with + // replaceNetFunc (WRITE the lookup function pointers). wg sync.WaitGroup disableServiceConfig bool } -// ResolveNow invoke an immediate resolution of the target that this dnsResolver watches. +// ResolveNow invoke an immediate resolution of the target that this +// dnsResolver watches. func (d *dnsResolver) ResolveNow(resolver.ResolveNowOptions) { select { case d.rn <- struct{}{}: @@ -220,8 +225,8 @@ func (d *dnsResolver) watcher() { var timer *time.Timer if err == nil { - // Success resolving, wait for the next ResolveNow. However, also wait 30 seconds at the very least - // to prevent constantly re-resolving. + // Success resolving, wait for the next ResolveNow. However, also wait 30 + // seconds at the very least to prevent constantly re-resolving. backoffIndex = 1 timer = newTimerDNSResRate(minDNSResRate) select { @@ -231,7 +236,8 @@ func (d *dnsResolver) watcher() { case <-d.rn: } } else { - // Poll on an error found in DNS Resolver or an error received from ClientConn. + // Poll on an error found in DNS Resolver or an error received from + // ClientConn. timer = newTimer(backoff.DefaultExponential.Backoff(backoffIndex)) backoffIndex++ } @@ -278,7 +284,8 @@ func (d *dnsResolver) lookupSRV() ([]resolver.Address, error) { } func handleDNSError(err error, lookupType string) error { - if dnsErr, ok := err.(*net.DNSError); ok && !dnsErr.IsTimeout && !dnsErr.IsTemporary { + dnsErr, ok := err.(*net.DNSError) + if ok && !dnsErr.IsTimeout && !dnsErr.IsTemporary { // Timeouts and temporary errors should be communicated to gRPC to // attempt another DNS query (with backoff). Other errors should be // suppressed (they may represent the absence of a TXT record). @@ -307,10 +314,12 @@ func (d *dnsResolver) lookupTXT() *serviceconfig.ParseResult { res += s } - // TXT record must have "grpc_config=" attribute in order to be used as service config. + // TXT record must have "grpc_config=" attribute in order to be used as + // service config. if !strings.HasPrefix(res, txtAttribute) { logger.Warningf("dns: TXT record %v missing %v attribute", res, txtAttribute) - // This is not an error; it is the equivalent of not having a service config. + // This is not an error; it is the equivalent of not having a service + // config. return nil } sc := canaryingSC(strings.TrimPrefix(res, txtAttribute)) @@ -352,9 +361,10 @@ func (d *dnsResolver) lookup() (*resolver.State, error) { return &state, nil } -// formatIP returns ok = false if addr is not a valid textual representation of an IP address. -// If addr is an IPv4 address, return the addr and ok = true. -// If addr is an IPv6 address, return the addr enclosed in square brackets and ok = true. +// formatIP returns ok = false if addr is not a valid textual representation of +// an IP address. If addr is an IPv4 address, return the addr and ok = true. +// If addr is an IPv6 address, return the addr enclosed in square brackets and +// ok = true. func formatIP(addr string) (addrIP string, ok bool) { ip := net.ParseIP(addr) if ip == nil { @@ -366,10 +376,10 @@ func formatIP(addr string) (addrIP string, ok bool) { return "[" + addr + "]", true } -// parseTarget takes the user input target string and default port, returns formatted host and port info. -// If target doesn't specify a port, set the port to be the defaultPort. -// If target is in IPv6 format and host-name is enclosed in square brackets, brackets -// are stripped when setting the host. +// parseTarget takes the user input target string and default port, returns +// formatted host and port info. If target doesn't specify a port, set the port +// to be the defaultPort. If target is in IPv6 format and host-name is enclosed +// in square brackets, brackets are stripped when setting the host. // examples: // target: "www.google.com" defaultPort: "443" returns host: "www.google.com", port: "443" // target: "ipv4-host:80" defaultPort: "443" returns host: "ipv4-host", port: "80" @@ -385,12 +395,14 @@ func parseTarget(target, defaultPort string) (host, port string, err error) { } if host, port, err = net.SplitHostPort(target); err == nil { if port == "" { - // If the port field is empty (target ends with colon), e.g. "[::1]:", this is an error. + // If the port field is empty (target ends with colon), e.g. "[::1]:", + // this is an error. return "", "", errEndsWithColon } // target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port if host == "" { - // Keep consistent with net.Dial(): If the host is empty, as in ":80", the local system is assumed. + // Keep consistent with net.Dial(): If the host is empty, as in ":80", + // the local system is assumed. host = "localhost" } return host, port, nil