Reduce map lookups in syserr

PiperOrigin-RevId: 208755352
Change-Id: Ia24630f452a4a42940ab73a8113a2fd5ea2cfca2

1 files changed, 18 insertions, 132 deletions

diff --git a/pkg/syserr/host_linux.go b/pkg/syserr/host_linux.go
index ffd78e8f8..22009a799 100644
--- a/pkg/syserr/host_linux.go
+++ b/pkg/syserr/host_linux.go
@@ -17,144 +17,30 @@
 package syserr
 
 import (
+	"fmt"
 	"syscall"
 )
 
-var linuxHostTranslations = map[syscall.Errno]*Error{
-	syscall.EPERM:           ErrNotPermitted,
-	syscall.ENOENT:          ErrNoFileOrDir,
-	syscall.ESRCH:           ErrNoProcess,
-	syscall.EINTR:           ErrInterrupted,
-	syscall.EIO:             ErrIO,
-	syscall.ENXIO:           ErrDeviceOrAddress,
-	syscall.E2BIG:           ErrTooManyArgs,
-	syscall.ENOEXEC:         ErrEcec,
-	syscall.EBADF:           ErrBadFD,
-	syscall.ECHILD:          ErrNoChild,
-	syscall.EAGAIN:          ErrTryAgain,
-	syscall.ENOMEM:          ErrNoMemory,
-	syscall.EACCES:          ErrPermissionDenied,
-	syscall.EFAULT:          ErrBadAddress,
-	syscall.ENOTBLK:         ErrNotBlockDevice,
-	syscall.EBUSY:           ErrBusy,
-	syscall.EEXIST:          ErrExists,
-	syscall.EXDEV:           ErrCrossDeviceLink,
-	syscall.ENODEV:          ErrNoDevice,
-	syscall.ENOTDIR:         ErrNotDir,
-	syscall.EISDIR:          ErrIsDir,
-	syscall.EINVAL:          ErrInvalidArgument,
-	syscall.ENFILE:          ErrFileTableOverflow,
-	syscall.EMFILE:          ErrTooManyOpenFiles,
-	syscall.ENOTTY:          ErrNotTTY,
-	syscall.ETXTBSY:         ErrTestFileBusy,
-	syscall.EFBIG:           ErrFileTooBig,
-	syscall.ENOSPC:          ErrNoSpace,
-	syscall.ESPIPE:          ErrIllegalSeek,
-	syscall.EROFS:           ErrReadOnlyFS,
-	syscall.EMLINK:          ErrTooManyLinks,
-	syscall.EPIPE:           ErrBrokenPipe,
-	syscall.EDOM:            ErrDomain,
-	syscall.ERANGE:          ErrRange,
-	syscall.EDEADLOCK:       ErrDeadlock,
-	syscall.ENAMETOOLONG:    ErrNameTooLong,
-	syscall.ENOLCK:          ErrNoLocksAvailable,
-	syscall.ENOSYS:          ErrInvalidSyscall,
-	syscall.ENOTEMPTY:       ErrDirNotEmpty,
-	syscall.ELOOP:           ErrLinkLoop,
-	syscall.ENOMSG:          ErrNoMessage,
-	syscall.EIDRM:           ErrIdentifierRemoved,
-	syscall.ECHRNG:          ErrChannelOutOfRange,
-	syscall.EL2NSYNC:        ErrLevelTwoNotSynced,
-	syscall.EL3HLT:          ErrLevelThreeHalted,
-	syscall.EL3RST:          ErrLevelThreeReset,
-	syscall.ELNRNG:          ErrLinkNumberOutOfRange,
-	syscall.EUNATCH:         ErrProtocolDriverNotAttached,
-	syscall.ENOCSI:          ErrNoCSIAvailable,
-	syscall.EL2HLT:          ErrLevelTwoHalted,
-	syscall.EBADE:           ErrInvalidExchange,
-	syscall.EBADR:           ErrInvalidRequestDescriptor,
-	syscall.EXFULL:          ErrExchangeFull,
-	syscall.ENOANO:          ErrNoAnode,
-	syscall.EBADRQC:         ErrInvalidRequestCode,
-	syscall.EBADSLT:         ErrInvalidSlot,
-	syscall.EBFONT:          ErrBadFontFile,
-	syscall.ENOSTR:          ErrNotStream,
-	syscall.ENODATA:         ErrNoDataAvailable,
-	syscall.ETIME:           ErrTimerExpired,
-	syscall.ENOSR:           ErrStreamsResourceDepleted,
-	syscall.ENONET:          ErrMachineNotOnNetwork,
-	syscall.ENOPKG:          ErrPackageNotInstalled,
-	syscall.EREMOTE:         ErrIsRemote,
-	syscall.ENOLINK:         ErrNoLink,
-	syscall.EADV:            ErrAdvertise,
-	syscall.ESRMNT:          ErrSRMount,
-	syscall.ECOMM:           ErrSendCommunication,
-	syscall.EPROTO:          ErrProtocol,
-	syscall.EMULTIHOP:       ErrMultihopAttempted,
-	syscall.EDOTDOT:         ErrRFS,
-	syscall.EBADMSG:         ErrInvalidDataMessage,
-	syscall.EOVERFLOW:       ErrOverflow,
-	syscall.ENOTUNIQ:        ErrNetworkNameNotUnique,
-	syscall.EBADFD:          ErrFDInBadState,
-	syscall.EREMCHG:         ErrRemoteAddressChanged,
-	syscall.ELIBACC:         ErrSharedLibraryInaccessible,
-	syscall.ELIBBAD:         ErrCorruptedSharedLibrary,
-	syscall.ELIBSCN:         ErrLibSectionCorrupted,
-	syscall.ELIBMAX:         ErrTooManySharedLibraries,
-	syscall.ELIBEXEC:        ErrSharedLibraryExeced,
-	syscall.EILSEQ:          ErrIllegalByteSequence,
-	syscall.ERESTART:        ErrShouldRestart,
-	syscall.ESTRPIPE:        ErrStreamPipe,
-	syscall.EUSERS:          ErrTooManyUsers,
-	syscall.ENOTSOCK:        ErrNotASocket,
-	syscall.EDESTADDRREQ:    ErrDestinationAddressRequired,
-	syscall.EMSGSIZE:        ErrMessageTooLong,
-	syscall.EPROTOTYPE:      ErrWrongProtocolForSocket,
-	syscall.ENOPROTOOPT:     ErrProtocolNotAvailable,
-	syscall.EPROTONOSUPPORT: ErrProtocolNotSupported,
-	syscall.ESOCKTNOSUPPORT: ErrSocketNotSupported,
-	syscall.EOPNOTSUPP:      ErrEndpointOperation,
-	syscall.EPFNOSUPPORT:    ErrProtocolFamilyNotSupported,
-	syscall.EAFNOSUPPORT:    ErrAddressFamilyNotSupported,
-	syscall.EADDRINUSE:      ErrAddressInUse,
-	syscall.EADDRNOTAVAIL:   ErrAddressNotAvailable,
-	syscall.ENETDOWN:        ErrNetworkDown,
-	syscall.ENETUNREACH:     ErrNetworkUnreachable,
-	syscall.ENETRESET:       ErrNetworkReset,
-	syscall.ECONNABORTED:    ErrConnectionAborted,
-	syscall.ECONNRESET:      ErrConnectionReset,
-	syscall.ENOBUFS:         ErrNoBufferSpace,
-	syscall.EISCONN:         ErrAlreadyConnected,
-	syscall.ENOTCONN:        ErrNotConnected,
-	syscall.ESHUTDOWN:       ErrShutdown,
-	syscall.ETOOMANYREFS:    ErrTooManyRefs,
-	syscall.ETIMEDOUT:       ErrTimedOut,
-	syscall.ECONNREFUSED:    ErrConnectionRefused,
-	syscall.EHOSTDOWN:       ErrHostDown,
-	syscall.EHOSTUNREACH:    ErrNoRoute,
-	syscall.EALREADY:        ErrAlreadyInProgress,
-	syscall.EINPROGRESS:     ErrInProgress,
-	syscall.ESTALE:          ErrStaleFileHandle,
-	syscall.EUCLEAN:         ErrStructureNeedsCleaning,
-	syscall.ENOTNAM:         ErrIsNamedFile,
-	syscall.EREMOTEIO:       ErrRemoteIO,
-	syscall.EDQUOT:          ErrQuotaExceeded,
-	syscall.ENOMEDIUM:       ErrNoMedium,
-	syscall.EMEDIUMTYPE:     ErrWrongMediumType,
-	syscall.ECANCELED:       ErrCanceled,
-	syscall.ENOKEY:          ErrNoKey,
-	syscall.EKEYEXPIRED:     ErrKeyExpired,
-	syscall.EKEYREVOKED:     ErrKeyRevoked,
-	syscall.EKEYREJECTED:    ErrKeyRejected,
-	syscall.EOWNERDEAD:      ErrOwnerDied,
-	syscall.ENOTRECOVERABLE: ErrNotRecoverable,
+const maxErrno = 134
+
+type linuxHostTranslation struct {
+	err *Error
+	ok  bool
 }
 
+var linuxHostTranslations [maxErrno]linuxHostTranslation
+
 // FromHost translates a syscall.Errno to a corresponding Error value.
 func FromHost(err syscall.Errno) *Error {
-	e, ok := linuxHostTranslations[err]
-	if !ok {
-		panic("Unknown host errno " + err.Error())
+	if err < 0 || int(err) >= len(linuxHostTranslations) || !linuxHostTranslations[err].ok {
+		panic(fmt.Sprintf("unknown host errno %q (%d)", err.Error(), err))
+	}
+	return linuxHostTranslations[err].err
+}
+
+func addLinuxHostTranslation(host syscall.Errno, trans *Error) {
+	if linuxHostTranslations[host].ok {
+		panic(fmt.Sprintf("duplicate translation for host errno %q (%d)", host.Error(), host))
 	}
-	return e
+	linuxHostTranslations[host] = linuxHostTranslation{err: trans, ok: true}
 }