Documentation
¶
Overview ¶
Package x contains some very common utilities used by Dgraph. These utilities are of "miscellaneous" nature, e.g., error checking.
Index ¶
- Constants
- Variables
- func AddInit(f func())
- func AssertTrue(b bool)
- func AssertTruef(b bool, format string, args ...interface{})
- func Check(err error)
- func Check2(_ interface{}, err error)
- func Check2f(_ interface{}, err error, format string, args ...interface{})
- func Checkf(err error, format string, args ...interface{})
- func DataKey(attr string, uid uint64) []byte
- func Err(entry *logrus.Entry, err error) *logrus.Entry
- func Errorf(format string, args ...interface{}) error
- func Fatalf(format string, args ...interface{})
- func IndexKey(attr, term string) []byte
- func Init()
- func IsTestRun() bool
- func Log(p string) *logrus.Entry
- func ParseRequest(w http.ResponseWriter, r *http.Request, data interface{}) bool
- func Printf(format string, args ...interface{})
- func ReadLine(r *bufio.Reader, buf *bytes.Buffer) error
- func Reply(w http.ResponseWriter, rep interface{})
- func ReverseKey(attr string, uid uint64) []byte
- func SetError(prev *error, n error)
- func SetStatus(w http.ResponseWriter, code, msg string)
- func SetTestRun()
- func Trace(ctx context.Context, format string, args ...interface{})
- func TraceError(ctx context.Context, err error)
- func Wrap(err error) error
- func Wrapf(err error, format string, args ...interface{}) error
- type Mark
- type ParsedKey
- type RaftValue
- type SafeMutex
- type SafeWait
- type Status
- type WaterMark
Constants ¶
const ( Success = "Success" ErrorInvalidMethod = "ErrorInvalidMethod" ErrorInvalidRequest = "ErrorInvalidRequest" ErrorMissingRequired = "ErrorMissingRequired" Error = "Error" ErrorNoData = "ErrorNoData" ErrorUptodate = "ErrorUptodate" ErrorNoPermission = "ErrorNoPermission" ErrorInvalidMutation = "ErrorInvalidMutation" )
Error constants representing different types of errors.
Variables ¶
var Nilbyte []byte
var WhiteSpace = strings.NewReplacer(" ", "", "\t", "")
WhiteSpace Replacer removes spaces and tabs from a string.
Functions ¶
func AddInit ¶
func AddInit(f func())
AddInit adds a function to be run in x.Init, which should be called at the beginning of all mains.
func AssertTrue ¶
func AssertTrue(b bool)
AssertTrue asserts that b is true. Otherwise, it would log fatal.
func AssertTruef ¶
AssertTruef is AssertTrue with extra info.
func Check2 ¶
func Check2(_ interface{}, err error)
Check2 acts as convenience wrapper around Check, using the 2nd argument as error.
func ParseRequest ¶
func ParseRequest(w http.ResponseWriter, r *http.Request, data interface{}) bool
func Printf ¶
func Printf(format string, args ...interface{})
Printf does a log.Printf. We often do printf for debugging but has to keep adding import "fmt" or "log" and removing them after we are done. Let's add Printf to "x" and include "x" almost everywhere. Caution: Do remember to call x.Init. For tests, you need a TestMain that calls x.Init.
func ReadLine ¶
Reads a single line from a buffered reader. The line is read into the passed in buffer to minimize allocations. This is the preferred method for loading long lines which could be longer than the buffer size of bufio.Scanner.
func Reply ¶
func Reply(w http.ResponseWriter, rep interface{})
func ReverseKey ¶
func SetStatus ¶
func SetStatus(w http.ResponseWriter, code, msg string)
SetStatus sets the error code, message and the newly assigned uids in the http response.
func SetTestRun ¶
func SetTestRun()
func TraceError ¶
TraceError is like Trace but it logs just an error, which may have stacktrace.
Types ¶
type Mark ¶
type Mark struct {
Index uint64
Indices []uint64
Done bool // Set to true if the pending mutation is done.
}
Mark contains raft proposal id and a done boolean. It is used to update the WaterMark struct about the status of a proposal.
type ParsedKey ¶
type ParsedKey struct {
Attr string
Uid uint64
Term string
// contains filtered or unexported fields
}
func (ParsedKey) DataPrefix ¶
DataPrefix returns the prefix for data keys.
func (ParsedKey) IndexPrefix ¶
IndexPrefix returns the prefix for index keys.
func (ParsedKey) SkipPredicate ¶
func (ParsedKey) SkipRangeOfSameType ¶
type RaftValue ¶
RaftValue contains the raft group and the raft proposal id. This is attached to the context, so the information could be passed down to the many posting lists, involved in mutations.
type SafeMutex ¶
type SafeMutex struct {
// contains filtered or unexported fields
}
SafeLock can be used in place of sync.RWMutex
func (*SafeMutex) AssertLock ¶
func (s *SafeMutex) AssertLock()
func (*SafeMutex) AssertRLock ¶
func (s *SafeMutex) AssertRLock()
type WaterMark ¶
WaterMark is used to keep track of the maximum done index. The right way to use this is to send a Mark with Done set to false, as soon as an index is known. WaterMark will store the index in a min-heap. It would only advance, if the minimum entry in the heap has been successfully done.
Some time later, when this index task is completed, send another Mark, this time with Done set to true. It would mark the index as done, and so the min-heap can now advance and update the maximum done water mark.
func (*WaterMark) Init ¶
func (w *WaterMark) Init()
Init initializes a WaterMark struct. MUST be called before using it.
func (*WaterMark) WaitingFor ¶
WaitingFor returns whether we are waiting for a task to be done.
Source Files