1 files changed, 366 insertions, 0 deletions
diff --git a/vendor/github.com/wiggin77/cfg/config.go b/vendor/github.com/wiggin77/cfg/config.go
new file mode 100644
index 00000000..0e958102
--- /dev/null
+++ b/vendor/github.com/wiggin77/cfg/config.go
@@ -0,0 +1,366 @@
+package cfg
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/wiggin77/cfg/timeconv"
+)
+
+// ErrNotFound returned when an operation is attempted on a
+// resource that doesn't exist, such as fetching a non-existing
+// property name.
+var ErrNotFound = errors.New("not found")
+
+type sourceEntry struct {
+	src   Source
+	props map[string]string
+}
+
+// Config provides methods for retrieving property values from one or more
+// configuration sources.
+type Config struct {
+	mutexSrc         sync.RWMutex
+	mutexListeners   sync.RWMutex
+	srcs             []*sourceEntry
+	chgListeners     []ChangedListener
+	shutdown         chan interface{}
+	wantPanicOnError bool
+}
+
+// PrependSource inserts one or more `Sources` at the beginning of
+// the list of sources such that the first source will be the
+// source checked first when resolving a property value.
+func (config *Config) PrependSource(srcs ...Source) {
+	arr := config.wrapSources(srcs...)
+
+	config.mutexSrc.Lock()
+	if config.shutdown == nil {
+		config.shutdown = make(chan interface{})
+	}
+	config.srcs = append(arr, config.srcs...)
+	config.mutexSrc.Unlock()
+
+	for _, se := range arr {
+		if _, ok := se.src.(SourceMonitored); ok {
+			config.monitor(se)
+		}
+	}
+}
+
+// AppendSource appends one or more `Sources` at the end of
+// the list of sources such that the last source will be the
+// source checked last when resolving a property value.
+func (config *Config) AppendSource(srcs ...Source) {
+	arr := config.wrapSources(srcs...)
+
+	config.mutexSrc.Lock()
+	if config.shutdown == nil {
+		config.shutdown = make(chan interface{})
+	}
+	config.srcs = append(config.srcs, arr...)
+	config.mutexSrc.Unlock()
+
+	for _, se := range arr {
+		if _, ok := se.src.(SourceMonitored); ok {
+			config.monitor(se)
+		}
+	}
+}
+
+// wrapSources wraps one or more Source's and returns
+// them as an array of `sourceEntry`.
+func (config *Config) wrapSources(srcs ...Source) []*sourceEntry {
+	arr := make([]*sourceEntry, 0, len(srcs))
+	for _, src := range srcs {
+		se := &sourceEntry{src: src}
+		config.reloadProps(se)
+		arr = append(arr, se)
+	}
+	return arr
+}
+
+// SetWantPanicOnError sets the flag determining if Config
+// should panic when `GetProps` or `GetLastModified` errors
+// for a `Source`.
+func (config *Config) SetWantPanicOnError(b bool) {
+	config.mutexSrc.Lock()
+	config.wantPanicOnError = b
+	config.mutexSrc.Unlock()
+}
+
+// ShouldPanicOnError gets the flag determining if Config
+// should panic when `GetProps` or `GetLastModified` errors
+// for a `Source`.
+func (config *Config) ShouldPanicOnError() (b bool) {
+	config.mutexSrc.RLock()
+	b = config.wantPanicOnError
+	config.mutexSrc.RUnlock()
+	return b
+}
+
+// getProp returns the value of a named property.
+// Each `Source` is checked, in the order created by adding via
+// `AppendSource` and `PrependSource`, until a value for the
+// property is found.
+func (config *Config) getProp(name string) (val string, ok bool) {
+	config.mutexSrc.RLock()
+	defer config.mutexSrc.RUnlock()
+
+	var s string
+	for _, se := range config.srcs {
+		if se.props != nil {
+			if s, ok = se.props[name]; ok {
+				val = strings.TrimSpace(s)
+				return
+			}
+		}
+	}
+	return
+}
+
+// String returns the value of the named prop as a string.
+// If the property is not found then the supplied default `def`
+// and `ErrNotFound` are returned.
+func (config *Config) String(name string, def string) (val string, err error) {
+	if v, ok := config.getProp(name); ok {
+		val = v
+		err = nil
+		return
+	}
+
+	err = ErrNotFound
+	val = def
+	return
+}
+
+// Int returns the value of the named prop as an `int`.
+// If the property is not found then the supplied default `def`
+// and `ErrNotFound` are returned.
+//
+// See config.String
+func (config *Config) Int(name string, def int) (val int, err error) {
+	var s string
+	if s, err = config.String(name, ""); err == nil {
+		var i int64
+		if i, err = strconv.ParseInt(s, 10, 32); err == nil {
+			val = int(i)
+		}
+	}
+	if err != nil {
+		val = def
+	}
+	return
+}
+
+// Int64 returns the value of the named prop as an `int64`.
+// If the property is not found then the supplied default `def`
+// and `ErrNotFound` are returned.
+//
+// See config.String
+func (config *Config) Int64(name string, def int64) (val int64, err error) {
+	var s string
+	if s, err = config.String(name, ""); err == nil {
+		val, err = strconv.ParseInt(s, 10, 64)
+	}
+	if err != nil {
+		val = def
+	}
+	return
+}
+
+// Float64 returns the value of the named prop as a `float64`.
+// If the property is not found then the supplied default `def`
+// and `ErrNotFound` are returned.
+//
+// See config.String
+func (config *Config) Float64(name string, def float64) (val float64, err error) {
+	var s string
+	if s, err = config.String(name, ""); err == nil {
+		val, err = strconv.ParseFloat(s, 64)
+	}
+	if err != nil {
+		val = def
+	}
+	return
+}
+
+// Bool returns the value of the named prop as a `bool`.
+// If the property is not found then the supplied default `def`
+// and `ErrNotFound` are returned.
+//
+// Supports (t, true, 1, y, yes) for true, and (f, false, 0, n, no) for false,
+// all case-insensitive.
+//
+// See config.String
+func (config *Config) Bool(name string, def bool) (val bool, err error) {
+	var s string
+	if s, err = config.String(name, ""); err == nil {
+		switch strings.ToLower(s) {
+		case "t", "true", "1", "y", "yes":
+			val = true
+		case "f", "false", "0", "n", "no":
+			val = false
+		default:
+			err = errors.New("invalid syntax")
+		}
+	}
+	if err != nil {
+		val = def
+	}
+	return
+}
+
+// Duration returns the value of the named prop as a `time.Duration`, representing
+// a span of time.
+//
+// Units of measure are supported: ms, sec, min, hour, day, week, year.
+// See config.UnitsToMillis for a complete list of units supported.
+//
+// If the property is not found then the supplied default `def`
+// and `ErrNotFound` are returned.
+//
+// See config.String
+func (config *Config) Duration(name string, def time.Duration) (val time.Duration, err error) {
+	var s string
+	if s, err = config.String(name, ""); err == nil {
+		var ms int64
+		ms, err = timeconv.ParseMilliseconds(s)
+		val = time.Duration(ms) * time.Millisecond
+	}
+	if err != nil {
+		val = def
+	}
+	return
+}
+
+// AddChangedListener adds a listener that will receive notifications
+// whenever one or more property values change within the config.
+func (config *Config) AddChangedListener(l ChangedListener) {
+	config.mutexListeners.Lock()
+	defer config.mutexListeners.Unlock()
+
+	config.chgListeners = append(config.chgListeners, l)
+}
+
+// RemoveChangedListener removes all instances of a ChangedListener.
+// Returns `ErrNotFound` if the listener was not present.
+func (config *Config) RemoveChangedListener(l ChangedListener) error {
+	config.mutexListeners.Lock()
+	defer config.mutexListeners.Unlock()
+
+	dest := make([]ChangedListener, 0, len(config.chgListeners))
+	err := ErrNotFound
+
+	// Remove all instances of the listener by
+	// copying list while filtering.
+	for _, s := range config.chgListeners {
+		if s != l {
+			dest = append(dest, s)
+		} else {
+			err = nil
+		}
+	}
+	config.chgListeners = dest
+	return err
+}
+
+// Shutdown can be called to stop monitoring of all config sources.
+func (config *Config) Shutdown() {
+	config.mutexSrc.RLock()
+	defer config.mutexSrc.RUnlock()
+	if config.shutdown != nil {
+		close(config.shutdown)
+	}
+}
+
+// onSourceChanged is called whenever one or more properties of a
+// config source has changed.
+func (config *Config) onSourceChanged(src SourceMonitored) {
+	defer func() {
+		if p := recover(); p != nil {
+			fmt.Println(p)
+		}
+	}()
+	config.mutexListeners.RLock()
+	defer config.mutexListeners.RUnlock()
+	for _, l := range config.chgListeners {
+		l.ConfigChanged(config, src)
+	}
+}
+
+// monitor periodically checks a config source for changes.
+func (config *Config) monitor(se *sourceEntry) {
+	go func(se *sourceEntry, shutdown <-chan interface{}) {
+		var src SourceMonitored
+		var ok bool
+		if src, ok = se.src.(SourceMonitored); !ok {
+			return
+		}
+		paused := false
+		last := time.Time{}
+		freq := src.GetMonitorFreq()
+		if freq <= 0 {
+			paused = true
+			freq = 10
+			last, _ = src.GetLastModified()
+		}
+		timer := time.NewTimer(freq)
+		for {
+			select {
+			case <-timer.C:
+				if !paused {
+					if latest, err := src.GetLastModified(); err != nil {
+						if config.ShouldPanicOnError() {
+							panic(fmt.Sprintf("error <%v> getting last modified for %v", err, src))
+						}
+					} else {
+						if last.Before(latest) {
+							last = latest
+							config.reloadProps(se)
+							// TODO: calc diff and provide detailed changes
+							config.onSourceChanged(src)
+						}
+					}
+				}
+				freq = src.GetMonitorFreq()
+				if freq <= 0 {
+					paused = true
+					freq = 10
+				} else {
+					paused = false
+				}
+				timer.Reset(freq)
+			case <-shutdown:
+				// stop the timer and exit
+				if !timer.Stop() {
+					<-timer.C
+				}
+				return
+			}
+		}
+	}(se, config.shutdown)
+}
+
+// reloadProps causes a Source to reload its properties.
+func (config *Config) reloadProps(se *sourceEntry) {
+	config.mutexSrc.Lock()
+	defer config.mutexSrc.Unlock()
+
+	m, err := se.src.GetProps()
+	if err != nil {
+		if config.wantPanicOnError {
+			panic(fmt.Sprintf("GetProps error for %v", se.src))
+		}
+		return
+	}
+
+	se.props = make(map[string]string)
+	for k, v := range m {
+		se.props[k] = v
+	}
+}