Import of https://github.com/ciena/voltctl at commit 40d61fbf3f910ed4017cf67c9c79e8e1f82a33a5

Change-Id: I8464c59e60d76cb8612891db3303878975b5416c
diff --git a/vendor/github.com/davecgh/go-spew/spew/dump.go b/vendor/github.com/davecgh/go-spew/spew/dump.go
new file mode 100644
index 0000000..f78d89f
--- /dev/null
+++ b/vendor/github.com/davecgh/go-spew/spew/dump.go
@@ -0,0 +1,509 @@
+/*
+ * Copyright (c) 2013-2016 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package spew
+
+import (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var (
+	// uint8Type is a reflect.Type representing a uint8.  It is used to
+	// convert cgo types to uint8 slices for hexdumping.
+	uint8Type = reflect.TypeOf(uint8(0))
+
+	// cCharRE is a regular expression that matches a cgo char.
+	// It is used to detect character arrays to hexdump them.
+	cCharRE = regexp.MustCompile(`^.*\._Ctype_char$`)
+
+	// cUnsignedCharRE is a regular expression that matches a cgo unsigned
+	// char.  It is used to detect unsigned character arrays to hexdump
+	// them.
+	cUnsignedCharRE = regexp.MustCompile(`^.*\._Ctype_unsignedchar$`)
+
+	// cUint8tCharRE is a regular expression that matches a cgo uint8_t.
+	// It is used to detect uint8_t arrays to hexdump them.
+	cUint8tCharRE = regexp.MustCompile(`^.*\._Ctype_uint8_t$`)
+)
+
+// dumpState contains information about the state of a dump operation.
+type dumpState struct {
+	w                io.Writer
+	depth            int
+	pointers         map[uintptr]int
+	ignoreNextType   bool
+	ignoreNextIndent bool
+	cs               *ConfigState
+}
+
+// indent performs indentation according to the depth level and cs.Indent
+// option.
+func (d *dumpState) indent() {
+	if d.ignoreNextIndent {
+		d.ignoreNextIndent = false
+		return
+	}
+	d.w.Write(bytes.Repeat([]byte(d.cs.Indent), d.depth))
+}
+
+// unpackValue returns values inside of non-nil interfaces when possible.
+// This is useful for data types like structs, arrays, slices, and maps which
+// can contain varying types packed inside an interface.
+func (d *dumpState) unpackValue(v reflect.Value) reflect.Value {
+	if v.Kind() == reflect.Interface && !v.IsNil() {
+		v = v.Elem()
+	}
+	return v
+}
+
+// dumpPtr handles formatting of pointers by indirecting them as necessary.
+func (d *dumpState) dumpPtr(v reflect.Value) {
+	// Remove pointers at or below the current depth from map used to detect
+	// circular refs.
+	for k, depth := range d.pointers {
+		if depth >= d.depth {
+			delete(d.pointers, k)
+		}
+	}
+
+	// Keep list of all dereferenced pointers to show later.
+	pointerChain := make([]uintptr, 0)
+
+	// Figure out how many levels of indirection there are by dereferencing
+	// pointers and unpacking interfaces down the chain while detecting circular
+	// references.
+	nilFound := false
+	cycleFound := false
+	indirects := 0
+	ve := v
+	for ve.Kind() == reflect.Ptr {
+		if ve.IsNil() {
+			nilFound = true
+			break
+		}
+		indirects++
+		addr := ve.Pointer()
+		pointerChain = append(pointerChain, addr)
+		if pd, ok := d.pointers[addr]; ok && pd < d.depth {
+			cycleFound = true
+			indirects--
+			break
+		}
+		d.pointers[addr] = d.depth
+
+		ve = ve.Elem()
+		if ve.Kind() == reflect.Interface {
+			if ve.IsNil() {
+				nilFound = true
+				break
+			}
+			ve = ve.Elem()
+		}
+	}
+
+	// Display type information.
+	d.w.Write(openParenBytes)
+	d.w.Write(bytes.Repeat(asteriskBytes, indirects))
+	d.w.Write([]byte(ve.Type().String()))
+	d.w.Write(closeParenBytes)
+
+	// Display pointer information.
+	if !d.cs.DisablePointerAddresses && len(pointerChain) > 0 {
+		d.w.Write(openParenBytes)
+		for i, addr := range pointerChain {
+			if i > 0 {
+				d.w.Write(pointerChainBytes)
+			}
+			printHexPtr(d.w, addr)
+		}
+		d.w.Write(closeParenBytes)
+	}
+
+	// Display dereferenced value.
+	d.w.Write(openParenBytes)
+	switch {
+	case nilFound:
+		d.w.Write(nilAngleBytes)
+
+	case cycleFound:
+		d.w.Write(circularBytes)
+
+	default:
+		d.ignoreNextType = true
+		d.dump(ve)
+	}
+	d.w.Write(closeParenBytes)
+}
+
+// dumpSlice handles formatting of arrays and slices.  Byte (uint8 under
+// reflection) arrays and slices are dumped in hexdump -C fashion.
+func (d *dumpState) dumpSlice(v reflect.Value) {
+	// Determine whether this type should be hex dumped or not.  Also,
+	// for types which should be hexdumped, try to use the underlying data
+	// first, then fall back to trying to convert them to a uint8 slice.
+	var buf []uint8
+	doConvert := false
+	doHexDump := false
+	numEntries := v.Len()
+	if numEntries > 0 {
+		vt := v.Index(0).Type()
+		vts := vt.String()
+		switch {
+		// C types that need to be converted.
+		case cCharRE.MatchString(vts):
+			fallthrough
+		case cUnsignedCharRE.MatchString(vts):
+			fallthrough
+		case cUint8tCharRE.MatchString(vts):
+			doConvert = true
+
+		// Try to use existing uint8 slices and fall back to converting
+		// and copying if that fails.
+		case vt.Kind() == reflect.Uint8:
+			// We need an addressable interface to convert the type
+			// to a byte slice.  However, the reflect package won't
+			// give us an interface on certain things like
+			// unexported struct fields in order to enforce
+			// visibility rules.  We use unsafe, when available, to
+			// bypass these restrictions since this package does not
+			// mutate the values.
+			vs := v
+			if !vs.CanInterface() || !vs.CanAddr() {
+				vs = unsafeReflectValue(vs)
+			}
+			if !UnsafeDisabled {
+				vs = vs.Slice(0, numEntries)
+
+				// Use the existing uint8 slice if it can be
+				// type asserted.
+				iface := vs.Interface()
+				if slice, ok := iface.([]uint8); ok {
+					buf = slice
+					doHexDump = true
+					break
+				}
+			}
+
+			// The underlying data needs to be converted if it can't
+			// be type asserted to a uint8 slice.
+			doConvert = true
+		}
+
+		// Copy and convert the underlying type if needed.
+		if doConvert && vt.ConvertibleTo(uint8Type) {
+			// Convert and copy each element into a uint8 byte
+			// slice.
+			buf = make([]uint8, numEntries)
+			for i := 0; i < numEntries; i++ {
+				vv := v.Index(i)
+				buf[i] = uint8(vv.Convert(uint8Type).Uint())
+			}
+			doHexDump = true
+		}
+	}
+
+	// Hexdump the entire slice as needed.
+	if doHexDump {
+		indent := strings.Repeat(d.cs.Indent, d.depth)
+		str := indent + hex.Dump(buf)
+		str = strings.Replace(str, "\n", "\n"+indent, -1)
+		str = strings.TrimRight(str, d.cs.Indent)
+		d.w.Write([]byte(str))
+		return
+	}
+
+	// Recursively call dump for each item.
+	for i := 0; i < numEntries; i++ {
+		d.dump(d.unpackValue(v.Index(i)))
+		if i < (numEntries - 1) {
+			d.w.Write(commaNewlineBytes)
+		} else {
+			d.w.Write(newlineBytes)
+		}
+	}
+}
+
+// dump is the main workhorse for dumping a value.  It uses the passed reflect
+// value to figure out what kind of object we are dealing with and formats it
+// appropriately.  It is a recursive function, however circular data structures
+// are detected and handled properly.
+func (d *dumpState) dump(v reflect.Value) {
+	// Handle invalid reflect values immediately.
+	kind := v.Kind()
+	if kind == reflect.Invalid {
+		d.w.Write(invalidAngleBytes)
+		return
+	}
+
+	// Handle pointers specially.
+	if kind == reflect.Ptr {
+		d.indent()
+		d.dumpPtr(v)
+		return
+	}
+
+	// Print type information unless already handled elsewhere.
+	if !d.ignoreNextType {
+		d.indent()
+		d.w.Write(openParenBytes)
+		d.w.Write([]byte(v.Type().String()))
+		d.w.Write(closeParenBytes)
+		d.w.Write(spaceBytes)
+	}
+	d.ignoreNextType = false
+
+	// Display length and capacity if the built-in len and cap functions
+	// work with the value's kind and the len/cap itself is non-zero.
+	valueLen, valueCap := 0, 0
+	switch v.Kind() {
+	case reflect.Array, reflect.Slice, reflect.Chan:
+		valueLen, valueCap = v.Len(), v.Cap()
+	case reflect.Map, reflect.String:
+		valueLen = v.Len()
+	}
+	if valueLen != 0 || !d.cs.DisableCapacities && valueCap != 0 {
+		d.w.Write(openParenBytes)
+		if valueLen != 0 {
+			d.w.Write(lenEqualsBytes)
+			printInt(d.w, int64(valueLen), 10)
+		}
+		if !d.cs.DisableCapacities && valueCap != 0 {
+			if valueLen != 0 {
+				d.w.Write(spaceBytes)
+			}
+			d.w.Write(capEqualsBytes)
+			printInt(d.w, int64(valueCap), 10)
+		}
+		d.w.Write(closeParenBytes)
+		d.w.Write(spaceBytes)
+	}
+
+	// Call Stringer/error interfaces if they exist and the handle methods flag
+	// is enabled
+	if !d.cs.DisableMethods {
+		if (kind != reflect.Invalid) && (kind != reflect.Interface) {
+			if handled := handleMethods(d.cs, d.w, v); handled {
+				return
+			}
+		}
+	}
+
+	switch kind {
+	case reflect.Invalid:
+		// Do nothing.  We should never get here since invalid has already
+		// been handled above.
+
+	case reflect.Bool:
+		printBool(d.w, v.Bool())
+
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		printInt(d.w, v.Int(), 10)
+
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint:
+		printUint(d.w, v.Uint(), 10)
+
+	case reflect.Float32:
+		printFloat(d.w, v.Float(), 32)
+
+	case reflect.Float64:
+		printFloat(d.w, v.Float(), 64)
+
+	case reflect.Complex64:
+		printComplex(d.w, v.Complex(), 32)
+
+	case reflect.Complex128:
+		printComplex(d.w, v.Complex(), 64)
+
+	case reflect.Slice:
+		if v.IsNil() {
+			d.w.Write(nilAngleBytes)
+			break
+		}
+		fallthrough
+
+	case reflect.Array:
+		d.w.Write(openBraceNewlineBytes)
+		d.depth++
+		if (d.cs.MaxDepth != 0) && (d.depth > d.cs.MaxDepth) {
+			d.indent()
+			d.w.Write(maxNewlineBytes)
+		} else {
+			d.dumpSlice(v)
+		}
+		d.depth--
+		d.indent()
+		d.w.Write(closeBraceBytes)
+
+	case reflect.String:
+		d.w.Write([]byte(strconv.Quote(v.String())))
+
+	case reflect.Interface:
+		// The only time we should get here is for nil interfaces due to
+		// unpackValue calls.
+		if v.IsNil() {
+			d.w.Write(nilAngleBytes)
+		}
+
+	case reflect.Ptr:
+		// Do nothing.  We should never get here since pointers have already
+		// been handled above.
+
+	case reflect.Map:
+		// nil maps should be indicated as different than empty maps
+		if v.IsNil() {
+			d.w.Write(nilAngleBytes)
+			break
+		}
+
+		d.w.Write(openBraceNewlineBytes)
+		d.depth++
+		if (d.cs.MaxDepth != 0) && (d.depth > d.cs.MaxDepth) {
+			d.indent()
+			d.w.Write(maxNewlineBytes)
+		} else {
+			numEntries := v.Len()
+			keys := v.MapKeys()
+			if d.cs.SortKeys {
+				sortValues(keys, d.cs)
+			}
+			for i, key := range keys {
+				d.dump(d.unpackValue(key))
+				d.w.Write(colonSpaceBytes)
+				d.ignoreNextIndent = true
+				d.dump(d.unpackValue(v.MapIndex(key)))
+				if i < (numEntries - 1) {
+					d.w.Write(commaNewlineBytes)
+				} else {
+					d.w.Write(newlineBytes)
+				}
+			}
+		}
+		d.depth--
+		d.indent()
+		d.w.Write(closeBraceBytes)
+
+	case reflect.Struct:
+		d.w.Write(openBraceNewlineBytes)
+		d.depth++
+		if (d.cs.MaxDepth != 0) && (d.depth > d.cs.MaxDepth) {
+			d.indent()
+			d.w.Write(maxNewlineBytes)
+		} else {
+			vt := v.Type()
+			numFields := v.NumField()
+			for i := 0; i < numFields; i++ {
+				d.indent()
+				vtf := vt.Field(i)
+				d.w.Write([]byte(vtf.Name))
+				d.w.Write(colonSpaceBytes)
+				d.ignoreNextIndent = true
+				d.dump(d.unpackValue(v.Field(i)))
+				if i < (numFields - 1) {
+					d.w.Write(commaNewlineBytes)
+				} else {
+					d.w.Write(newlineBytes)
+				}
+			}
+		}
+		d.depth--
+		d.indent()
+		d.w.Write(closeBraceBytes)
+
+	case reflect.Uintptr:
+		printHexPtr(d.w, uintptr(v.Uint()))
+
+	case reflect.UnsafePointer, reflect.Chan, reflect.Func:
+		printHexPtr(d.w, v.Pointer())
+
+	// There were not any other types at the time this code was written, but
+	// fall back to letting the default fmt package handle it in case any new
+	// types are added.
+	default:
+		if v.CanInterface() {
+			fmt.Fprintf(d.w, "%v", v.Interface())
+		} else {
+			fmt.Fprintf(d.w, "%v", v.String())
+		}
+	}
+}
+
+// fdump is a helper function to consolidate the logic from the various public
+// methods which take varying writers and config states.
+func fdump(cs *ConfigState, w io.Writer, a ...interface{}) {
+	for _, arg := range a {
+		if arg == nil {
+			w.Write(interfaceBytes)
+			w.Write(spaceBytes)
+			w.Write(nilAngleBytes)
+			w.Write(newlineBytes)
+			continue
+		}
+
+		d := dumpState{w: w, cs: cs}
+		d.pointers = make(map[uintptr]int)
+		d.dump(reflect.ValueOf(arg))
+		d.w.Write(newlineBytes)
+	}
+}
+
+// Fdump formats and displays the passed arguments to io.Writer w.  It formats
+// exactly the same as Dump.
+func Fdump(w io.Writer, a ...interface{}) {
+	fdump(&Config, w, a...)
+}
+
+// Sdump returns a string with the passed arguments formatted exactly the same
+// as Dump.
+func Sdump(a ...interface{}) string {
+	var buf bytes.Buffer
+	fdump(&Config, &buf, a...)
+	return buf.String()
+}
+
+/*
+Dump displays the passed parameters to standard out with newlines, customizable
+indentation, and additional debug information such as complete types and all
+pointer addresses used to indirect to the final value.  It provides the
+following features over the built-in printing facilities provided by the fmt
+package:
+
+	* Pointers are dereferenced and followed
+	* Circular data structures are detected and handled properly
+	* Custom Stringer/error interfaces are optionally invoked, including
+	  on unexported types
+	* Custom types which only implement the Stringer/error interfaces via
+	  a pointer receiver are optionally invoked when passing non-pointer
+	  variables
+	* Byte arrays and slices are dumped like the hexdump -C command which
+	  includes offsets, byte values in hex, and ASCII output
+
+The configuration options are controlled by an exported package global,
+spew.Config.  See ConfigState for options documentation.
+
+See Fdump if you would prefer dumping to an arbitrary io.Writer or Sdump to
+get the formatted result as a string.
+*/
+func Dump(a ...interface{}) {
+	fdump(&Config, os.Stdout, a...)
+}