ref: 7ad721fd78b473ae7d9b05418bb029c51d1d9251
dir: /helpers/general.go/
// Copyright 2015 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package helpers
import (
"bytes"
"crypto/md5"
"encoding/hex"
"errors"
"fmt"
"io"
"net"
"path/filepath"
"reflect"
"strings"
"sync"
"unicode"
"unicode/utf8"
"github.com/spf13/cast"
bp "github.com/spf13/hugo/bufferpool"
jww "github.com/spf13/jwalterweatherman"
"github.com/spf13/pflag"
)
// FilePathSeparator as defined by os.Separator.
const FilePathSeparator = string(filepath.Separator)
// Strips carriage returns from third-party / external processes (useful for Windows)
func normalizeExternalHelperLineFeeds(content []byte) []byte {
return bytes.Replace(content, []byte("\r"), []byte(""), -1)
}
// FindAvailablePort returns an available and valid TCP port.
func FindAvailablePort() (*net.TCPAddr, error) {
l, err := net.Listen("tcp", ":0")
if err == nil {
defer l.Close()
addr := l.Addr()
if a, ok := addr.(*net.TCPAddr); ok {
return a, nil
}
return nil, fmt.Errorf("Unable to obtain a valid tcp port. %v", addr)
}
return nil, err
}
// InStringArray checks if a string is an element of a slice of strings
// and returns a boolean value.
func InStringArray(arr []string, el string) bool {
for _, v := range arr {
if v == el {
return true
}
}
return false
}
// GuessType attempts to guess the type of file from a given string.
func GuessType(in string) string {
switch strings.ToLower(in) {
case "md", "markdown", "mdown":
return "markdown"
case "asciidoc", "adoc", "ad":
return "asciidoc"
case "mmark":
return "mmark"
case "rst":
return "rst"
case "html", "htm":
return "html"
case "org":
return "org"
}
return "unknown"
}
// FirstUpper returns a string with the first character as upper case.
func FirstUpper(s string) string {
if s == "" {
return ""
}
r, n := utf8.DecodeRuneInString(s)
return string(unicode.ToUpper(r)) + s[n:]
}
// UniqueStrings returns a new slice with any duplicates removed.
func UniqueStrings(s []string) []string {
var unique []string
set := map[string]interface{}{}
for _, val := range s {
if _, ok := set[val]; !ok {
unique = append(unique, val)
set[val] = val
}
}
return unique
}
// ReaderToBytes takes an io.Reader argument, reads from it
// and returns bytes.
func ReaderToBytes(lines io.Reader) []byte {
if lines == nil {
return []byte{}
}
b := bp.GetBuffer()
defer bp.PutBuffer(b)
b.ReadFrom(lines)
bc := make([]byte, b.Len(), b.Len())
copy(bc, b.Bytes())
return bc
}
// ToLowerMap makes all the keys in the given map lower cased and will do so
// recursively.
// Notes:
// * This will modify the map given.
// * Any nested map[interface{}]interface{} will be converted to map[string]interface{}.
func ToLowerMap(m map[string]interface{}) {
for k, v := range m {
switch v.(type) {
case map[interface{}]interface{}:
v = cast.ToStringMap(v)
ToLowerMap(v.(map[string]interface{}))
case map[string]interface{}:
ToLowerMap(v.(map[string]interface{}))
}
lKey := strings.ToLower(k)
if k != lKey {
delete(m, k)
m[lKey] = v
}
}
}
// ReaderToString is the same as ReaderToBytes, but returns a string.
func ReaderToString(lines io.Reader) string {
if lines == nil {
return ""
}
b := bp.GetBuffer()
defer bp.PutBuffer(b)
b.ReadFrom(lines)
return b.String()
}
// ReaderContains reports whether subslice is within r.
func ReaderContains(r io.Reader, subslice []byte) bool {
if r == nil || len(subslice) == 0 {
return false
}
bufflen := len(subslice) * 4
halflen := bufflen / 2
buff := make([]byte, bufflen)
var err error
var n, i int
for {
i++
if i == 1 {
n, err = io.ReadAtLeast(r, buff[:halflen], halflen)
} else {
if i != 2 {
// shift left to catch overlapping matches
copy(buff[:], buff[halflen:])
}
n, err = io.ReadAtLeast(r, buff[halflen:], halflen)
}
if n > 0 && bytes.Contains(buff, subslice) {
return true
}
if err != nil {
break
}
}
return false
}
// ThemeSet checks whether a theme is in use or not.
func (p *PathSpec) ThemeSet() bool {
return p.theme != ""
}
type logPrinter interface {
// Println is the only common method that works in all of JWWs loggers.
Println(a ...interface{})
}
// DistinctLogger ignores duplicate log statements.
type DistinctLogger struct {
sync.RWMutex
logger logPrinter
m map[string]bool
}
// Println will log the string returned from fmt.Sprintln given the arguments,
// but not if it has been logged before.
func (l *DistinctLogger) Println(v ...interface{}) {
// fmt.Sprint doesn't add space between string arguments
logStatement := strings.TrimSpace(fmt.Sprintln(v...))
l.print(logStatement)
}
// Printf will log the string returned from fmt.Sprintf given the arguments,
// but not if it has been logged before.
// Note: A newline is appended.
func (l *DistinctLogger) Printf(format string, v ...interface{}) {
logStatement := fmt.Sprintf(format, v...)
l.print(logStatement)
}
func (l *DistinctLogger) print(logStatement string) {
l.RLock()
if l.m[logStatement] {
l.RUnlock()
return
}
l.RUnlock()
l.Lock()
if !l.m[logStatement] {
l.logger.Println(logStatement)
l.m[logStatement] = true
}
l.Unlock()
}
// NewDistinctErrorLogger creates a new DistinctLogger that logs ERRORs
func NewDistinctErrorLogger() *DistinctLogger {
return &DistinctLogger{m: make(map[string]bool), logger: jww.ERROR}
}
// NewDistinctWarnLogger creates a new DistinctLogger that logs WARNs
func NewDistinctWarnLogger() *DistinctLogger {
return &DistinctLogger{m: make(map[string]bool), logger: jww.WARN}
}
// NewDistinctFeedbackLogger creates a new DistinctLogger that can be used
// to give feedback to the user while not spamming with duplicates.
func NewDistinctFeedbackLogger() *DistinctLogger {
return &DistinctLogger{m: make(map[string]bool), logger: jww.FEEDBACK}
}
var (
// DistinctErrorLog can be used to avoid spamming the logs with errors.
DistinctErrorLog = NewDistinctErrorLogger()
// DistinctWarnLog can be used to avoid spamming the logs with warnings.
DistinctWarnLog = NewDistinctWarnLogger()
// DistinctFeedbackLog can be used to avoid spamming the logs with info messages.
DistinctFeedbackLog = NewDistinctFeedbackLogger()
)
// InitLoggers sets up the global distinct loggers.
func InitLoggers() {
DistinctErrorLog = NewDistinctErrorLogger()
DistinctWarnLog = NewDistinctWarnLogger()
DistinctFeedbackLog = NewDistinctFeedbackLogger()
}
// Deprecated informs about a deprecation, but only once for a given set of arguments' values.
// If the err flag is enabled, it logs as an ERROR (will exit with -1) and the text will
// point at the next Hugo release.
// The idea is two remove an item in two Hugo releases to give users and theme authors
// plenty of time to fix their templates.
func Deprecated(object, item, alternative string, err bool) {
if err {
DistinctErrorLog.Printf("%s's %s is deprecated and will be removed in Hugo %s. %s.", object, item, NextHugoReleaseVersion(), alternative)
} else {
// Make sure the users see this while avoiding build breakage. This will not lead to an os.Exit(-1)
DistinctFeedbackLog.Printf("WARNING: %s's %s is deprecated and will be removed in a future release. %s.", object, item, alternative)
}
}
// SliceToLower goes through the source slice and lowers all values.
func SliceToLower(s []string) []string {
if s == nil {
return nil
}
l := make([]string, len(s))
for i, v := range s {
l[i] = strings.ToLower(v)
}
return l
}
// Md5String takes a string and returns its MD5 hash.
func Md5String(f string) string {
h := md5.New()
h.Write([]byte(f))
return hex.EncodeToString(h.Sum([]byte{}))
}
// IsWhitespace determines if the given rune is whitespace.
func IsWhitespace(r rune) bool {
return r == ' ' || r == '\t' || r == '\n' || r == '\r'
}
// Seq creates a sequence of integers.
// It's named and used as GNU's seq.
// Examples:
// 3 => 1, 2, 3
// 1 2 4 => 1, 3
// -3 => -1, -2, -3
// 1 4 => 1, 2, 3, 4
// 1 -2 => 1, 0, -1, -2
func Seq(args ...interface{}) ([]int, error) {
if len(args) < 1 || len(args) > 3 {
return nil, errors.New("Seq, invalid number of args: 'first' 'increment' (optional) 'last' (optional)")
}
intArgs := cast.ToIntSlice(args)
if len(intArgs) < 1 || len(intArgs) > 3 {
return nil, errors.New("Invalid argument(s) to Seq")
}
var inc = 1
var last int
var first = intArgs[0]
if len(intArgs) == 1 {
last = first
if last == 0 {
return []int{}, nil
} else if last > 0 {
first = 1
} else {
first = -1
inc = -1
}
} else if len(intArgs) == 2 {
last = intArgs[1]
if last < first {
inc = -1
}
} else {
inc = intArgs[1]
last = intArgs[2]
if inc == 0 {
return nil, errors.New("'increment' must not be 0")
}
if first < last && inc < 0 {
return nil, errors.New("'increment' must be > 0")
}
if first > last && inc > 0 {
return nil, errors.New("'increment' must be < 0")
}
}
// sanity check
if last < -100000 {
return nil, errors.New("size of result exceeds limit")
}
size := ((last - first) / inc) + 1
// sanity check
if size <= 0 || size > 2000 {
return nil, errors.New("size of result exceeds limit")
}
seq := make([]int, size)
val := first
for i := 0; ; i++ {
seq[i] = val
val += inc
if (inc < 0 && val < last) || (inc > 0 && val > last) {
break
}
}
return seq, nil
}
// DoArithmetic performs arithmetic operations (+,-,*,/) using reflection to
// determine the type of the two terms.
func DoArithmetic(a, b interface{}, op rune) (interface{}, error) {
av := reflect.ValueOf(a)
bv := reflect.ValueOf(b)
var ai, bi int64
var af, bf float64
var au, bu uint64
switch av.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
ai = av.Int()
switch bv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
bi = bv.Int()
case reflect.Float32, reflect.Float64:
af = float64(ai) // may overflow
ai = 0
bf = bv.Float()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
bu = bv.Uint()
if ai >= 0 {
au = uint64(ai)
ai = 0
} else {
bi = int64(bu) // may overflow
bu = 0
}
default:
return nil, errors.New("Can't apply the operator to the values")
}
case reflect.Float32, reflect.Float64:
af = av.Float()
switch bv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
bf = float64(bv.Int()) // may overflow
case reflect.Float32, reflect.Float64:
bf = bv.Float()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
bf = float64(bv.Uint()) // may overflow
default:
return nil, errors.New("Can't apply the operator to the values")
}
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
au = av.Uint()
switch bv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
bi = bv.Int()
if bi >= 0 {
bu = uint64(bi)
bi = 0
} else {
ai = int64(au) // may overflow
au = 0
}
case reflect.Float32, reflect.Float64:
af = float64(au) // may overflow
au = 0
bf = bv.Float()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
bu = bv.Uint()
default:
return nil, errors.New("Can't apply the operator to the values")
}
case reflect.String:
as := av.String()
if bv.Kind() == reflect.String && op == '+' {
bs := bv.String()
return as + bs, nil
}
return nil, errors.New("Can't apply the operator to the values")
default:
return nil, errors.New("Can't apply the operator to the values")
}
switch op {
case '+':
if ai != 0 || bi != 0 {
return ai + bi, nil
} else if af != 0 || bf != 0 {
return af + bf, nil
} else if au != 0 || bu != 0 {
return au + bu, nil
}
return 0, nil
case '-':
if ai != 0 || bi != 0 {
return ai - bi, nil
} else if af != 0 || bf != 0 {
return af - bf, nil
} else if au != 0 || bu != 0 {
return au - bu, nil
}
return 0, nil
case '*':
if ai != 0 || bi != 0 {
return ai * bi, nil
} else if af != 0 || bf != 0 {
return af * bf, nil
} else if au != 0 || bu != 0 {
return au * bu, nil
}
return 0, nil
case '/':
if bi != 0 {
return ai / bi, nil
} else if bf != 0 {
return af / bf, nil
} else if bu != 0 {
return au / bu, nil
}
return nil, errors.New("Can't divide the value by 0")
default:
return nil, errors.New("There is no such an operation")
}
}
// NormalizeHugoFlags facilitates transitions of Hugo command-line flags,
// e.g. --baseUrl to --baseURL, --uglyUrls to --uglyURLs
func NormalizeHugoFlags(f *pflag.FlagSet, name string) pflag.NormalizedName {
switch name {
case "baseUrl":
name = "baseURL"
break
case "uglyUrls":
name = "uglyURLs"
break
}
return pflag.NormalizedName(name)
}
// DiffStringSlices returns the difference between two string slices.
// Useful in tests.
// See:
// http://stackoverflow.com/questions/19374219/how-to-find-the-difference-between-two-slices-of-strings-in-golang
func DiffStringSlices(slice1 []string, slice2 []string) []string {
diffStr := []string{}
m := map[string]int{}
for _, s1Val := range slice1 {
m[s1Val] = 1
}
for _, s2Val := range slice2 {
m[s2Val] = m[s2Val] + 1
}
for mKey, mVal := range m {
if mVal == 1 {
diffStr = append(diffStr, mKey)
}
}
return diffStr
}