Add go-charset and chardet to vendor

vendor/github.com/paulrosania/go-charset/charset/iconv/iconv.go

@@ -0,0 +1,184 @@
+// The iconv package provides an interface to the GNU iconv character set
+// conversion library (see http://www.gnu.org/software/libiconv/).
+// It automatically registers all the character sets with the charset package,
+// so it is usually used simply for the side effects of importing it.
+// Example:
+//   import (
+//		"go-charset.googlecode.com/hg/charset"
+//		_ "go-charset.googlecode.com/hg/charset/iconv"
+//   )
+package iconv
+
+//#cgo darwin LDFLAGS: -liconv
+//#include <stdlib.h>
+//#include <iconv.h>
+//#include <errno.h>
+//iconv_t iconv_open_error = (iconv_t)-1;
+//size_t iconv_error = (size_t)-1;
+import "C"
+import (
+	"errors"
+	"fmt"
+	"github.com/paulrosania/go-charset/charset"
+	"runtime"
+	"strings"
+	"syscall"
+	"unicode/utf8"
+	"unsafe"
+)
+
+type iconvTranslator struct {
+	cd      C.iconv_t
+	invalid rune
+	scratch []byte
+}
+
+func canonicalChar(c rune) rune {
+	if c >= 'a' && c <= 'z' {
+		return c - 'a' + 'A'
+	}
+	return c
+}
+
+func canonicalName(s string) string {
+	return strings.Map(canonicalChar, s)
+}
+
+func init() {
+	charset.Register(iconvFactory{})
+}
+
+type iconvFactory struct {
+}
+
+func (iconvFactory) TranslatorFrom(name string) (charset.Translator, error) {
+	return Translator("UTF-8", name, utf8.RuneError)
+}
+
+func (iconvFactory) TranslatorTo(name string) (charset.Translator, error) {
+	// BUG This is wrong.  The target character set may not be ASCII
+	// compatible.  There's no easy solution to this other than
+	// removing the offending code point.
+	return Translator(name, "UTF-8", '?')
+}
+
+// Translator returns a Translator that translates between
+// the named character sets. When an invalid multibyte
+// character is found, the bytes in invalid are substituted instead.
+func Translator(toCharset, fromCharset string, invalid rune) (charset.Translator, error) {
+	cto, cfrom := C.CString(toCharset), C.CString(fromCharset)
+	cd, err := C.iconv_open(cto, cfrom)
+
+	C.free(unsafe.Pointer(cfrom))
+	C.free(unsafe.Pointer(cto))
+
+	if cd == C.iconv_open_error {
+		if err == syscall.EINVAL {
+			return nil, errors.New("iconv: conversion not supported")
+		}
+		return nil, err
+	}
+	t := &iconvTranslator{cd: cd, invalid: invalid}
+	runtime.SetFinalizer(t, func(*iconvTranslator) {
+		C.iconv_close(cd)
+	})
+	return t, nil
+}
+
+func (iconvFactory) Names() []string {
+	all := aliases()
+	names := make([]string, 0, len(all))
+	for name, aliases := range all {
+		if aliases[0] == name {
+			names = append(names, name)
+		}
+	}
+	return names
+}
+
+func (iconvFactory) Info(name string) *charset.Charset {
+	name = strings.ToLower(name)
+	all := aliases()
+	a, ok := all[name]
+	if !ok {
+		return nil
+	}
+	return &charset.Charset{
+		Name:    name,
+		Aliases: a,
+	}
+}
+
+func (p *iconvTranslator) Translate(data []byte, eof bool) (rn int, rd []byte, rerr error) {
+	n := 0
+	p.scratch = p.scratch[:0]
+	for len(data) > 0 {
+		p.scratch = ensureCap(p.scratch, len(p.scratch)+len(data)*utf8.UTFMax)
+		cData := (*C.char)(unsafe.Pointer(&data[:1][0]))
+		nData := C.size_t(len(data))
+
+		ns := len(p.scratch)
+		cScratch := (*C.char)(unsafe.Pointer(&p.scratch[ns : ns+1][0]))
+		nScratch := C.size_t(cap(p.scratch) - ns)
+		r, err := C.iconv(p.cd, &cData, &nData, &cScratch, &nScratch)
+
+		p.scratch = p.scratch[0 : cap(p.scratch)-int(nScratch)]
+		n += len(data) - int(nData)
+		data = data[len(data)-int(nData):]
+
+		if r != C.iconv_error || err == nil {
+			return n, p.scratch, nil
+		}
+		switch err := err.(syscall.Errno); err {
+		case C.EILSEQ:
+			// invalid multibyte sequence - skip one byte and continue
+			p.scratch = appendRune(p.scratch, p.invalid)
+			n++
+			data = data[1:]
+		case C.EINVAL:
+			// incomplete multibyte sequence
+			return n, p.scratch, nil
+		case C.E2BIG:
+			// output buffer not large enough; try again with larger buffer.
+			p.scratch = ensureCap(p.scratch, cap(p.scratch)+utf8.UTFMax)
+		default:
+			panic(fmt.Sprintf("unexpected error code: %v", err))
+		}
+	}
+	return n, p.scratch, nil
+}
+
+// ensureCap returns s with a capacity of at least n bytes.
+// If cap(s) < n, then it returns a new copy of s with the
+// required capacity.
+func ensureCap(s []byte, n int) []byte {
+	if n <= cap(s) {
+		return s
+	}
+	// logic adapted from appendslice1 in runtime
+	m := cap(s)
+	if m == 0 {
+		m = n
+	} else {
+		for {
+			if m < 1024 {
+				m += m
+			} else {
+				m += m / 4
+			}
+			if m >= n {
+				break
+			}
+		}
+	}
+	t := make([]byte, len(s), m)
+	copy(t, s)
+	return t
+}
+
+func appendRune(buf []byte, r rune) []byte {
+	n := len(buf)
+	buf = ensureCap(buf, n+utf8.UTFMax)
+	nu := utf8.EncodeRune(buf[n:n+utf8.UTFMax], r)
+	return buf[0 : n+nu]
+}