bindata/translate.go

154 lines
3.2 KiB
Go
Raw Normal View History

// This work is subject to the CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
// license. Its contents can be found at:
// http://creativecommons.org/publicdomain/zero/1.0/
package main
import (
"compress/gzip"
"fmt"
"io"
)
// translate translates the input file to go source code.
func translate(input io.Reader, output io.Writer, pkgname, funcname string, uncompressed, nomemcpy bool) {
if nomemcpy {
if uncompressed {
translate_nomemcpy_uncomp(input, output, pkgname, funcname)
} else {
translate_nomemcpy_comp(input, output, pkgname, funcname)
}
} else {
if uncompressed {
translate_memcpy_uncomp(input, output, pkgname, funcname)
} else {
translate_memcpy_comp(input, output, pkgname, funcname)
}
}
}
// input -> gzip -> gowriter -> output.
func translate_memcpy_comp(input io.Reader, output io.Writer, pkgname, funcname string) {
fmt.Fprintf(output, `package %s
import (
"bytes"
"compress/gzip"
"io"
)
// %s returns raw, uncompressed file data.
func %s() []byte {
gz, err := gzip.NewReader(bytes.NewBuffer([]byte{`, pkgname, funcname, funcname)
gz := gzip.NewWriter(&ByteWriter{Writer: output})
io.Copy(gz, input)
gz.Close()
fmt.Fprint(output, `
}))
if err != nil {
panic("Decompression failed: " + err.Error())
}
var b bytes.Buffer
io.Copy(&b, gz)
gz.Close()
return b.Bytes()
}`)
}
// input -> gzip -> gowriter -> output.
func translate_memcpy_uncomp(input io.Reader, output io.Writer, pkgname, funcname string) {
fmt.Fprintf(output, `package %s
// %s returns raw file data.
func %s() []byte {
return []byte{`, pkgname, funcname, funcname)
io.Copy(&ByteWriter{Writer: output}, input)
fmt.Fprint(output, `
}
}`)
}
// input -> gzip -> gowriter -> output.
func translate_nomemcpy_comp(input io.Reader, output io.Writer, pkgname, funcname string) {
fmt.Fprintf(output, `package %s
import (
"bytes"
"compress/gzip"
"io"
"reflect"
"unsafe"
)
var _%s = "`, pkgname, funcname)
gz := gzip.NewWriter(&StringWriter{Writer: output})
io.Copy(gz, input)
gz.Close()
fmt.Fprintf(output, `"
// %s returns raw, uncompressed file data.
func %s() []byte {
var empty [0]byte
sx := (*reflect.StringHeader)(unsafe.Pointer(&_%s))
b := empty[:]
bx := (*reflect.SliceHeader)(unsafe.Pointer(&b))
bx.Data = sx.Data
bx.Len = len(_%s)
bx.Cap = bx.Len
gz, err := gzip.NewReader(bytes.NewBuffer(b))
if err != nil {
panic("Decompression failed: " + err.Error())
}
var buf bytes.Buffer
io.Copy(&buf, gz)
gz.Close()
return buf.Bytes()
}
`, funcname, funcname, funcname, funcname)
}
// input -> gowriter -> output.
func translate_nomemcpy_uncomp(input io.Reader, output io.Writer, pkgname, funcname string) {
fmt.Fprintf(output, `package %s
import (
"reflect"
"unsafe"
)
var _%s = "`, pkgname, funcname)
io.Copy(&StringWriter{Writer: output}, input)
fmt.Fprintf(output, `"
// %s returns raw file data.
//
// WARNING: The returned byte slice is READ-ONLY.
// Attempting to alter the slice contents will yield a runtime panic.
func %s() []byte {
var empty [0]byte
sx := (*reflect.StringHeader)(unsafe.Pointer(&_%s))
b := empty[:]
bx := (*reflect.SliceHeader)(unsafe.Pointer(&b))
bx.Data = sx.Data
bx.Len = len(_%s)
bx.Cap = bx.Len
return b
}
`, funcname, funcname, funcname, funcname)
}