Fix generated code for both compressed and uncompressed modes. We now no longer require a memcpy to read the static file data and can get it directly from the .rodata section. This addresses issue #1

README.md

@@ -1,57 +1,37 @@
 ## bindata
 
 This tool converts any file into managable Go source code. Useful for embedding
-binary data into a go program. The file data is gzip compressed before being
-converted to a raw byte slice.
+binary data into a go program. The file data is optionally gzip compressed
+before being converted to a raw byte slice.
 
 ### Usage
 
 The simplest invocation is to pass it only the input file name.
 The output file and code settings are inferred from this automatically.
 
-    $ bindata -i testdata/gophercolor.png
+    $ go-bindata -i testdata/gophercolor.png
     [w] No output file specified. Using 'testdata/gophercolor.png.go'.
     [w] No package name specified. Using 'main'.
     [w] No function name specified. Using 'gophercolor_png'.
     [i] Done.
 
-This creates the "testdata/gophercolor.png.go" file which has a package
-declaration with name 'main' and one function named 'gophercolor_png'.
-It looks like this:
+This creates the `testdata/gophercolor.png.go` file which has a package
+declaration with name `main` a variable holding the file data in a read-only
+string and one function named `gophercolor_png` with the following signature:
 
-     // gophercolor_png returns the decompressed binary data.
-     // It panics if an error occurred.
-     func gophercolor_png() []byte {
-	      gz, err := gzip.NewReader(bytes.NewBuffer([]byte{
-              ...
-          }))
-          
-          if err != nil {
-              panic("Decompression failed: " + err.Error())
-          }
-
-          var b bytes.Buffer
-          io.Copy(&b, gz)
-          gz.Close()
-          
-          return b.Bytes()
-     }
+    func gophercolor_png() []byte
 
 You can now simply include the new .go file in your program and call
-gophercolor_png() to get the uncompressed image data. The function panics
-if something went wrong during decompression. This makes any faults appearant
-during initialization of your program, so it can quickly be fixed. Additionally,
-this approach allows us to assign the decompressed file data to global
-variables where necessary.
-
-See the testdata directory for example input and output.
+`gophercolor_png()` to get the uncompressed image data. The function panics
+if something went wrong during decompression. See the testdata directory for
+example input and output.
 
 Aternatively, you can pipe the input file data into stdin. bindata will then
 spit out the generated Go code to stdout. This does require explicitly naming
 the desired function name, as it can not be inferred from the input data.
 The package name will still default to 'main'.
 
-     $ cat testdata/gophercolor.png | ./bindata -f gophercolor_png | gofmt
+     $ cat testdata/gophercolor.png | go-bindata -f gophercolor_png | gofmt
 
 Invoke the program with the -h flag for more options.
 
@@ -59,12 +39,12 @@ Invoke the program with the -h flag for more options.
 ### Optional compression
 
 When the `-u` flag is given, the supplied resource is *not* GZIP compressed
-before being turned into Go code. This also alters the generated output in that
-we no longer need a function that decompresses the data. The resource's raw
-byte data is simply assigned to a global variable of the same name as the 
-function would otherwise get. This feature is useful if you do not care for
-compression, or the supplied resource is already compressed. Doing it again
-would not add any value and may even increase the size of the data.
+before being turned into Go code. The data should still be accessed through
+a function call, so nothing changes in the usage of the generated file.
+
+This feature is useful if you do not care for compression, or the supplied
+resource is already compressed. Doing it again would not add any value and may
+even increase the size of the data.
 
 The default behaviour of the program is to use compression.
 

bindata.go

@@ -1,54 +0,0 @@
-// 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 the input file without GZIP compression.
-// input -> gowriter -> output.
-func translate_uncompressed(input io.Reader, output io.Writer, pkgname, funcname string) {
-	fmt.Fprintf(output, "package %s\n\nvar %s []byte = []byte{", pkgname, funcname)
-	io.Copy(&GoWriter{Writer: output}, input)
-	fmt.Fprint(output, "\n}")
-}
-
-// Translate the input file with GZIP compression.
-// input -> gzip -> gowriter -> output.
-func translate_compressed(input io.Reader, output io.Writer, pkgname, funcname string) {
-	fmt.Fprintf(output, `package %s
-
-import (
-	"bytes"
-	"compress/gzip"
-	"io"
-)
-
-// %s returns the decompressed binary data.
-// It panics if an error occurred.
-func %s() []byte {
-	gz, err := gzip.NewReader(bytes.NewBuffer([]byte{`, pkgname, funcname, funcname)
-
-	gz := gzip.NewWriter(&GoWriter{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()
-}`)
-}

gowriter.go

@@ -9,7 +9,7 @@ import (
 	"io"
 )
 
-var newline = []byte{'\n'}
+var line = []byte("\"+\n\"")
 
 type GoWriter struct {
 	io.Writer
@@ -22,12 +22,12 @@ func (w *GoWriter) Write(p []byte) (n int, err error) {
 	}
 
 	for n = range p {
-		if w.c%12 == 0 {
-			w.Writer.Write(newline)
+		if w.c%16 == 0 {
+			w.Writer.Write(line)
 			w.c = 0
 		}
 
-		fmt.Fprintf(w.Writer, "0x%02x,", p[n])
+		fmt.Fprintf(w.Writer, "\\x%02x", p[n])
 		w.c++
 	}
 

main.go

@@ -16,7 +16,7 @@ import (
 
 const (
 	AppName    = "bindata"
-	AppVersion = "0.7"
+	AppVersion = "0.8"
 )
 
 func main() {
@@ -95,12 +95,7 @@ func main() {
 	// Read the input file, transform it into a gzip compressed data stream and
 	// write it out as a go source file.
 	if pipe {
-		if *uncompressed {
-			translate_uncompressed(os.Stdin, os.Stdout, *pkgname, *funcname)
-		} else {
-			translate_compressed(os.Stdin, os.Stdout, *pkgname, *funcname)
-		}
-
+		translate(os.Stdin, os.Stdout, *pkgname, *funcname, *uncompressed)
 		fmt.Fprintln(os.Stdout, "[i] Done.")
 		return
 	}
@@ -122,11 +117,6 @@ func main() {
 
 	defer fd.Close()
 
-	if *uncompressed {
-		translate_uncompressed(fs, fd, *pkgname, *funcname)
-	} else {
-		translate_compressed(fs, fd, *pkgname, *funcname)
-	}
-
+	translate(fs, fd, *pkgname, *funcname, *uncompressed)
 	fmt.Fprintln(os.Stdout, "[i] Done.")
 }

translate.go

@@ -0,0 +1,88 @@
+// 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 the input file with optional GZIP compression.
+// input [-> gzip] -> gowriter -> output.
+func translate(input io.Reader, output io.Writer, pkgname, funcname string, uncompressed bool) {
+	fmt.Fprintf(output, `package %s
+
+import (`, pkgname)
+
+	if uncompressed {
+		fmt.Fprint(output, `
+		"reflect"
+		"unsafe"`)
+	} else {
+		fmt.Fprint(output, `
+		"bytes"
+		"compress/gzip"
+		"io"
+		"reflect"
+		"unsafe"`)
+	}
+
+	fmt.Fprintf(output, `
+)
+
+var _%s = "`, funcname)
+
+	if uncompressed {
+		io.Copy(&GoWriter{Writer: output}, input)
+	} else {
+		gz := gzip.NewWriter(&GoWriter{Writer: output})
+		io.Copy(gz, input)
+		gz.Close()
+	}
+
+	fmt.Fprintf(output, `"
+
+// %s returns the binary data for a given file.
+func %s() []byte {`, funcname, funcname)
+
+	if uncompressed {
+		fmt.Fprintf(output, `
+		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)
+	} else {
+		fmt.Fprintf(output, `
+		// This bit of black magic ensures we do not get
+		// unneccesary memcpy's and can read directly from
+		// the .rodata section.
+		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)
+	}
+
+	fmt.Fprintf(output, "\n}")
+}