Browse Source

Performs some minor cleanup.

Adds testdata output for a debug build.
Fixes README to reflect new features and behaviour.
pull/4/head v3.0.1
Jim Teeuwen 9 years ago
parent
commit
c385518c06
  1. 93
      README.md
  2. 1
      go-bindata/main.go
  3. 80
      testdata/out/debug.go

93
README.md

@ -1,13 +1,59 @@
## bindata
This tool converts any file into managable Go source code. Useful for embedding
binary data into a go program. The file data is optionally gzip compressed
before being converted to a raw byte slice.
This package converts any file into managable Go source code. Useful for
embedding binary data into a go program. The file data is optionally gzip
compressed before being converted to a raw byte slice.
It comes with a command line tool in the `go-bindata` sub directory.
This tool offers a set of command line options, used to customize the
output being generated.
### Usage
TODO
Conversion is done on a tree of files. They are all embedded in a new
Go source file, along with a table of contents and an `Asset` function,
which allows quick access to the asset, based on its name.
The simplest invocation generates a `bindata.go` file in the current
working directory. It includes all assets from the `data` directory and its
subdirectories.
$ go-bindata data/
To specify the name of the output file being generated, we use the following:
$ go-bindata data/ myfile.go
The following paragraphs detail some of the command line options which can
supplied to `go-bindata`. These options allow us to customize the layout of
the generated code.
Refer to the `testdata/out` directory for various output examples from
the assets in `testdata/in`. Each example uses different command line options.
### Debug vs Release builds
When invoking the program with the `-debug` flag, the generated code does
not actually include the asset data. Instead, it generates function stubs
which load the data from the original file on disk. The asset API remains
identical between debug and release builds, so your code will not have to
change.
This is useful during development when you expect the assets to change often.
The host application using these assets uses the same API in both cases and
will not have to care where the actual data comes from.
An example is a Go webserver with some embedded, static web content like
HTML, JS and CSS files. While developing it, you do not want to rebuild the
whole server and restart it every time you make a change to a bit of
javascript. You just want to build and launch the server once. Then just press
refresh in the browser to see those changes. Embedding the assets with the
`debug` flag allows you to do just that. When you are finished developing and
ready for deployment, just re-invoke `go-bindata` without the `-debug` flag.
It will now embed the latest version of the assets.
### Lower memory footprint
@ -62,9 +108,9 @@ func myfile() []byte {
### Optional compression
When the `-uncompressed` flag is given, the supplied resource is *not* GZIP compressed
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.
When the `-nocompress` flag is given, the supplied resource is *not* GZIP
compressed 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
@ -73,33 +119,36 @@ even increase the size of the data.
The default behaviour of the program is to use compression.
#### Table of Contents keys
#### Path prefix stripping
The keys used in the `go_bindata` map, are the same as the input file name passed to `go-bindata`.
This includes the fully qualified (absolute) path. In most cases, this is not desireable, as it
puts potentially sensitive information in your code base. For this purpose, the tool supplies
another command line flag `-prefix`. This accepts a portion of a path name, which should be
stripped off from the map keys and function names.
The keys used in the `_bindata` map, are the same as the input file name
passed to `go-bindata`. This includes the path. In most cases, this is not
desireable, as it puts potentially sensitive information in your code base.
For this purpose, the tool supplies another command line flag `-prefix`.
This accepts a portion of a path name, which should be stripped off from
the map keys and function names.
For example, running without the `-prefix` flag, we get:
$ go-bindata /path/to/templates/foo.html
go_bindata["/path/to/templates/foo.html"] = path_to_templates_foo_html
$ go-bindata /path/to/templates/
_bindata["/path/to/templates/foo.html"] = path_to_templates_foo_html
Running with the `-prefix` flag, we get:
$ go-bindata -prefix "/path/to/" /path/to/templates/foo.html
go_bindata["templates/foo.html"] = templates_foo_html
$ go-bindata -prefix "/path/to/" /path/to/templates/
_bindata["templates/foo.html"] = templates_foo_html
#### Build tags
With the optional -tags flag, you can specify any go build tags that
With the optional `-tags` flag, you can specify any go build tags that
must be fulfilled for the output file to be included in a build. This
is useful for including binary data in multiple formats, where the desired
format is specified at build time with the appropriate tag(s).
is useful when including binary data in multiple formats, where the desired
format is specified at build time with the appropriate tags.
The tags are appended to a `// +build` line in the beginning of the output file
and must follow the build tags syntax specified by the go tool.

1
go-bindata/main.go

@ -18,6 +18,7 @@ func main() {
if err != nil {
fmt.Fprintf(os.Stderr, "bindata: %v\n", err)
os.Exit(1)
}
}

80
testdata/out/debug.go

@ -0,0 +1,80 @@
package main
import (
"bytes"
"io"
"log"
"os"
)
// bindata_read reads the given file from disk.
// It panics if anything went wrong.
func bindata_read(path, name string) []byte {
fd, err := os.Open(path)
if err != nil {
log.Fatalf("Read %s: %v", name, err)
}
defer fd.Close()
var buf bytes.Buffer
_, err = io.Copy(&buf, fd)
if err != nil {
log.Fatalf("Read %s: %v", name, err)
}
return buf.Bytes()
}
// in_b_test_asset reads file data from disk.
// It panics if something went wrong in the process.
func in_b_test_asset() []byte {
return bindata_read(
"/a/code/go/src/github.com/jteeuwen/go-bindata/testdata/in/b/test.asset",
"in/b/test.asset",
)
}
// in_test_asset reads file data from disk.
// It panics if something went wrong in the process.
func in_test_asset() []byte {
return bindata_read(
"/a/code/go/src/github.com/jteeuwen/go-bindata/testdata/in/test.asset",
"in/test.asset",
)
}
// in_a_test_asset reads file data from disk.
// It panics if something went wrong in the process.
func in_a_test_asset() []byte {
return bindata_read(
"/a/code/go/src/github.com/jteeuwen/go-bindata/testdata/in/a/test.asset",
"in/a/test.asset",
)
}
// in_c_test_asset reads file data from disk.
// It panics if something went wrong in the process.
func in_c_test_asset() []byte {
return bindata_read(
"/a/code/go/src/github.com/jteeuwen/go-bindata/testdata/in/c/test.asset",
"in/c/test.asset",
)
}
// Asset loads and returns the asset for the given name.
// This returns nil of the asset could not be found.
func Asset(name string) []byte {
if f, ok := _bindata[name]; ok {
return f()
}
return nil
}
// _bindata is a table, holding each asset generator, mapped to its name.
var _bindata = map[string]func() []byte{
"in/b/test.asset": in_b_test_asset,
"in/test.asset": in_test_asset,
"in/a/test.asset": in_a_test_asset,
"in/c/test.asset": in_c_test_asset,
}
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