bindata

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Published: Mar 21, 2021 License: CC0-1.0 Imports: 13 Imported by: 0

README

Bindata

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 bindata sub directory. This tool offers a set of command line options, used to customize the output being generated.

Installation

To install the library and command line program, use the following:

go get -u code.afis.me/bindata/...
Usage

Conversion is done on one or more sets 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.

bindata data/

To include all input sub-directories recursively, use the elipsis postfix as defined for Go import paths. Otherwise it will only consider assets in the input directory itself.

bindata data/...

To specify the name of the output file being generated, we use the following:

bindata -o myfile.go data/

Multiple input directories can be specified if necessary.

bindata dir1/... /path/to/dir2/... dir3

To ignore files, pass in regexes using -ignore, for example:

bindata -ignore=\\.gitignore data/...
Accessing an asset

To access asset data, we use the Asset(string) ([]byte, error) function which is included in the generated output.

data, err := Asset("pub/style/foo.css")
if err != nil {
 // Asset was not found.
}

// use asset data

Serve assets with net/http

With the -fs flag, bindata will add an AssetFile(string) method returning an http.FileSystem interface:

r := mux.NewRouter().StrictSlash(true)
r.PathPrefix("/static").Handler(http.StripPrefix("/static/", http.FileServer(AssetFile(""))))
r.PathPrefix("/static").Handler(http.StripPrefix("/static/", http.FileServer(AssetFile("assets/dist"))))
#cloning and modif from
https://github.com/go-bindata/go-bindata
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 bindata without the -debug flag. It will now embed the latest version of the assets.

Documentation

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func Translate

func Translate(c *Config) error

Translate reads assets from an input directory, converts them to Go code and writes new files to the output specified in the given configuration.

Types

type Asset

type Asset struct {
	Path string // Full file path.
	Name string // Key used in TOC -- name by which asset is referenced.
	Func string // Function name for the procedure returning the asset contents.
}

Asset holds information about a single asset to be processed.

type ByName

type ByName []os.FileInfo

ByName implements sort.Interface for []os.FileInfo based on Name()

func (ByName) Len

func (v ByName) Len() int

func (ByName) Less

func (v ByName) Less(i, j int) bool

func (ByName) Swap

func (v ByName) Swap(i, j int)

type ByteWriter

type ByteWriter struct {
	io.Writer
	// contains filtered or unexported fields
}

ByteWriter -

func (*ByteWriter) Write

func (w *ByteWriter) Write(p []byte) (n int, err error)

type Config

type Config struct {
	// Name of the package to use. Defaults to 'main'.
	Package string

	// Tags specify a set of optional build tags, which should be
	// included in the generated output. 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.
	Tags string

	// Input defines the directory path, containing all asset files as
	// well as whether to recursively process assets in any sub directories.
	Input []InputConfig

	// Output defines the output file for the generated code.
	// If left empty, this defaults to 'bindata.go' in the current
	// working directory.
	Output string

	// Prefix defines a path prefix which should be stripped from all
	// file names when generating the keys in the table of contents.
	// For example, running without the `-prefix` flag, we get:
	//
	// 	$ go-bindata /path/to/templates
	// 	go_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
	Prefix string

	// NoMemCopy will alter the way the output file is generated.
	//
	// It will employ a hack that allows us to read the file data directly from
	// the compiled program's `.rodata` section. This ensures that when we call
	// call our generated function, we omit unnecessary mem copies.
	//
	// The downside of this, is that it requires dependencies on the `reflect` and
	// `unsafe` packages. These may be restricted on platforms like AppEngine and
	// thus prevent you from using this mode.
	//
	// Another disadvantage is that the byte slice we create, is strictly read-only.
	// For most use-cases this is not a problem, but if you ever try to alter the
	// returned byte slice, a runtime panic is thrown. Use this mode only on target
	// platforms where memory constraints are an issue.
	//
	// The default behaviour is to use the old code generation method. This
	// prevents the two previously mentioned issues, but will employ at least one
	// extra memcopy and thus increase memory requirements.
	//
	// For instance, consider the following two examples:
	//
	// This would be the default mode, using an extra memcopy but gives a safe
	// implementation without dependencies on `reflect` and `unsafe`:
	//
	// 	func myfile() []byte {
	// 		return []byte{0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a}
	// 	}
	//
	// Here is the same functionality, but uses the `.rodata` hack.
	// The byte slice returned from this example can not be written to without
	// generating a runtime error.
	//
	// 	var _myfile = "\x89\x50\x4e\x47\x0d\x0a\x1a"
	//
	// 	func myfile() []byte {
	// 		var empty [0]byte
	// 		sx := (*reflect.StringHeader)(unsafe.Pointer(&_myfile))
	// 		b := empty[:]
	// 		bx := (*reflect.SliceHeader)(unsafe.Pointer(&b))
	// 		bx.Data = sx.Data
	// 		bx.Len = len(_myfile)
	// 		bx.Cap = bx.Len
	// 		return b
	// 	}
	NoMemCopy bool

	// NoCompress means the assets are /not/ GZIP compressed before being turned
	// into Go code. The generated function will automatically unzip
	// the file data when called. Defaults to false.
	NoCompress bool

	// HTTPFileSystem means whether generate return http.FileSystem interface
	// instance's function.When true,will generate relate code.
	HTTPFileSystem bool

	// Perform a debug build. This generates an asset file, which
	// loads the asset contents directly from disk at their original
	// location, instead of embedding the contents in the code.
	//
	// This is mostly useful if you anticipate that the assets are
	// going to change during your development cycle. You will always
	// want your code to access the latest version of the asset.
	// Only in release mode, will the assets actually be embedded
	// in the code. The default behaviour is Release mode.
	Debug bool

	// Perform a dev build, which is nearly identical to the debug option. The
	// only difference is that instead of absolute file paths in generated code,
	// it expects a variable, `rootDir`, to be set in the generated code's
	// package (the author needs to do this manually), which it then prepends to
	// an asset's name to construct the file path on disk.
	//
	// This is mainly so you can push the generated code file to a shared
	// repository.
	Dev bool

	// When true, size, mode and modtime are not preserved from files
	NoMetadata bool
	// When nonzero, use this as mode for all files.
	Mode uint
	// When nonzero, use this as unix timestamp for all files.
	ModTime int64

	// Ignores any filenames matching the regex pattern specified, e.g.
	// path/to/file.ext will ignore only that file, or \\.gitignore
	// will match any .gitignore file.
	//
	// This parameter can be provided multiple times.
	Ignore []*regexp.Regexp
}

Config defines a set of options for the asset conversion.

func NewConfig

func NewConfig() *Config

NewConfig returns a default configuration struct.

type InputConfig

type InputConfig struct {
	// Path defines a directory containing asset files to be included
	// in the generated output.
	Path string

	// Recursive defines whether subdirectories of Path
	// should be recursively included in the conversion.
	Recursive bool
}

InputConfig defines options on a asset directory to be convert.

type StringWriter

type StringWriter struct {
	io.Writer
	// contains filtered or unexported fields
}

StringWriter -

func (*StringWriter) Write

func (w *StringWriter) Write(p []byte) (n int, err error)

Directories

Path Synopsis

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