Merge pull request #425 from wader/wasm-doc

wasm: Add some documentation

README.md

@@ -128,7 +128,7 @@ vp8_frame,
 vp9_cfm,
 vp9_frame,
 vpx_ccr,
-wasm,
+[wasm](doc/formats.md#wasm),
 wav,
 webp,
 xing,

doc/formats.md

@@ -104,7 +104,7 @@
 |`vp9_cfm`                         |VP9&nbsp;Codec&nbsp;Feature&nbsp;Metadata                                                |<sub></sub>|
 |`vp9_frame`                       |VP9&nbsp;frame                                                                           |<sub></sub>|
 |`vpx_ccr`                         |VPX&nbsp;Codec&nbsp;Configuration&nbsp;Record                                            |<sub></sub>|
-|`wasm`                            |WebAssembly&nbsp;Binary&nbsp;Format                                                      |<sub></sub>|
+|[`wasm`](#wasm)                   |WebAssembly&nbsp;Binary&nbsp;Format                                                      |<sub></sub>|
 |`wav`                             |WAV&nbsp;file                                                                            |<sub>`id3v2` `id3v1` `id3v11`</sub>|
 |`webp`                            |WebP&nbsp;image                                                                          |<sub>`vp8_frame`</sub>|
 |`xing`                            |Xing&nbsp;header                                                                         |<sub></sub>|
@@ -506,6 +506,26 @@ Current only supports plain RTMP (not RTMPT or encrypted variants etc) with AMF0
 - https://rtmp.veriskope.com/docs/spec/
 - https://rtmp.veriskope.com/pdf/video_file_format_spec_v10.pdf
 
+## wasm
+
+### Count opcode usage
+```sh
+$ fq '.sections[] | select(.id == "code_section") | [.. | .opcode? // empty] | count | map({key: .[0], value: .[1]}) | from_entries' file.wasm
+```
+
+### List exports and imports
+```sh
+$ fq '.sections | {import: map(select(.id == "import_section").content.im.x[].nm.b), export: map(select(.id == "export_section").content.ex.x[].nm.b)}' file.wasm
+```
+
+### Authors
+- Takashi Oguma
+[@bitbears-dev](https://github.com/bitbears-dev)
+[@0xb17bea125](https://twitter.com/0xb17bea125)
+
+### References
+- https://webassembly.github.io/spec/core/
+
 ## xml
 
 ### Options

format/all/help.fqtest

@@ -1209,6 +1209,20 @@ out   $ fq -d wasm . file
 out   # Decode value as wasm
 out   ... | wasm
 out 
+out # Count opcode usage
+out 
+out   $ fq '.sections[] | select(.id == "code_section") | [.. | .opcode? // empty] | count | map({key: .[0], value: .[1]}) | from_entries' file.wasm
+out   
+out # List exports and imports
+out 
+out   $ fq '.sections | {import: map(select(.id == "import_section").content.im.x[].nm.b), export: map(select(.id == "export_section").content.ex.x[].nm.b)}' file.wasm
+out   
+out # Authors
+out - Takashi Oguma @bitbears-dev (https://github.com/bitbears-dev) @0xb17bea125 (https://twitter.com/0xb17bea125)
+out 
+out # References
+out - https://webassembly.github.io/spec/core/
+out 
 "help(wav)"
 out wav: WAV file decoder
 out 

format/wasm/wasm.go

@@ -3,6 +3,7 @@ package wasm
 // https://webassembly.github.io/spec/core/
 
 import (
+	"embed"
 	"math"
 	"sync"
 
@@ -12,6 +13,9 @@ import (
 	"github.com/wader/fq/pkg/scalar"
 )
 
+//go:embed wasm.md
+var wasmFS embed.FS
+
 func init() {
 	interp.RegisterFormat(decode.Format{
 		Name:        format.WASM,
@@ -19,6 +23,7 @@ func init() {
 		DecodeFn:    decodeWASM,
 		Groups:      []string{format.PROBE},
 	})
+	interp.RegisterFS(wasmFS)
 }
 
 const (

format/wasm/wasm.md

@@ -0,0 +1,17 @@
+### Count opcode usage
+```sh
+$ fq '.sections[] | select(.id == "code_section") | [.. | .opcode? // empty] | count | map({key: .[0], value: .[1]}) | from_entries' file.wasm
+```
+
+### List exports and imports
+```sh
+$ fq '.sections | {import: map(select(.id == "import_section").content.im.x[].nm.b), export: map(select(.id == "export_section").content.ex.x[].nm.b)}' file.wasm
+```
+
+### Authors
+- Takashi Oguma
+[@bitbears-dev](https://github.com/bitbears-dev)
+[@0xb17bea125](https://twitter.com/0xb17bea125)
+
+### References
+- https://webassembly.github.io/spec/core/