Merge pull request #75 from QwertygidQ/master

Added Zstandard support

internal/matchers/archive.go

@@ -84,3 +84,10 @@ func Rar(in []byte) bool {
 func Warc(in []byte) bool {
 	return bytes.HasPrefix(in, []byte("WARC/"))
 }
+
+// Zstd matches a Zstandard archive file.
+func Zstd(in []byte) bool {
+	return len(in) >= 4 &&
+		(0x22 <= in[0] && in[0] <= 0x28 || in[0] == 0x1E) && // Different Zstandard versions.
+		bytes.HasPrefix(in[1:], []byte{0xB5, 0x2F, 0xFD})
+}

mime_test.go

@@ -50,6 +50,7 @@ var files = map[string]*node{
 	"mobi.mobi":   mobi,
 	"lit.lit":     lit,
 	"warc.warc":   warc,
+	"zst.zst":     zstd,
 
 	// images
 	"png.png":          png,

supported_mimes.md

@@ -1,4 +1,4 @@
-## 135 Supported MIME types
+## 136 Supported MIME types
 This file is automatically generated when running tests. Do not edit manually.
 
 Extension | MIME type
@@ -138,3 +138,4 @@ Extension | MIME type
 **mrc** | application/marc
 **mdb** | application/x-msaccess
 **accdb** | application/x-msaccess
+**zst** | application/zstd

tree.go

@@ -11,7 +11,7 @@ var root = newNode("application/octet-stream", "", matchers.True,
 	wav, aiff, au, mpeg, quickTime, mqv, mp4, webM, threeGP, threeG2, avi, flv,
 	mkv, asf, aac, voc, aMp4, m4a, txt, gzip, class, swf, crx, woff, woff2, otf,
 	eot, wasm, shx, dbf, dcm, rar, djvu, mobi, lit, bpg, sqlite3, dwg, nes, macho,
-	qcp, icns, heic, heicSeq, heif, heifSeq, mrc, mdb, accdb,
+	qcp, icns, heic, heicSeq, heif, heifSeq, mrc, mdb, accdb, zstd,
 )
 
 // The list of nodes appended to the root node
@@ -150,4 +150,5 @@ var (
 	mrc       = newNode("application/marc", "mrc", matchers.Marc)
 	mdb       = newNode("application/x-msaccess", "mdb", matchers.MsAccessMdb)
 	accdb     = newNode("application/x-msaccess", "accdb", matchers.MsAccessAce)
+	zstd      = newNode("application/zstd", "zst", matchers.Zstd)
 )