feat(c/libuv/demo): Add libuv async_fs demo

Signed-off-by: hackerchai <i@hackerchai.com>

fix(c/libuv): fix fs demo

Signed-off-by: hackerchai <i@hackerchai.com>

refactor(c/libuv): neat comment and adapt merge

Signed-off-by: hackerchai <i@hackerchai.com>

c/libuv/_demo/libuv/fs.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/libuv"
+	"github.com/goplus/llgo/c/os"
+	"golang.org/x/tools/container/intsets"
+	"unsafe"
+)
+
+const bufferSize = 1024
+
+var buffer []c.Char
+var iov libuv.Buf
+
+var loop *libuv.Loop
+var readReq *libuv.Fs
+var closeReq *libuv.Fs
+var openReq *libuv.Fs
+
+func initBuffer() {
+	buffer = make([]c.Char, bufferSize)
+}
+
+func main() {
+	loop = libuv.DefaultLoop()
+	initBuffer()
+
+	file := libuv.NewFile(loop, openReq)
+
+	path := c.Str("example.txt")
+
+	file.Open(path, os.O_RDONLY, 0, onOpen)
+
+	loop.Run(libuv.RUN_DEFAULT)
+
+	libuv.FsReqCleanup(openReq)
+	loop.Close()
+	c.Free(unsafe.Pointer(loop))
+}
+
+func onOpen(req *libuv.Fs) {
+	if req.GetResult() < 0 {
+		c.Fprintf(c.Stderr, c.Str("Error opening file: %s\n"), libuv.Strerror(req.GetResult()))
+	} else {
+		iov = libuv.InitBuf(unsafe.SliceData(buffer), c.Uint(unsafe.Sizeof(buffer)))
+		libuv.FsRead(loop, readReq, req.GetResult(), []libuv.Buf{iov}, 1, -1, onRead)
+	}
+	libuv.FsReqCleanup(req)
+}
+
+func onRead(req *libuv.Fs) {
+	if req.GetResult() < 0 {
+		c.Fprintf(c.Stderr, c.Str("Read error: %s\n"), libuv.Strerror(req.GetResult()))
+	} else if req.GetResult() == 0 {
+		libuv.FsClose(loop, closeReq, req.GetResult(), onClose)
+	} else {
+		if req.GetResult() > intsets.MaxInt {
+			c.Fprintf(c.Stderr, c.Str("Too big file.\n"))
+		}
+		c.Printf(c.Str("%.*s"), c.Int(req.GetResult()), buffer)
+		libuv.FsRead(loop, req, req.GetResult(), []libuv.Buf{iov}, 1, -1, onRead)
+	}
+	libuv.FsReqCleanup(req)
+}
+
+func onClose(req *libuv.Fs) {
+	c.Printf(c.Str("\nFile closed.\n"))
+	libuv.FsReqCleanup(req)
+}

c/libuv/fs.go

@@ -5,6 +5,47 @@ import (
 	_ "unsafe"
 )
 
+const (
+	FS_UNKNOWN   FsType = -1
+	FS_CUSTOM    FsType = 0
+	FS_OPEN      FsType = 1
+	FS_CLOSE     FsType = 2
+	FS_READ      FsType = 3
+	FS_WRITE     FsType = 4
+	FS_SENDFILE  FsType = 5
+	FS_STAT      FsType = 6
+	FS_LSTAT     FsType = 7
+	FS_FSTAT     FsType = 8
+	FS_FTRUNCATE FsType = 9
+	FS_UTIME     FsType = 10
+	FS_FUTIME    FsType = 11
+	FS_ACCESS    FsType = 12
+	FS_CHMOD     FsType = 13
+	FS_FCHMOD    FsType = 14
+	FS_FSYNC     FsType = 15
+	FS_FDATASYNC FsType = 16
+	FS_UNLINK    FsType = 17
+	FS_RMDIR     FsType = 18
+	FS_MKDIR     FsType = 19
+	FS_MKDTEMP   FsType = 20
+	FS_RENAME    FsType = 21
+	FS_SCANDIR   FsType = 22
+	FS_LINK      FsType = 23
+	FS_SYMLINK   FsType = 24
+	FS_READLINK  FsType = 25
+	FS_CHOWN     FsType = 26
+	FS_FCHOWN    FsType = 27
+	FS_REALPATH  FsType = 28
+	FS_COPYFILE  FsType = 29
+	FS_LCHOWN    FsType = 30
+	FS_OPENDIR   FsType = 31
+	FS_READDIR   FsType = 32
+	FS_CLOSEDIR  FsType = 33
+	FS_STATFS    FsType = 34
+	FS_MKSTEMP   FsType = 35
+	FS_LUTIME    FsType = 36
+)
+
 const (
 	DirentUnknown DirentType = iota
 	DirentFile
@@ -16,8 +57,12 @@ const (
 	DirentBlock
 )
 
+type FsType int
+
 type DirentType int
 
+// ----------------------------------------------
+
 /* Handle types. */
 
 type Fs struct {
@@ -42,6 +87,14 @@ type File struct {
 	Req  *Fs
 }
 
+type Stat struct {
+	Unused [0]byte
+}
+
+// ----------------------------------------------
+
+/* Function type */
+
 // llgo:type C
 type FsCb func(req *Fs)
 
@@ -51,14 +104,40 @@ type FsEventCb func(handle *FsEvent, filename *c.Char, events c.Int, status c.In
 // llgo:type C
 type FsPollCb func(handle *FsPoll, status c.Int, events c.Int)
 
-/* Request types. */
-
-/* None of the above. */
-
 // ----------------------------------------------
 
 /* Fs related function and method */
 
+// llgo:link (*Fs).GetType C.uv_fs_get_type
+func (f *Fs) GetType() *FsType {
+	return nil
+}
+
+// llgo:link (*Fs).GetPath C.uv_fs_get_path
+func (f *Fs) GetPath() *c.Char {
+	return nil
+}
+
+// llgo:link (*Fs).GetResult C.uv_fs_get_result
+func (f *Fs) GetResult() c.Int {
+	return 0
+}
+
+// llgo:link (*Fs).GetPtr C.uv_fs_get_ptr
+func (f *Fs) GetPtr() c.Pointer {
+	return nil
+}
+
+// llgo:link (*Fs).GetSystemError C.uv_fs_get_system_error
+func (f *Fs) GetSystemError() c.Int {
+	return 0
+}
+
+// llgo:link (*Fs).GetStatBuf C.uv_fs_get_statbuf
+func (f *Fs) GetStatBuf() *Stat {
+	return nil
+}
+
 //go:linkname FsReqCleanup C.uv_fs_req_cleanup
 func FsReqCleanup(req *Fs)
 

c/libuv/libuv.go

@@ -27,10 +27,6 @@ type Loop struct {
 	Unused [0]byte
 }
 
-type Handle struct {
-	Unused [0]byte
-}
-
 type Buf struct {
 	Base *c.Char
 	Len  uintptr
@@ -45,6 +41,8 @@ type WalkCb func(handle *Handle, arg c.Pointer)
 
 // ----------------------------------------------
 
+/* Loop related functions and method. */
+
 //go:linkname LoopSize C.uv_loop_size
 func LoopSize() uintptr
 
@@ -122,20 +120,9 @@ func (l *Loop) BackendTimeout() int {
 	return 0
 }
 
-// llgo:link (*Handle).Ref C.uv_ref
-func (h *Handle) Ref() {
-	return
-}
+// ----------------------------------------------
 
-// llgo:link (*Handle).Unref C.uv_unref
-func (h *Handle) Unref() {
-	return
-}
-
-// llgo:link (*Handle).HasRef C.uv_has_ref
-func (h *Handle) HasRef() int {
-	return 0
-}
+/* Buf related functions and method. */
 
 //go:linkname InitBuf C.uv_buf_init
 func InitBuf(base *c.Char, len c.Uint) Buf

c/libuv/signal.go

@@ -5,10 +5,16 @@ import (
 	_ "unsafe"
 )
 
+/* Handle types. */
+
 type Signal struct {
 	Unused [0]byte
 }
 
+// ----------------------------------------------
+
+/* Signal related functions and method. */
+
 // llgo:type C
 type SignalCb func(handle *Signal, sigNum c.Int)