Rolled back some stuff here like the package stuff

This will add support to view live data
2024-10-27 22:48:32 +00:00
parent 62a38da3b3
commit 2bc756a2f0
14 changed files with 1500 additions and 765 deletions
@@ -0,0 +1,88 @@
+package sharedMem
+
+import (
+	"fmt"
+	"io"
+)
+
+// Memory is shared memory struct
+type Memory struct {
+	m   *shmi
+	pos int64
+}
+
+// Create is create shared memory
+func Create(name string, size uint32) (*Memory, error) {
+	m, err := create(name, size)
+	if err != nil {
+		return nil, err
+	}
+	return &Memory{m, 0}, nil
+}
+
+// Open is open exist shared memory
+func Open(name string, size uint32) (*Memory, error) {
+	m, err := open(name, size)
+	if err != nil {
+		return nil, err
+	}
+	return &Memory{m, 0}, nil
+}
+
+// Close is close & discard shared memory
+func (o *Memory) Close() (err error) {
+	if o.m != nil {
+		err = o.m.close()
+		if err == nil {
+			o.m = nil
+		}
+	}
+	return err
+}
+
+// Read is read shared memory (current position)
+func (o *Memory) Read(p []byte) (n int, err error) {
+	n, err = o.ReadAt(p, o.pos)
+	if err != nil {
+		return 0, err
+	}
+	o.pos += int64(n)
+	return n, nil
+}
+
+// ReadAt is read shared memory (offset)
+func (o *Memory) ReadAt(p []byte, off int64) (n int, err error) {
+	return o.m.readAt(p, off)
+}
+
+// Seek is move read/write position at shared memory
+func (o *Memory) Seek(offset int64, whence int) (int64, error) {
+	switch whence {
+	case io.SeekStart:
+		offset += int64(0)
+	case io.SeekCurrent:
+		offset += o.pos
+	case io.SeekEnd:
+		offset += int64(o.m.size)
+	}
+	if offset < 0 || offset >= int64(o.m.size) {
+		return 0, fmt.Errorf("invalid offset")
+	}
+	o.pos = offset
+	return offset, nil
+}
+
+// Write is write shared memory (current position)
+func (o *Memory) Write(p []byte) (n int, err error) {
+	n, err = o.WriteAt(p, o.pos)
+	if err != nil {
+		return 0, err
+	}
+	o.pos += int64(n)
+	return n, nil
+}
+
+// WriteAt is write shared memory (offset)
+func (o *Memory) WriteAt(p []byte, off int64) (n int, err error) {
+	return o.m.writeAt(p, off)
+}
@@ -0,0 +1,157 @@
+//go:build darwin && cgo
+// +build darwin,cgo
+
+package sharedMem
+
+/*
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/errno.h>
+
+int _create(const char* name, int size, int flag) {
+	mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
+
+	int fd = shm_open(name, flag, mode);
+	if (fd < 0) {
+		return -1;
+	}
+
+	struct stat mapstat;
+	int ret = fstat(fd, &mapstat);
+	if (ret != -1 && mapstat.st_size == 0) {
+		if (ftruncate(fd, size) != 0) {
+			close(fd);
+			return -2;
+		}
+	} else if (ret == -1) {
+		close(fd);
+		return -3;
+	}
+
+	return fd;
+}
+
+int Create(const char* name, int size) {
+	int flag = O_RDWR | O_CREAT;
+	return _create(name, size, flag);
+}
+
+int Open(const char* name, int size) {
+	int flag = O_RDWR;
+	return _create(name, size, flag);
+}
+
+void* Map(int fd, int size) {
+	void* p = mmap(
+		NULL, size,
+		PROT_READ | PROT_WRITE,
+		MAP_SHARED, fd, 0);
+	if (p == MAP_FAILED) {
+		return NULL;
+	}
+	return p;
+}
+
+void Close(int fd, void* p, int size) {
+	if (p != NULL) {
+		munmap(p, size);
+	}
+	if (fd != 0) {
+		close(fd);
+	}
+}
+
+void Delete(const char* name) {
+	shm_unlink(name);
+}
+*/
+import "C"
+
+import (
+	"fmt"
+	"io"
+	"unsafe"
+)
+
+type shmi struct {
+	name   string
+	fd     C.int
+	v      unsafe.Pointer
+	size   int32
+	parent bool
+}
+
+// create shared memory. return shmi object.
+// name should not be more than 31 bytes.
+func create(name string, size int32) (*shmi, error) {
+	name = "/" + name
+
+	fd := C.Create(C.CString(name), C.int(size))
+	if fd < 0 {
+		return nil, fmt.Errorf("create")
+	}
+
+	v := C.Map(fd, C.int(size))
+	if v == nil {
+		C.Close(fd, nil, C.int(size))
+		C.Delete(C.CString(name))
+	}
+
+	return &shmi{name, fd, v, size, true}, nil
+}
+
+// open shared memory. return shmi object.
+// name should not be more than 31 bytes.
+func open(name string, size int32) (*shmi, error) {
+	name = "/" + name
+
+	fd := C.Open(C.CString(name), C.int(size))
+	if fd < 0 {
+		return nil, fmt.Errorf("open")
+	}
+
+	v := C.Map(fd, C.int(size))
+	if v == nil {
+		C.Close(fd, nil, C.int(size))
+		C.Delete(C.CString(name))
+	}
+
+	return &shmi{name, fd, v, size, false}, nil
+}
+
+func (o *shmi) close() error {
+	if o.v != nil {
+		C.Close(o.fd, o.v, C.int(o.size))
+		o.v = nil
+	}
+	if o.parent {
+		C.Delete(C.CString(o.name))
+	}
+	return nil
+}
+
+// read shared memory. return read size.
+func (o *shmi) readAt(p []byte, off int64) (n int, err error) {
+	if off >= int64(o.size) {
+		return 0, io.EOF
+	}
+	if max := int64(o.size) - off; int64(len(p)) > max {
+		p = p[:max]
+	}
+	return copyPtr2Slice(uintptr(o.v), p, off, o.size), nil
+}
+
+// write shared memory. return write size.
+func (o *shmi) writeAt(p []byte, off int64) (n int, err error) {
+	if off >= int64(o.size) {
+		return 0, io.EOF
+	}
+	if max := int64(o.size) - off; int64(len(p)) > max {
+		p = p[:max]
+	}
+	return copySlice2Ptr(p, uintptr(o.v), off, o.size), nil
+}
@@ -0,0 +1,148 @@
+//go:build linux && cgo
+// +build linux,cgo
+
+package sharedMem
+
+/*
+#cgo LDFLAGS: -lrt
+
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int _create(const char* name, int size, int flag) {
+	mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
+
+	int fd = shm_open(name, flag, mode);
+	if (fd < 0) {
+		return -1;
+	}
+
+	if (ftruncate(fd, size) != 0) {
+		close(fd);
+		return -2;
+	}
+	return fd;
+}
+
+int Create(const char* name, int size) {
+	int flag = O_RDWR | O_CREAT;
+	return _create(name, size, flag);
+}
+
+int Open(const char* name, int size) {
+	int flag = O_RDWR;
+	return _create(name, size, flag);
+}
+
+void* Map(int fd, int size) {
+	void* p = mmap(
+		NULL, size,
+		PROT_READ | PROT_WRITE,
+		MAP_SHARED, fd, 0);
+	if (p == MAP_FAILED) {
+		return NULL;
+	}
+	return p;
+}
+
+void Close(int fd, void* p, int size) {
+	if (p != NULL) {
+		munmap(p, size);
+	}
+	if (fd != 0) {
+		close(fd);
+	}
+}
+
+void Delete(const char* name) {
+	shm_unlink(name);
+}
+*/
+import "C"
+
+import (
+	"fmt"
+	"io"
+	"unsafe"
+)
+
+type shmi struct {
+	name   string
+	fd     C.int
+	v      unsafe.Pointer
+	size   int32
+	parent bool
+}
+
+// create shared memory. return shmi object.
+func create(name string, size int32) (*shmi, error) {
+	name = "/" + name
+
+	fd := C.Create(C.CString(name), C.int(size))
+	if fd < 0 {
+		return nil, fmt.Errorf("create")
+	}
+
+	v := C.Map(fd, C.int(size))
+	if v == nil {
+		C.Close(fd, nil, C.int(size))
+		C.Delete(C.CString(name))
+	}
+
+	return &shmi{name, fd, v, size, true}, nil
+}
+
+// open shared memory. return shmi object.
+func open(name string, size int32) (*shmi, error) {
+	name = "/" + name
+
+	fd := C.Open(C.CString(name), C.int(size))
+	if fd < 0 {
+		return nil, fmt.Errorf("open")
+	}
+
+	v := C.Map(fd, C.int(size))
+	if v == nil {
+		C.Close(fd, nil, C.int(size))
+		C.Delete(C.CString(name))
+	}
+
+	return &shmi{name, fd, v, size, false}, nil
+}
+
+func (o *shmi) close() error {
+	if o.v != nil {
+		C.Close(o.fd, o.v, C.int(o.size))
+		o.v = nil
+	}
+	if o.parent {
+		C.Delete(C.CString(o.name))
+	}
+	return nil
+}
+
+// read shared memory. return read size.
+func (o *shmi) readAt(p []byte, off int64) (n int, err error) {
+	if off >= int64(o.size) {
+		return 0, io.EOF
+	}
+	if max := int64(o.size) - off; int64(len(p)) > max {
+		p = p[:max]
+	}
+	return copyPtr2Slice(uintptr(o.v), p, off, o.size), nil
+}
+
+// write shared memory. return write size.
+func (o *shmi) writeAt(p []byte, off int64) (n int, err error) {
+	if off >= int64(o.size) {
+		return 0, io.EOF
+	}
+	if max := int64(o.size) - off; int64(len(p)) > max {
+		p = p[:max]
+	}
+	return copySlice2Ptr(p, uintptr(o.v), off, o.size), nil
+}
@@ -0,0 +1,82 @@
+package sharedMem
+
+import (
+	"io"
+	"log"
+
+	"golang.org/x/sys/windows"
+)
+
+type shmi struct {
+	h    windows.Handle
+	v    uintptr
+	size uint32
+}
+
+// create shared memory. return shmi object.
+func create(name string, size uint32) (*shmi, error) {
+	fnPtr, _ := windows.UTF16PtrFromString(name)
+
+	flProtect := uint32(windows.PAGE_READONLY)
+
+	h, errno := windows.CreateFileMapping(
+		windows.InvalidHandle,
+		nil,
+		flProtect,
+		0,
+		size,
+		fnPtr)
+	if h == 0 {
+		log.Fatal("could not open memmap file: ", errno)
+	}
+
+	addr, errno := windows.MapViewOfFile(h,
+		windows.FILE_MAP_READ,
+		0,
+		0,
+		uintptr(size))
+	if addr == 0 {
+		log.Printf("error in MapViewOfFile: %v", errno)
+	}
+
+	return &shmi{h, addr, size}, nil
+}
+
+// open shared memory. return shmi object.
+func open(name string, size uint32) (*shmi, error) {
+	return create(name, size)
+}
+
+func (o *shmi) close() error {
+	if o.v != uintptr(0) {
+		windows.UnmapViewOfFile(o.v)
+		o.v = uintptr(0)
+	}
+	if o.h != windows.InvalidHandle {
+		windows.CloseHandle(o.h)
+		o.h = windows.InvalidHandle
+	}
+	return nil
+}
+
+// read shared memory. return read size.
+func (o *shmi) readAt(p []byte, off int64) (n int, err error) {
+	if off >= int64(o.size) {
+		return 0, io.EOF
+	}
+	if max := int64(o.size) - off; int64(len(p)) > max {
+		p = p[:max]
+	}
+	return copyPtr2Slice(o.v, p, off, o.size), nil
+}
+
+// write shared memory. return write size.
+func (o *shmi) writeAt(p []byte, off int64) (n int, err error) {
+	if off >= int64(o.size) {
+		return 0, io.EOF
+	}
+	if max := int64(o.size) - off; int64(len(p)) > max {
+		p = p[:max]
+	}
+	return copySlice2Ptr(p, o.v, off, o.size), nil
+}
@@ -0,0 +1,15 @@
+package sharedMem
+
+import (
+	"unsafe"
+)
+
+func copySlice2Ptr(b []byte, p uintptr, off int64, size uint32) int {
+	bb := unsafe.Slice((*byte)(*(*unsafe.Pointer)(unsafe.Pointer(&p))), int(size))
+	return copy(bb[off:], b)
+}
+
+func copyPtr2Slice(p uintptr, b []byte, off int64, size uint32) int {
+	bb := unsafe.Slice((*byte)(*(*unsafe.Pointer)(unsafe.Pointer(&p))), int(size))
+	return copy(b, bb[off:size])
+}