Add readString, writeString method (#243)

crates/lune-std-ffi/src/data/box_data/mod.rs

@@ -138,6 +138,9 @@ impl LuaUserData for BoxData {
     }
     fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
         method_provider::provide_copy_from(methods);
+        method_provider::provide_read_string(methods);
+        method_provider::provide_write_string(methods);
+
         // For convenience, :zero returns box itself.
         methods.add_function_mut("zero", |_lua, this: LuaAnyUserData| {
             this.borrow_mut::<BoxData>()?.zero();

crates/lune-std-ffi/src/data/helper.rs

@@ -26,10 +26,10 @@ pub mod method_provider {
                 let src = src.get_ffi_data()?;
 
                 if !src.check_inner_boundary(src_offset, length) {
-                    return Err(LuaError::external("Source boundary check failed"));
+                    return Err(LuaError::external("Source out of bounds"));
                 }
                 if !this.check_inner_boundary(dst_offset, length) {
-                    return Err(LuaError::external("Self boundary check failed"));
+                    return Err(LuaError::external("Self out of bounds"));
                 }
 
                 this.copy_from(&src, length, dst_offset, src_offset);
@@ -39,6 +39,61 @@ pub mod method_provider {
         );
     }
 
-    // TODO: writeString, readString, writeBase64 and readBase64 methods
-    // TODO: Bit operation support
+    // Implement readString method
+    pub fn provide_read_string<'lua, Target, M>(methods: &mut M)
+    where
+        Target: FfiData,
+        M: LuaUserDataMethods<'lua, Target>,
+    {
+        methods.add_method(
+            "readString",
+            |lua, this, (length, offset): (usize, Option<isize>)| unsafe {
+                let offset = offset.unwrap_or(0);
+
+                if !this.check_inner_boundary(offset, length) {
+                    return Err(LuaError::external("Source out of bounds"));
+                }
+
+                lua.create_string(this.read_string(length, offset))
+            },
+        );
+    }
+
+    // Implement writeString method
+    pub fn provide_write_string<'lua, Target, M>(methods: &mut M)
+    where
+        Target: FfiData,
+        M: LuaUserDataMethods<'lua, Target>,
+    {
+        methods.add_method(
+            "writeString",
+            |_lua,
+             this,
+             (string, length, dst_offset, src_offset): (
+                LuaString,
+                usize,
+                Option<isize>,
+                Option<usize>,
+            )| unsafe {
+                let dst_offset = dst_offset.unwrap_or(0);
+                let src_offset = src_offset.unwrap_or(0);
+
+                // Source string boundary check
+                if string.as_bytes().len() < src_offset + length {
+                    return Err(LuaError::external("Source out of bounds"));
+                }
+
+                // Self boundary check
+                if !this.check_inner_boundary(dst_offset, length) {
+                    return Err(LuaError::external("Self out of bounds"));
+                }
+
+                this.write_string(string, length, dst_offset, src_offset);
+                Ok(())
+            },
+        );
+    }
+
+    // TODO: Bit operation support
+    // TODO: writeBase64 and readBase64 methods
 }

crates/lune-std-ffi/src/data/ref_data/mod.rs

@@ -165,6 +165,8 @@ impl FfiData for RefData {
 impl LuaUserData for RefData {
     fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
         method_provider::provide_copy_from(methods);
+        method_provider::provide_read_string(methods);
+        method_provider::provide_write_string(methods);
 
         methods.add_method("deref", |_lua, this, ()| unsafe { this.dereference() });
         methods.add_function("offset", |lua, (this, offset): (LuaAnyUserData, isize)| {

crates/lune-std-ffi/src/ffi/mod.rs

@@ -71,8 +71,33 @@ pub trait FfiData {
         src_offset: isize,
     ) {
         self.get_inner_pointer()
+            .cast::<u8>()
             .byte_offset(dst_offset)
-            .copy_from(src.get_inner_pointer().byte_offset(src_offset), length);
+            .copy_from(
+                src.get_inner_pointer().cast::<u8>().byte_offset(src_offset),
+                length,
+            );
+    }
+    unsafe fn read_string(&self, length: usize, offset: isize) -> Vec<u8> {
+        let mut string = Vec::<u8>::with_capacity(length);
+        string.as_mut_ptr().copy_from(
+            self.get_inner_pointer().cast::<u8>().byte_offset(offset),
+            length,
+        );
+        string.set_len(length);
+        string
+    }
+    unsafe fn write_string(
+        &self,
+        src: LuaString,
+        length: usize,
+        dst_offset: isize,
+        src_offset: usize,
+    ) {
+        self.get_inner_pointer()
+            .cast::<u8>()
+            .byte_offset(dst_offset)
+            .copy_from(src.to_pointer().cast::<u8>().byte_add(src_offset), length);
     }
 }
 

types/ffi.luau

@@ -125,9 +125,9 @@ export type RefData = {
 		Copy content from another data with specific length.
 
 		@param src The source data
-		@param len The amount of data to copy, in bytes
-		@param dstOffset The offset in the destination where the data will be pasted
-		@param srcOffset The offset in the source data from where the data will be copied
+		@param length The amount of data to copy, in bytes
+		@param dstOffset The offset in the destination where the content will be pasted
+		@param srcOffset The offset in the source data from where the content will be copied
 	]=]
 	copyFrom: (
 		self: RefData,
@@ -136,6 +136,37 @@ export type RefData = {
 		dstOffset: number,
 		srcOffset: number
 	) -> (),
+	--[=[
+		@within RefData
+		@tag Method
+		@method readString
+
+		Read string from data with specific length.
+
+		@param length The amount of data to read, in bytes
+		@param offset Offset to read string from
+		@return A string
+	]=]
+	readString: (self: RefData, length: number, offset: number?) -> string,
+	--[=[
+		@within RefData
+		@tag Method
+		@method writeString
+
+		Write string into data.
+
+		@param src The source string
+		@param length The amount of data to write, in bytes
+		@param dstOffset The offset in the destination where the content will be pasted
+		@param srcOffset The offset in the source string from where the content will be copied
+	]=]
+	writeString: (
+		self: RefData,
+		src: string,
+		length: number,
+		dstOffset: number,
+		srcOffset: number
+	) -> (),
 }
 
 --[=[
@@ -197,9 +228,9 @@ export type BoxData = {
 		Copy content from another data with specific length.
 
 		@param src The source data
-		@param len The amount of data to copy, in bytes
-		@param dstOffset The offset in the destination where the data will be pasted
-		@param srcOffset The offset in the source data from where the data will be copied
+		@param length The amount of data to copy, in bytes
+		@param dstOffset The offset in the destination where the content will be pasted
+		@param srcOffset The offset in the source data from where the content will be copied
 	]=]
 	copyFrom: (
 		self: BoxData,
@@ -208,6 +239,37 @@ export type BoxData = {
 		dstOffset: number,
 		srcOffset: number
 	) -> (),
+	--[=[
+		@within BoxData
+		@tag Method
+		@method readString
+
+		Read string from data with specific length.
+
+		@param length The amount of data to read, in bytes
+		@param offset Offset to read string from
+		@return A string
+	]=]
+	readString: (self: BoxData, length: number, offset: number?) -> string,
+	--[=[
+		@within BoxData
+		@tag Method
+		@method writeString
+
+		Write string into data.
+
+		@param src The source string
+		@param length The amount of data to write, in bytes
+		@param dstOffset The offset in the destination where the content will be pasted
+		@param srcOffset The offset in the source string from where the content will be copied
+	]=]
+	writeString: (
+		self: BoxData,
+		src: string,
+		length: number,
+		dstOffset: number,
+		srcOffset: number
+	) -> (),
 }
 
 --[=[
@@ -305,10 +367,10 @@ export type CTypeInfo<T, R> = {
 
 		Create an array subtype with specific length.
 
-		@param len The length of the array
+		@param length The length of the array
 		@return An array subtype
 	]=]
-	arr: (self: CTypeInfo<T, R>, len: number) -> CArrInfo<CTypeInfo<T, R>, R>,
+	arr: (self: CTypeInfo<T, R>, length: number) -> CArrInfo<CTypeInfo<T, R>, R>,
 
 	-- Create/Read/Write/Copy
 	--[=[
@@ -353,10 +415,10 @@ export type CTypeInfo<T, R> = {
 	
 		Copy values ​​from the source and paste them into the target.
 
-		@param dst Where the data will be pasted
+		@param dst Where the content will be pasted
 		@param src The source data
-		@param dstOffset The offset in the destination where the data will be pasted
-		@param srcOffset The offset in the source data from where the data will be copied
+		@param dstOffset The offset in the destination where the content will be pasted
+		@param srcOffset The offset in the source data from where the content will be copied
 	]=]
 	copyData: (
 		self: CTypeInfo<T, R>,
@@ -434,10 +496,10 @@ export type CPtrInfo<T> = {
 
 		Create an array subtype with specific length.
 
-		@param len The length of the array
+		@param length The length of the array
 		@return An array subtype
 	]=]
-	arr: (self: CPtrInfo<T>, len: number) -> any,
+	arr: (self: CPtrInfo<T>, length: number) -> any,
 	-- FIXME: recursive types; result 'any' should be CPtrInfo<CPtrInfo<T>>
 	--[=[
 		@within CPtrInfo
@@ -585,10 +647,10 @@ export type CArrInfo<T, R> = {
 	
 		Copy values ​​from the source and paste them into the target.
 	
-		@param dst Where the data will be pasted
+		@param dst Where the content will be pasted
 		@param src The source data
-		@param dstOffset The offset in the dst where the data will be pasted
-		@param srcOffset The offset in the source data from where the data will be copied
+		@param dstOffset The offset in the dst where the content will be pasted
+		@param srcOffset The offset in the source data from where the content will be copied
 	]=]
 	copyData: (
 		self: CArrInfo<T, R>,
@@ -677,10 +739,10 @@ export type CStructInfo = {
 
 		Create a struct array type.
 
-		@param len The length of the array
+		@param length The length of the array
 		@return A struct array type
 	]=]
-	arr: (self: CStructInfo, len: number) -> CArrInfo<CStructInfo, { any }>,
+	arr: (self: CStructInfo, length: number) -> CArrInfo<CStructInfo, { any }>,
 	--[=[
 		@within CSturctInfo
 		@tag Method
@@ -740,10 +802,10 @@ export type CStructInfo = {
 
 		Copy values from the source and paste them into the target.
 
-		@param dst Where the data will be pasted
+		@param dst Where the content will be pasted
 		@param src The source data
-		@param dstOffset The offset in the destination where the data will be pasted
-		@param srcOffset The offset in the source data from where the data will be copied
+		@param dstOffset The offset in the destination where the content will be pasted
+		@param srcOffset The offset in the source data from where the content will be copied
 	]=]
 	copyData: (
 		self: CStructInfo,