Create a script system

1 files changed, 182 insertions, 0 deletions

diff --git a/scripts/src/libs/buffer.rs b/scripts/src/libs/buffer.rs
new file mode 100644
index 0000000..b4cee77
--- /dev/null
+++ b/scripts/src/libs/buffer.rs
@@ -0,0 +1,182 @@
+use wasmtime::Caller;
+
+use crate::{ScriptManager, WasmScriptState};
+
+use super::{system::_get_memory, LIBRARY_NAME};
+
+fn memory_search(mut caller: Caller<'_, WasmScriptState>, ptr: u32, ch: u32, len: u32) -> u32 {
+	let (_, mem_ptr) = _get_memory(&mut caller);
+	let len = len as usize;
+	let ptr = ptr as usize;
+	let ch = ch as u8;
+	if (len + ptr) > mem_ptr.len() {
+		return 4;
+	}
+
+	for i in 0..len {
+		if mem_ptr[ptr + i] == ch {
+			return (ptr + i) as u32;
+		}
+	}
+
+	0
+}
+
+fn memory_search_last(mut caller: Caller<'_, WasmScriptState>, ptr: u32, ch: u32, len: u32) -> u32 {
+	let (_, mem_ptr) = _get_memory(&mut caller);
+	let len = len as usize;
+	let ptr = ptr as usize;
+	let ch = ch as u8;
+	if (len + ptr) > mem_ptr.len() {
+		return 4;
+	}
+
+	for i in 0..len {
+		let index = ptr + len - i - 1;
+		if mem_ptr[index] == ch {
+			return index as u32;
+		}
+	}
+
+	0
+}
+
+fn memory_compare(
+	mut caller: Caller<'_, WasmScriptState>,
+	lhs: u32,
+	rhs: u32,
+	len: u32,
+) -> (u32, u32) {
+	let (_, mem_ptr) = _get_memory(&mut caller);
+	let len = len as usize;
+	let lhs = lhs as usize;
+	let rhs = rhs as usize;
+	if (len + lhs) > mem_ptr.len() || (len + rhs) > mem_ptr.len() {
+		return (4, 0);
+	}
+
+	for i in 0..len {
+		let diff = mem_ptr[lhs + i] - mem_ptr[rhs + i];
+		if diff != 0 {
+			return (0, diff as u32);
+		}
+	}
+
+	(0, 0)
+}
+
+fn memory_fill(mut caller: Caller<'_, WasmScriptState>, dest: u32, ch: u32, len: u32) -> u32 {
+	let (_, mem_ptr) = _get_memory(&mut caller);
+	let len = len as usize;
+	let dest = dest as usize;
+	let ch = ch as u8;
+
+	if (len + dest) > mem_ptr.len() {
+		return 4;
+	}
+
+	for i in 0..len {
+		mem_ptr[dest + i] = ch;
+	}
+
+	0
+}
+
+fn memory_copy(mut caller: Caller<'_, WasmScriptState>, dest: u32, src: u32, len: u32) -> u32 {
+	let (_, mem_ptr) = _get_memory(&mut caller);
+	let len = len as usize;
+	let dest = dest as usize;
+	let src = src as usize;
+	if (len + dest) > mem_ptr.len() || (len + src) > mem_ptr.len() {
+		return 4;
+	}
+
+	// check for overlap
+	if (dest < src && dest + len > src) || (src < dest && src + len > dest) {
+		let src = mem_ptr[src..src + len].to_vec();
+		let dest = &mut mem_ptr[dest..dest + len];
+		dest.clone_from_slice(&src);
+	} else {
+		for i in 0..len {
+			mem_ptr[dest + i] = mem_ptr[src + i];
+		}
+	}
+
+	0
+}
+
+fn memory_copy_until(
+	mut caller: Caller<'_, WasmScriptState>,
+	dest: u32,
+	src: u32,
+	len: u32,
+	delimiter: u32,
+) -> u32 {
+	let (_, mem_ptr) = _get_memory(&mut caller);
+	let len = len as usize;
+	let dest = dest as usize;
+	let src = src as usize;
+	let delimiter = delimiter as u8;
+	if (len + dest) > mem_ptr.len() || (len + src) > mem_ptr.len() {
+		return 4;
+	}
+
+	// check for overlap
+	if (dest < src && dest + len > src) || (src < dest && src + len > dest) {
+		let cloned_src = mem_ptr[src..src + len].to_vec();
+		let dest = &mut mem_ptr[dest..dest + len];
+		for i in 0..len {
+			let ch = cloned_src[i];
+			dest[i] = ch;
+			if ch == delimiter {
+				return (src + i + 1) as u32;
+			}
+		}
+	} else {
+		for i in 0..len {
+			let ch = mem_ptr[src + i];
+			mem_ptr[dest + i] = ch;
+			if ch == delimiter {
+				return (src + i + 1) as u32;
+			}
+		}
+	}
+
+	0
+}
+
+fn memory_concatenate(
+	mut caller: Caller<'_, WasmScriptState>,
+	dest: u32,
+	src: u32,
+	dest_len: u32,
+	src_len: u32,
+) -> u32 {
+	let (_, mem_ptr) = _get_memory(&mut caller);
+	let dest = dest as usize;
+	let src = src as usize;
+	let dest_len = dest_len as usize;
+	let src_len = src_len as usize;
+	if (dest_len + src_len + dest) > mem_ptr.len() || (src_len + src) > mem_ptr.len() {
+		return 4;
+	}
+
+	let src = mem_ptr[src..src + src_len].to_vec();
+	let dest_offset = dest + dest_len;
+	let dest = &mut mem_ptr[dest_offset..dest_offset + src_len];
+	dest.clone_from_slice(&src);
+
+	0
+}
+
+pub fn library(manager: &mut ScriptManager) -> Option<()> {
+	manager.add_library_function(LIBRARY_NAME, "memchr", memory_search)?;
+	manager.add_library_function(LIBRARY_NAME, "memrchr", memory_search_last)?;
+	manager.add_library_function(LIBRARY_NAME, "memcmp", memory_compare)?;
+	manager.add_library_function(LIBRARY_NAME, "memset", memory_fill)?;
+	manager.add_library_function(LIBRARY_NAME, "memcpy", memory_copy)?;
+	manager.add_library_function(LIBRARY_NAME, "memccpy", memory_copy_until)?;
+	manager.add_library_function(LIBRARY_NAME, "memcat", memory_concatenate)?;
+
+	Some(())
+}