use crate::{
BinaryReader, BinaryReaderError, ExternalKind, Range, Result, SectionIteratorLimited,
SectionReader, SectionWithLimitedItems,
};
#[derive(Clone)]
pub struct InstanceSectionReader<'a> {
reader: BinaryReader<'a>,
count: u32,
}
impl<'a> InstanceSectionReader<'a> {
pub fn new(data: &'a [u8], offset: usize) -> Result<InstanceSectionReader<'a>> {
let mut reader = BinaryReader::new_with_offset(data, offset);
let count = reader.read_var_u32()?;
Ok(InstanceSectionReader { reader, count })
}
pub fn original_position(&self) -> usize {
self.reader.original_position()
}
pub fn get_count(&self) -> u32 {
self.count
}
pub fn read(&mut self) -> Result<Instance<'a>> {
let instance = Instance::new(
&self.reader.buffer[self.reader.position..],
self.original_position(),
)?;
let mut args = instance.args()?;
for _ in 0..args.get_count() {
args.read()?;
}
self.reader = args.reader;
Ok(instance)
}
}
impl<'a> SectionReader for InstanceSectionReader<'a> {
type Item = Instance<'a>;
fn read(&mut self) -> Result<Self::Item> {
InstanceSectionReader::read(self)
}
fn eof(&self) -> bool {
self.reader.eof()
}
fn original_position(&self) -> usize {
InstanceSectionReader::original_position(self)
}
fn range(&self) -> Range {
self.reader.range()
}
}
impl<'a> SectionWithLimitedItems for InstanceSectionReader<'a> {
fn get_count(&self) -> u32 {
InstanceSectionReader::get_count(self)
}
}
impl<'a> IntoIterator for InstanceSectionReader<'a> {
type Item = Result<Instance<'a>>;
type IntoIter = SectionIteratorLimited<InstanceSectionReader<'a>>;
fn into_iter(self) -> Self::IntoIter {
SectionIteratorLimited::new(self)
}
}
#[derive(Clone)]
pub struct Instance<'a> {
reader: BinaryReader<'a>,
module: u32,
}
impl<'a> Instance<'a> {
pub fn new(data: &'a [u8], offset: usize) -> Result<Instance<'a>> {
let mut reader = BinaryReader::new_with_offset(data, offset);
if reader.read_u8()? != 0 {
return Err(BinaryReaderError::new(
"instantiate instruction not found",
offset,
));
}
let module = reader.read_var_u32()?;
Ok(Instance { module, reader })
}
pub fn original_position(&self) -> usize {
self.reader.original_position()
}
pub fn module(&self) -> u32 {
self.module
}
pub fn args(&self) -> Result<InstanceArgsReader<'a>> {
let mut reader = self.reader.clone();
let count = reader.read_var_u32()?;
Ok(InstanceArgsReader {
count,
remaining: count,
reader,
})
}
}
#[derive(Clone)]
pub struct InstanceArgsReader<'a> {
reader: BinaryReader<'a>,
count: u32,
remaining: u32,
}
#[derive(Debug)]
pub struct InstanceArg<'a> {
pub name: &'a str,
pub kind: ExternalKind,
pub index: u32,
}
impl<'a> InstanceArgsReader<'a> {
pub fn original_position(&self) -> usize {
self.reader.original_position()
}
pub fn read(&mut self) -> Result<InstanceArg<'a>> {
self.remaining -= 1;
Ok(InstanceArg {
name: self.reader.read_string()?,
kind: self.reader.read_external_kind()?,
index: self.reader.read_var_u32()?,
})
}
}
impl<'a> SectionReader for InstanceArgsReader<'a> {
type Item = InstanceArg<'a>;
fn read(&mut self) -> Result<Self::Item> {
InstanceArgsReader::read(self)
}
fn eof(&self) -> bool {
self.remaining == 0
}
fn original_position(&self) -> usize {
InstanceArgsReader::original_position(self)
}
fn range(&self) -> Range {
self.reader.range()
}
}
impl<'a> SectionWithLimitedItems for InstanceArgsReader<'a> {
fn get_count(&self) -> u32 {
self.count
}
}
impl<'a> IntoIterator for InstanceArgsReader<'a> {
type Item = Result<InstanceArg<'a>>;
type IntoIter = SectionIteratorLimited<InstanceArgsReader<'a>>;
fn into_iter(self) -> Self::IntoIter {
SectionIteratorLimited::new(self)
}
}