From 5b19c5fb941c5bd969464c549fbcdbb95f5fa984 Mon Sep 17 00:00:00 2001
From: Simon Heath <icefoxen@gmail.com>
Date: Wed, 17 Jan 2018 13:16:31 -0500
Subject: [PATCH] Added VarUint8 serialization/deserialization type.

---
 src/elements/mod.rs        |  2 +-
 src/elements/ops.rs        |  8 ++++----
 src/elements/primitives.rs | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/src/elements/mod.rs b/src/elements/mod.rs
index 25cf74f..27f1010 100644
--- a/src/elements/mod.rs
+++ b/src/elements/mod.rs
@@ -25,7 +25,7 @@ pub use self::import_entry::{ImportEntry, ResizableLimits, MemoryType, TableType
 pub use self::export_entry::{ExportEntry, Internal};
 pub use self::global_entry::GlobalEntry;
 pub use self::primitives::{
-    VarUint32, VarUint7, VarUint1, VarInt7, Uint32, VarInt32, VarInt64,
+    VarUint32, VarUint7, VarUint8, VarUint1, VarInt7, Uint32, VarInt32, VarInt64,
     Uint64, VarUint64, CountedList, CountedWriter, CountedListWriter,
 };
 pub use self::types::{Type, ValueType, BlockType, FunctionType, TableElementType};
diff --git a/src/elements/ops.rs b/src/elements/ops.rs
index 5dd5ae1..cccea83 100644
--- a/src/elements/ops.rs
+++ b/src/elements/ops.rs
@@ -1,7 +1,7 @@
 use std::{io, fmt};
 use super::{
     Serialize, Deserialize, Error, VarUint7,
-    VarUint32, CountedList, BlockType,
+    VarUint8, VarUint32, CountedList, BlockType,
     Uint32, Uint64, CountedListWriter,
     VarInt32, VarInt64,
 };
@@ -346,7 +346,7 @@ impl Deserialize for Opcode {
                 0x10 => Call(VarUint32::deserialize(reader)?.into()),
                 0x11 => CallIndirect(
                     VarUint32::deserialize(reader)?.into(),
-                    VarUint7::deserialize(reader)?.into()),
+                    VarUint8::deserialize(reader)?.into()),
                 0x1a => Drop,
                 0x1b => Select,
 
@@ -449,8 +449,8 @@ impl Deserialize for Opcode {
                     VarUint32::deserialize(reader)?.into()),
 
 
-                0x3f => CurrentMemory(VarUint7::deserialize(reader)?.into()),
-                0x40 => GrowMemory(VarUint7::deserialize(reader)?.into()),
+                0x3f => CurrentMemory(VarUint8::deserialize(reader)?.into()),
+                0x40 => GrowMemory(VarUint8::deserialize(reader)?.into()),
 
                 0x41 => I32Const(VarInt32::deserialize(reader)?.into()),
                 0x42 => I64Const(VarInt64::deserialize(reader)?.into()),
diff --git a/src/elements/primitives.rs b/src/elements/primitives.rs
index 4d67418..d2deeb0 100644
--- a/src/elements/primitives.rs
+++ b/src/elements/primitives.rs
@@ -206,6 +206,43 @@ impl Serialize for VarInt7 {
     }
 }
 
+/// 8-bit unsigned integer, NOT encoded in LEB128;
+/// it's just a single byte.
+#[derive(Debug, Copy, Clone)]
+pub struct VarUint8(u8);
+
+impl From<VarUint8> for u8 {
+    fn from(v: VarUint8) -> u8 {
+        v.0
+    }
+}
+
+impl From<u8> for VarUint8 {
+    fn from(v: u8) -> Self {
+        VarUint8(v)
+    }
+}
+
+impl Deserialize for VarUint8 {
+    type Error = Error;
+
+    fn deserialize<R: io::Read>(reader: &mut R) -> Result<Self, Self::Error> {
+        let mut u8buf = [0u8; 1];
+        reader.read_exact(&mut u8buf)?;
+        Ok(VarUint8(u8buf[0]))
+    }
+}
+
+impl Serialize for VarUint8 {
+    type Error = Error;
+
+    fn serialize<W: io::Write>(self, writer: &mut W) -> Result<(), Self::Error> {
+        writer.write_all(&[self.0])?;
+        Ok(())
+    }
+}
+
+
 /// 32-bit signed integer, encoded in LEB128 (can be 1-5 bytes length)
 #[derive(Debug, Copy, Clone)]
 pub struct VarInt32(i32);