remove the need for full reserve

Cargo.lock

@@ -79,9 +79,9 @@ dependencies = [
 
 [[package]]
 name = "bitbuffer"
-version = "0.9.7"
+version = "0.9.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c69c4d2ef0cb9cd4cbb53bf5cd13746e6bc73c6ff2aedbfee0951c18553232d3"
+checksum = "72133b9e2c77f4bc4243ad82b246f2c6d0f1399e519258eeb0644f84a9d9bae5"
 dependencies = [
  "bitbuffer_derive",
  "err-derive",
@@ -526,9 +526,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.27"
+version = "1.0.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0d8caf72986c1a598726adc988bb5984792ef84f5ee5aa50209145ee8077038"
+checksum = "5c7ed8b8c7b886ea3ed7dde405212185f423ab44682667c8c6dd14aa1d9f6612"
 dependencies = [
  "unicode-xid",
 ]
@@ -665,9 +665,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.73"
+version = "1.0.74"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f71489ff30030d2ae598524f61326b902466f72a0fb1a8564c001cc63425bcc7"
+checksum = "1873d832550d4588c3dbc20f01361ab00bfe741048f71e3fecf145a7cc18b29c"
 dependencies = [
  "proc-macro2",
  "quote",

src/bin/reencode.rs

@@ -23,8 +23,8 @@ const COPY_TYPES: &[PacketType] = &[
     // PacketType::SyncTick,   // bit perfect
     // PacketType::ConsoleCmd, // bit perfect
     // PacketType::DataTables, // bit perfect
-    // PacketType::StringTables, // clone enough
+    // PacketType::StringTables, // close enough
-                              // PacketType::UserCmd,      // bit perfect
+    // PacketType::UserCmd, // close enough
 ];
 
 fn main() -> Result<(), MainError> {
@@ -63,21 +63,15 @@ fn main() -> Result<(), MainError> {
                 match &mut packet {
                     Packet::Sigon(message_packet) | Packet::Message(message_packet) => {
                         message_packet.meta.view_angles = Default::default();
-                        let messages = std::mem::take(&mut message_packet.messages);
+                        message_packet
-                        let messages = messages
+                            .messages
-                            .into_iter()
+                            .iter_mut()
-                            .filter(|msg| msg.get_message_type() != MessageType::SetView)
+                            .for_each(|msg| match msg {
-                            .map(|mut msg| {
+                                Message::ServerInfo(info) => {
-                                match &mut msg {
+                                    info.stv = true;
-                                    Message::ServerInfo(info) => {
+                                }
-                                        info.stv = true;
+                                _ => {}
-                                    }
+                            });
-                                    _ => {}
-                                };
-                                msg
-                            })
-                            .collect::<Vec<_>>();
-                        message_packet.messages = messages;
                     }
                     _ => {}
                 }

src/demo/message/packetentities.rs

@@ -160,7 +160,7 @@ fn test_bit_var_roundtrip() {
             write.bit_len()
         };
         let mut read = BitReadStream::new(BitReadBuffer::new(&data, LittleEndian));
-        assert_eq!(val, read_bit_var(&mut read).unwrap());
+        assert_eq!(val, read_bit_var::<u32>(&mut read).unwrap());
         assert_eq!(pos, read.pos());
     }
     bit_var_normal(0);
@@ -291,7 +291,7 @@ impl Encode for PacketEntitiesMessage {
         self.base_line.write_sized(stream, 1)?;
         self.entities.len().write_sized(stream, 11)?;
 
-        stream.reserve(20, |length_stream, stream| {
+        stream.reserve_int(20, |stream| {
             self.updated_base_line.write(stream)?;
 
             let length_start = stream.bit_len();
@@ -338,9 +338,7 @@ impl Encode for PacketEntitiesMessage {
 
             let length_end = stream.bit_len();
 
-            (length_end - length_start).write_sized(length_stream, 20)?;
+            Ok((length_end - length_start) as u64)
-
-            Ok(())
         })
     }
 }

src/demo/message/stringtable.rs

@@ -164,33 +164,24 @@ impl Encode for CreateStringTableMessage<'_> {
         let encode_bits = log_base2(table.max_entries) as usize;
         (table.entries.len() as u16).write_sized(stream, encode_bits + 1)?;
 
-        // since length is encoded with a dynamic bit size, we can't use the normal "reserve" tricks
+        stream.reserve_int::<ParseError, _>(40, |stream| {
-        // so instead we write the body to a temporary vec first
+            table.fixed_user_data_size.is_some().write(stream)?;
-        let mut target_vec = Vec::with_capacity(table.entries.len() * 32);
-        let (target_length_start, target_end) = {
-            let mut target = BitWriteStream::new(&mut target_vec, LittleEndian);
-
-            table.fixed_user_data_size.is_some().write(&mut target)?;
             if let Some(fixed_size) = table.fixed_user_data_size {
-                fixed_size.write(&mut target)?;
+                fixed_size.write(stream)?;
             }
 
             // no compression for now
-            false.write(&mut target)?;
+            false.write(stream)?;
 
-            let target_length_start = target.bit_len();
+            let start = stream.bit_len();
 
             let table_meta = table.get_table_meta();
 
-            write_string_table_update(&table.entries, &mut target, &table_meta)?;
+            write_string_table_update(&table.entries, stream, &table_meta)?;
-            let target_end = target.bit_len();
-            (target_length_start, target_end)
-        };
-        let mut body_reader =
-            BitReadStream::new(BitReadBuffer::new_owned(target_vec, LittleEndian));
 
-        write_var_int((target_end - target_length_start) as u32, stream)?;
+            let end = stream.bit_len();
-        body_reader.read_bits(target_end)?.write(stream)?;
+            Ok(encode_var_int_fixed((end - start) as u32))
+        })?;
 
         Ok(())
     }
@@ -728,6 +719,19 @@ pub fn write_var_int(mut int: u32, stream: &mut BitWriteStream<LittleEndian>) ->
     (int as u8).write(stream)
 }
 
+// encode the int in such a way that it has a fixed size, but still decodes the same
+// result is the first 40 bits of the return value
+pub fn encode_var_int_fixed(mut int: u32) -> u64 {
+    let mut out = 0;
+    for i in 0..4 {
+        let byte: u8 = int as u8 & 0x7F;
+        out |= ((byte | 0x80) as u64) << i * 8;
+        int >>= 7;
+    }
+    out |= (int as u64) << 32;
+    out
+}
+
 #[test]
 fn test_var_int_roundtrip() {
     fn var_int_roundtrip(int: u32) {
@@ -750,6 +754,30 @@ fn test_var_int_roundtrip() {
     var_int_roundtrip(123125412);
 }
 
+#[test]
+fn test_var_int_fixed_roundtrip() {
+    fn var_int_roundtrip(int: u32) {
+        let mut data = Vec::new();
+        let pos = {
+            let mut write = BitWriteStream::new(&mut data, LittleEndian);
+            let encoded = encode_var_int_fixed(int);
+            encoded.write_sized(&mut write, 40).unwrap();
+            write.bit_len()
+        };
+        assert_eq!(40, pos);
+        let mut read = BitReadStream::new(BitReadBuffer::new(&data, LittleEndian));
+        assert_eq!(int, read_var_int(&mut read).unwrap());
+        assert_eq!(pos, read.pos());
+    }
+    var_int_roundtrip(0);
+    var_int_roundtrip(1);
+    var_int_roundtrip(10);
+    var_int_roundtrip(55);
+    var_int_roundtrip(355);
+    var_int_roundtrip(12354);
+    var_int_roundtrip(123125412);
+}
+
 pub fn log_base2<T: PrimInt + Unsigned>(num: T) -> u32 {
     // log(0) = inf, but that's a useless result
     // since this would only happen in malformed demos, we just return 0

src/demo/message/tempentities.rs

@@ -1,14 +1,12 @@
 use super::stringtable::read_var_int;
 use crate::demo::message::packetentities::PacketEntitiesMessage;
-use crate::demo::message::stringtable::{log_base2, write_var_int};
+use crate::demo::message::stringtable::{encode_var_int_fixed, log_base2};
 use crate::demo::packet::datatable::ClassId;
 use crate::demo::parser::{Encode, ParseBitSkip};
 use crate::demo::sendprop::SendProp;
 use crate::Result;
 use crate::{Parse, ParseError, ParserState, Stream};
-use bitbuffer::{
+use bitbuffer::{BitWrite, BitWriteSized, BitWriteStream, LittleEndian};
-    BitReadBuffer, BitReadStream, BitWrite, BitWriteSized, BitWriteStream, LittleEndian,
-};
 
 #[derive(Debug, PartialEq)]
 pub struct TempEntitiesMessage {
@@ -107,26 +105,25 @@ impl Encode for TempEntitiesMessage {
         };
         count.write(stream)?;
 
-        let mut out = Vec::with_capacity(self.events.len() * 16);
+        stream.reserve_int::<ParseError, _>(40, |stream| {
-        let bits = {
+            let start = stream.bit_len();
-            let mut write = BitWriteStream::new(&mut out, LittleEndian);
             let mut last_class_id = u16::MAX.into();
 
             for event in self.events.iter() {
                 if event.fire_delay > 0.0 {
-                    true.write(&mut write)?;
+                    true.write(stream)?;
-                    ((event.fire_delay * 100.0) as u8).write(&mut write)?;
+                    ((event.fire_delay * 100.0) as u8).write(stream)?;
                 } else {
-                    false.write(&mut write)?;
+                    false.write(stream)?;
                 }
 
                 if event.class_id != last_class_id {
-                    true.write(&mut write)?;
+                    true.write(stream)?;
                     let bits = log_base2(state.server_classes.len()) + 1;
                     let id: u16 = event.class_id.into();
-                    (id + 1).write_sized(&mut write, bits as usize)?;
+                    (id + 1).write_sized(stream, bits as usize)?;
                 } else {
-                    false.write(&mut write)?;
+                    false.write(stream)?;
                 }
                 last_class_id = event.class_id;
 
@@ -134,14 +131,11 @@ impl Encode for TempEntitiesMessage {
                     .send_tables
                     .get(usize::from(event.class_id))
                     .ok_or(ParseError::UnknownServerClass(event.class_id))?;
-                PacketEntitiesMessage::write_update(&event.props, &mut write, send_table)?;
+                PacketEntitiesMessage::write_update(&event.props, stream, send_table)?;
             }
-            write.bit_len()
+            let end = stream.bit_len();
-        };
+            Ok(encode_var_int_fixed((end - start) as u32))
-        let mut data = BitReadStream::new(BitReadBuffer::new(&out, LittleEndian));
+        })?;
-
-        write_var_int(bits as u32, stream)?;
-        data.read_bits(bits)?.write(stream)?;
         Ok(())
     }
 }