1 files changed, 107 insertions, 0 deletions
diff --git a/shared/src/respack.rs b/shared/src/respack.rs
new file mode 100644
index 0000000..8c0b9d8
--- /dev/null
+++ b/shared/src/respack.rs
@@ -0,0 +1,107 @@
+/*
+    wearechat - generic multiplayer game with voip
+    Copyright (C) 2025 metamuffin
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, version 3 of the License only.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+use crate::{packets::Resource, resources::RespackEntry, store::ResourceStore};
+use anyhow::{Result, bail};
+use log::{info, warn};
+use std::{
+    io::{Read, Seek, SeekFrom, Write},
+    marker::PhantomData,
+};
+
+const MAGIC: &[u8; 16] = b"\x0f\x0cWEARE\x01RESPACK\x02";
+
+pub fn save_respack(
+    mut output: impl Write,
+    store: &ResourceStore,
+    resources: &[Resource],
+    entry: Option<Resource<RespackEntry>>,
+) -> Result<()> {
+    output.write_all(MAGIC)?;
+    output.write_all(&entry.map(|e| e.0).unwrap_or([0u8; 32]))?;
+    output.write_all(&u64::to_be_bytes(resources.len() as u64))?;
+    let mut off =
+        (MAGIC.len() + 32 + size_of::<u64>() + (32 + size_of::<u64>() * 2) * resources.len())
+            as u64;
+    for r in resources {
+        let size = store.get_raw_size(*r)?.unwrap() as u64;
+        output.write_all(&r.0)?;
+        output.write_all(&u64::to_be_bytes(off))?;
+        output.write_all(&u64::to_be_bytes(size))?;
+        off += size;
+    }
+    for r in resources {
+        output.write_all(&store.get_raw(*r)?.unwrap())?;
+    }
+    Ok(())
+}
+
+pub fn load_respack(
+    mut input: impl Read + Seek,
+    store: &ResourceStore,
+) -> Result<Option<Resource<RespackEntry>>> {
+    let mut magic = [0u8; MAGIC.len()];
+    input.read_exact(&mut magic)?;
+    if magic != *MAGIC {
+        bail!("wrong magic bytes");
+    }
+    let mut entry = [0u8; 32];
+    input.read_exact(&mut entry)?;
+    let entry = if entry != [0u8; 32] {
+        Some(Resource(entry, PhantomData))
+    } else {
+        None
+    };
+
+    let mut count = [0u8; size_of::<u64>()];
+    input.read_exact(&mut count)?;
+    let count = u64::from_be_bytes(count);
+
+    let mut load_queue = Vec::new();
+    let mut found_entry = false;
+    for _ in 0..count {
+        let mut res = [0u8; 32];
+        let mut off = [0u8; size_of::<u64>()];
+        let mut size = [0u8; size_of::<u64>()];
+        input.read_exact(&mut res)?;
+        input.read_exact(&mut off)?;
+        input.read_exact(&mut size)?;
+
+        found_entry |= Some(Resource(res, PhantomData)) == entry;
+        if store.get_raw_size(Resource(res, PhantomData))?.is_none() {
+            load_queue.push((res, u64::from_be_bytes(off), u64::from_be_bytes(size)))
+        }
+    }
+    if !found_entry && entry.is_some() {
+        warn!("respack does not contain its entry resource")
+    }
+    info!(
+        "loading {} of {count} resources from pack",
+        load_queue.len(),
+    );
+
+    for (res, off, size) in load_queue {
+        input.seek(SeekFrom::Start(off))?;
+        let mut buf = Vec::new();
+        input.by_ref().take(size).read_to_end(&mut buf)?;
+        let key = store.set_raw(&buf)?;
+        if key.0 != res {
+            warn!("respack containes mislabeled resources")
+        }
+    }
+
+    Ok(entry)
+}