Slabs

Cargo.toml

@@ -32,6 +32,7 @@ chrono = "0.4"
 clap = "2"
 download = {path = "download", default-features = false}
 effective-limits = "0.5.2"
+enum-map = "1.1.0"
 flate2 = "1"
 git-testament = "0.1.4"
 home = {git = "https://github.com/rbtcollins/home", rev = "a243ee2fbee6022c57d56f5aa79aefe194eabe53"}
@@ -52,6 +53,7 @@ scopeguard = "1"
 semver = "0.11"
 serde = {version = "1.0", features = ["derive"]}
 sha2 = "0.9"
+sharded-slab = "0.1.1"
 strsim = "0.10"
 tar = "0.4.26"
 tempfile = "3.1"

src/cli/common.rs

@@ -148,6 +148,9 @@ impl NotifyOnConsole {
                 NotificationLevel::Error => {
                     err!("{}", n);
                 }
+                NotificationLevel::Debug => {
+                    debug!("{}", n);
+                }
             }
         }
     }

src/diskio/immediate.rs

@@ -11,7 +11,7 @@ use std::{
     time::Instant,
 };
 
-use super::{CompletedIo, Executor, Item};
+use super::{CompletedIo, Executor, FileBuffer, Item};
 
 #[derive(Debug)]
 pub struct _IncrementalFileState {
@@ -70,7 +70,11 @@ impl Executor for ImmediateUnpacker {
         item.result = match &mut item.kind {
             super::Kind::Directory => super::create_dir(&item.full_path),
             super::Kind::File(ref contents) => {
-                super::write_file(&item.full_path, &contents, item.mode)
+                if let super::FileBuffer::Immediate(ref contents) = &contents {
+                    super::write_file(&item.full_path, contents, item.mode)
+                } else {
+                    unreachable!()
+                }
             }
             super::Kind::IncrementalFile(_incremental_file) => {
                 return {
@@ -124,6 +128,14 @@ impl Executor for ImmediateUnpacker {
             super::IncrementalFileState::Immediate(self.incremental_state.clone())
         }
     }
+
+    fn get_buffer(&mut self, capacity: usize) -> super::FileBuffer {
+        super::FileBuffer::Immediate(Vec::with_capacity(capacity))
+    }
+
+    fn buffer_available(&self, _len: usize) -> bool {
+        true
+    }
 }
 
 /// The non-shared state for writing a file incrementally
@@ -160,10 +172,15 @@ impl IncrementalFileWriter {
         })
     }
 
-    pub fn chunk_submit(&mut self, chunk: Vec<u8>) -> bool {
+    pub fn chunk_submit(&mut self, chunk: FileBuffer) -> bool {
         if (self.state.lock().unwrap()).is_none() {
             return false;
         }
+        let chunk = if let FileBuffer::Immediate(v) = chunk {
+            v
+        } else {
+            unreachable!()
+        };
         match self.write(chunk) {
             Ok(v) => v,
             Err(e) => {

src/diskio/mod.rs

@@ -57,6 +57,7 @@ mod test;
 pub mod threaded;
 
 use std::io::{self, Write};
+use std::ops::{Deref, DerefMut};
 use std::path::{Path, PathBuf};
 use std::sync::mpsc::Receiver;
 use std::time::{Duration, Instant};
@@ -66,12 +67,73 @@ use anyhow::{Context, Result};
 
 use crate::process;
 use crate::utils::notifications::Notification;
+use threaded::PoolReference;
+
+/// Carries the implementation specific data for complete file transfers into the executor.
+#[derive(Debug)]
+pub enum FileBuffer {
+    Immediate(Vec<u8>),
+    // A reference to the object in the pool, and a handle to write to it
+    Threaded(PoolReference),
+}
+
+impl FileBuffer {
+    /// All the buffers space to be re-used when the last reference to it is dropped.
+    pub(crate) fn clear(&mut self) {
+        if let FileBuffer::Threaded(ref mut contents) = self {
+            contents.clear()
+        }
+    }
+
+    pub(crate) fn len(&self) -> usize {
+        match self {
+            FileBuffer::Immediate(ref vec) => vec.len(),
+            FileBuffer::Threaded(PoolReference::Owned(owned, _)) => owned.len(),
+            FileBuffer::Threaded(PoolReference::Mut(mutable, _)) => mutable.len(),
+        }
+    }
+
+    pub(crate) fn finished(self) -> Self {
+        match self {
+            FileBuffer::Threaded(PoolReference::Mut(mutable, pool)) => {
+                FileBuffer::Threaded(PoolReference::Owned(mutable.downgrade(), pool))
+            }
+            _ => self,
+        }
+    }
+}
+
+impl Deref for FileBuffer {
+    type Target = Vec<u8>;
+
+    fn deref(&self) -> &Self::Target {
+        match self {
+            FileBuffer::Immediate(ref vec) => &vec,
+            FileBuffer::Threaded(PoolReference::Owned(owned, _)) => owned,
+            FileBuffer::Threaded(PoolReference::Mut(mutable, _)) => mutable,
+        }
+    }
+}
+
+impl DerefMut for FileBuffer {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        match self {
+            FileBuffer::Immediate(ref mut vec) => vec,
+            FileBuffer::Threaded(PoolReference::Owned(_, _)) => {
+                unimplemented!()
+            }
+            FileBuffer::Threaded(PoolReference::Mut(mutable, _)) => mutable,
+        }
+    }
+}
+
+pub(crate) const IO_CHUNK_SIZE: usize = 16_777_216;
 
 /// Carries the implementation specific channel data into the executor.
 #[derive(Debug)]
 pub enum IncrementalFile {
     ImmediateReceiver,
-    ThreadedReceiver(Receiver<Vec<u8>>),
+    ThreadedReceiver(Receiver<FileBuffer>),
 }
 
 // The basic idea is that in single threaded mode we get this pattern:
@@ -116,7 +178,7 @@ pub enum IncrementalFile {
 #[derive(Debug)]
 pub enum Kind {
     Directory,
-    File(Vec<u8>),
+    File(FileBuffer),
     IncrementalFile(IncrementalFile),
 }
 
@@ -160,7 +222,7 @@ impl Item {
         }
     }
 
-    pub fn write_file(full_path: PathBuf, content: Vec<u8>, mode: u32) -> Self {
+    pub fn write_file(full_path: PathBuf, mode: u32, content: FileBuffer) -> Self {
         let len = content.len();
         Self {
             full_path,
@@ -177,7 +239,7 @@ impl Item {
         full_path: PathBuf,
         mode: u32,
         state: IncrementalFileState,
-    ) -> Result<(Self, Box<dyn FnMut(Vec<u8>) -> bool + 'a>)> {
+    ) -> Result<(Self, Box<dyn FnMut(FileBuffer) -> bool + 'a>)> {
         let (chunk_submit, content_callback) = state.incremental_file_channel(&full_path, mode)?;
         let result = Self {
             full_path,
@@ -210,19 +272,19 @@ impl IncrementalFileState {
         &self,
         path: &Path,
         mode: u32,
-    ) -> Result<(Box<dyn FnMut(Vec<u8>) -> bool>, IncrementalFile)> {
+    ) -> Result<(Box<dyn FnMut(FileBuffer) -> bool>, IncrementalFile)> {
         use std::sync::mpsc::channel;
         match *self {
             IncrementalFileState::Threaded => {
-                let (tx, rx) = channel::<Vec<u8>>();
+                let (tx, rx) = channel::<FileBuffer>();
                 let content_callback = IncrementalFile::ThreadedReceiver(rx);
-                let chunk_submit = move |chunk: Vec<u8>| tx.send(chunk).is_ok();
+                let chunk_submit = move |chunk: FileBuffer| tx.send(chunk).is_ok();
                 Ok((Box::new(chunk_submit), content_callback))
             }
             IncrementalFileState::Immediate(ref state) => {
                 let content_callback = IncrementalFile::ImmediateReceiver;
                 let mut writer = immediate::IncrementalFileWriter::new(path, mode, state.clone())?;
-                let chunk_submit = move |chunk: Vec<u8>| writer.chunk_submit(chunk);
+                let chunk_submit = move |chunk: FileBuffer| writer.chunk_submit(chunk);
                 Ok((Box::new(chunk_submit), content_callback))
             }
         }
@@ -258,6 +320,14 @@ pub trait Executor {
 
     /// Get any state needed for incremental file processing
     fn incremental_file_state(&self) -> IncrementalFileState;
+
+    /// Get a disk buffer E.g. this gets the right sized pool object for
+    /// optimized situations, or just a malloc when optimisations are off etc
+    /// etc.
+    fn get_buffer(&mut self, len: usize) -> FileBuffer;
+
+    /// Query the memory budget to see if a particular size buffer is available
+    fn buffer_available(&self, len: usize) -> bool;
 }
 
 /// Trivial single threaded IO to be used from executors.
@@ -267,7 +337,17 @@ pub fn perform<F: Fn(usize)>(item: &mut Item, chunk_complete_callback: F) {
     // Files, write them.
     item.result = match &mut item.kind {
         Kind::Directory => create_dir(&item.full_path),
-        Kind::File(ref contents) => write_file(&item.full_path, &contents, item.mode),
+        Kind::File(ref mut contents) => {
+            contents.clear();
+            match contents {
+                FileBuffer::Immediate(ref contents) => {
+                    write_file(&item.full_path, &contents, item.mode)
+                }
+                FileBuffer::Threaded(ref mut contents) => {
+                    write_file(&item.full_path, &contents, item.mode)
+                }
+            }
+        }
         Kind::IncrementalFile(incremental_file) => write_file_incremental(
             &item.full_path,
             incremental_file,
@@ -367,6 +447,7 @@ pub fn create_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// Get the executor for disk IO.
 pub fn get_executor<'a>(
     notify_handler: Option<&'a dyn Fn(Notification<'_>)>,
+    ram_budget: usize,
 ) -> Result<Box<dyn Executor + 'a>> {
     // If this gets lots of use, consider exposing via the config file.
     let thread_count = match process().var("RUSTUP_IO_THREADS") {
@@ -377,6 +458,6 @@ pub fn get_executor<'a>(
     };
     Ok(match thread_count {
         0 | 1 => Box::new(immediate::ImmediateUnpacker::new()),
-        n => Box::new(threaded::Threaded::new(notify_handler, n)),
+        n => Box::new(threaded::Threaded::new(notify_handler, n, ram_budget)),
     })
 }