add runtime dataset fetch and parse in-place

.gitignore

@@ -1,7 +1,2 @@
 /target
 /Cargo.lock
-
-# This is generated by the benchmarks crate build script, do not version with git.
-/benchmarks/benches/datasets_paths.rs
-/benchmarks/target
-/benchmarks/Cargo.lock

benchmarks/.gitignore

@@ -0,0 +1,3 @@
+/target
+/Cargo.lock
+/real-roaring-datasets

benchmarks/Cargo.toml

@@ -10,6 +10,10 @@ publish = false
 roaring = { path = ".." }
 
 [dev-dependencies]
+once_cell = "1.9.0"
+git2 = "0.13.25"
+zip = "0.5.13"
+indicatif = "0.16.2"
 criterion = { version = "0.3", features = ["html_reports"] }
 quickcheck = "0.9"
 quickcheck_macros = "0.9"

benchmarks/benches/datasets.rs

@@ -0,0 +1,186 @@
+use std::env;
+use std::fs::File;
+use std::io::BufReader;
+use std::path::{Path, PathBuf};
+
+use git2::FetchOptions;
+use once_cell::sync::OnceCell as SyncOnceCell;
+
+use roaring::RoaringBitmap;
+
+static INSTANCE: SyncOnceCell<Vec<Dataset>> = SyncOnceCell::new();
+
+pub struct Datasets;
+
+pub struct DatasetsIter {
+    iter: std::slice::Iter<'static, Dataset>,
+}
+
+impl Iterator for DatasetsIter {
+    type Item = &'static Dataset;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter.next()
+    }
+}
+
+impl IntoIterator for Datasets {
+    type Item = &'static Dataset;
+    type IntoIter = DatasetsIter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        DatasetsIter {
+            iter: INSTANCE
+                .get_or_init(|| {
+                    init_datasets().and_then(parse_datasets).expect("a collection of datasets")
+                })
+                .iter(),
+        }
+    }
+}
+
+pub struct Dataset {
+    pub name: String,
+    pub bitmaps: Vec<RoaringBitmap>,
+}
+
+fn init_datasets() -> Result<PathBuf, Box<dyn std::error::Error>> {
+    let out_dir = env::var_os("CARGO_MANIFEST_DIR").ok_or(env::VarError::NotPresent)?;
+
+    let out_path = Path::new(&out_dir);
+    let repo_path = out_path.join("real-roaring-datasets");
+
+    // Setup progress callbacks
+
+    let pb_cell = once_cell::unsync::OnceCell::new();
+    let mut cb = git2::RemoteCallbacks::new();
+
+    cb.transfer_progress(|progress| {
+        let pb = pb_cell.get_or_init(|| {
+            indicatif::ProgressBar::new(progress.total_objects() as u64)
+                .with_style(
+                    indicatif::ProgressStyle::default_bar()
+                        .template(&format!(
+                            "{{prefix}}{{msg:.cyan/blue}} [{{bar}}] {{pos}}/{}",
+                            progress.total_objects()
+                        ))
+                        .progress_chars("#> "),
+                )
+                .with_prefix("    ")
+                .with_message("Recieving objects")
+        });
+
+        pb.set_position((progress.local_objects() + progress.received_objects()) as u64);
+        true
+    });
+
+    let mut fetch_opts = FetchOptions::new();
+    fetch_opts.remote_callbacks(cb);
+
+    // Do update
+
+    if !Path::new(&repo_path).exists() {
+        git2::build::RepoBuilder::new()
+            .fetch_options(fetch_opts)
+            .clone("git://github.com/RoaringBitmap/real-roaring-datasets.git", &repo_path)?;
+    } else {
+        let repo = git2::Repository::open(&repo_path)?;
+        repo.find_remote("origin")?.fetch(&["master"], Some(&mut fetch_opts), None)?;
+
+        let head = repo.head()?.peel_to_commit()?;
+        let origin_master_head = repo
+            .find_branch("origin/master", git2::BranchType::Remote)?
+            .into_reference()
+            .peel_to_commit()?;
+
+        if head.id() != origin_master_head.id() {
+            repo.reset(origin_master_head.as_object(), git2::ResetType::Hard, None)?;
+        }
+    }
+
+    if let Some(pb) = pb_cell.get() {
+        pb.finish()
+    }
+
+    Ok(repo_path)
+}
+
+fn parse_datasets<P: AsRef<Path>>(path: P) -> Result<Vec<Dataset>, Box<dyn std::error::Error>> {
+    const DATASET_FILENAME_WHITELIST: &[&str] = &[
+        "census-income.zip",
+        "census-income_srt.zip",
+        "census1881.zip",
+        "census1881_srt.zip",
+        "weather_sept_85.zip",
+        "weather_sept_85_srt.zip",
+        "wikileaks-noquotes.zip",
+        "wikileaks-noquotes_srt.zip",
+    ];
+
+    use indicatif::{ProgressBar, ProgressStyle};
+    use std::io::BufRead;
+    use zip::ZipArchive;
+
+    let dir = path.as_ref().read_dir()?;
+
+    let mut datasets = Vec::new();
+
+    // Future work: Reuse this buffer to parse croaring bitmaps for comparison
+    let mut numbers = Vec::new();
+
+    for dir_entry_result in dir {
+        let dir_entry = dir_entry_result?;
+        let metadata = dir_entry.metadata()?;
+        let file_name = dir_entry.file_name();
+        // TODO dont panic
+        let file_name_str = file_name.to_str().expect("utf-8 filename");
+
+        if metadata.is_file() && DATASET_FILENAME_WHITELIST.contains(&file_name_str) {
+            let file = File::open(dir_entry.path())?;
+            let name = file_name_str.split_at(file_name_str.len() - ".zip".len()).0.to_string();
+
+            let mut zip = ZipArchive::new(file)?;
+
+            let mut total_size = 0;
+            for i in 0..zip.len() {
+                let file = zip.by_index(i)?;
+                total_size += file.size();
+            }
+
+            let pb = ProgressBar::new(total_size)
+                .with_style(
+                    ProgressStyle::default_bar()
+                        .template("    {prefix:.green} [{bar}] {msg}")
+                        .progress_chars("#> "),
+                )
+                .with_prefix("Parsing")
+                .with_message(name.clone());
+
+            let mut bitmaps = Vec::with_capacity(zip.len());
+            for i in 0..zip.len() {
+                let file = zip.by_index(i)?;
+                let size = file.size();
+                let buf = BufReader::new(file);
+
+                for bytes in buf.split(b',') {
+                    let bytes = bytes?;
+                    let str = String::from_utf8(bytes)?;
+                    let n = str.trim().parse::<u32>()?;
+                    numbers.push(n);
+                }
+
+                let bitmap = RoaringBitmap::from_sorted_iter(numbers.iter().copied())?;
+                numbers.clear();
+                bitmaps.push(bitmap);
+
+                pb.set_position(pb.position() + size);
+            }
+
+            pb.finish();
+            datasets.push(Dataset { name, bitmaps });
+        }
+    }
+    datasets.sort_unstable_by(|a, b| a.name.cmp(&b.name));
+    println!();
+    Ok(datasets)
+}