user_dependencies/
user-dependencies.rs

1//! $ cargo run --release --example user-dependencies
2//!
3//! Computes the percentage of crates.io which depends directly on at least one
4//! crate by the specified user.
5
6use std::collections::btree_map::Entry;
7use std::collections::{BTreeMap as Map, BTreeSet as Set};
8
9const USER: &str = "dtolnay";
10
11fn main() -> db_dump::Result<()> {
12    // Map of crate id to the most recently published version of that crate.
13    let mut most_recent = Map::new();
14
15    let mut user_id = None;
16    let mut crates = 0;
17    let mut crate_owners = Vec::new();
18    let mut dependencies = Vec::new();
19    db_dump::Loader::new()
20        .users(|row| {
21            if row.gh_login == USER {
22                user_id = Some(row.id);
23            }
24        })
25        .crates(|_row| crates += 1)
26        .crate_owners(|row| crate_owners.push(row))
27        .dependencies(|row| dependencies.push(row))
28        .versions(|row| match most_recent.entry(row.crate_id) {
29            Entry::Vacant(entry) => {
30                entry.insert(row);
31            }
32            Entry::Occupied(mut entry) => {
33                if row.created_at > entry.get().created_at {
34                    entry.insert(row);
35                }
36            }
37        })
38        .load("./db-dump.tar.gz")?;
39
40    // User id of the crate author we care about.
41    let user_id = user_id.expect("no such user");
42
43    // Set of crate ids currently owned by that user.
44    let mut their_crates = Set::new();
45    for crate_owner in crate_owners {
46        if crate_owner.owner_id == user_id {
47            their_crates.insert(crate_owner.crate_id);
48        }
49    }
50
51    // Set of version ids which are the most recently published of their crate.
52    let most_recent = Set::from_iter(most_recent.values().map(|version| version.id));
53
54    // Set of version ids which depend directly on at least one crate by the
55    // user.
56    let mut dep_on_them = Set::new();
57    for dep in dependencies {
58        if their_crates.contains(&dep.crate_id) {
59            dep_on_them.insert(dep.version_id);
60        }
61    }
62
63    // Number of crates whose most recent version depends on at least one crate
64    // by the user.
65    let result = dep_on_them.intersection(&most_recent).count();
66
67    println!(
68        "{} / {} = {:.1}%",
69        result,
70        crates,
71        100.0 * result as f64 / crates as f64,
72    );
73
74    Ok(())
75}
user_dependencies/user-dependencies.rs

user_dependencies/
user-dependencies.rs
